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Auxin signaling regulates growth and developmental processes in plants. The core of nuclear auxin signaling relies on just three components: TIR1/AFBs, Aux/IAAs, and ARFs. Each component is itself made up of several domains, all of which contribute to the regulation of auxin signaling. Studies of the structural aspects of these three core signaling components have deepened our understanding of auxin signaling dynamics and regulation. In addition to the structured domains of these components, intrinsically disordered regions within the proteins also impact auxin signaling outcomes. New research is beginning to uncover the role intrinsic disorder plays in auxin-regulated degradation and subcellular localization. Structured and intrinsically disordered domains affect auxin perception, protein degradation dynamics, and DNA binding. Taken together, subtle differences within the domains and motifs of each class of auxin signaling component affect signaling outcomes and specificity.

We measured community-level traits of vascular plants, lichens, and bryophytes in an alpine Dryas octopetala L. heath in Finse, Norway, after nearly two decades of experimental warming by open-top chambers. We hypothesized that under warming (1) vascular plant traits would shift from resource conservative towards more resource acquisitive, and (2) lichen and bryophyte traits would shift to those associated with drier conditions, due to increased evapotranspiration. Both hypotheses were not supported, as vascular plant nitrogen concentration decreased, whereas carbon to nitrogen ratio increased with warming, indicative of a less resource acquisitive strategy, and lichen specific thallus area and water holding capacity were unresponsive. Bryophyte specific shoot length increased, and carbon concentration and water holding capacity tended to decrease under warming, concurrent with increased vegetation height and litter cover indicating stronger competition from vascular plants. Intraspecific variation was most important for vascular plant and lichen traits, whereas species turnover was the main driver of bryophyte trait variation. This indicates that bryophytes may be affected more strongly by future warming than vascular plants and lichens in our study system. We highlight the importance of studying traits of different primary producer groups simultaneously, as they may respond differently to the same environmental changes.

During evolution, chloroplasts, which originated by endosymbiosis of a prokaryotic ancestor of today’s cyanobacteria with a eukaryotic host cell, were established as the site for photosynthesis. Therefore, chloroplast organelles are loaded with transition metals including iron, copper, and manganese, which are essential for photosynthetic electron transport due to their redox capacity. Although transport, storage, and cofactor-assembly of metal ions in chloroplasts are tightly controlled and crucial throughout plant growth and development, knowledge on the molecular nature of chloroplast metal-transport proteins is still fragmentary. Here, we characterized the soluble, ATP-binding ABC-transporter subunits ABCI10 and ABCI11 in Arabidopsis thaliana, which show similarities to components of prokaryotic, multisubunit ABC transporters. Both ABCI10 and ABCI11 proteins appear to be strongly attached to chloroplast-intrinsic membranes, most likely inner envelopes for ABCI10 and possibly plastoglobuli for ABCI11. Loss of ABCI10 and ABCI11 gene products in Arabidopsis leads to extremely dwarfed, albino plants showing impaired chloroplast biogenesis and deregulated metal homeostasis. Further, we identified the membrane-intrinsic protein ABCI12 as potential interaction partner for ABCI10 in the inner envelope. Our results suggest that ABCI12 inserts into the chloroplast inner envelope membrane most likely with five predicted α-helical transmembrane domains and represents the membrane-intrinsic subunit of a prokaryotic-type, energy-coupling factor (ECF) ABC-transporter complex. In bacteria, these multisubunit ECF importers are widely distributed for the uptake of nickel and cobalt metal ions as well as for import of vitamins and several other metabolites. Therefore, we propose that ABCI10 (as the ATPase A-subunit) and ABCI12 (as the membrane-intrinsic, energy-coupling T-subunit) are part of a novel, chloroplast envelope-localized, AAT energy-coupling module of a prokaryotic-type ECF transporter, most likely involved in metal ion uptake.

Low temperature studies with winter-dormant buds are severely limited by the lack of a rapid,non-destructive assay for their viability. Investigations involving the winter harvest of ecodormant buds of woody subjects, including cryopreservation, are restricted if viability cannot be assessed until dormancy is broken. If post-treatment grafting indicates low survival of the harvested population then further collection and study has to be delayed until the next winter season. This study trials the use of a portable gas exchange system able to discriminate between live and dead buds rapidly, with the assay confirmed as non-destructive by subsequent micropropagation. Active respiration was recorded for 85% of a winter-dormant Malus domestica buds population that showed 91% viability when grafted (n = 45). Lethally stressed material gave no false positive results. When micropropagated after respiratory measurement, a population viability of 76% was recorded. There was a significant, positive correlation between respiration and fresh weight for buds of mass >10 mg, from a population with a mean fresh weight of 17 mg.

Aloe dhufarensis Lavranos is an important medicinal plant, however, the endophytic microorganisms associated with this plant and their antagonistic activities are not known. In this study, endophytic fungi and bacteria were isolated from the leaf tissues of A. dhufarensis and their antagonistic activity against the plant pathogens Fusarium sp. and Cladosporium sp. were evaluated using a dual culture assay. A total of 3 fungal endophytes and 12 bacterial endophytes were isolated from the leaf tissue segments of A. dhufarensis. Among them, two endophytic fungal isolates designated as SQUCC-F2-2 and SQUCC-F3-1 exhibited inhibitory activity against the phytopathogenic fungi tested. In addition, scanning electron microscopy analysis showed that they induced shriveling, pit formation and disintegration of the hyphae of the phytopathogenic fungi. These two endophytic fungal isolates were identified as Sarocladium kiliense (SQUCC-F2-2) and Penicillium oxalicum (SQUCC-F3-1) on the basis of nuclear ribosomal DNA internal transcribed spacer (ITS) region. Analysis of the metabolites produced by these endophytes revealed the presence of fatty acids, fatty acid methyl esters, furfuryl alcohol, 1,2-diols and amide, which have been identified in the literature as antimicrobial compounds. P. oxalicum produced 7 compounds, of which 2-Furanmethanol, Dodecanoic acid and Tetradecanoic acid were dominant. S. kiliense produced 8 compounds with 2,3-Butanediol as the main constituent. This is the first report of endophytic fungi of A. dhufarensis with antagonistic activity against phytopathogenic fungi.

The genus Aloe is widely used for medicinal purposes throughout its predominantly African distribution, but detailed knowledge of the contemporary value of aloes is patchy. The main aim of this study was to determine the value of Aloe in the Highlands of Ethiopia, a region of rich Aloe diversity, by documenting local uses and perceptions of the sustainability of the species used. Amhara and Tigray community members participated in semi-structured interviews from 110 respondents aged 24-72. Eleven species of Aloe were recorded for medicine, social and environmental uses, animal food, and as bee plants managed for honey production. Of these, the majority of use records were for human medicine to treat malaria and wounds. We found no evidence of non-sustainable harvesting for medicine, but extensive habitat loss and interest in the commercial uses of Aloe present acute threats and indicate the vulnerability of Aloe species in the central and northern Highlands of Ethiopia.

