Powdery Mildew Research Articles

Ensuring Tree Protection, Growth and Sustainability by Microbial Isolates

Antimicrobial properties of the new strains of micro-organisms isolated from natural sources of various ecological niches in the Moscow region and the Republic of Tatarstan were studied. Antifungal activity of isolates was detected in a test culture of toxin-producing microscopic fungi that can cause animal and plant diseases: Aspergillus flavus, Candida albicans, Fusarium oxysporum and Penicillium spp. Of the 46 studied micro-organisms of genera Bacillus, Lactobacillus, Lactococcus and Streptomyces isolates, there are four strains (Bacillus subtilis, Lactobacillus plantarum, Propionibacterium freudenreichii and Streptomyces spp.) that showed an ability to produce biologically active metabolites with a pronounced antimicrobial potential against phytopathogenic fungi metabolites. Based on the selected four strains, a Bacterial product LRV composition has been created. Scots pine, pedunculate oak and small-leaved linden seedlings with single and double foliar treatment and Bacterial product LRV at a concentration of 10 mL/L led to an increase in the growth of the aboveground part by 31.8, 51.9 and 25.4%, respectively, and the underground part by 25.0, 37.2 and 25.7%, respectively, compared to the control. The weight of seedlings at the end of the study exceeded the control variant by an average of 26.0, 44.0 and 78.0%, respectively. Plant protection Bacterial product LRV use did not have a significant effect on the group of molds that caused the powdery mildew and Schütte disease damage to trees. The Biological product LRV provided plant protection from fungal diseases caused by Lophodermium pinastri Chev. and Microsphaera alphitoides.

Detection of Podosphaera macularis in Air Samples by Quantitative PCR.

Detection and quantification of pathogen propagules in the air or other environmental samples is facilitated by culture-independent assays. We developed a quantitative PCR assay for the hop powdery mildew fungus, Podosphaera macularis, for detection of the organism from air samples. The assay uses primers and a TaqMan probe designed to target species-specific sequences in the 28S large subunit of the nuclear ribosomal DNA. Analytical sensitivity was not affected by the presence of an exogenous internal control or potential PCR inhibitors associated with DNA extracted from soil. The level of quantification of the assay was between 200 and 350 conidia when DNA was extracted from a fixed number of conidia. The assay amplified all isolates of P. macularis tested and had minimal cross-reactivity with other Podosphaera species when assayed with biologically relevant quantities of DNA. Standard curves generated independently in two other laboratories indicated that assay sensitivity was qualitatively similar and reproducible. All laboratories successfully detected eight unknown isolates of P. macularis and correctly discriminated Pseudoperonospora humuli and a water control. The usefulness of the assay for air sampling for late-season inoculum of P. macularis was demonstrated in field studies in 2019 and 2020. In both years, airborne populations of P. macularis in hop yards were detected consistently and increased during bloom and cone development.

Transcriptome, hormonal, and secondary metabolite changes in leaves of DEFENSE NO DEATH 1 (DND1) silenced potato plants

DEFENSE NO DEATH 1 (DND1) is a cyclic nucleotide-gated ion channel protein. Earlier, it was shown that the silencing of DND1 in the potato (Solanum tuberosum L.) leads to resistance to late blight, powdery mildew, and gray mold diseases. At the same time, however, it can reduce plant growth and cause leaf necrosis. To obtain knowledge of the molecular events behind the pleiotropic effect of DND1 downregulation in the potato, metabolite and transcriptome analyses were performed on three DND1 silenced lines of the cultivar ‘Désirée.’ A massive increase in the salicylic acid content of leaves was detected. Concentrations of jasmonic acid and chlorogenic acid and their derivatives were also elevated. Expression of 1866 genes was altered in the same way in all three DND1 silenced lines, including those related to the synthesis of secondary metabolites. The activation of several alleles of leaf rust, late blight, and other disease resistance genes, as well as the induction of pathogenesis-related genes, was detected. WRKY and NAC transcription factor families were upregulated, whereas bHLHs were downregulated, indicating their central role in transcriptome changes. These results suggest that the maintenance of the constitutive defense state leads to the reduced growth of DND1 silenced potato plants.

