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It is urgent to mine novel blast-resistant genes in rice and develop new rice varieties with pyramiding blast-resistant genes. In this study, a new blast-resistant gene, OsBRW1, was screened from a set of rice near-isogenic lines (NILs) with different blast-resistant ability. Under the infection of Magnaporthe oryzae (M. oryzae), OsBRW1 in the resistant NIL Pi-4b was highly induced than that in the susceptible NIL Pi-1 and their parent line CO39, and the blast-resistant ability of OsBRW1 was further confirmed by using CRISPR/Cas9 knockout and over-expression methods. The protein encoded by OsBRW1 was a typical NBS-LRR with NB-ARC domain and localized in both cytoplasm and nucleus, and the transient expression of OsBRW1 was capable of triggering hypersensitive response in tobacco leaves. Protein interaction experiments showed that OsBRW1 protein directly interacted with OsSRFP1. At the early infection stage of M. oryzae, OsBRW1 gene induced OsSRFP1 to highly expression level and accumulated H 2 O 2 , up-regulated the defence responsive signalling transduction genes and the pathogenesis-related genes and increased JA and SA content in the resistant NIL Pi-4b. By contrary, lower content of endogenous JA and SA in osbrw1 mutants was found at the same stage. After that, OsSRFP1 was down-regulated to constitution abundance to balance the growth of the resistant NIL Pi-4b. In summary, OsBRW1 solicited OsSRFP1 to resist the infection of blast fungus in rice by inducing the synergism of induced systemic resistance (ISR) and system acquired resistance (SAR) and to balance the growth of rice plants., (© 2024 The Author(s). Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.)

Background: Rice is the main food crop for much of the population in China. Therefore, selecting and breeding new disease resistance and drought tolerance in rice is essential to ensure national food security. The utilization of heterosis has significantly enhanced rice productivity, yet many of the molecular mechanisms underlying this phenomenon remain largely unexplored. 'Nei 6 You 7075' ('N6Y7075') is a novel hybrid rice cultivar with exceptional quality, developed through the crossbreeding of 'Fuhui 7075' ('FH7075') and 'Neixiang 6 A' ('NX6A'). However, the precise mechanisms underlying the disease resistance and drought tolerance in 'N6Y7075' are poorly understood. In this study, we investigated the resistance of hybrid rice 'N6Y7075' to bacterial blight (Xanthomonas oryzae pv. oryzae), rice blast (Magnaporthe oryzae), and drought and identified differentially expressed genes between hybrid rice 'N6Y7075' and its parents through RNA-seq analysis., Results: Our research found that the hybrid 'N6Y7075' and its female parent 'NX6A' were less susceptible to bacterial blight and rice blast than the male parent 'FH7075', while 'FH7075' showed better drought tolerance than 'NX6A'. The hybrid 'N6Y7075' exhibited heterosis. Clustering results revealed that the expression profiles of the F1 hybrid closely resembled those of its parental lines rather than exhibiting an intermediate profile between the two parental lines. The disease resistance of hybrid rice 'N6Y7075' may be attributed to the plant-pathogen interaction pathways involving Xa21, CDPK, and RPM1-mediated hypersensitive response and WRKY1-induced defense-related gene expression and programmed cell death. The MAPK signaling pathway PR1 could also be associated with plant defense responses. Hybrid rice 'N6Y7075' may enhance drought tolerance by regulating MAPKKK17 and WAK60 in the MAPK signaling pathway. These proteins affect ABA stress adaptation and stomatal development in plants, respectively., Conclusions: Our results provide a preliminary exploration of 'N6Y7075' disease resistance and drought tolerance and provide a relevant theoretical basis for its further study and use. This study provides insights into the molecular mechanisms of heterosis in hybrid rice and identifies potential associated genes., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Accession numbers: Sequence data from this article can be found in the National Center for Biotechnology Information under the following accession numbers: Xa21 (LOC4328724), CDPK-1 (LOC9269646), CDPK-2 (LOC4352046), RGA4 (LOC107277700), RPM1 (LOC4340717), RGH1A (LOC4352347), RGA2 (LOC9266802), WRKY45-1 (LOC4338413), PR1a (LOC4342318), PR1b (LOC4325422), MAPKKK17 (LOC4326920), and WAK60 (LOC4335593). Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Well-conserved mitogen-activated protein kinase (MAPK) cascades are essential for orchestrating of a wide range of cellular processes in plants, including defense responses against pathogen attack. NAC transcription factors (TFs) play important roles in plant immunity, but their targets and how they are regulated remain largely unknown. Here, we identified the TF OsNAC29 as a key component of a MAPK signaling pathway involved in rice (Oryza sativa) disease resistance. OsNAC29 binds directly to CACGTG motifs in the promoters of OsTPS28 and OsCYP71Z2, which are crucial for the biosynthesis of the phytoalexin 5,10-diketo-casbene and consequently rice blast resistance. OsNAC29 positively regulates rice blast resistance by promoting the expression of of OsTPS28 and OsCYP71Z2, and the function of OsNAC29 is genetically dependent on OsCYP71Z2 and OsTPS28. Furthermore, OsNAC29 interacts with OsRACK1A and OsMAPK3/6 to form an immune complex; OsMAPK3 phosphorylates OsNAC29 at Thr304 to prevent its proteasome-mediated degradation and promote its function against rice blast fungus. Phosphorylation of OsNAC29 at Thr304 is induced upon Magnaporthe oryzae infection and chitin treatment. Our data demonstrate the positive role of the OsMAPK3-OsNAC29-OsTPS28/OsCYP71Z2 module in rice blast resistance, providing insights into the molecular regulatory network and fine-tuning of NAC TFs in rice immunity., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Resistance in pathogenic fungi necessitates the development of fungicides with new mechanisms of action. The Mps1 MAPK of Magnaporthe oryzae , the pathogen of rice blast disease, has been shown to be a molecular target for fungicide research. Here, we present compound TAK-733 that interacts with the common docking (CD) site of Mps1 and can be used in combination with ATP-competitive inhibitors. We initially identified compounds PLX-4720 and TAK-733 that interact with Mps1. Subsequent assays show that PLX-4720 is an ATP-competitive inhibitor, whereas TAK-733 binds to the CD site of Mps1─an interaction site for its MAPKK─but not to the ATP-binding pocket as it does in the kinase MEK1. In vivo assays demonstrated that TAK-733 exhibits combinational effects with ATP-competitive inhibitors PLX-4720 and A378-0. Collectively, we present TAK-733 as having a new mechanism of action suitable for combinational application with ATP-competitive inhibitors in the management of pathogenic fungi.

Sweet potato ( Ipomoea batatas ) serves as a significant food and economic crop worldwide. However, its production and safety are jeopardized by black rot, a disease caused by Ceratocystis fimbriata . Although polyamines (PAs) are common biological growth factors, their function in the storage of fruits and vegetables remains poorly understood. This study examines the physiological roles of both exogenous and endogenous PAs in C. fimbriata , particularly their metabolism via gene knockout techniques. Additionally, we assessed how exogenous PAs affect sweet potato storage resistance. Our findings reveal that PAs are crucial in managing oxidative and cell wall stress in C. fimbriata . At high concentrations, PAs displayed cytotoxic effects through the upregulation of nitric oxide synthase ( TAH18 ). Furthermore, exogenous PAs significantly enhanced the defense mechanisms of sweet potatoes during storage. The concurrent use of perillaldehyde (PAE), a natural antibacterial compound, additionally decreased the incidence of black rot in sweet potatoes. This study provides a novel strategy and theoretical basis for the prevention and control of fungal diseases in stored fruits and vegetables.