The genus Aloe (family: Xanthorrhoeaceae) encompasses 490 shrubby-succulent-perennial species which are native to Africa. Among these, Aloe vera has grabbed the limelight in the arena of herbal medicine due to the presence of unique phytochemicals such as Aloin A and B, Homonataloin, Aloe emodin, acemannan etc. in its latex. Moreover, its leaf extract contains 99% water, and 75 active compounds including vitamins (A, B1, B2, B3, B6, B9, B12, C, and E), minerals (Zn, Se, Na, Mn, Mg, K, Cu, Cr, Ca), amino acids, and enzymes (peroxidase, lipase, cellulase, catalase, carboxypeptidase, bradykinase, amylase, alkaline phosphatase). Thus, Aloe vera is revered as a ‘wonder plant’ as it possesses multiple pharmaceutical properties such as anti-oxidant, anti-inflammatory, anti-tumor, anti-fungal, anti-diabetic, anti-ulcer, anti-hypertensive and its juice helps to cure gastrointestinal disorders, and dermal diseases, it also strengthens the immune system. Being a xerophyte, Aloe vera is commercially cultivated in many countries which include South Africa, America, Australia, India etc. The Aloe gel, is meticulously extracted, processed and stabilized before using it in preparation of various health care products. This review focuses on the explicit information on origin, botanical description, phytochemistry, nutritional and medicinal benefits, with special emphasis on value-added products of Aloe vera. The review revealed 46 value-added Aloe-products that are being manufactured by different companies worldwide. Thus, sustainable Aloe-cultivation must be ensured to meet the rising global demands for Aloe vera gel and allied products.

Heavy metals like cadmium (Cd) are a serious threat for living organisms due to increased global environmental pollution. Aloe ferox Mill. is a very important species of the genus Aloe, especially from a medical point of view, because it is a source of biologically active substances and it is often used in the traditional medicine. Since the knowledge about the effect of heavy metals, like Cd on growth of Aloe species is scarce, this study showed the effect of Cd on anatomical, morphological and physiological properties of this important medicinal plant species. We found that Cd affected the leaf morphology and decreased biomass of the aboveground plant part. Cd also affected cuticle deposition and increased the number of stomata in the abaxial and adaxial epidermis of leaves. Roots treated with Cd showed lower lignification and decreased level of membrane lipids peroxidation than control roots. Cadmium concentration was the highest in the roots; however, relatively high portion of Cd is being translocated to the leaves. This might be dangerous as Aloe is well known medicinal plant with content of active secondary metabolites mainly in the leaves.

Aloe vera (Aloe barbadensis Miller) is a perennial drought tolerant medicinal species. This research study investigates the influence of biofertilizers on mycorrhizal fungi colonization, leaf number and width, plant height, offset number, leaf relative elongation rate (RER), leaf dry weight and leaf gel weight, water productivity (WP) for the gel, and aloin content in Aloe vera plants. The experiments were carried out in the warm and dry climate of Bushehr Province, Iran during 2016–2018. Treatments are reported to include irrigation regimes and biofertilizers at four levels. In terms of irrigation regimes, 25%, 50%, 75%, and 100% of water requirement accompanied the following treatments for biofertilizers, phosphorus-solubilizing bacteria (PSB), mycorrhizal fungi (MF), PSB+MF, and control (without any biofertilizers). The PSB includes Pseudomonas putida strain P13 and Pantoea agglomerans strain P5, in addition to Glomus mosseae as MF. The biofertilizer benefits (remarkably PSB+MF) on investigated traits were observed in three harvests. The results confirm the positive impacts of biofertilizers on important traits such as offset number (an economical part of Aloe vera planting), water productivity with less water consumption, and root colonization, which is the main reason of increasing the mentioned traits. Considering the minimal difference between 100%, 75% and 50% of water requirement in terms of gel fresh weight and more aloin content in 50% of our experiments, Aloe vera is reported as a high drought tolerant plant which merely requires an acceptable gel yield and aloin content. Moreover, better water productivity and consumption is possible in warm and arid regions by applying 50% of Aloe vera water requirement as well as biofertilizers.

Aloe vera L. is used largely in the pharmaceutical, cosmetic, and agro-food industries. The in vitro technique was proposed as an alternative method for large-scale propagation and/or conservation breeding programmes in response to the increasing demand for Aloe vera. Unfortunately, a major problem in the application of plant tissue culture is the browning of cultured tissues and microbial contamination. This work investigates for the first time the efficacy of using Essential Oils (EOs) to control enzymatic browning and contamination of cultures from Aloe vera. Murashige and Skoog (MS) (1962) medium supplemented with 1 mg/L β-indole butyric acid (IBA) was used as a basic medium for A. vera for in vitro culture. The effect of the addition of charcoal (at 0.5 g/L), thyme (Thymus vulgaris L.) and rosemary (Rosmarinus officinalis L.) essential oils (at concentrations of 0.1 and 0.2%) to the basic medium was assessed. While thyme Essential Oil (EO) inhibited explant growth, rosemary EO induced the highest explant survival percentage, the lowest browning diffusion and contamination percentage. Moreover, a second experiment was conducted to determine the optimal rosemary EO concentration (0.025, 0.05, 0.075, and 0.1%). Explant survival percentage was 100% after four weeks of culture with rosemary EO concentrations of 0.05, 0.075, and 0.1% with no signs of browning. The lowest infection percentage (10%) was observed for media containing 0.075 and 0.1% of rosemary EO. The highest average number of leaves per explant was 3.71 with 0.1% rosemary EO and the greatest leaf length was 3.18 cm with 0.05%. The analytical techniques used to detect rosemary EO compounds were GC-FID (gas chromatography - flame ionization detection) and GC–MS (gas chromatography-mass spectrometry). The main constituents found were 1,8-cineole (53.92%), α-pinene (15.86%), β-pinene (10.79%), and camphor (7.99%). Additionally, the antioxidant activity of the rosemary EO was determined by the DPPH (Free radical-scavenging activity) (24.66 µg mL−1) and FRAP (Ferric reducing antioxidant power) (35.16 mmol Fe2+L − 1) tests. The chemical composition together with the antioxidant effect and the most widely recognized anti-infectious properties of the used rosemary EO could explain its role in the inhibition of both enzymatic browning and microbial growth in culture media. These results could be a scope for further screening of EOs to be used for the improvement of in vitro culture of A. vera and other industrial crops.

Late blight caused by the oomycete Phytophthora infestans is considered to be one of the most severe diseases of potato and tomato worldwide. Whilst current synthetic fungicides are efficient at controlling this disease, they are an environmental and economic burden. In line with EU directives to reduce the use of synthetic pesticides and increase the use of sustainable alternative disease control strategies that can form part of integrated pest management systems, practical biological control solutions are urgently needed. Despite the fact that there has been a large body of scientific research into microorganisms with potential for the biological control of late blight disease, relatively few commercial biocontrol agents, licensed to control late blight, exist. Furthermore, the practical uptake of those in Europe is lower than might be expected, suggesting that such solutions are not yet feasible, or effective. Here we review the scientific literature, focusing on the most recent developments in the hunt for efficient and sustainable biological control of late blight disease. We discuss the progress in our mechanistic understanding of mycoparasite–prey interactions, in the context of late blight and the challenges and limitations to the use of such knowledge in practical disease control within a European context.

Ash dieback, caused by Hymenoscyphus fraxineus, is a serious disease of common and narrow-leaved ash in Europe. The resistance of individual trees seems to be important for the maintenance of ash in European forests. In this in situ wound inoculation study, the susceptibility and differences in resistance to H. fraxineus between Fraxinus excelsior and F. angustifolia clones were assessed. Neither of the tested clones revealed total resistance to ash dieback; variety between the tested clones was observed. Differences in necroses lengths were significant between clones and between two ash species. Longer necroses were formed in F. angustifolia than in F. excelsior. Some clones exhibiting some resistance to the pathogen were identified.

