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Anthracnose, caused by the fungus Colletotrichum lindemuthianum, poses a significant and widespread threat to the common bean crop. The use of plant genetic resistance has proven to be the most effective strategy for managing anthracnose disease. The Amendoim Cavalo (AC) Andean cultivar has resistance against multiple races of C. lindemuthianum, which is conferred by the Co-AC gene. Fine mapping of this resistance gene to common bean chromosome Pv01 enabled the identification of Phvul.001G244300, Phvul.001G244400, and Phvul.001G244500 candidate genes for further validation. In this study, the relative expression of Co-AC candidate genes was assessed, as well as other putative genes in the vicinity of this locus and known resistance genes, in the AC cultivar following inoculation with the race 73 of C. lindemuthianum. Gene expression analysis revealed significantly higher expression levels of Phvul.001G244500. Notably, Phvul.001G244500 encodes a putative Basic Helix-Loop-Helix transcription factor, suggesting its involvement in the regulation of defense responses. Furthermore, a significant modulation of the expression of defense-related genes PR1a, PR1b, and PR2 was observed in a time-course experiment. These findings contribute to the development of improved strategies for breeding anthracnose-resistant common bean cultivars, thereby mitigating the impact of this pathogen on crop yields and ensuring sustainable bean production.

Olive anthracnose is the most important fungal disease of the olive fruit worldwide, with the fungus Colletotrichum acutatum as the main cause of the disease in Greece. A total of 11 commercial biological plant protection products (bioPPPs) (Amylo-X®, Botector®, FytoSave®, LBG 01F34®, Mevalone®, Polyversum®, Remedier®, Serenade® ASO, Sonata®, Trianum-P®, Vacciplant®), with various modes of action against the fungus C. acutatum, were evaluated by bioassays using detached fruits of two important olive Greek varieties, cv. Koroneiki and cv. Kalamon. Subsequently, the most effective bioPPPs were evaluated for their ability to induce plant defense mechanisms, by determining the expression levels of ten Olea europaea defense genes (Pal, CuaO, Aldh1, Bglu, Mpol, Lox, Phely, CHI-2, PR-10, PR-5). Remedier®, Trianum-P®, Serenade® ASO, Sonata®, and Mevalone® were the most effective in reducing disease severity, and/or inhibiting the conidia production by the fungus at high rates. Post bioPPPs application, high expression levels of several olive plant defense genes were observed. This study provides insights into commercial bioPPPs' effectiveness in controlling olive anthracnose, as well as biocontrol-agents-mediated modulation of olive defense mechanisms. [ABSTRACT FROM AUTHOR]

Anthracnose (ANT) and angular leaf spot (ALS) are significant diseases in common bean, leading to considerable yield losses under specific environmental conditions. The California Dark Red Kidney (CDRK) bean cultivar is known for its resistance to multiple races of both pathogens. Previous studies have identified the CoPv01CDRK/PhgPv01CDRK resistance loci on chromosome Pv01. Here, we evaluated the expression levels of ten candidate genes near the CoPv01CDRK/PhgPv01CDRK loci and plant defense genes using quantitative real-time PCR in CDRK cultivar inoculated with races 73 of Colletotrichum lindemuthianum and 63-39 of Pseudocercospora griseola. Gene expression analysis revealed that the Phvul.001G246300 gene exhibited the most elevated levels, showing remarkable 7.8-fold and 8.5-fold increases for ANT and ALS, respectively. The Phvul.001G246300 gene encodes an abscisic acid (ABA) receptor with pyrabactin resistance, PYR1-like (PYL) protein, which plays a central role in the crosstalk between ABA and jasmonic acid responses. Interestingly, our results also showed that the other defense genes were initially activated. These findings provide critical insights into the molecular mechanisms underlying plant defense against these diseases and could contribute to the development of more effective disease management strategies in the future. [ABSTRACT FROM AUTHOR]