Amino acid transporters (AATs) have been shown to be involved in immune responses during plant-pathogen interactions; however, the molecular mechanism by which they function in this process remains unclear. Here, we used a joint analysis of a genome-wide association study and quantitative trait locus (QTL) mapping to identify MEMBRANE PROTEIN 1, which acts as a QTL in rice against blast fungus. Heterogeneous expression of OsMP1 in yeast supported its function in transporting a wide range of amino acids, including Thr, Ser, Phe, His, and Glu. OsMP1 could also mediate 15N-Glu efflux and influx in Xenopus oocyte cells. The expression of OsMP1 was significantly induced by Magnaporthe oryzae in the resistant rice landrace Heikezijing, whereas no such induction was observed in the susceptible landrace Suyunuo. Overexpressing OsMP1 in Suyunuo enhanced disease resistance to blast fungus and leaf blight bacterium without resulting in a yield penalty. In addition, the overexpression of OsMP1 led to increased accumulation of Thr, Ser, Phe, and His in the leaves and this contributed to the reduced disease susceptibility, which was associated with up-regulation of the jasmonic acid pathway. Our results demonstrate the important role of OsMP1 in disease resistance in rice and provide a potential target for breeding more resistant cultivars without reducing yield., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Aims: Rice blast, caused by Magnaporthe oryzae, is one of the most devastating diseases of rice (Oryza sativa L.). The aim of this study was to investigate the biocontrol potential of rice rhizosphere actinomycetes against M. oryzae Guy 11, and elucidate the antagonistic mechanisms., Methods and Results: An isolate characterized as a Streptomyces corchorusii strain (Sc75) using the 16S rRNA gene exhibited superior antifungal activity. Sc75 had an inhibitory effect of 69.25% ± 0.15% against M. oryzae and broad antifungal activity on other fungal plant pathogens in the dual culture assay. Its cell-free culture filtrate inhibited fungal growth and reduced mycelial mass. Also, the ethyl acetate crude extract completely inhibited conidia germination and appressoria formation on the hydrophobic coverslips and detached leaf at a concentration of 20 mg/ml. Its volatile organic compounds (VOCs) suppressed fungal growth by 98.42%. GC-MS analysis of the VOCs identified butanoic acid, 2-methyl-, methyl ester; di-tert-butyl peroxide; furan, 2-pentyl-; and undecanoic acid, 10-methyl-, methyl ester as the main components. In the greenhouse experiment, the disease severity was reduced and growth promotion was evident. Molecular investigation revealed that Sc75 upregulated defense-related genes involved in the synthesis of jasmonic acid, salicylic acid signaling pathway, and led to callose deposition and ROS production in the leaves. Finally, Sc75 produced hydrolytic enzymes, siderophore, indole acetic acid, gibberellic acid, phosphate solubilization, and 1-aminocyclopropane-1-carboxylate deaminase., Conclusions: The rice rhizosphere soil harbors actinomycetes that can be explored as biocontrol agents against fungal pathogens such as M. oryzae. The isolate Sc75 had superior antifungal activity against M. oryzae and other selected plant pathogenic fungi. It showed remarkable antagonistic activity through direct antibiosis, production of VOCs, antifungal metabolites in the culture filtrates and crude extracts, and produced enzymes. In addition, the isolate promoted plant growth, reduced rice blast disease index in the greenhouse experiment, and elicited defense-related responses. Sc75 is a promising candidate for future exploration as a biofungicide and a biofertilizer., (© The Author(s) 2024. Published by Oxford University Press on behalf of Applied Microbiology International.)

Verticillium wilt, a significant pathogen affecting cotton, has historically been challenging to control, posing a substantial threat to the sustainable development of the cotton industry. This study demonstrates that resistance to Verticillium dahliae in cotton can be enhanced by treating the roots with an ethyl acetate extract (EAAA) extracted from Artemisia argyi. The mechanisms by which EAAA activates immunity in cotton were elucidated by examining the expression levels of resistance genes post-treatment, evaluating salicylic acid (SA) and jasmonic acid (JA) levels, analyzing transcriptome data, and employing virus-induced gene silencing (VIGS) technology. Additionally, pot experiments were conducted to validate the efficacy of EAAA in controlling Verticillium wilt. The flavonoid content in EAAA was qualitatively analyzed using Ultra-Performance Liquid Chromatography coupled with Tandem Mass Spectrometry (UPLC-MS/MS), identifying three specific flavonoids that were further screened to verify their roles in activating cotton immunity. Cotton plants treated with EAAA exhibited reduced leaf chlorosis and browning in the vascular bundles. Genes involved in SA and JA synthesis and signaling in the root system were highly expressed, resulting in increased levels of SA and JA. Transcriptome analysis revealed that most upregulated differentially expressed genes were primarily enriched in the Mitogen-Activated Protein Kinase (MAPK) signaling pathway. Two specific genes, RLK and MAPKKK18, were identified through VIGS technology as key regulators of the immune pathway in cotton. The flavonoid monomer activation experiment demonstrated that eupatilin, hispidulin, jaceosidin, and a mixture of these three could induce the expression of cotton-related resistance genes. Collectively, these findings provide a research basis for the development of EAAA as a natural plant immune-inducing agent against cotton Verticillium wilt., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Co-infection, caused by multiple pathogen attacks on an organism, can lead to disease development or immunity. This complex interaction can be synergetic, co-existing, or antagonistic, ultimately influencing disease severity. The interaction between fungus, bacterium, and virus (three kingdom pathogens) is most prevalent. However, the underlying mechanisms of co-infection need to be explored further. In this study, we investigated the co-infection phenomenon in rice plants exposed to multiple pathogen species, specifically Rice necrosis mosaic virus (RNMV) and rice blast fungus (Magnaporthe oryzae, MO), bacterial leaf blight (Xanthomonas oryzae pv. oryzae, XO) or Cucumber mosaic virus (CMV). Our research showed that RNMV interacts synergistically with MO, XO, or CMV, increasing pathogen growth and lesion size. These findings suggest positive synergy in RNMV co-infections with three kingdom pathogens, increasing accumulation and symptoms. Additionally, to investigate the role of RNAi in pathogen synergism, we analyzed rice mutant lines deficient in RNA-dependent RNA polymerase 1 (OsRDR1) or 6 (OsRDR6). Notably, we observed the loss of synergy in each mutant line, highlighting the crucial role of OsRDR1 and OsRDR6 in maintaining the positive interaction between RNMV and three kingdom pathogens. Hence, our study emphasized the role of the RNA silencing pathway in the intricate landscape of pathogen interactions; the study's outcome could be applied to understand the plant defense response to improve crop yields., Competing Interests: Declaration of Competing Interest All the authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Rice blast disease, caused by Magnaporthe oryzae, reigns as the top-most cereal killer, jeopardizing global food security. This necessitates the timely scouting of pathogen stress-responsive genes during the early infection stages. Thus, we integrated time-series microarray (GSE95394) and RNA-Seq (GSE131641) datasets to decipher rice transcriptome responses at 12- and 24-h post-infection (Hpi). Our analysis revealed 1580 differentially expressed genes (DEGs) overlapped between datasets. We constructed a protein-protein interaction (PPI) network for these DEGs and identified significant subnetworks using the MCODE plugin. Further analysis with CytoHubba highlighted eight plausible hub genes for pathogenesis: RPL8 (upregulated) and RPL27, OsPRPL3, RPL21, RPL9, RPS5, OsRPS9, and RPL17 (downregulated). We validated the expression levels of these hub genes in response to infection, finding that RPL8 exhibited significantly higher expression compared with other downregulated genes. Remarkably, RPL8 formed a distinct cluster in the co-expression network, whereas other hub genes were interconnected, with RPL9 playing a central role, indicating its pivotal role in coordinating gene expression during infection. Gene Ontology highlighted the enrichment of hub genes in the ribosome and protein translation processes. Prior studies suggested that plant immune defence activation diminishes the energy pool by suppressing ribosomes. Intriguingly, our study aligns with this phenomenon, as the identified ribosomal proteins (RPs) were suppressed, while RPL8 expression was activated. We anticipate that these RPs could be targeted to develop new stress-resistant rice varieties, beyond their housekeeping role. Overall, integrating transcriptomic data revealed more common DEGs, enhancing the reliability of our analysis and providing deeper insights into rice blast disease mechanisms., Competing Interests: Declarations Research involving human participants and/or animals This article does not contain any studies with human participants or animals performed by any of the authors. Consent for publication We affirm that all the authors have seen, prepared, and agreed to the submission of the paper and their inclusion of names as co-authors. Conflict of interest The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Institute of Plant Genetics Polish Academy of Sciences.)

Bacillus velezensis YL2021 has extensive antimicrobial activities against phytopathogens, and its genome harbors a catechol-type siderophore biosynthesis gene cluster. Here, we describe the characterization of siderophores produced by strain YL2021 and its antimicrobial activity in vitro and in vivo. A few types of siderophores were detected by chrome azurol S plates coupled with Arnow's test, purified, and identified by reversed-phase high-performance liquid chromatography. We found that strain YL2021 can produce different antimicrobial compounds under low-iron M9 medium or iron-sufficient Luria-Bertani medium, although antimicrobial activities can be easily observed on the two media as described above in vitro. Strain YL2021 can produce at least three catechol-type siderophores in low-iron M9 medium, whereas no siderophores were produced in Luria-Bertani medium. Among them, the main antimicrobial siderophore produced by strain YL2021 was bacillibactin, with m/z 882, based on the liquid chromatography-tandem mass spectrometry analysis, which has broad-spectrum antimicrobial activities against gram-positive and gram-negative bacteria, the oomycete Phytophthora capsici , and phytopathogenic fungi. Moreover, the antifungal activity of siderophores, including bacillibactin, observed in vitro was correlated with control efficacies against rice sheath blight disease caused by Rhizoctonia solani and rice blast disease caused by Magnaporthe oryzae in vivo. Collectively, the results demonstrate that siderophores, including bacillibactin, produced by B. velezensis YL2021 are promising biocontrol agents for application in rice disease control., Competing Interests: The author(s) declare no conflict of interest.