Anthracnose disease caused by Colletotrichum lindemuthianum (Sacc. and Magnus) Lams- -Scrib is one of the most devastating seed-borne diseases of common bean (Phaseolus vulgaris L.). In the present study, we evaluated the antifungal activity of Bunium persicum essential oil (EO) and its main constituents on mycelial growth, sporulation and spore germination inhibition of C. lindemuthianum. The main objective of this study was to investigate the effect of EO and its main constituents on decreasing the activity of cell wall degrading enzymes (CWDEs) produced by C. lindemuthianum, which are associated with disease progress. Also, the effects of seed treatment and foliar application of EO and its main constituent, cuminaldehyde, on anthracnose disease severity was investigated. The essential oil of B. persicum, was obtained by using a clevenger apparatus and its major constituents were identified by gas chromatography-mass spectrometry (GC-MS). The EO was characterized by the presence of major compounds such as cuminaldehyde (37.7%), γ-terpinene (17.1%) and β-pinene (15.4%), which indicated antifungal effects against C. lindemuthianum. This pathogen did not grow in the presence of EO, cuminaldehyde and γ-terpinene, β-pinene at 1,500; 1,010 and 1,835 ppm concentrations, respectively. Also, sporulation and spore germination of C. lindemuthianum was completely inhibited by EO and cuminaldehyde. Synergistic effects of the main constituents showed that combing γ-terpinene with cuminaldehyde induced a synergistic activity against C. lindemuthianum and in combination with β-pinene caused an additive effect. Activities of pectinase, cellulase and xylanase, as main CWDEs, were decreased by EO and its main constituents at low concentration without affecting mycelial growth. Seed treatment and foliar application of peppermint EO and/or cuminaldehyde significantly reduced the development of bean anthracnose. We introduced B. persicum EO and constituents, cuminaldehyde and γ-terpinene, as possible control agents for bean anthracnose.

The response of the Mi-1 gene to different densities of Meloidogyne incognita race 2 was investigated under controlled conditions. Susceptible and resistant tomato seedlings were inoculated with 25, 50, 100, 200, 400, 1000, 2000, 5000 and 10 000 second-stage juveniles of M. incognita. Plants were uprooted 8 weeks after inoculation and the numbers of egg masses and galls on the roots, and second-stage juveniles in 100 g soil per pot were counted. In susceptible plants, there was a correlation between the number of egg masses on roots until 2000 J2 inoculum densities. In resistant plants, when inoculum densities increased, the number of egg masses and galls also increased. The reproduction factor ratio was >1 in the susceptible plant and

The tuber necrotic strain of Potato virus Y (PVYNTN) causes widespread disease and has severe negative effects on the growth and yields of plants, especially those of the Solanaceae family. The consequences of residual toxicity and non-biodegradation of synthetic chemicals and pollution of the environment has led to investigations into new non-toxic and biological treatments to control plant viral diseases. Ethanolic extracts of Bowiea volubilis (bulbs), Cotyledon orbiculata (leaves), Gomphocarpus fruticosus (leaves), Merwilla plumbea (dry and fresh bulbs), Nerium oleander (leaves), and the fruits and leaves of Strophanthus speciosus, were evaluated against PVYNTN in vivo and in vitro. At a concentration of 20 mg · ml−1, ethanolic extracts of Strophanthus speciosus (leaves) and fruits (50 mg · ml−1) significantly reduced the expression of PVYNTN symptoms on tobacco plants in vitro without affecting the normal growth and development of the plant. Similarly, at 50 mg · ml−1, N. oleander, C. orbiculata and B. volubilis (fresh bulbs) and S. speciousus leaves at 20 mg · ml−1 extracts showed significant differences in PVYNTN symptoms in the in vivo experiment. Strophanthus speciosus leaf and fruit extracts showed significant inhibition in the in vitro and in vivo assays and demonstrated that S. speciosus has potential to be used as an antiphytoviral treatment.

Toxicity and physiological alterations were determined in Pseudococcus viburni nymphs treated with Artemisia annua methanolic extract. The leaf dipping bioassay showed LC50 values of 0.287% and 0.194% 24 and 48 hours post-exposure. Activities of general esterases were significantly higher in the control nymphs than in those which had been treated except for the 48 h time interval using α-naphtyl acetate. The activity of glutathione S-transferase using CDNB (1-chloro-2,4-dinitrobenzene) in the control nymphs, was significantly higher than in the control at both time intervals while no significant difference was observed after 24 h in addition to the higher enzymatic activity in the treated nymphs after 48 h. All three aminotransferases were significantly more active in the control nymphs except for time intervals of 24 h for γ-glutamyl transferase and 48 h for alanine aminotransferase. Higher activities of lactate dehydrogenase, acid- and alkaline phosphatase were found in the control nymphs than in treated nymphs for all time intervals. Activities of the enzymes involved in the antioxidant system including catalase, peroxidase, superoxide dismutase, ascorbate peroxidase and glucose-6-phosphate dehydrogenase was increased in the treated nymphs compared to the control. Results of the current study demonstrated toxic effects of A. annua methanolic extract on P. viburni nymphs causing mortality and physiological turbulences.

Silicon (Si) is the second most abundant element present in the lithosphere, and it constitutes one of the major inorganic nutrient elements of many plants. Although Si is a nonessential nutrient element, its beneficial role in stimulating the growth and development of many plant species has been generally recognized. Silicon is known to effectively reduce disease severity in many plant pathosystems. The key mechanisms of Si-mediated increased plant disease resistance involve improving mechanical properties of cell walls, activating multiple signaling pathways leading to the expression of defense responsive genes and producing antimicrobial compounds. This article highlights the importance and applicability of Si fertilizers in integrated disease management for crops.

In August 2016, tomato plants grown during a hot, wet summer with heavy soil flooding, displaying symptoms of wilting, dead plant, root rot with crown and stem rot, at Beni Suef and Fayoum governorates were examined. A number of 16 fungal isolates were isolated from tomato plants displaying the above symptoms. These isolates were classified as belonging to six species, namely: Alternaria solani, Chaetomium globosum, Fusarium solani, Fusarium oxysporum, Pythium spp. and Rhizoctonia solani. Isolates of Pythium spp. were prevalent and were found to be more pathogenic than the other fungal isolates. This species causes damping-off, root rot, sudden death, stem rot and fruit rot. The pathogen was identified as Pythium aphanidermatum based on morphological, cultural, and molecular characteristics. Biogenic silver nanoparticles (AgNPs) were produced using the F. oxysporum strain and characterized by transmission electron microscopy (TEM). The size of these spherical particles ranged from 10 to 30 nm. In vitro, biogenic AgNPs showed antifungal activity against P. aphanidermatum. In greenhouse and field experiments, AgNPs treatment significantly reduced the incidence of dead tomato plants due to root rot caused by P. aphanidermatum compared to the control. All of the investigated treatments were effective and the treatment of root dipping plus soil drenching was the most effective. To the best of our knowledge, this study describes P. aphanidermatum on tomato in Egypt for the first time. Also, biogenic AgNPs could be used for controlling root rot disease caused by this pathogen.