Evaluation of Germicidal UV-C Light for Suppression of Grape Powdery Mildew and Botrytis Bunch Rot in Western Oregon.

Germicidal UV light (UV-C) has been shown to effectively suppress several plant pathogens as well as some arthropod pests. Recent reports describe the efficacy of nighttime applications of UV-C at doses from 100 to 200 J/m2 in vineyards to reduce grape powdery mildew (Erysiphe necator). Our in vitro studies confirmed the efficacy of UV-C to inhibit germination of E. necator and Botrytis cinerea conidia, demonstrated a range of tolerances to UV-C within a collection of E. necator isolates, and showed growth stage-specific effects of UV-C on B. cinerea. Nighttime use of UV-C was evaluated at 48 to 96 J/m2 in small plot trials (<1,000 vines) from 2020 to 2023. Once- or twice-weekly UV-C applications significantly reduced the incidence of foliar powdery mildew compared with non-UV-C-treated controls (P < 0.02). Suppression of powdery mildew on fruit was less consistent, where once or twice weekly UV-C exposure reduced powdery mildew disease severity in 2020 (P = 0.04), 2021 (P = 0.02), and 2023 (P = 0.003) but less so in 2022 (P = 0.07). Bunch rot severity was not significantly reduced with UV-C treatment in any year of the study. Application of UV-C until the onset of fruit color change (veraison) also had a minimal effect on the fruit-soluble solids, pH, anthocyanins, or phenolics in harvested fruit at any UV-C dose or frequency (P > 0.10). Suppression of powdery mildew by nighttime application of UV-C at lower doses in small plots suggests that such treatments merit further evaluation in larger-scale studies in Western Oregon.

Occurrence and epidemiological consequences of Erysiphe neolycopersici on tomato plants in Mauritius

Leveillula taurica has until recently been believed to be the causal pathogen of powdery mildew of tomatoes in Mauritius. However, in the year 2022, another powdery mildew species was detected on tomatoes under culture in various tomato growing localities of the island. Based on morphological comparison and molecular analysis, its identity was confirmed as Erysiphe neolycopersici (anam. Pseudoidium neolycopersici). This species has a worldwide distribution causing severe epidemics mainly on greenhouse tomatoes. There is evidence of the rapid spread of this pathogen during 2022–2023 causing serious infection of all tomato cultivars in greenhouse culture in Mauritius. The origin of these infections and its epidemiological consequences are discussed.

Exploitation of the genetic potential of Thinopyrum and Agropyron genera to protect wheat from diseases and environmental stresses.

Common wheat is one of the most important food crops in the world. Grain harvests can be increased by reducing losses from diseases and environmental stresses. The tertiary gene pool, including Thinopyrum spp., is a valuable resource for increasing genetic diversity and wheat resistance to fungal diseases and abiotic stresses. Distant hybridization between wheat and Thinopyrum spp. began in the 1920s in Russia, and later continued in different countries. The main results were obtained using the species Th. ponticum and Th. intermedium. Additionally, introgression material was created based on Th. elongatum, Th. bessarabicum, Th. junceiforme, Agropyron cristatum. The results of introgression for resistance to diseases (leaf, stem, and stripe rusts; powdery mildew; Fusarium head blight; and Septoria blotch) and abiotic stresses (drought, extreme temperatures, and salinity) to wheat was reviewed. Approaches to improving the agronomic properties of introgression breeding material (the use of irradiation, ph-mutants and compensating Robertsonian translocations) were described. The experience of long-term use in the world of a number of genes from the tertiary gene pool in protecting wheat from leaf and stem rust was observed. Th. ponticum is a nonhost for Puccinia triticina (Ptr) and P. graminis f. sp. tritici (Pgt) and suppresses the development of rust fungi on the plant surface. Wheat samples with the tall wheatgrass genes Lr19, Lr38, Sr24, Sr25 and Sr26 showed defence mechanisms similar to nonhosts resistance. Their influence led to disruption of the development of surface infection structures and fungal death when trying to penetrate the stomata (prehaustorial resistance or stomatal immunity). Obviously, a change in the chemical properties of fungal surface structures of races virulent to Lr19, Lr24, Sr24, Sr25, and Sr26 leads to a decrease in their adaptability to the environment. This possibly determined the durable resistance of cultivars to leaf and stem rusts in different regions. Alien genes with a similar effect are of interest for breeding cultivars with durable resistance to rust diseases and engineering crops with the help of molecular technologies.