Anthracnose, caused by the fungus Colletotrichum lindemuthianum, poses a significant and widespread threat to the common bean crop. The use of plant genetic resistance has proven to be the most effective strategy for managing anthracnose disease. The Amendoim Cavalo (AC) Andean cultivar has resistance against multiple races of C. lindemuthianum, which is conferred by the Co-AC gene. Fine mapping of this resistance gene to common bean chromosome Pv01 enabled the identification of Phvul.001G244300, Phvul.001G244400, and Phvul.001G244500 candidate genes for further validation. In this study, the relative expression of Co-AC candidate genes was assessed, as well as other putative genes in the vicinity of this locus and known resistance genes, in the AC cultivar following inoculation with the race 73 of C. lindemuthianum. Gene expression analysis revealed significantly higher expression levels of Phvul.001G244500. Notably, Phvul.001G244500 encodes a putative Basic Helix–Loop–Helix transcription factor, suggesting its involvement in the regulation of defense responses. Furthermore, a significant modulation of the expression of defense-related genes PR1a, PR1b, and PR2 was observed in a time-course experiment. These findings contribute to the development of improved strategies for breeding anthracnose-resistant common bean cultivars, thereby mitigating the impact of this pathogen on crop yields and ensuring sustainable bean production.

Olive anthracnose is the most important fungal disease of the olive fruit worldwide, with the fungus Colletotrichum acutatum as the main cause of the disease in Greece. A total of 11 commercial biological plant protection products (bioPPPs) (Amylo-X®, Botector®, FytoSave®, LBG 01F34®, Mevalone®, Polyversum®, Remedier®, Serenade® ASO, Sonata®, Trianum-P®, Vacciplant®), with various modes of action against the fungus C. acutatum, were evaluated by bioassays using detached fruits of two important olive Greek varieties, cv. Koroneiki and cv. Kalamon. Subsequently, the most effective bioPPPs were evaluated for their ability to induce plant defense mechanisms, by determining the expression levels of ten Olea europaea defense genes (Pal, CuaO, Aldh1, Bglu, Mpol, Lox, Phely, CHI-2, PR-10, PR-5). Remedier®, Trianum-P®, Serenade® ASO, Sonata®, and Mevalone® were the most effective in reducing disease severity, and/or inhibiting the conidia production by the fungus at high rates. Post bioPPPs application, high expression levels of several olive plant defense genes were observed. This study provides insights into commercial bioPPPs’ effectiveness in controlling olive anthracnose, as well as biocontrol-agents-mediated modulation of olive defense mechanisms.

Anthracnose (ANT) and angular leaf spot (ALS) are significant diseases in common bean, leading to considerable yield losses under specific environmental conditions. The California Dark Red Kidney (CDRK) bean cultivar is known for its resistance to multiple races of both pathogens. Previous studies have identified the CoPv01CDRK/PhgPv01CDRK resistance loci on chromosome Pv01. Here, we evaluated the expression levels of ten candidate genes near the CoPv01CDRK/PhgPv01CDRK loci and plant defense genes using quantitative real-time PCR in CDRK cultivar inoculated with races 73 of Colletotrichum lindemuthianum and 63-39 of Pseudocercospora griseola. Gene expression analysis revealed that the Phvul.001G246300 gene exhibited the most elevated levels, showing remarkable 7.8-fold and 8.5-fold increases for ANT and ALS, respectively. The Phvul.001G246300 gene encodes an abscisic acid (ABA) receptor with pyrabactin resistance, PYR1-like (PYL) protein, which plays a central role in the crosstalk between ABA and jasmonic acid responses. Interestingly, our results also showed that the other defense genes were initially activated. These findings provide critical insights into the molecular mechanisms underlying plant defense against these diseases and could contribute to the development of more effective disease management strategies in the future.