The molluscicidal activity of six monoterpenes and two phenylpropenes against Theba pisana adults was evaluated using fumigation and direct contact methods. In the fumigant toxicity assay, (-)-citronellal showed the highest toxicity with LC50 value of 7.79 μl · l−1 air after 24 h of treatment, followed by (-)-terpinen-4-ol (LC50 = 12.06 μl · l−1), (-)-menthone (LC50 = 12.28 μl · l−1 air) and p-cymene (LC50 = 16.07 μl · l−1 air). Eugenol and trans-cinnamaldehyde were the most potent contact toxicants against T. pisana. Their LD50 values were 0.18 and 0.29 mg · snail−1 after 24 h of treatment, respectively. These two compounds were more toxic than a reference molluscicide, methomyl. In contrast, α-terpinene and (-)-citronellal were the least toxic compounds. In another experiment, the synergistic effect of piperonyl butoxide (PBO) on tested monoterpenes and phenylpropenes by topical application was examined. The results showed that the toxicity of the tested compounds was increased when mixed with PBO at a ratio [compound/PBO (1 : 2)] except for α-pinene and (-)-terpinen-4-ol in which the toxicity of binary mixtures was less than for single compounds. The synergistic effect of PBO improved with increased exposure time. The highest synergistic effect was observed with (-)-menthone and α-terpinene with synergistic ratios of 9.25 and 4.37, respectively. Monoterpenes and phenylpropenes and their mixtures with PBO described herein merit further studies as potential T. pisana control agents.

The homeodomain-leucine zipper (HD-Zip) family has been shown to perform a multitude of functions during plant development and stress responses; however, the family members and functions have not been identified in apple (Malus × domestica). In this study, 83 HD-Zips (MdHDZs) were identified in the apple genome. They were assembled into four subgroups according to the classification in Arabidopsis, where MdHDZs in the same subgroup had similar gene structures and conserved protein motifs. Putative cis-element analysis of MdHDZs promoter regions uncovered numerous elements related to the response of stress and plant hormones. In addition, twelve transcripts of the MdHDZs showed different expression patterns under salt, drought, low temperature and ABA stresses by quantitative reverse transcription-PCR (qRT-PCR) assay. To further explore the function of MdHDZs in apple, MdHDZ3 was selected to verify its function under salt, low temperature and ABA stresses; and genetic transformation was used to obtain MdHDZ3 transgenic apple calli. The results demonstrated that MdHDZ3 increased sensitivity to salt, low temperature and abscisic acid in apple calli, suggesting that MdHDZ3 plays an important role in response to stresses. Subcellular localization and three-dimensional structural analysis revealed that MdHDZ3 was a nuclear-localized protein. Taken together, these findings provide potential information for further identification of HD-Zip proteins in apple.

Boron (B) is an essential micronutrient for vascular plant growth. Both B deficiency and toxicity can impair tissue development in diverse plant species, but little is known about the effect of B on reproductive panicle development and grain yield. In this study, a mutant of Setaria italica exhibiting necrotic panicle apices was identified and designated as sibor1. Sequencing revealed a candidate gene, SiBOR1, with a G-to-A alteration at the seventh exon. Knockout transgenic lines generated by clustered regularly interspaced short palindromic repeats and their associated protein-9 also had necrotic panicles, verifying the function of SiBOR1. SiBOR1 encoded a membrane-localized B efflux transporter, co-orthologous to the rice BOR1 protein. SiBOR1 was dominantly expressed in panicles and displayed a distinct expression pattern from those of its orthologs in other species. The induced mutation in SiBOR1 caused a reduction in the B content of panicle primary branches, and B deficiency-associated phenotypes such as thicker cell walls and higher cell porosity compared with Yugu 1. Transcriptome analysis indicated that differentially expressed genes involved in cell wall biogenesis, jasmonic acid synthesis, and programmed cell death response pathways were enriched in sibor1. qPCR analysis identified several key genes, including phenylalanine ammonia-lyase (SiPAL) and jasmonate-ZIM-domain (SiJAZ) genes, responsive to B-deficient conditions. These results indicate that SiBOR1 helps to regulate panicle primary branch development to maintain grain yield in S. italica. Our findings shed light on molecular mechanisms underlying the relationship between B transport and plant development in S. italica.

A set of 45 diverse Asian and African origin/bred populations of pearl millet were investigated multi-locationally for morphological traits including grain yield and assessed for their fertility restoration ability on three cytoplasmic male sterility (CMS) systems in two contrasting seasons. Significant genetic variation was found for all the yield linked traits. Multivariate analysis for grain yield and its component traits grouped these populations into five clusters. Most of the Asian origin populations grouped into single cluster (Cluster III) and separated from the rest of the African origin populations indicating the presence of correspondence between clustering pattern and geographical origin of the populations. Clusters dominated with Asian populations (As-As) had linkages with early flowering, short plant height, more number of tillers, small and thin panicles, small seeded and low grain yield compared to the clusters dominated by African populations (Af-Af) or African origin and Asian bred (Af-As) populations. Genetically related populations having common parentage were found grouped in same clusters. Fertility restoration/maintainer frequency of 45 populations on three diverse CMS systems revealed that overall fertility restoration frequency was highest for A1 (86%) followed by A4 (37%) and for A5 (7%) CMS system. Five populations were identified as potential sources for developing maintainer lines for all three CMS systems and eight populations were identified specifically for A4 and A5 CMS systems. A set of 11 and four populations were identified for restorer line development exclusively for A1 and A5 CMS system, respectively. Six populations were identified for the development of dual restorers for both A1 and A4 CMS system.

Family Botryosphaeriaceae and the genus Diaporthe (family Diaporthaceae) represent diverse groups of plant pathogens, which include causal agents of leaf spot, shoot blight, branch and stem cankers, dieback, and pre- and postharvest apple fruit decay. Apple fruit with symptoms of light to dark brown decay were collected during and after harvest from 2016 to 2018. Thirty selected isolates, on which pathogenicity was confirmed, were identified and characterized based on multilocus phylogeny and morphology. Five species from the family Botryosphaeriaceae and two from the genus Diaporthe (fam. Diaporthaceae) were discovered. The most commonly isolated was Diplodia seriata followed by Botryosphaeria dothidea. In this work, Diaporthe rudis is described as a new postharvest pathogen of apple fruit. Diplodia bulgarica, Diplodia sapinea, Neofusicoccum yunnanense, and Diaporthe eres are initially described as postharvest apple and D. sapinea as postharvest quince and medlar fruit pathogens in Serbia. Because species of the family Botryosphaeriaceae and the genus Diaporthe are known to cause other diseases on their hosts, have an endophytic nature, and have a wide host range, findings from this study imply that they may become a new challenge for successful fruit production.

Phosphate is an essential macronutrient for fungal proliferation as well as a key mediator of antagonistic, beneficial, and pathogenic interactions between fungi and other organisms. In this review, we summarize recent insights into the integration of phosphate metabolism with mechanisms of fungal adaptation that support growth and survival. In particular, we highlight aspects of phosphate sensing important for responses to stress and regulation of cell-surface changes with an impact on fungal pathogenesis, host immune responses, and disease outcomes. Additionally, new studies provide insights into the influence of phosphate availability on cooperative or antagonistic interactions between fungi and other microbes, the associations of mycorrhizal and endophytic fungi with plants, and connections with plant immunity. Overall, phosphate homeostasis is emerging as an integral part of fungal metabolism and communication to support diverse lifestyles.

Xanthomonas arboricola pv. corylina is the causal agent of bacterial blight of hazelnut. The bacterium has been listed as an A2 quarantine pathogen in Europe since 1978 and on the regulated non-quarantine pest list since 2019. Three isolates from various geographic regions and isolated at different times were sequenced using a hybrid approach with short- and long-read technologies to generate closed genome and plasmid sequences in order to better understand the biology of this pathogen.