Following leaf cuticle penetration by specialized appressorial cells, the devastating blast fungus Magnaporthe oryzae grows as invasive hyphae (IH) in living rice cells. IH are separated from host cytoplasm by plant-derived membranes forming an apoplastic compartment and a punctate biotrophic interfacial complex (BIC) that mediate the molecular host-pathogen interaction. What molecular and cellular processes determine the temperature range for this biotrophic growth stage is an unanswered question pertinent to a broader understanding of how phytopathogens may cope with environmental stresses arising under climate change. Here, we shed light on thermal adaptation in M. oryzae by disrupting the ACB1 gene encoding the single acyl-CoA-binding protein, an intracellular transporter of long-chain acyl-CoA esters. Loss of ACB1 affected fatty acid desaturation levels and abolished pathogenicity at optimal (26°C) and low (22°C) but not elevated (29°C) infection temperatures (the latter following post-penetration shifts from 26°C). Relative to wild type, the Δacb1 mutant strain exhibited poor vegetative growth and impaired membrane trafficking at 22°C and 26°C, but not at 29°C. In planta, Δacb1 biotrophic growth was inhibited at 26°C-which was accompanied by a multi-BIC phenotype-but not at 29°C, where BIC formation was normal. Underpinning the Δacb1 phenotype was impaired membrane fluidity at 22°C and 26°C but not at elevated temperatures, indicating Acb1 suppresses membrane rigidity at optimal- and suboptimal- but not supraoptimal temperatures. Deducing a temperature-dependent role for Acb1 in maintaining membrane fluidity homeostasis reveals how the thermal range for rice blast disease is both mechanistically determined and wider than hitherto appreciated., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Richter et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The construction of controlled-release formulations improves the sustained-release performance and utilization efficiency of pesticides, which are important aspects in plant protection and environmental chemistry. The current study employs kasugamycin (Kas), which is widely used to control Magnaporthe oryzae , conjugated with carboxyl-functionalized ZnO quantum dots via amide linkages to yield a pH-responsive pesticide delivery system (Kas@ZnO). Physicochemical characterizations indicated the successful preparation of the Kas@ZnO nanoparticles. In vitro drug release assessments indicated that Kas@ZnO exhibited a loading capacity of 21.05% and could effect the controlled release of Kas in an acidic environment, which is beneficial given the unique acidic microenvironment of M. oryzae . Bioactivity assays demonstrated that Kas@ZnO could simultaneously inhibit mycelial growth and spore germination. Additionally, bioactivity tests showed that the control efficacy of Kas@ZnO against rice blast reached 67.43% after 14 days of in vivo spray inoculation, which was higher than that obtained with Kas (55.50%), suggesting improved beneficial effects of Kas@ZnO application over a prolonged duration. Moreover, Kas@ZnO enhanced the activity of defense-related enzymes in rice and upregulated the expression of defense-related genes, such as OsPR2 , OsPR3 , OsPR5 , OsWRKY45 , OsLYP6 , and OsNAC4 . Ultimately, the biosafety assessments revealed that Kas@ZnO did not exert any harmful effects on rice and demonstrated slight toxicity toward zebrafish. These findings indicate that Kas@ZnO can function as a pH-sensitive pesticide delivery system, allowing for targeted release of the pesticide within plant tissues. This technology demonstrates significant potential for eco-friendly plant disease management.

The gray blight incited by Pestalotiopsis and allied genera is a prevalent disease affecting tea cultivation, and managing it with Trichoderma spp. is an alternative to synthetic fungicides. Plants modify their arsenal system against pathogens when they are exposed to Trichoderma spp., which produces proteins and enzymes associated with pathogenesis. Understanding the expression pattern of defense-related markers will help in developing gray blight resistance tea cultivars. Thus, this study intended to induce resistance against gray blight in tea by Trichoderma harzianum TIND02. For this, a total of eight Trichoderma isolates originated from organic tea rhizospheres were characterized and evaluated for their efficacy. Dual culture test revealed isolate TIND02 as the most potential candidate with 74.6% inhibitory activity against gray blight pathogen Pseudopestalotiopsis theae. Molecular characterization based on ITS and tef-1 alpha genes confirmed isolate TIND02 as T. harzianum. Scanning electron microscopic study showed the mycoparasitic nature of T. harzianum TIND02 (TH-TIND02) to Ps. theae. The ethyl acetate extract of TH-TIND02 at 100 and 200 μg mL -1 showed potential inhibitory activity (>69.9%) against Ps. theae which confirmed the presence of higher volatile metabolites. Gas chromatography-Mass spectrometry study revealed that ethyl acetate extract of TH-TIND02 was composed of 21 major and minor volatile organic compounds with acetamide, 2, 2, 2-trifluoro-N, N-bis trimethyIsilyl-C (94.74%) as a major component. The isolate also produced chitinase, cellulase, β-1, 3 glucanase, and protease hydrolytic enzymes. Nursery experiments revealed that 2% and 5% doses (2 × 10 6  CFU mL -1 ) of TH-TIND02 significantly reduced respective 65.0% and 70.0% disease severity over control with improved plant growth. Besides, expressions of defense-related enzymes (chitinase, pHenolics, peroxidase, phenylalanine ammonia lyase, β-1, 3-glucanase, and polyphenol oxidase) and pathogenesis-related genes (chitinase and β-1, 3-glucanase) due to TH-TIND02 were determined. The secretion of defense-related enzymes was highly upregulated in plants applied with TH-TIND02 followed by Ps. theae inoculation compared to controls. The RT-qPCR analysis showed that the expression of both genes in co-inoculated plants was two-fold higher than in control after 21-day post incubation. These results suggest that TH-TIND02 application reduced gray blight severity by elevated enzyme activity and overexpressed pathogenesis-related genes in tea plants which offer for its eco-friendly and sustainable use as a bio-fungicide in tea gardens., Competing Interests: Declaration of competing interest Authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Autophagy is vital for plant defense against pathogens, with ATG6 being a key gene in this process. At present, little has been reported on the potential function and molecular mechanisms of ATG6 mediated pathogen resistance in pear. This study investigates the function of the pear homolog of ATG6 (PbrATG6) in resistance to Botryosphaeria dothidea. PbrATG6 is expressed differentially in pear tissues and its expression increases upon infection. Overexpression of PbrATG6 enhances resistance in Arabidopsis and pear calli, while silencing it increases susceptibility. PbrTLP15, a pathogenesis-related protein belonging to the PR5 family, was found that interacts with PbrATG6 by a yeast two-hybrid screening. Yeast two-hybrid, luciferase complementation imaging, bimolecular fluorescence complementation assays and pull-down assays showed that PbrATG6 interacts with PbrTLP15. The transient silencing transgenic assays of PbrATG6 and PbrTLP15 revealed that PbrATG6 could cooperate with PbrTLP15 to regulate pear B. dothidea resistance. In addition, transcriptional analyses of autophagy key genes in pTRV-PbrTLP15 and transmission electron microscopy (TEM) assays also implied that PbrTLP15 does affect autophagy. Hence, PbrATG6 and PbrTLP15 may synergistically enhance pear B. dothidea disease resistance. It provides a new strategy for the study of autophagy in pear disease resistance and enriches the research on pear disease resistance mechanism., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The Ribosomal protein L18 (RPL18) protein gene family plays an important role in plant growth, development and stress response. Although the RPL18 genes have been identified in several plant species, the RPL18 gene family in wheat (Triticum aestivum) is still unexplored. This study found 8 TaRPL18 genes, each of which has a significantly different gene sequence length and is evenly distributed on the chromosome; Additionally, these proteins have similar physicochemical characteristics as well as secondary and tertiary structures. 17 RPL18 genes in 4 species (wheat, Arabidopsis, rice, and maize) were classified into 5 groups, and the TaRPL18 genes within the same group showed similar structures and conserved motifs. Analysis of the cis-acting elements in the TaRPL18 genes promoter regions revealed the presence of developmental and stress-responsive elements in the majority of the genes. Through yeast two-hybrid (Y2H) experiments, it was confirmed that the powdery mildew resistance protein TaPm46 physically interacts with the Class IV TaRPL18-1. Functional analysis indicated that TaRPL18-1-silenced wheat plants show reduced resistance to powdery mildew compared to the wild type (WT), with decreased expression levels of PAL and PPO genes, and increased expression levels of the PR gene. The findings of this study provide a basis for clarifying the function of the TaRPL18 genes and will be useful for the selection of disease-resistant varieties of wheat., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Soybean red leaf blotch (RLB), caused by the fungus Coniothyrium glycines , represents a foliar disease of soybean that is thus far restricted to Africa. The fungus is listed as a Select Agent by the Federal Select Agent Program because it could pose a severe threat to plant health were it to establish in the United States. Previous work uncovered tremendous molecular diversity at the internal transcribed spacer region, suggesting that there may be multiple species causing RLB. To determine whether multiple species cause RLB, we reconstructed the phylogeny of C. glycines and taxonomic allies using sequence data from four genes. We included 33 C. glycines isolates collected from six African countries and determined that all isolates form a well-supported, monophyletic lineage. Within this lineage there are at least six well-supported clades that largely correspond to geography, with one clade exclusively composed of isolates from Ethiopia, another exclusively composed of isolates from Uganda, and four composed of isolates from southern Africa. However, we did not detect any concordance for these clades between the four genes, indicating that all isolates included in this analysis are representative of a single species. Isolates in the Ethiopia clade are morphologically distinct from isolates in the other clades, as they produce larger sclerotia and smaller pycnida and more sclerotia in planta. Additionally, ancestral range estimations suggest that the C. glycines lineage emerged in southern Africa. These results show that there is significantly more genetic and morphological diversity than was initially suspected with this high-consequence fungal plant pathogen.