Enhancing Panax notoginseng Leaf Disease Classification with Inception-SSNet and Image Generation via Improved Diffusion Model

The rapid and accurate classification of Panax notoginseng leaf diseases is vital for timely disease control and reducing economic losses. Recently, image classification algorithms have shown great promise for plant disease diagnosis, but dataset quantity and quality are crucial. Moreover, classifying P. notoginseng leaf diseases faces severe challenges, including the small features of anthrax and the strong similarity between round spot and melasma diseases. In order to address these problems, we have proposed an ECA-based diffusion model and Inception-SSNet for the classification of the six major P. notoginseng leaf diseases, namely gray mold, powdery mildew, virus infection, anthrax, melasma, and round spot. Specifically, we propose an image generation scheme, in which the lightweight attention mechanism, ECA, is used to capture the dependencies between channels for improving the dataset quantity and quality. To extract disease features more accurately, we developed an Inception-SSNet hybrid model with skip connection, attention feature fusion, and self-calibrated convolutional. These innovative methods enable the model to make better use of local and global information, especially when dealing with diseases with similar features and small targets. The experimental results show that our proposed ECA-based diffusion model FID reaches 42.73, compared with the baseline model, which improved by 74.71%. Further, we tested the classification model using the data set of P. notoginseng leaf disease generation, and the accuracy of 11 mainstream classification models was improved. Our proposed Inception-SSNet classification model achieves an accuracy of 97.04% on the non-generated dataset, which is an improvement of 0.11% compared with the baseline model. On the generated dataset, the accuracy reached 99.44%, which is an improvement of 1.02% compared to the baseline model. This study provides an effective solution for the monitoring of Panax notoginseng diseases.

Identification and confirmation of powdery mildew (Erysiphe polygoni) resistance in pea germplasm

Erysiphe polygoni DC, the causative agent of powdery mildew, poses a significant threat to pea crop, resulting in substantial yield and economic losses. To address this menace, an exploration of intrinsic resistance within pea germplasm becomes imperative for effective disease management. In our study, phenotyping of 1095 pea accessions, sourced from both indigenous and exotic origins, under natural epiphytotic conditions during Rabi 2021-22, revealed a prevailing susceptibility, with over 60 per cent disease severity in majority of accessions. Remarkably, only 22 accessions, including IC208327, IC220109, IC220378, IC258401, IC262762, IC262849, IC267140, IC267174, IC267727, IC274039, IC274040, IC310074, IC311066, IC345548, IC424898, IC552779, IC613133, IC629544, IC629687, NC57793, IC220193 and EC598669, exhibited resistance with a disease score of &amp;lt;1. Subsequent, pot screening of these 22 resistant accessions under artificial epiphytotic conditions during Rabi 2022-23 confirmed their resistance showing disease severity ranging from 5.83 - 17.50 per cent. Recognizing the pivotal role of resistant varieties in disease management, these identified accessions hold immense potential as resistant donors in crop improvement programs.. KEYWORDS :Germplasm, pea, powdery mildew, resistance

Multiple routes to fungicide resistance: Interaction of Cyp51 gene sequences, copy number and expression.

We examined the molecular basis of triazole resistance in Blumeria graminis f. sp. tritici (wheat mildew, Bgt), a model organism among powdery mildews. Four genetic models for responses to triazole fungicides were identified among US and UK isolates, involving multiple genetic mechanisms. Firstly, only two amino acid substitutions in CYP51B lanosterol demethylase, the target of triazoles, were associated with resistance, Y136F and S509T (homologous to Y137F and S524T in the reference fungus Zymoseptoria tritici). As sequence variation did not explain the wide range of resistance, we also investigated Cyp51B copy number and expression, the latter using both reverse transcription-quantitative PCR and RNA-seq. The second model for resistance involved higher copy number and expression in isolates with a resistance allele; thirdly, however, moderate resistance was associated with higher copy number of wild-type Cyp51B in some US isolates. A fourth mechanism was heteroallelism with multiple alleles of Cyp51B. UK isolates, with significantly higher mean resistance than their US counterparts, had higher mean copy number, a high frequency of the S509T substitution, which was absent from the United States, and in the most resistant isolates, heteroallelism involving both sensitivity residues Y136+S509 and resistance residues F136+T509. Some US isolates were heteroallelic for Y136+S509 and F136+S509, but this was not associated with higher resistance. The obligate biotrophy of Bgt may constrain the tertiary structure and thus the sequence of CYP51B, so other variation that increases resistance may have a selective advantage. We describe a process by which heteroallelism may be adaptive when Bgt is intermittently exposed to triazoles.