Bacterial wilt disease caused by Ralstonia solanacearum impacts negatively on potato production. This study evaluated the effects of thymol and eugenol encapsulated in chitosan nanoparticles (TCNP and ECNP) on the virulence genes (PhcA, XpsR and HrpG) of R. solanacearum and their in vivo efficacy against bacterial wilt. Gene expression levels of virulence genes in the presence of TCNP (5.6 and 11.3 µg mL−1) and ECNP (11.3 and 22.5 µg mL−1) together with those of plant defense genes (chitinase and β-l,3-glucanase) were determined through RT-qPCR. All the virulence genes were downregulated when exposed to both TCNP and ECNP while glucanase and chitinase genes increased and peaked after 18 hours post inoculation. The lowest disease severity index (10.3%) was recorded with plants treated with 90 µg mL−1 ECNP. The results of this study show that both TCNP and ECNP have a potential to be used as bacterial wilt bactericides. [ABSTRACT FROM AUTHOR]

Background: Rice sheath blight (caused by Rhizoctonia solani) and tobacco mosaic virus are very important plant diseases, causing a huge loss in global crop production. Paenibacillus kribbensis PS04 is a broad-spectrum biocontrol agent, used for controlling these diseases. Previously, extracellular polysaccharides (EPS) from P. kribbensis PS04 had been purified and their structure was inferred to be fructosan. This study aimed to evaluate the effects of exogenous EPS treatment on plant–pathogen interactions. Results: Plant defense genes such as phenylalanine ammonia-lyase, catalase, chitinase, allene oxide synthase, and PR1a proteins were significantly induced by exogenous EPS treatment. Moreover, subsequent challenge of EPS-pretreated plants with the pathogens (R. solani or tobacco mosaic virus) resulted in higher expression of defense-associated genes. Increased activities of defense-associated enzymes, total phenols, and flavonoids were also observed in EPS pretreated plants. The contents of malondialdehyde in plants, which act as indicator of lipid peroxidation, were reduced by EPS treatment. Conclusions: This study comprehensively showed that EPS produced from P. kribbensis PS04 enhances disease resistance in plants by the activation of defense-associated genes as well as through the enhancement of activities of defense-related enzymes. How to cite: Canwei S, Xiaoyun H, Ahmed N, et al. Fructosan form Paenibacillus kribbensis PS04 enhance disease resistance against Rhizoctonia solani and tobacco mosaic virus. Electron J Biotechnol 2020;47. https://doi.org/10.1016/j.ejbt.2020.07.002

• An endophytic Bacillus effectively controlled multiple rice diseases. • The Bacillus enhanced rice yield and rice resistance to wind. • The Bacillus suppressed rice defense genes upon introduction. • The Bacillus via seed treatment persists endophytically in rice until maturity. • Seed treatment with the Bacillus provides various benefits for rice cultivation. Rice (Oryza sativa) is a globally important staple food, but its production was influenced by various biotic and abiotic stresses. This study involved screening endophytic bacterial strains for their antagonistic activities and control efficacy against multiple rice pathogens in planta assays. Subsequent greenhouse investigations identified Bacillus velezensis LS123N as the most promising strain for effectively controlling various rice diseases, including bacterial blight, rice blast, bakanae disease, Pythium disease, and brown spot disease. Field trials further demonstrated that LS123N significantly reduced naturally occurring brown spot disease caused by Bipolaris oryzae in both seedlings and mature rice plants, and increased rice yields. For disease control against bacterial blight, Pythium disease, and brown spot, only a single treatment during seed germination resulted in significant disease control efficacy. The application of LS123N during seed germination aligns with common rice cultivation practices. Additionally, LS123N exhibited the capacity to improve rice resistance to wind stress and enhance rice growth during the seedling stage. Endophytic colonization of LS123N was evidenced from seed to mature rice plants after seed treatment. Interestingly, the expression of many rice defense genes was suppressed within 48 h of the LS123N introduction. In vitro assays showed that LS123N inhibited spore germination and normal growth of germ tubes of B. oryzae , produced multiple hydrolases, siderophores, and IAA, and had the ability to solubilize phosphorus compounds. In summary, these results indicate that B. velezensis LS123N is a promising biocontrol agent and has the potential to be developed into a biofungicide, biofertilizer, and biostimulator. [ABSTRACT FROM AUTHOR]