The lignin biosynthesis pathway plays a crucial role in the defense response against V. dahliae in cotton, and it is essential to identify the key regulators in this pathway for disease-resistant breeding. In a previous study, the cotton laccase gene GhLac1 was identified as mediating plant broad-spectrum biotic stress tolerance by manipulating phenylpropanoid metabolism. However, the upstream master regulators and regulatory mechanism of lignin are still largely unknown. This study aims to identify the upstream regulators of GhLac1 and explore the molecular mechanism underlying cotton's disease resistance response to V. dahliae. Through the study, three WRKY, three MYB, and one APETALA2/ETHYLENE RESPONSIVE FACTOR (ERF) TFs were identified as differentially responding to V. dahliae infection in cotton. Among these TFs, GhWRKY30, GhWRKY41, GhMYB42, and GhTINY2 were found to directly bind to the GhLac1 promoter and activate its expression. Transient overexpression of these four TFs in cotton led to increased expression of GhLac1 and other the laccase family members, while knockdown of these TFs resulted in reduced lignin accumulation and increased susceptibility to V. dahliae. Additionally, GhWRKY30 and GhWRKY41 were observed to interact with themselves and with each other, synergistically transactivating the GhLac1 promoter. This study reveals a GhLac1-centered transcriptional regulatory cascade of lignin synthesis that contributes to cotton's defense response by modulating lignin metabolism., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Plant pathogens cause devastating diseases, leading to serious losses to agriculture. Mechanistic understanding of pathogenesis of plant pathogens lays the foundation for the development of fungicides for disease control. Mitophagy, a specific form of autophagy, is important for fungal virulence. The role of cardiolipin, mitochondrial signature phospholipid, in mitophagy and pathogenesis is largely unknown in plant pathogenic fungi. The functions of enzymes involved in cardiolipin biosynthesis and relevant inhibitors were assessed using a set of assays, including genetic deletion, plant infection, lipidomics, chemical-protein interaction, chemical inhibition, and field trials. Our results showed that the cardiolipin biosynthesis-related gene MoGEP4 of the rice blast fungus Magnaporthe oryzae regulates growth, conidiation, cardiolipin biosynthesis, and virulence. Mechanistically, MoGep4 regulated mitophagy and Mps1-MAPK phosphorylation, which are required for virulence. Chemical alexidine dihydrochloride (AXD) inhibited the enzyme activity of MoGep4, cardiolipin biosynthesis and mitophagy. Importantly, AXD efficiently inhibited the growth of 10 plant pathogens and controlled rice blast and Fusarium head blight in the field. Our study demonstrated that MoGep4 regulates mitophagy, Mps1 phosphorylation and pathogenesis in M. oryzae. In addition, we found that the MoGep4 inhibitor, AXD, displays broad-spectrum antifungal activity and is a promising candidate for fungicide development., (© 2024 John Wiley & Sons Ltd.)

Apple Valsa canker (AVC) caused by the Ascomycete Valsa mali, seriously constrains the production and quality of apple fruits. The symptomless incubation characteristics of Valsa mali make it highly challenging to detect AVC at an early infection stage. After infecting the wound of apple bark, the pathogenic hyphae of AVC will expand and colonize the phloem tissue. Meanwhile, various enzymes and toxic substances released by hyphae cause the decomposition of cellulose and lignin, and the generation of poisonous secondary metabolites in bark tissue. However, these early symptoms of AVC are invisible from the bark's appearance. Fortunately, Terahertz Spectral Imaging (ThzSI) technology with the advantage of penetrating, and fingerprinting is promising for detecting hidden or slight symptoms of the fungal infection. This study is a preliminary investigation of terahertz frequency-domain spectra for AVC in the early stage of infection. Healthy and two-week-infected apple tree branches were prepared for capturing ThzS images, and the spectral data were preprocessed by Multivariate scattering correction (MSC), Savitzky-Golay convolution smoothing (SG), and standard normal variate (SNV) respectively to remove data noise and improve data quality. Principal component analysis (PCA), competitive adaptive reweighted sampling (CARS), and random frog (RFROG) were employed to extract the spectral feature bands to eliminate redundant data and improve computational efficiency. Machine learning models were established based on the spectral features to detect AVC at an early infection stage, where 11 of them exhibited the best performance with F1-score of 99.72%. To further explore disease information in spatial spectra, imaging data were acquired using terahertz imaging technology. Based on imaging data, pseudo-color imaging, histogram equalization, and Otsu segmentation were employed to visualize early infection areas in apple barks. Furthermore, histogram feature (HF), shape feature (SF), and local binary pattern (LBP) extracted from terahertz spectral images were utilized to establish the SVM, RF, and KNN models. HF-SF-KNN and HF-SF-LBP-KNN with the best performance achieved F1-score of 98.82%. This study presents a preliminary application of terahertz spectral and imaging technology for early-stage AVC detection and demonstrates its feasibility. Additionally, it provides a new way to detect AVC, which expands the application of ThzSI technology in tree disease detection in orchards and lays the foundation for further research., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The ubiquitin-proteasome system (UPS) plays crucial roles in cellular processes including plant growth, development, and stress responses. In this study, we report that a pair of E3 ubiquitin ligases, AvrPiz-t-interaction protein 6 (APIP6) and IPA1-interaction protein 1 (IPI1), intricately target early flowering3 (ELF3) paralogous proteins to control rice immunity and flowering. APIP6 forms homo-oligomers or hetero-oligomers with IPI1. Both proteins interact with OsELF3-2, promoting its degradation to positively control resistance against the rice blast fungus (Magnaporthe oryzae). Intriguingly, overexpression of IPI1 in Nipponbare caused significantly late-flowering phenotypes similar to the oself3-1 mutant. Except for late flowering, oself3-1 enhances resistance against M. oryzae. IPI1 also interacts with and promotes the degradation of OsELF3-1, a paralog of OsELF3-2. Notably, IPI1 and APIP6 synergistically modulate OsELF3s degradation, finely tuning blast disease resistance by targeting OsELF3-2, while IPI1 controls both disease resistance and flowering by targeting OsELF3-1. This study unravels multiple functions for a pair of E3 ligases in rice., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Isw2 proteins, ubiquitous across eukaryotes, exhibit a propensity for DNA binding and exert dynamic influences on local chromosome condensation in an ATP-dependent fashion, thereby modulating the accessibility of neighboring genes to transcriptional machinery. Here, we report the deletion of a putative MoISW2 gene, yielding substantial ramifications on plant pathogenicity. Subsequent gene complementation and chromatin immunoprecipitation sequencing (ChIP-seq) analyses were conducted to delineate binding sites. RNA sequencing (RNA-seq) assays revealed discernible impacts on global gene regulation along chromosomes in both mutant and wild-type strains, with comparative analyses against 55 external RNA-seq data sets corroborating these findings. Notably, MoIsw2-mediated binding and activities delineate genomic loci characterized by pronounced gene expression variability proximal to MoIsw2 binding sites, juxtaposed with comparatively stable expression in surrounding regions. The contingent genes influenced by MoIsw2 activity predominantly encompass niche-determinant genes, including those encoding secreted proteins, secondary metabolites, and stress-responsive elements, alongside avirulence genes. Furthermore, our investigations unveil a spatial correlation between MoIsw2 binding motifs and known transposable elements (TEs), suggesting a potential interplay wherein TE transposition at these loci could modulate the transcriptional landscape of Magnaporthe oryzae in a strain-specific manner. Collectively, these findings position MoIsw2 as a plausible master regulator orchestrating the delicate equilibrium between genes vital for biomass proliferation, akin to housekeeping genes, and niche-specific determinants crucial for ecological adaptability. Stress-induced TE transposition, in conjunction with MoIsw2 activity, emerges as a putative mechanism fostering enhanced mutagenesis and accelerated evolution of niche-determinant genes relative to housekeeping counterparts.IMPORTANCEIsw2 proteins are conserved in plants, fungi, animals, and other eukaryotes. We show that a fungal Isw2 protein in the rice pathogen Magnaporthe oryzae binds to retrotransposon (RT) DNA motifs and affects the epigenetic gene expression landscape of the fungal genome. Mainly ecological niche determinant genes close to the binding motifs are affected. RT elements occur frequently in DNA between genes in most organisms. They move place and multiply in the genome, especially under physiological stress. We further discuss the Isw2 and RT combined activities as a possible sought-after mechanism that can cause biased mutation rates and faster evolution of genes necessary for reacting to abiotic and biotic challenges. The most important biotic challenges for plant pathogens are the ones from the host plants' innate immunity. The overall result of these combined activities will be an adaptation-directed evolution of niche-determinant genes., Competing Interests: The authors declare no conflict of interest.