Sweet basil (Ocimum basilicum, 2n = 4x = 48) is susceptible to downy mildew caused by Peronospora belbahrii. The Pb1 gene exhibits complete resistance to the disease. However, Pb1 became prone to disease because of occurrence of new virulent races. Here, we show that Zambian accession PI 500950 (Ocimum americanum var. pilosum) is highly resistant to the new races. From an interspecies backcross between PI 500950 and the susceptible ‘Sweet basil’ we obtained, by embryo rescue, a population of 131 BC1F1 plants. This population segregated 73 resistant (58) and susceptible (1:1; P = 0.22) plants, suggesting that resistance is controlled by one incompletely dominant gene called Pb2. To determine whether allelic relationship exists between Pb1 and Pb2, we used two differential races: race 0, which is avirulent to both PI 500945 (Pb1) and PI 500950 (Pb2), and race 1, which is virulent to PI 500945 but avirulent to PI 500950. F1 plants obtained from ‘12-4-6’ (BC6F3 derived from PI 500945) and ‘56’ (BC3F3 derived from PI 500950) showed resistant superiority to both races through dominant complementary interaction. F2 plants segregated to race 0 as follows: 12:3:1 (immune/incomplete resistant/susceptible) as opposed to 9:3:4 to race 1, indicating that Pb1 and Pb2 are not alleles. Because joint action is contributed in F1 plants and in advanced [BC3F3(56) × BC6F3(12-4-6) F4] populations that carry both genes, it can be assumed that both accessions carry two unlinked genes but share a common signal transduction pathway, which leads to dominant complementation superiority of the resistance against different races of basil downy mildew.

Thermosensitive genic male sterility (TGMS) has been widely used in two-line hybrid rice breeding. Due to hybrid seed production being highly affected by changeable environments, its application scope is limited to some extent. Thus, it is of great importance to identify potential TGMS genes in specific rice varieties. Here, Diannong S-1 xuan (DNS-1X), a reverse TGMS (RTGMS) japonica male sterile line, was identified from Diannong S-1. Genetic analysis showed that male sterility was tightly controlled by a single recessive gene, which was supported by the phenotype of the F1 and F2:3 populations derived from the cross between DNS-1X and Yunjing 26 (YJ26). Combining simple sequence repeat (SSR) markers and bulked segregation analysis (BSA), we identified a 215 kb region on chromosome 10 as a candidate reverse TGMS region, which was designated as rtms1-D.It was narrower than the previously reported RTGMS genes rtms1 and tms6(t). The fertility conversion detected in the natural environment showed that DNS-1X was sterile below 28–30 °C; otherwise, it was fertile. Histological analysis further indicated that the pollen abortion was occurred in the young microspore stage. This study will provide new resources for two-line hybrid rice and pave the way for molecular breeding of RTGMS lines.

Gray mold caused by Botrytis cinerea is one of the most widespread and damaging diseases in cannabis crops worldwide. With challenging restrictions on pesticide use and few effective control measures, biocontrol agents are needed to manage this disease. The aim of this study was to identify bacterial biocontrol agents with wide-spectrum activity against B. cinerea and other cannabis fungal pathogens. Twelve Bacillus and Pseudomonas strains were first screened with in vitro confrontational assays against 10 culturable cannabis pathogens, namely B. cinerea, Sclerotinia sclerotiorum, Fusarium culmorum, F. sporotrichoides, F. oxysporum, Nigrospora sphaerica, N. oryzae, Alternaria alternata, Phoma sp., and Cercospora sp. Six strains displaying the highest inhibitory activity, namely Bacillus velezensis LBUM279, FZB42, LBUM1082, Bacillus subtilis LBUM979, P. synxantha LBUM223, and P. protegens Pf-5, were further assessed in planta where all, except LBUM223, significantly controlled gray mold development on cannabis leaves. Notably, LBUM279 and FZB42 reduced disease severity by at least half compared with water-treated plants and prevented lesion development and/or sporulation up to 9 days after pathogen inoculation. Genomes of LBUM279, LBUM1082, and LBUM979 were sequenced de novo and taxonomic affiliations were determined to ensure nonrelatedness with pathogenic strains. Moreover, the genomes were exempt of detrimental genes encoding major toxins and virulence factors that could otherwise pose a biosafety risk when used on crops. Eighteen gene clusters of potential biocontrol interest were also identified. To our knowledge, this is the first reported attempt to control cannabis fungal diseases in planta by direct antagonism with beneficial bacteria.

Endemic plants are important for understanding phylogenetic relationships, biogeographical history, and genetic variation because of their restricted distribution and their role in conserving biodiversity. Here, we investigated the phylogenetic relationships of the Korean endemic Fraxinus chiisanensis by reconstructing the molecular phylogeny of Fraxinus based on two nuclear DNA (nrITS and phantastica) and two chloroplast DNA (psbA-trnH and rpl32-trnL) regions. Within our fossil-calibrated phylogenetic framework, we also inferred the biogeographical history of F. chiisanensis. To provide a scientific basis for the conservation of F. chiisanensis, we determined the levels of genetic diversity and genetic differentiation in this species. Combining information from nuclear and chloroplast DNA sequence data, our molecular phylogenetic analyses identified F. chiisanensis as a genetically distinct unit from its sister group, Fraxinus platypoda from Japan. Our molecular dating analyses using nuclear and chloroplast DNA data sets show F. chiisanensis diverged from its sister F. platypoda in the Early or Middle Miocene and differentiated in the Late Miocene on the Korean Peninsula. Our results suggest that the divergence of F. chiisanensis was associated with the submergence of the East China Sea land bridge and enhanced monsoons in East Asia. When compared to F. platypoda, F. chiisanensis exhibits low genetic diversity within populations and high genetic differentiation among populations. These results help us to understand the evolutionary history of F. chiisanensis and to develop a conservation strategy for this species.

Aqueous and hydroethanoic extracts prepared from leaves of Aloysia triphylla (L'Her.) Britton (lemon verbena) and Trigonella foenum-graecum L. (fenugreek) seeds were evaluated for in vivo hypocholesterolemic and anti-inflammatory effects. The results of administration of A.triphylla leaf and T. foenum-graecum extracts on serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL) and very-low density lipoprotein (VLDL) in hypocholesterolemic mice were evaluated. Mice groups treated with both aqueous and hydroethanoic extracts of A. triphylla showed reduced total cholesterol (161.60 and 162.60 mg/dl, for mice groups treated with respective extracts) and LDL (79.16 and 99.04 mg/dl, for mice groups treated with respective extracts) levels as compared to the hypercholesterolemic group (253.00 and 160.00 mg/dl for TC and LDL, respectively). A similar trend was observed with the aqueous and hydroethanoic extracts of T. foenum-groecum seeds. Mice treated with hydroethanoic extracts (200 mg/kg body weight) of A. triphylla leaves and T. foenum-groecum seeds showed significantly reduced triglyceride and VLDL levels compared to the group treated with atorvastatin (18.76 and 18.20 mg/dl, respectively). In terms of phytochemical composition, caffeic acid were detected in both A. triphylla leaves and T. foenum-graecum seeds extracts. However, rutin and luteolin have not been detected in any extracts of A. triphylla and T. foenum-graecum. Data collected from this study support the fact of future development of novel botanical remedies from A. triphylla leaves and T. foenum-graecum seeds for managing hypercholesterolemia and atherosclerosis.