Among other environmental factors, phytopathogens have key roles in limiting global crop production. While an in-depth understanding of plant-pathogen interactions is therefore necessary to develop sustainable crop protection strategies, the genetic basis of plant-pathogen interactions is poorly understood. In this study, we tested the growth and resistance of an important phytopathogen, Pseudomonas syringae pv tomato DC3000 ( Pst DC3000), in 80 gene knockouts, identified previously through genome-wide association mapping of global Arabidopsis thaliana populations. Amongst these, most of the genes are previously known to regulate multiple functions in plants including cellular mechanisms, growth, reproduction, hormonal signaling, and tolerance to both biotic and abiotic stresses (extreme temperature, drought, salinity, pollutants, and nutrient stresses, etc.). The Pst DC3000 demonstrated two distinct growth patterns in all gene knockouts, showing maximum growth after 4 or 7 days of inoculation (DOI). Mostly, the wild-type ( Col-0) demonstrated higher phytopathogen growth than almost all gene knockouts after 4 or 7 DOI. The differential abundance of Pst DC3000 in the multiple gene knockouts reveals a number of new genes important for plant defense. Meanwhile, our results and a review of previous literature suggest interaction of plant defense with plant growth, reproduction, hormonal and abiotic stress tolerance. Thus in future studies, a mechanistic understanding of the genetic, ecological and physiological basis of plant-pathogen interactions, and pleiotropic interactions may prove instrumental in developing sustainable plant protection practices. [ABSTRACT FROM AUTHOR]

The presence of multiple resistance genes in common bean and the diverse race spectrum of Colletotrichum lindemuthianum suggests that a broad spectrum of resistance mechanisms needs to be deployed in resistance breeding. However, limited studies on the interaction of anthracnose resistance genes and other plant defense genes exist in common bean. Therefore, we analyzed four candidate genes of Co-1 2 allele at the Co-1 locus and plant defense genes via quantitative real time PCR, to determine the fine-tuned timing and magnitude of expression of the resistance reaction. In the present study, a pair of near isogenic lines (NILs; T9576R and T9576S) that differ for the Co-1 2 resistance allele, was used that upon infection with race 73 of C. lindemuthianum show differential gene expression between the NILs. Our aim was to identify a particular gene that is effective against race 73 among other candidate genes located at the Co-1 locus. Gene expression analysis revealed higher expression levels of the Phvul.001G243800 gene. Expression was nearly 144 fold higher in the resistant NIL, than in the susceptible NIL and could be a possible candidate gene effective against race 73. In addition, we found that initially the other defense genes are activated which suggests that both defense and candidate gene activation is necessary to effect resistance against the anthracnose pathogen of common bean. Image 1 • In the present investigation, expression profile of four plant defense and overlapping candidate genes at Co-1 locus were investigated over a time course. • In the susceptible NIL, the plant defense genes activate late in the necrotrophic phase of pathogen. • Our findings identified the candidate gene (Phvul.001G243800) effective against the race 73 of C lindemuthianum. [ABSTRACT FROM AUTHOR]

Phytopathogenic microorganisms have a significant influence on survival and productivity of several crop plants. Transcription factors (TFs) are important players in the response to biotic stresses, as insect attack and pathogen infection. In face of such adversities many TFs families have been previously reported as differentially expressed in plants as a reaction to bacterial, fungal and viral infection. This review highlights recent progresses in understanding the structure, function, signal regulation and interaction of transcription factors with other proteins in response to pathogens. Hence, we focus on three families of transcription factors: ERF, bZIP and WRKY, due to their abundance, importance and the availability of functionally well-characterized members in response to pathogen attack. Their roles and the possibilities related to the use of this knowledge for engineering pathogen resistance in crop plants are also discussed., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)