Nucleotide-binding site and leucine-rich repeat (NLR) proteins are activated by detecting pathogen effectors, which in turn trigger host defenses and cell death. Although many NLRs have been identified, the mechanisms responsible for NLR-triggered defense responses are still poorly understood. In this study, through a genome-wide association study approach, we identified a novel NLR gene, Blast Resistance Gene 8 (BRG8), which confers resistance to rice blast and bacterial blight diseases. BRG8 overexpression and complementation lines exhibit enhanced resistance to both pathogens. Subcellular localization assays showed that BRG8 is localized in both the cytoplasm and the nucleus. Additional evidence revealed that nuclear-localized BRG8 can enhance rice immunity without a hypersensitive response (HR)-like phenotype. We also demonstrated that the coiled-coil domain of BRG8 not only physically interacts with itself but also interacts with the KNOX Ⅱ protein HOMEOBOX ORYZA SATIVA59 (HOS59). Knockout mutants of HOS59 in the BRG8 background show enhanced resistance to Magnaporthe oryzae strain CH171 and Xoo strain CR4, similar to that of the BRG8 background. By contrast, overexpression of HOS59 in the BRG8 background will compromise the HR-like phenotype and resistance response. Further analysis revealed that HOS59 promotes the degradation of BRG8 via the 26S proteasome pathway. Collectively, our study highlights HOS59 as an NLR immune regulator that fine-tunes BRG8-mediated immune responses against pathogens, providing new insights into NLR associations and functions in plant immunity., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Valsa sordida and Botryosphaeria dothidea are two crucial necrotrophic fungal pathogens that damage many plant hosts, particularly species in the genus Populus. These two fungal pathogens occur mainly in poplar branches, stems, and twigs, causing classic symptoms such as canker lesions, canopy dieback, and wilting. Pathogen inoculation is the most efficient pathway to study the mechanism of plant disease. Besides the canker lesions around the inoculation sites on the stems, a novel developmental phenomenon, copious adventitious roots (ARs) with bright red color, were observed in poplar species after stem canker pathogen inoculations. In this study, we described the method for inducing ARs using fungal pathogens in poplar trees. The crucial step of this method is the pathogen inoculation after (phloem or epidermis) girdling manipulation. The second crucial step is the application of the moisturizing material. Compared to the moisturizing manipulation with Parafilm, wrapping the inoculated sites with household polyethylene (PE) plastic wrap can produce colorful, numerous, and robust ARs in 20 days after girdling-inoculation. Finally, white ARs sprouted from the inoculated rings in the poplar stems after shading treatment (wrapping the stems with aluminum foil). This method introduces a novel experimental system for studying root development and morphogenesis, which is crucial for understanding the biology of root development, morphogenesis, and response under disease stress. Furthermore, when combined with shading treatment, this study can provide a convenient experimental system for investigating light response-related processes, for example, the biosynthesis of flavonoids, anthocyanins, or other related metabolites, and genes or transcription factors involved in these processes.

Three Hordeum spontaneum-derived resistances (referred to as 145L2, 41T1 and 40Y5) have demonstrated long-term effectiveness against barley scald, caused by Rhynchosporium commune, in western Canada. Genetic mapping of these resistances in three populations, and the use of five barley genome assemblies, revealed they co-located to a narrowly defined 0.58-1.2 Mbp region of chromosome 6HS containing the Rrs13 scald resistance gene. Differential disease reactions among the three resistances and a Rrs13 carrier (AB6) to a panel of 24 scald isolates indicated that the four resistances were unique from one another. A marker created to target the 6HS scald locus was screened across a panel of barley germplasm that included H. vulgare, H. spontaneum and H. bulbosum lines. The marker showed specificity to H. vulgare lines known to carry the 6HS scald resistances and to two H. spontaneum lines that trace their origins to Jordan. Within the 0.58-1.2 Mbp region were 2-7 tandemly repeated leucine-rich repeat receptor-like proteins (LRR-RLP) and one lectin receptor-like kinase (Lec-RLK) genes with abundant sequence variation between them. The well-defined role that RLP and RLK genes play in plant defense responses make them logical candidate resistance genes, with one possible hypothesis being that each unique scald resistance may be encoded by a different RLP that interacts with a common RLK. It is suggested the three scald resistances be temporarily named Rrs13 145L2 , Rrs13 41T1 and Rrs13 40Y5 to recognize their co-location to the Rrs13 locus until it is determined whether these resistances represent unique genes or alleles of the same gene., (© 2024. The Author(s).)

Background: Powdery mildew is a disease with one of the most substantial impacts on cucumber production globally. The most efficient approach for controlling powdery mildew is the development of genetic resistance; however, few genes associated with inherent variations in cucumber powdery mildew resistance have been identified as of yet., Results: In this study, we re-sequence 299 cucumber accessions, which are divided into four geographical groups. A genome-wide association study identifies 50 sites significantly associated with natural variations in powdery mildew resistance. Linkage disequilibrium analysis further divides these 50 sites into 32 linkage disequilibrium blocks containing 41 putative genes. Virus-induced gene silencing and gene expression analysis implicate CsGy5G015960, which encodes a phosphate transporter, as the candidate gene regulating powdery mildew resistance. On the basis of the resequencing data, we generate five CsGy5G015960 haplotypes, identifying Hap.1 as the haplotype most likely associated with powdery mildew resistance. In addition, we determine that a 29-bp InDel in the 3' untranslated region of CsGy5G015960 is responsible for mRNA stability. Overexpression of CsGy5G015960 Hap.1 in the susceptible line enhances powdery mildew resistance and phosphorus accumulation. Further comparative RNA-seq analysis demonstrates that CsGy5G015960 Hap.1 may regulate cucumber powdery mildew resistance by maintaining a higher H 2 O 2 level through the depletion of multiple class III peroxidases., Conclusions: Here we identify a candidate powdery mildew-resistant gene in cucumber using GWAS. The identified gene may be a promising target for molecular breeding and genetic engineering in cucumber to enhance powdery mildew resistance., (© 2024. The Author(s).)

Rice blast disease caused by Magnaporthe oryzae significantly reduces yield production. Blast resistance is closely associated with iron (Fe) status, but the mechanistic basis linking iron status to immune function in rice remains largely unknown. Here, iron-binding haemerythrin RING ubiquitin ligases OsHRZ1 was confirmed to play key roles in iron-mediated rice blast resistance. The expression of OsHRZ1 was suppressed by M. oryzae inoculation and high iron treatment. Both mutants of OsHRZ1 enhanced rice resistance to M. oryzae. OsPR1a was up-regulated in OsHRZ1 mutants. Yeast two-hybrid, bimolecular fluorescence complementation, and Co-IP assay results indicated that OsHRZ1 interacts with Vascular Plant One Zinc Finger 2 (OsVOZ2) in the nucleus. Additionally, the vitro ubiquitination assay indicated that OsHRZ1 can ubiquitinate OsVOZ2 and mediate the degradation of OsVOZ2. The mutants of OsVOZ2 showed reduced resistance to M. oryzae and down-regulated the expression of OsPR1a. Yeast one-hybrid, EMSA, and dual-luciferase reporter assay results indicated that OsVOZ2 directly binds to the promoter of OsPR1a, activating its expression. In summary, OsHRZ1 plays an important role in rice disease resistance by mediated degradation of OsVOZ2 thus shaping PR gene expression dynamics in rice cells. This highlights an important link between iron signaling and rice pathogen defenses., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Messenger RNA modifications play pivotal roles in RNA biology, but comprehensive landscape changes of epitranscriptomes remain largely unknown in plant immune response. Here we report translational reprogramming directed by ac4C mRNA modification upon pathogen challenge. We first investigate the dynamics of translatomes and epitranscriptomes and uncover that the change in ac4C at single-base resolution promotes translational reprogramming upon Magnaporthe oryzae infection. Then by characterizing the specific distributions of m1A, 2'O-Nm, ac4C, m5C, m6A and m7G, we find that ac4Cs, unlike other modifications, are enriched at the 3rd position of codons, which stabilizes the Watson-Crick base pairing. Importantly, we demonstrate that upon pathogen infection, the increased expression of the ac4C writer OsNAT10/OsACYR (N-ACETYLTRANSFERASE FOR CYTIDINE IN RNA) promotes translation to facilitate rapid activation of immune responses, including the enhancement of jasmonic acid biosynthesis. Our study provides an atlas of mRNA modifications and insights into ac4C function in plant immunity., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