Although open-central canopy (OCC) is popular in apple (Malus × domestica) orchards in Loess Plateau of China, its relevant photosynthetic mechanisms have not been elucidated. In this study, changes in photosynthetically active radiation (PAR), gas exchange, chlorophyll fluorescence quenching and fruit quality in apple trees were measured in OCC and compared with those in the conventional condensed round and large canopy (RLC). Results showed that light intercepted at different orientations was 44% higher by OCC than that by RLC. The improved light environment within OCC remarkably increased leaf maximum net photosynthetic rate (Pnmax) and significantly decreased stomatal limitation. Under high light, the ratio of photorespiratory rate to gross photosynthetic rate (Pr/Pg) in OCC was higher than that in RLC. Moreover, reversible component in non-photochemical quenching (r(qE)) was increased, while irreversible component (r(qI)) was decreased in OCC than in RLC. As a result, the fruit quality in OCC was greatly boosted as evidenced by the significantly increased single fruit weight, fruit flesh firmness and fruit soluble solid contents and the sharply decreased fruit titratable acid contents. PAR intercepted by the canopy and the fruit soluble solid contents, leaf Pnmax or single fruit weight were positively correlated, while PAR or Pnmax was negatively correlated with the fruit titratable acid contents. Accordingly, the improved crown light environment and the enhanced leaf photosynthetic performance and photoprotective capacity in OCC led to the boosted fruit quality.

Blood fruit is a tropical liana bearing edible fruit rich in anthocyanins. The species is distributed in many Asian countries, wherein it provides livelihood and nutritional security to native dwellers. However, in many of these regions produce is harvested from the wild by employing destructive harvesting practices, thereby damaging the natural stand. Systematic studies were initiated to popularize this species as a novel crop in the humid tropical parts of the world. Present study aims at studying four collections (HV/NE/TRI, HV/MA/KAL, HV/MA/SNU and HV/MA/SND) for morphological and biochemical traits. Results revealed considerable variability for fruit and seed traits, total soluble solids and pH. Total anthocyanin content among the collections varied between 183.63 and 328.28 mg CE/ 100 g pulp. Strong positive correlation was noticed between fruit dimensions with fruit weight, while negative correlation was noticed between pulp content and peel thickness. Ratio of material: solvent for obtaining better anthocyanins recovery was optimized to 1:15 (w/v). Promising genotype (HV/MA/SND) with superior fruit size, TSS content and total anthocyanins content was identified for further exploitation.

Hormones play important roles in vegetative and reproductive processes; however, the regulatory roles of hormones in Nelumbo nucifera (Lotus) growth and development are unclear. In this study, nine types of endogenous hormones, including gibberellins (GA1, GA3, and GA4), indole-3-acetic acid (IAA), brassinolide (BR), ethylene (ETH), jasmonic acid (JA), abscisic acid (ABA), and zeatin (ZT) were detected in dormant shoot tips, vegetative shoot tips, developing leaf buds, and developing flower buds of lotus. The results indicated that GA, ETH, and BR signaling can promote vegetative and reproductive development of lotus. GA signaling regulates plant height and stimulates flower bud differentiation. GA levels were the highest in the flower buds; exogenous GA3+4 increased plant height by approximately 90%, increased flower quantity by nearly 40%, and advanced flowering by 4 d. Suppressing GA biosynthesis using paclobutrazol decreased plant height and flower quantity by 38% and 87.1%, respectively, and delayed flowering by 15.6 d. ETH signaling has positive regulatory effects on vegetative growth and flower development. The ETH concentration in the developing leaf buds was at least 50% higher than that in other samples. Ethephon spraying led to remarkable increases in plant height and leaf thickness and extended the flowering duration. BR signaling acts as a growth promoter during vegetative and reproductive development in lotus. The highest BR levels were detected in the vegetative shoot tips. External application of 28-epihomobrassinolide resulted in growth-promoting phenotypes including longer scapes, thicker leaves, and prolonged flowering.

The fruits of Coccinia grandis (L.) Voigt have been used to treat several aliments in traditional medicine whereas Coccinia rehmannii Cogn. fruits are consumed as food due to their high starch content. Coccinia rehmannii are also known to contain vast amounts of indispensable bioactive compounds that are used in various cosmetics, foods, and medicines. Among these compounds are hydroxycinnamic acids (HCAs) which are usually conjugated/esterified to quinic acid (QA), tartaric acid, citric acid, shikimic acid and sugars and are collectively referred to as chlorogenic acids (CGAs). Over the years, metabolite profiling has been used in plant taxonomy and species classification. Herein, UPLC-qTOF-MS/MS semi-targeted approached was use to profile HCA conjugates from two closely related plant species i.e. C. grandis and C. rehmannii leaves in order to distinguish them from each other. Examination of their relative metabolite contents showed that the two closely related Coccinia species utilise contrasting means of HCA conjugations as means of metabolite diversification strategy. C. grandis was found to conjugate its HCA derivatives to a QA, whilst C. rehmannii conjugates its HCA derivatives to mainly flavonoid glycosides and to QA, even though present in low concentration in this plant. These results shows that plants from the same genus can utilise different chemical diversification means for storage of their metabolites and that processes such as conjugation and isomerization can be exploited as chemotaxonomic markers. Future studies can also be designed to look at the pharmacological potency of these plants as a function of their contrasting chemical differences.

Sonchus oleraceus (L.) L. (sow thistle) is an underutilised functional leafy vegetable with both high nutritional and pharmacological values. In the current study, high performance liquid chromatography ion trap time-of flight mass spectrometry (HPLC-IT-Tof-MS)-based metabolomics in combination with principal component analysis (PCA) were used to provide an overall phytochemical composition of different tissues (leaf, stem and roots) of this underutilised plant. A total of 32 phytochemicals, comprising hydroxycinnamic acids, flavonoids and terpene classes were identified across the three different tissues of S. oleraceus. The study used the new approach of colour coded PCA models to info-graphically depict the metabolic profiles across different parts of the plant. The results of the current study indicate S. oleraceus as a potential source of metabolites with highly claimed nutraceutical properties. As such, the results herein can be used as a template reference for further biological studies aimed at the evaluation of nutraceutical properties of the S. oleraceus plant.

Prunus cerasoides D. Don is a plant of great venerative value in the Himalayan region. The fruits and seed kernels of this plant are traditionally used for the treatment of urinary stones. Present study was aimed to demonstrate the in vitro and preclinical antilithic potential of the hydroethanolic extract of Prunus cerasoides fruits against calcium oxalate urolithiasis. In vitro antiurolithiatic screening was done by nucleation, and aggregation assay, while preclinical evaluation was carried out on ethylene glycol (0.75% v/v) and ammonium chloride (1% w/v) rendered urolithiasic male Wistar rats. P. cerasoides fruit extract induced nucleation of multiple small sized calcium oxalate crystals and inhibited their aggregation in the metastable solutions. P. cerasoides fruit extract to a large extent prevented lithogenic treatment induced anorexia, weight loss, polydipsia, polyuria, crystalluria, hypercalciuria, hyperoxaluria, hyperuricosuria, hyperphosphaturia, hypocitraturia and hypomagnesuria. It also showed preventive effect on the deposition of calcium, oxalate and phosphate in kidney tissues and exhibited ameliorative effect on serum urea, creatinine and uric acid. Moreover, inhibitory effect on oxidative stress induced degeneration of renal tissue was also recorded from histopathological analysis of the kidneys. PCFE showed promising outcomes as an antiurolithiatic both prophylactically and curatively. The effects can be attributed to its ability to restore the equilibrium between the urinary promoters and inhibitors of CaOx crystallization, its anticrystallization activity and its ameliorating effects on renal cellularity, urine and serum chemistry.

Phytophthora sojae, the causal agent of Phytophthora root and stem rot of soybean, has been managed with single Rps genes since the 1960s but has subsequently adapted to many of these resistance genes, rendering them ineffective. The objective of this study was to examine the pathotype and genetic diversity of P. sojae from soil samples across Illinois, Indiana, Kentucky, and Ohio by assessing which Rps genes were still effective and identifying possible population clusters. There were 218 pathotypes identified from 473 P. sojae isolates with an average of 6.7 out of 15 differential soybean lines exhibiting a susceptible response for each isolate. Genetic characterization of 103 P. sojae isolates from across Illinois, Indiana, Kentucky, and Ohio with 19 simple sequence repeat markers identified 92 multilocus genotypes. There was a moderate level of population differentiation between these four states, with pairwise FSTvalues ranging from 0.026 to 0.246. There were also moderate to high levels of differentiation between fields, with pairwise FSTvalues ranging from 0.071 to 0.537. Additionally, cluster analysis detected the presence of P. sojae population structure across neighboring states. The level of pathotype and genetic diversity, in addition to the identification of population clusters, supports the hypothesis of occasional outcrossing events that allow an increase in diversity and the potential to select for a loss in avirulence to specific resistance genes within regions. The trend of suspected gene flow among neighboring fields is expected to be an ongoing issue with current agricultural practices.

Pollen morphology of herbarium specimens of four Centranthus species (C. ruber, C. longiflorus, C. kellereri and C. calcitrapae) was studied using LM and SEM. The research aim was to provide data on their pollen characteristics and to evaluate the taxonomic value of these data for species-specific identification. Pollen grains are tricolpate, suboblate to prolate (P/E = 0.81–1.42); medium- or large-sized (P = 49.21–90.44 µm; E = 43.89–93.10 µm). Colpi are long or medium-length, wide at equator, tapered to acute or obtuse ends. Exine sculpture is echinate-microechinate-nanoechinate; echini (1.00–1.39 µm high) and microechini (0.55–0.98 µm) are conical, with straight or convex sides and acute apices, nanoechini are 0.22–0.46 µm high. Most important characters of taxa diagnostic at species level for the taxonomy are: size of pollen and colpi, exine structure, size of echini and microechini, and pattern of tectum in areas between echini. Pollen grains of C. calcitrapae and C. macrosiphon (sect. Calcitrapa) are generally smaller in size than grains of C. ruber, C. longiflorus and C. kellereri (sect. Centranthus). Pollen of C. kellereri was analysed for the first time in the current study.

Capacity for dispersal is a fundamental fitness component of plant pathogens. Characterization of plant pathogen dispersal is important for understanding how pathogen populations change in time and space. We devised a systematic approach to measure and analyze rain splash-driven dispersal of plant pathogens in field conditions, using the major fungal wheat pathogen Zymoseptoria tritici as a case study. We inoculated field plots of wheat ( Triticum aestivum) with two distinct Z. tritici strains. Next, we measured disease intensity as counts of fruiting bodies (pycnidia) using automated image analysis. These measurements characterized primary disease gradients, which we used to estimate effective dispersal of the pathogen population. Genotyping of reisolated pathogen strains with strain-specific PCR confirmed the conclusions drawn from phenotypic data. Consistently with controlled environment studies, we found that the characteristic scale of dispersal is tens of centimeters. We analyzed the data using a spatially explicit mathematical model that incorporates the spatial extent of the source, rather than assuming a point source, which allows for a more accurate estimation of dispersal kernels. We employed bootstrapping methods for statistical testing and adopted a two-dimensional hypotheses test based on kernel density estimation, enabling more robust inference compared with standard methods. We report the first estimates of dispersal kernels of the pathogen in field conditions. However, repeating the experiment in other environments would lead to more robust conclusions. We put forward advanced methodology that paves the way for further measurements of plant pathogen dispersal in field conditions, which can inform spatially targeted plant disease management. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

Cotton architecture is partly determined by shoot branching and flowering patterns. GhBRC1 was previously identified by RNA-seq analysis of nulliplex-branching and normal-branching cotton. However, the roles of GhBRC1 in cotton remain unclear. In the present study, investigations of nuclear localization and transcriptional activity indicated that GhBRC1 has characteristics typical of transcription factors. Gene expression analysis showed that GhBRC1 was highly expressed in axillary buds but displayed different expression patterns between the two branching types. Overexpression of GhBRC1 in Arabidopsis significantly inhibited the number of branches and promoted flowering. In contrast, silencing GhBRC1 in cotton significantly promoted seedling growth. GhBRC1 was induced by multiple hormones, including strigolactones, which promoted seedling growth and seed germination of Arabidopsis plants overexpressing GhBRC1. Consistent with these findings, RNA-seq analysis of virus-induced gene silencing treated cotton revealed that a large number of genes were differentially expressed between GhBRC1-silenced and control plants, and these genes were significantly enriched in plant hormone signalling pathways. Together, our data indicates that GhBRC1 regulates plant branching and flowering through multiple regulatory pathways, especially those regulating plant hormones, with functions partly differing from those of Arabidopsis BRC1. These results provide insights into the molecular mechanisms controlling plant architecture, which is important for breeding cotton with ideal plant architecture and high yield.

Sugar transportation and sugar-to-starch metabolism are considered important processes in seed development and embryo viability. A few plant SWEET proteins acting as sugar transporters have been reported to function in inflorescence and/or seed development. Here, we identified seven members of the 21 OsSWEET genes in rice that play essential roles in sugar transportation and sugar-to-starch conversion in seed development. Nineteen OsSWEET genes exhibiting different expression patterns during inflorescence and seed development were knocked out individually by CRISPR/Cas9. One third of the mutants showed decreased fertile pollen viability and shriveled mature caryopses, resulting in weakened seed traits. Grain fill-related genes but not representative grain shape-regulating genes showed attenuated expression in the mutants. Seed of each of these mutants accumulated more sucrose, glucose or fructose but less starch. Among all OsSWEET genes, OsSWEET4 and OsSWEET11 had major effects on caryopsis development. The sugar-to-starch metabolic pathway was significantly altered in ossweet11 mutants based on differential expression analysis in RNA sequencing assays, confirming that OsSWEET11 functions as a sugar transporter with a key role in seed development. These results help to decipher the multiple functions of OsSWEET genes and to show how they might be used in genetic improvement of rice.

The content and composition of wheat storage proteins are the major determinants of dough rheological properties and breadmaking quality and are influenced by cultivation conditions. This study aimed to investigate the effects of water deficit and high N-fertilizer application on wheat storage protein synthesis, gluten secondary structure, and breadmaking quality. Reverse-phase ultrahigh-performance liquid chromatography analysis showed that storage protein and gluten macropolymer accumulation was promoted under both independent applications and a combination of water-deficit and high N-fertilizer treatments. Fourier-transform infrared spectroscopy showed that water deficit and high N-fertilizer treatments generally improved protein secondary structure formation and lipid accumulation, and reduced flour moisture. In particular, high N-fertilizer application increased β-sheet content by 10.4% and the combination of water-deficit and high N-fertilizer treatments increased random coil content by 7.6%. These changes in gluten content and secondary structure led to improved dough rheological properties and breadmaking quality, including superior loaf internal structure, volume, and score. Our results demonstrate that moderately high N-fertilizer application under drought conditions can improve gluten accumulation, gluten secondary structure formation, and baking quality.