C2H2 zinc effectors are a class of pathogen proteins that play a dual role in plant-pathogen interactions, promoting pathogenicity and enhancing plant defense. In our previous research, we identified Magnaporthe oryzae Systemic Defense Trigger 1 (MoSDT1) as a C2H2 zinc effector that activates rice (Oryza sativa) defense when overexpressed in rice. However, its regulatory roles in pathogenicity and defense require further investigation. In this study, we generated an MoSDT1 overexpressing strain and 2 knockout strains of M. oryzae to assess the impact of MoSDT1 on pathogenicity, rice defense, and phenotypic characteristics. Our analyses revealed that MoSDT1 substantially influenced vegetative growth, conidia size, and conidiation, and was crucial for the virulence of M. oryzae while suppressing rice defense. MoSDT1 localized to the nucleus and cytoplasm of rice, either dependent or independent of M. oryzae delivery. Through RNA-seq, scRNA-seq, and ChIP-seq, we identified that MoSDT1 modulates rice defense by regulating the phosphorylation and ubiquitination of various rice signaling proteins, including transcription factors, transcription repressors, kinases, phosphatases, and the ubiquitin system. These findings provide valuable insights into the regulatory mechanisms of C2H2 zinc finger effector proteins and offer important foundational information for utilizing their target genes in disease resistance breeding and the design of targets for disease management., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Plants form two immune systems, pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI), to combat Blumeria graminis f. sp. tritici (Bgt) infection during the evolutionary process. In PTI, receptor-like kinases (RLKs) play important roles during pathogen infections. Based on our previous reports, there were 280 TaRLKs identified in early response to powdery mildew infection, which were divided into 34 subfamilies in this study. Differences in gene structures, cis-acting elements, and expression levels implied the function diversity of TaRLKs. TaRLK2.4, a member of LRK10L-RLKs subfamily, contained 665 amino acids, and located on the cell membrane. The main objective of this study was to investigate the role of the receptor-like kinase gene TaRLK2.4 in conferring powdery mildew resistance in wheat. Real-time quantitative PCR results indicated that TaRLK2.4 expressed during Bgt infection process, and exhibited a transgressive expression characteristic in disease resistance NILs (BJ-1). To elucidate the function of TaRLK2.4 during Bgt infection, the comprehensive analysis of virus induced gene silence and over-expression demonstrated that TaRLK2.4 promoted powdery mildew resistance positively. In summary, these results contribute to a deeper understanding of the complex and diverse biological functions of RLKs, and provide new genetic resources for wheat molecular breeding., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Mitogen-activated protein kinase (MAPK) signalling cascades are functionally important signalling modules in eukaryotes. Transcriptome reprogramming of immune-related genes is a key process in plant immunity. Emerging evidence shows that plant MAPK cascade is associated with processing (P)-body components and contributes to transcriptome reprogramming of immune-related genes. However, it remains largely unknown how this process is regulated. Here, we show that OsMPK12, which is induced by Magnaporthe oryzae infection, positively regulates rice blast resistance. Further analysis revealed that OsMPK12 directly interacts with enhancer of mRNA decapping protein 4 (OsEDC4), a P-body-located protein, and recruits OsEDC4 to where OsMPK12 is enriched. Importantly, OsEDC4 directly interacts with two decapping complex members OsDCP1 and OsDCP2, indicating that OsEDC4 is a subunit of the mRNA decapping complex. Additionally, we found that OsEDC4 positively regulates rice blast resistance by regulating expression of immune-related genes and maintaining proper mRNA levels of some negatively-regulated genes. And OsMPK12 and OsEDC4 are also involved in rice growth and development regulation. Taken together, our data demonstrate that OsMPK12 positively regulates rice blast resistance via OsEDC4-mediated mRNA decay of immune-related genes, providing new insight into not only the new role of the MAPK signalling cascade, but also posttranscriptional regulation of immune-related genes., (© 2024 John Wiley & Sons Ltd.)

Verticillium dahliae is among the most devastating fungal pathogens, causing significant economic harm to agriculture and forestry. To address this problem, researchers have focused on eliciting systemic resistance in host plants through utilizing volatile organic compounds (VOCs) produced by biological control agents. Herein, we meticulously measured the quantity of V. dahliae pathogens in plants via RTqPCR, as well as the levels of defensive enzymes and pathogenesis-related (PR) proteins within plants. Finally, the efficacy of VOCs in controlling Verticillium wilt in cotton was evaluated. Following treatment with Pseudomonas aurantiaca ST-TJ4, the expression of specific VdEF1-α genes in cotton decreased significantly. The incidence and disease indices also decreased following VOC treatment. In cotton, the salicylic acid (SA) signal was strongly activated 24 h posttreatment; then, hydrogen peroxide (H 2 O 2 ) levels increased at 48 h, and peroxidase (POD) and catalase (CAT) activities increased to varying degrees at different time points. The malondialdehyde (MDA) content and electrolyte leakage in cotton treated with VOCs were lower than those in the control group, and the expression levels of chitinase (CHI) and PR genes (PR10 and PR17), increased at various time points under the ST-TJ4 treatment. The activity of phenylalanine ammonia lyase (PAL) enzymes in cotton treated with VOCs was approximately 1.26 times greater than that in control plants at 24 h，while the contents of phenols and flavonoids increased significantly in the later stage. Additionally, 2-undecanone and 1-nonanol can induce a response in plants that enhances disease resistance. Collectively, these findings strongly suggest that VOCs from ST-TJ4 act as elicitors of plant defence and are valuable natural products for controlling Verticillium wilt., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests, (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Plants have powerful defense mechanisms and extensive immune receptor repertoires, yet crop monocultures are prone to epidemic diseases. Rice (Oryza sativa) is susceptible to many diseases, such as rice blast caused by Magnaporthe oryzae. Varietal resistance of rice to blast relies on intracellular nucleotide binding, leucine-rich repeat (NLR) receptors that recognize specific pathogen molecules and trigger immune responses. In the Yuanyang terraces in southwest China, rice landraces rarely show severe losses to disease whereas commercial inbred lines show pronounced field susceptibility. Here, we investigate within-landrace NLR sequence diversity of nine rice landraces and eleven modern varieties using complexity reduction techniques. We find that NLRs display high sequence diversity in landraces, consistent with balancing selection, and that balancing selection at NLRs is more pervasive in landraces than modern varieties. Notably, modern varieties lack many ancient NLR haplotypes that are retained in some landraces. Our study emphasizes the value of standing genetic variation that is maintained in farmer landraces as a resource to make modern crops and agroecosystems less prone to disease. The conservation of landraces is, therefore, crucial for ensuring food security in the face of dynamic biotic and abiotic threats., Competing Interests: Declaration of interests The authors declare no competing interests, (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The Ideal Plant Architecture 1 (IPA1) transcription factor promotes rice yield and immunity through phosphorylation at its amino acid residue Ser163 as a switch. Although phosphorylated IPA1 mimic, IPA1(S163D), directly targets the promoter of immune response gene WRKY45, it cannot activate its expression. Here, we identified a co-activator of IPA1(S163D), a RING-finger E3 ligase IPA1 interactor 7 (IPI7), which fine-tunes the transcriptional activity of IPA1 to timely promote plant immunity and simultaneously maintain growth for yield. IPI7 interacts with IPA1 and promotes K29-polyubiquitination of IPA1 in vitro and in vivo. However, the stability of IPA1 protein is not affected by IPI7-mediated ubiquitination. The IPI7-promoted K29-polyubiquitination of IPA1 is induced by Magnaporthe oryzae infection and required for phosphorylated IPA1 to transactivate WRKY45 expression for immune response but not for plain IPA1 to transactivate DENSE AND ERECT PANICLES 1 (DEP1) expression for panicle development. IPI7 knockout impairs IPA1-mediated immunity but not yield. Our study reveals that plants utilize non-proteolytic K29-ubiquitination as a response to pathogen infection to fine-tune IPA1 transactivation activity for promoting immunity., (© 2024. The Author(s).)

Protein posttranslational modifications play crucial roles in plant immunity through modulating a complicated signaling network mediated by different hormones. We previously demonstrated that OsATL32, an ATL-type E3 ligase, negatively contributes to rice immunity against Magnaporthe oryzae. Here, we show that OsATL32 forms a loop with OsPPKL2 and OsGSK2 through distinct protein posttranslational modifications to modulate rice immunity. OsATL32 ubiquitinates OsPPKL2, a protein phosphatase with Kelch-like repeat domains that exerts positive roles in regulating rice immunity against M. oryzae and chitin-triggered immune responses, for degradation. The glycogen synthase kinase 2 (OsGSK2), which acts as a negative regulator of rice immunity against M. oryzae and chitin-triggered immune responses, phosphorylates OsATL32 to elevate its protein stability and E3 ligase activity on OsPPKL2. Moreover, OsPPKL2 directly dephosphorylates OsGSK2, affecting its kinase activity on substrates including OsATL32 for phosphorylation. Like OsGSK2 as a BR signaling repressor, OsATL32 negatively regulates BR signaling; conversely, OsPPKL2 plays a positive role in BR signaling. These findings provide a molecular mechanism in which OsATL32 serves as a node connecting BR signaling and immunity by associating with OsPPKL2 and OsGSK2, assembling into a distinct protein posttranslational modifications-linked loop that functions in rice BR signaling and immunity., (© 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation.)