Postharvest water loss in pepper fruit (Capsicum annuum L.) reduces its shelf life. Fruit texture is one of the most important components of fruit quality for consumers. In this study, the anatomical traits of pepper fruit related to postharvest water loss and texture were assessed. There was a strong positive relationship between postharvest water loss and the thickness of the cuticular membrane, cuticular weight, total cutin weight, and polysaccharide-cutan weight. An amorphous fibrous structure that forms a path for diffusion and increases water loss was observed in the thick cuticle of the pericarp. In addition, positive correlations between the hardness of the exocarp and the weight of cuticular membrane, cutin content, and polysaccharide-cutan content were found. These results indicate that the thickness of the cuticular membrane wedged between subepidermal cells may influence water loss through the pericarp of pepper fruit and fruit with a high cutin and polysaccharide content have a hard tough texture.

Soybean (Glycine max [L.] Merr.) is a food and oil crop whose growth and yield are influenced by root and nodule development. In the present study, GmNMHC5 was found to promote the formation of nodules in overexpressing mutants. In contrast, the number of nodules in Gmnmhc5 edited with CRISPR/Cas9 decreased sharply. In 35S:GmNMHC5 mutants, expression levels of genes involved in nodulation were significantly up-regulated. Both in vitro and in vivo biochemical analyses showed that GmNMHC5 directly interacted with GmGAI (a DELLA protein), and the content of gibberellin 3 (GA3) in overexpressing mutants was lower than that in the wild type. These results revealed that GmNMHC5 participates in the classical GA signaling pathway, and may regulate the content of GA3 to match the optimal concentration required for nodule formation, thereby promoting nodulation by directly interacting with GmGAI. A model illustrating the mechanism by which GmNMHC5 promotes soybean nodulation is presented.

Autophagy is an evolutionarily ancient process wherein cells are able to break down intracellular contents to support normal physiology and development. Autophagosome formation is regulated by several different proteins, including the key cysteine protease Atg4. The contribution of Atg4 protein in the pathogenic fungus Cryphonectria parasitica, which causes blight in chestnut plants, has not been completely understood. In this context, we aimed to investigate the role of Atg4 during autophagy formation and their contribution to nonautophagic events in C. parasitica. By complementation assay, we determined that the CpAtg4 gene from C. parasitica was able to functionally complement the deletion of yeast Atg4. Using a yeast two-hybrid assay system, we confirmed that CpAtg4 and CpAtg8 directly interact with one another, and amino acids 377 to 409 of CpAtg4 were identified as being responsible for its binding with CpAtg8. The deletion mutant of CpAtg4 did not demonstrate positive monodansylcadaverine staining, which indicated that CpAtg4 is required for autophagy in C. parasitica. Moreover, the ΔCpAtg4 strain exhibited a decrease in aerial hyphae formation and sporulation, and reduction in virulence on apple and chestnut stem. The ΔCpAtg4 strains were also more sensitive to H2O2 and Congo red-induced stress. We further determined that amino acids 377 to 409 of CpAtg4 were essential for the function of CpAtg4 in vivo. Together, our findings indicated that CpAtg4 is required for the autophagy formation, fungal phenotypic traits, stress tolerance, and virulence in C. parasitica.

Fusarium oxysporum f. sp. apii race 4, which is in F. oxysporum species complex (FOSC) Clade 2, causes a new Fusarium wilt of celery. We compared F. oxysporum f. sp. apii race 4 with race 2, which causes Fusarium yellows of celery and is in FOSC Clade 3. Optimal temperatures for celery yield are 16 to 18°C. Soil temperatures in California celery production areas can range up to 26°C, and the maximal rate of hyphal extension of F. oxysporum f. sp. apii races 2 and 4 in culture are 25 and 28°C, respectively. Here, we compared the effect of temperatures from 16 to 26°C on growth of F. oxysporum f. sp. apii races 4 and 2 in two celery cultivars: Challenger, which is resistant to F. oxysporum f. sp. apii race 2 and susceptible to race 4; and Sonora, which is susceptible to both F. oxysporum f. sp. apii races 2 and 4. Based on linear regressions, as temperature increases, there is an increase in the log of F. oxysporum f. sp. apii race 4 DNA concentration in celery crowns and in the reduction in plant height. Based on logistic regressions, as temperature increases, the incidence of vascular discoloration increases in celery with either F. oxysporum f. sp. apii race 2 or 4 infection. In both cultivars, temperatures of 22°C and above resulted in a significantly (α = 0.05) greater concentration of F. oxysporum f. sp. apii race 4 than race 2 in planta. The concentration of F. oxysporum f. sp. apii race 2 in crowns in ‘Challenger’ is temperature-independent and comparatively low; consequently, ‘Challenger’ is, at least partly, resistant rather than tolerant to F. oxysporum f. sp. apii race 2.

Pyrenophora tritici-repentis causes tan spot, an important foliar disease of wheat. A collection of P. tritici-repentis isolates from Tunisia, located in one of the main secondary centers of diversification of durum wheat, was tested for phenotypic race classification based on virulence on a host differential set and for the presence of the necrotrophic effector (NE) genes ToxA, ToxB, and toxb by PCR analysis. While races 2, 4, 5, 6, 7, and 8 were identified according to their virulence phenotypes, PCR testing indicated the presence of “atypical” isolates that induced necrosis on the wheat differential ‘Glenlea,’ but lacked the expected ToxA gene, suggesting the involvement of other NEs in the P. tritici-repentis/wheat interaction. Genetic diversity and the P. tritici-repentis population structure were explored further by examining 59 Tunisian isolates and 35 isolates from Algeria, Azerbaijan, Canada, Iran, and Syria using 24 simple sequence repeat markers. Average genetic diversity, overall gene flow, and percentage polymorphic loci were estimated as 0.58, 2.09, and 87%, respectively. Analysis of molecular variance showed that 81% of the genetic variance occurred within populations and 19% occurred between populations. Cluster analysis by the unweighted pair group method indicated that ToxB– isolates grouped together and were distantly related to ToxB+ isolates. Based on Nei’s analysis, the global collection clustered into two distinct groups according to their region of origin. The results suggest that geographic origin and the host specificity imposed by different NEs can lead to differentiation among P. tritici-repentis populations.

Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici, is managed primarily with cultivar resistance and foliar fungicides. Quinone outside inhibitors (QoIs), which target the mitochondrial cytochrome b (cytb) gene, are one of the two main fungicide classes used on wheat. While European populations of B. graminis f. sp. tritici are widely insensitive to QoIs, largely because of the cytb mutation G143A, the QoI sensitivity of the U.S. B. graminis f. sp. tritici population had never been evaluated despite years of QoI use on U.S. wheat. A total of 381 B. graminis f. sp. tritici isolates from 15 central and eastern U.S. states were screened for sensitivity to QoI fungicides pyraclostrobin and picoxystrobin. A modest range of sensitivities was observed, with maximum resistance factors of 11.2 for pyraclostrobin and 5.3 for picoxystrobin. The F129L, G137R, and G143A cytb mutations were not detected in the U.S. B. graminis f. sp. tritici population, nor were mutations identified in the PEWY loop, a key part of the Qo site. Thus, no genetic basis for the observed quantitative variation in QoI sensitivity of U.S. B. graminis f. sp. tritici was identified. Isolate sporulation was weakly negatively associated with reduced QoI sensitivity, suggesting a fitness cost. In the course of the study, the complete B. graminis f. sp. tritici cytb gene sequence was determined for the first time in the isolate 96224 v. 3.16 reference genome. Contrary to previous reports, the gene has an intron that appears to belong to intron group II, which is unusual in fungi. The study was the first QoI sensitivity screening of a large, geographically diverse set of U.S. B. graminis f. sp. tritici isolates, and while the population as a whole remains relatively sensitive, some quantitative loss of efficacy was observed.