A method for separating M. oryzae from rice samples infected with multiple pathogens using basic laboratory equipment is described. We conducted a series of experiments to obtain a single spore of M. oryzae. This method can also be used to isolate spores from other fungal species., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Cotton (Gossypium hirsutum, Malvaceae) is the most important fiber crop in the world. There are published records of many fungal pathogens attacking Gossypium spp., causing numerous diseases, including powdery mildews. Recently, in 2022, non-cultivated spontaneous G. hirsutum plants bearing powdery mildews symptoms were found at roadsides in two municipalities of the state of Minas Gerais (Brazil): Varginha and Ubá. Such localities are situated ca. 260 km apart, suggesting a broader distribution of this fungus-host association in Brazil. Samples were taken to the laboratory, and an Ovulariopsis-like, asexual stage of Phyllactinia, was identified forming amphigenous colonies, that were more evident, white and cottony, abaxially. Morphological and molecular data- of the ITS and LSU regions- have shown that colonies from those two samples were of the same fungus species, belonging to a previously unknown species of Erysiphaceae (Ascomycota). The fungus fits into the Phyllactinia clade and is described herein as the new species Phyllactinia gossypina sp. nov. This new species belongs to the 'basal Phyllactinia group', a lineage that includes species known only from the Americas. This report expands the list of pathogenic fungi on cotton. It is early to anticipate whether this new powdery mildew represents a threat to cultivated cotton, which is a major crop in Brazil. Nevertheless, further studies about its infectivity to commercial cotton varieties are recommended, since all known Erysiphaceae are specialized obligate plant parasites and several species cause major losses to important crops., (© 2024. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)

Maize cultivation is under the growing threat of charcoal rot (Macrophomina phaseolina). Chemical control of diseases imparts serious health hazards to humans and the ecosystem. Biochar as an alternative disease management approach has been under consideration of the researchers for some time now. The biochar utilized in this study was derived from maize stalks and cobs. Crystallographic structure, inorganic minerals content and size of maize biochar were analyzed by powder X-ray diffractometer, while scanning electron microscopy revealed rough, irregular, tubular structure of the biochar surface. EDX spectra revealed that the maize biochar composition was dominated by 'C' followed by 'O'. The current study was designed to determine the synergistic effect of maize biochar (MB), and biocontrol agent (BCA) Trichoderma viride as soil amendments on the suppression of M. phaseolina. In vitro bioassays were conducted to check the efficiency of antagonistic effect of Trichoderma spp., in combination with maize biochar. On the basis of maximum mycelial growth inhibition T. viride was selected for a glasshouse experiment. Maize plants were grown in pots containing a mixture of soil with MB at application at the rate of 3 and 6% (v/v) separately, associated with or without T. viride. Treatments amended with 3% MB inoculated with M. phaseolina significantly reduced the percentage disease severity index by 40%. While in the presence of T. viride, 3% MB showed maximum disease suppression and a minimum percentage severity index i.e. 60 and 20%, respectively. Highest nitrogen contents were 18.4 g kg -1 observed in treatment 6% MB, while highest phosphorus and potassium contents were 3.11 and 15.2 g kg -1 , respectively in the treatment with 3% MB. Conclusively, the effect of variable concentrations of maize biochar and T. viride as soil amendment was evident on the development of charcoal rot, growth and physiology of maize plants. According to the available literature, our report is the first on the implementation of biochar in synergism with T. viride to suppress the charcoal rot in maize., (© 2024. The Author(s).)

Many disease resistance genes have been introgressed into wheat from its wild relatives. However, reduced recombination within the introgressed segments hinders the cloning of the introgressed genes. Here, we have cloned the powdery mildew resistance gene Pm13, which is introgressed into wheat from Aegilops longissima, using a method that combines physical mapping with radiation-induced chromosomal aberrations and transcriptome sequencing analysis of ethyl methanesulfonate (EMS)-induced loss-of-function mutants. Pm13 encodes a kinase fusion protein, designated MLKL-K, with an N-terminal domain of mixed lineage kinase domain-like protein (MLKL_NTD domain) and a C-terminal serine/threonine kinase domain bridged by a brace. The resistance function of Pm13 is validated through transient and stable transgenic complementation assays. Transient over-expression analyses in Nicotiana benthamiana leaves and wheat protoplasts reveal that the fragment Brace-Kinase 122-476 of MLKL-K is capable of inducing cell death, which is dependent on a functional kinase domain and the three α-helices in the brace region close to the N-terminus of the kinase domain., (© 2024. The Author(s).)

Terpene synthases (TPSs) are enzymes responsible for catalyzing the production of diverse terpenes, the largest class of secondary metabolites in plants. Here, we identified 107 TPS gene loci encompassing 92 full-length TPS genes in upland cotton (Gossypium hirsutum L.). Phylogenetic analysis showed they were divided into six subfamilies. Segmental duplication and tandem duplication events contributed greatly to the expansion of TPS gene family, particularly the TPS-a and TPS-b subfamilies. Expression profile analysis screened out that GhTPSs may mediate the interaction between cotton and Verticillium dahliae. Three-dimensional structures and subcellular localizations of the two selected GhTPSs, GhTPS6 and GhTPS47, which belong to the TPS-a subfamily, demonstrated similarity in protein structures and nucleus and cytoplasm localization. Virus-induced gene silencing (VIGS) of the two GhTPSs yielded plants characterized by increased wilting and chlorosis, more severe vascular browning, and higher disease index than control plants. Additionally, knockdown of GhTPS6 and GhTPS47 led to the down-regulation of cotton terpene synthesis following V. dahliae infection, indicating that these two genes may positively regulate resistance to V. dahliae through the modulation of disease-resistant terpene biosynthesis. Overall, our study represents a comprehensive analysis of the G. hirsutum TPS gene family, revealing their potential roles in defense responses against Verticillium wilt., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Bioengineering of plant immune receptors has emerged as a key strategy for generating novel disease resistance traits to counteract the expanding threat of plant pathogens to global food security. However, current approaches are limited by rapid evolution of plant pathogens in the field and may lack durability when deployed. Here, we show that the rice nucleotide-binding, leucine-rich repeat (NLR) immune receptor Pik-1 can be engineered to respond to a conserved family of effectors from the multihost blast fungus pathogen Magnaporthe oryzae . We switched the effector binding and response profile of the Pik NLR from its cognate rice blast effector AVR-Pik to the host-determining factor pathogenicity toward weeping lovegrass 2 (Pwl2) by installing a putative host target, OsHIPP43, in place of the native integrated heavy metal-associated domain (generating Pikm-1 OsHIPP43 ). This chimeric receptor also responded to other PWL alleles from diverse blast isolates. The crystal structure of the Pwl2/OsHIPP43 complex revealed a multifaceted, robust interface that cannot be easily disrupted by mutagenesis, and may therefore provide durable, broad resistance to blast isolates carrying PWL effectors in the field. Our findings highlight how the host targets of pathogen effectors can be used to bioengineer recognition specificities that have more robust properties compared to naturally evolved disease resistance genes., Competing Interests: Competing interests statement:S.K. receives funding from industry on NLR biology and cofounded a start-up company (Resurrect Bio Ltd.) on resurrecting disease resistance.

Ubiquitination-mediated protein degradation is integral to plant immunity, with E3 ubiquitin ligases acting as key factors in this process. Here, we report the functions of OsATL32, a plasma membrane-localized Arabidopsis Tóxicos En Levadura (ATL)-type E3 ubiquitin ligase, in rice (Oryza sativa) immunity and its associated regulatory network. We found that the expression of OsATL32 is downregulated in both compatible and incompatible interactions between rice and the rice blast fungus Magnaporthe oryzae. The OsATL32 protein level declines in response to infection by a compatible M. oryzae strain or to chitin treatment. OsATL32 negatively regulates rice resistance to blast and bacterial leaf blight diseases, as well as chitin-triggered immunity. Biochemical and genetic studies revealed that OsATL32 suppresses pathogen-induced reactive oxygen species (ROS) accumulation by mediating ubiquitination and degradation of the ROS-producing OsRac5-OsRbohB module, which enhances rice immunity against M. oryzae. The protein phosphatase PHOSPHATASE AND TENSIN HOMOLOG enhances rice blast resistance by dephosphorylating OsATL32 and promoting its degradation, preventing its negative effect on rice immunity. This study provides insights into the molecular mechanism by which the E3 ligase OsATL32 targets a ROS-producing module to undermine rice immunity., (© 2024 Institute of Botany, Chinese Academy of Sciences.)

Background: Climate influences the interaction between pathogens and their hosts significantly. This is particularly evident in the coffee industry, where fungal diseases like Cercospora coffeicola, causing brown-eye spot, can reduce yields drastically. This study focuses on forecasting coffee brown-eye spot using various models that incorporate agrometeorological data, allowing for predictions at least 1 week prior to the occurrence of disease. Data were gathered from eight locations across São Paulo and Minas Gerais, encompassing the South and Cerrado regions of Minas Gerais state. In the initial phase, various machine learning (ML) models and topologies were calibrated to forecast brown-eye spot, identifying one with potential for advanced decision-making. The top-performing models were then employed in the next stage to forecast and spatially project the severity of brown-eye spot across 2681 key Brazilian coffee-producing municipalities. Meteorological data were sourced from NASA's Prediction of Worldwide Energy Resources platform, and the Penman-Monteith method was used to estimate reference evapotranspiration, leading to a Thornthwaite and Mather water-balance calculation. Six ML models - K-nearest neighbors (KNN), artificial neural network multilayer perceptron (MLP), support vector machine (SVM), random forests (RF), extreme gradient boosting (XGBoost), and gradient boosting regression (GradBOOSTING) - were employed, considering disease latency to time define input variables., Results: These models utilized climatic elements such as average air temperature, relative humidity, leaf wetness duration, rainfall, evapotranspiration, water deficit, and surplus. The XGBoost model proved most effective in high-yielding conditions, demonstrating high precision and accuracy. Conversely, the SVM model excelled in low-yielding scenarios. The incidence of brown-eye spot varied noticeably between high- and low-yield conditions, with significant regional differences observed. The accuracy of predicting brown-eye spot severity in coffee plantations depended on the biennial production cycle. High-yielding trees showed superior results with the XGBoost model (R 2  = 0.77, root mean squared error, RMSE = 10.53), whereas the SVM model performed better under low-yielding conditions (precision 0.76, RMSE = 12.82)., Conclusion: The study's application of agrometeorological variables and ML models successfully predicted the incidence of brown-eye spot in coffee plantations with a 7 day lead time, illustrating that they were valuable tools for managing this significant agricultural challenge. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Introduction: Sessile plants engage in trade-offs between growth and defense capacity in response to fluctuating environmental cues. MYB is an important transcription factor that plays many important roles in controlling plant growth and defense. However, the mechanism behind how it keeps a balance between these two physiological processes is still largely unknown., Objectives: Our work focuses on the dissection of the molecular mechanism by which GhMYB33 regulates plant growth and defense., Methods: The CRISPR/Cas9 technique was used to generate mutants for deciphering GhMYB33 functions. Yeast two-hybrid, luciferase complementary imaging, and co-immunoprecipitation assays were used to prove that proteins interact with each other. We used the electrophoretic mobility shift assay, yeast one-hybrid, and luciferase activity assays to analyze GhMYB33 acting as a promoter. A β-glucuronidase fusion reporter and 5' RNA ligase mediated amplification of cDNA ends analysis showed that ghr-miR319c directedly cleaved the GhMYB33 mRNA., Results: Overexpressing miR319c-resistant GhMYB33 (rGhMYB33) promoted plant growth, accompanied by a significant decline in resistance against Verticillium dahliae. Conversely, its knockout mutant, ghmyb33, demonstrated growth restriction and concomitant augmentation of V. dahliae resistance. GhMYB33 was found to couple with the DELLA protein GhGAI1 and bind to the specific cis-elements of GhSPL9 and GhDFR1 promoters, thereby modulating internode elongation and plant resistance in V. dahliae infection. The ghr-miR319c was discovered to target and suppress GhMYB33 expression. The overexpression of ghr-miR319c led to enhanced plant resistance and a simultaneous reduction in plant height., Conclusion: Our findings demonstrate that GhMYB33 encodes a hub protein and controls the expression of GhSPL9 and GhDFR1, implicating a pivotal role for the miR319c-MYB33 module to regulate the trade-offs between plant growth and defense., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Production and hosting by Elsevier B.V.)

The inclusion of biological control in the integrated management of rice blast ( Magnaporthe oryzae [Mo]) reduces pesticide application. Phanerochaete australis (Pha) has been shown to be a potential inducer of resistance to rice blast. Pha was isolated saprophytically from the rice phylloplane and studied for its interaction with Mo in the defense process of upland rice plants against the pathogen attack. Investigating the Pha × Mo interaction in a completely randomized design, the suppression of leaf blast and the epidemiological components of disease development were quantified in vivo, whereas the physiological and biochemical aspects, as defense enzymes and oxidative complex components, were evaluated in vitro during the induction of resistance. In the Pha × Mo interaction, it was found that seed treatment can significantly reduce disease severity by up to 93%, increase the photosynthetic apparatus, mobilize photoassimilates to the defense system, intensify defense enzyme and oxidant complex activities (chitinase [CHI], β-1,3-glucanase [GLU], lipoxygenase [LOX], phenylalanine ammonia-lyase [PAL], poliphenoloxidase [PPO], peroxidase [POX], catalase [CAT], cuperoxide dismutase [SOD]), decrease phenolic compounds (TPCs), and increase photosynthetic pigment levels compared with the negative control (Mo). When treating the seed, we are referring to an induction process where there is no physical contact between the pathogens. The enzymes produced by the interaction between the microorganisms validate this process; thus, Pha acts as an inducer of resistance to upland rice plants challenged with Mo.

Panicle blast, caused by Magnaporthe oryzae , is a destructive disease of rice worldwide. Clarifying the susceptibility of rice panicles at different stages is of great significance for effective disease management. Field experiments were conducted in two paddy fields at Wuyuan County in 2016 and 2017 to determine the effects of head covering and its timing on the infection of rice panicle blast. Results revealed that panicle blast was reduced significantly by covering rice heads with sulfuric acid paper bags, regardless of the covering time, ranging from initial heading to 15 days afterward, suggesting that rice panicles could be infected by blast pathogen even 15 days after initial heading. Panicle blast incidence was also found to be significantly influenced by plant dates, with higher panicle blast incidence observed in plots planted on early dates, suggesting adjusting plant dates could help rice panicles escape the infection by blast pathogen. The results from this study also highlighted the importance of cultivars and environmental conditions to panicle blast. In conclusion, besides planting blast-resistant cultivars, it is important to protect rice heads from the initial heading to the early dough stages, and fungicides should be applied according to infection warnings based on host, inoculum, and weather conditions., Competing Interests: The author(s) declare no conflict of interest.

Blast disease caused by the fungus Magnaporthe oryzae is one of the most devastating rice diseases. Disease resistance genes such as Pi-ta or Pi-ta2 are critical in protecting rice production from blast. Published work reports that Pi-ta codes for a nucleotide-binding and leucine-rich repeat domain protein (NLR) that recognizes the fungal protease-like effector AVR-Pita by direct binding. However, this model was challenged by the recent discovery that Pi-ta2 resistance, which also relies on AVR-Pita detection, is conferred by the unconventional resistance gene Ptr, which codes for a membrane protein with a cytoplasmic armadillo repeat domain. Here, using NLR Pi-ta and Ptr RNAi knockdown and CRISPR/Cas9 knockout mutant rice lines, we found that AVR-Pita recognition relies solely on Ptr and that the NLR Pi-ta has no role in it, indicating that it is not the Pi-ta resistance gene. Different alleles of Ptr confer different recognition specificities. The A allele of Ptr (PtrA) detects all natural sequence variants of the effector and confers Pi-ta2 resistance, while the B allele of Ptr (PtrB) recognizes a restricted set of AVR-Pita alleles and, thereby, confers Pi-ta resistance. Analysis of the natural diversity in AVR-Pita and of mutant and transgenic strains identified one specific polymorphism in the effector sequence that controls escape from PtrB-mediated resistance. Taken together, our work establishes that the M. oryzae effector AVR-Pita is detected in an allele-specific manner by the unconventional rice resistance protein Ptr and that the NLR Pi-ta has no function in Pi-ta resistance and the recognition of AVR-Pita., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Rice blast, caused by Magnaporthe oryzae, significantly impacts grain yield, necessitating the identification of broad-spectrum resistance genes and their functional mechanisms for disease-resistant crop breeding. Here, we report that rice with knockdown OsHDAC1 gene expression displays enhanced broad-spectrum blast resistance without effects on plant height and tiller numbers compared to wild-type rice, while rice overexpressing OsHDAC1 is more susceptible to M. oryzae. We identify a novel blast resistance transcription factor, OsGRAS30, which genetically acts upstream of OsHDAC1 and interacts with OsHDAC1 to suppress its enzymatic activity. This inhibition increases the histone H3K27ac level, thereby boosting broad-spectrum blast resistance. Integrating genome-wide mapping of OsHDAC1 and H3K27ac targets with RNA sequencing analysis unveils how OsHDAC1 mediates the expression of OsSSI2, OsF3H, OsRLR1 and OsRGA5 to regulate blast resistance. Our findings reveal that the OsGRAS30-OsHDAC1 module is critical to rice blast control. Therefore, targeting either OsHDAC1 or OsGRAS30 offers a promising approach for enhancing crop blast resistance., (© 2024 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.)

Southern leaf blight (SLB) is a foliar disease caused by the fungus Cochliobolus heterostrophus infecting maize plants in humid, warm weather conditions. SLB causes production losses to corn producers in different regions of the world such as Latin America, Europe, India, and Africa. In this paper, we demonstrate a non-destructive method to quantify the signs of fungal infection in SLB-infected corn plants using a deep UV (DUV) fluorescence spectrometer, with a 248.6 nm excitation wavelength, to acquire the emission spectra of healthy and SLB-infected corn leaves. Fluorescence emission spectra of healthy and diseased leaves were used to train an Autoencoder (AE) anomaly detection algorithm-an unsupervised machine learning model-to quantify the phenotype associated with SLB-infected leaves. For all samples, the signature of corn leaves consisted of two prominent peaks around 450 nm and 325 nm. However, SLB-infected leaves showed a higher response at 325 nm compared to healthy leaves, which was correlated to the presence of C. heterostrophus based on disease severity ratings from Visual Scores (VS). Specifically, we observed a linear inverse relationship between the AE error and the VS (R2 = 0.94 and RMSE = 0.935). With improved hardware, this method may enable improved quantification of SLB infection versus visual scoring based on e.g., fungal spore concentration per unit area and spatial localization., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Banah et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)