Two New Isoindole Alkaloids from Aspergillus fumigatus as Potential Activators for Tobacco Powdery Mildew

Two New Isoindole Alkaloids from Aspergillus fumigatus as Potential Activators for Tobacco Powdery Mildew

Phospholipid production and signaling by a plant defense inducer against Podosphaera xanthii is genotype-dependent.

Biotrophic phytopathogenic fungi such as Podosphaera xanthii have evolved sophisticated mechanisms to adapt to various environments causing powdery mildews leading to substantial yield losses. Today, due to known adverse effects of pesticides, development of alternative control means is crucial and can be achieved by combining plant protection products with resistant genotypes. Using plant defense inducers, natural molecules that stimulate plant immune system mimicking pathogen attack is sustainable, but information about their mode of action in different hosts or host genotypes is extremely limited. Reynoutria sachalinensis extract, a known plant defense inducer, especially through the Salicylic acid pathway in Cucurbitaceae crops against P. xanthii, was employed to analyze the signaling cascade of defense activation. Here, we demonstrate that R. sachalinensis extract enhances phospholipid production and signaling in a Susceptible to P. xanthii courgette genotype, while limited response is observed in an Intermediate Resistance genotype due to genetic resistance. Functional enrichment and cluster analysis of the upregulated expressed genes revealed that inducer application promoted mainly lipid- and membrane-related pathways in the Susceptible genotype. On the contrary, the Intermediate Resistance genotype exhibited elevated broad spectrum defense pathways at control conditions, while inducer application did not promote any significant changes. This outcome was obvious and at the metabolite level. Main factor distinguishing the Intermediate Resistance form the Susceptible genotype was the epigenetic regulated increased expression of a G3P acyltransferase catalyzing phospholipid production. Our study provides evidence on phospholipid-based signaling after plant defense inducer treatment, and the selective role of plant's genetic background.

PREVALANCE AND MANAGEMENT OF SOME MAJOR DISEASES OF MANGO AT AFGOYE AND BALAD DISTRICT IN SOMALIA

The experiments were conducted in different mango orchards of Afgoye and Balad districts in Somalia under the faculty of Agriculture, Zamzam Universityof Science and Technology during February to April, 2020 on prevalence and management of mango diseases. Altogether, seven different diseases viz. Anthracnose, die-back, powdery mildew, sooty mold, red rust, bacterial leaf blight and bacterial leaf spot were recorded. All the diseases were common in both regions but these varied from orchard to orchard. Among the diseases, severity of Anthracnose (35.3%), die-(20.67%), powdery mildew (45.17%), red rust (13.75%) and bacterial leaf sight (54.33%) were found major problem in Balad districts. In Afgoye , Anthracnose (16.033%), sooty mold (18.90%), bacterial leaf blight( 19.833%) and bacterial leaf spot (8.927%) were found the highest severity. fungicides Caroozate 45, Carbazim, respectively, were evaluated and found that Carbazim were good effect in controlling Anthracnose, sooty mold, red rust and bacterial leaf spot. Caroozate 45 was also effective in controlling Anthracnose, die-back, powdery mildew, red rust al leaf spot disease. like similarly weused botanicals fungcide, Such as Neemand Garlic well cake.respectively,were evaluated and found that Neem with Garlic were good effect in controlling Anthracnose, sooty mold, red rust and bacterial leaf spot. Neem was also effective in controlling Anthracnose, die-back, powdery mildew, red rust al leaf spot disease.

Устойчивост на сортове и линии обикновена пшеница към брашнеста мана в млада и възрастова фаза

Powdery mildew caused by Blumeria graminis f. sp. tritici is an important disease of wheat throughout the world, especially in areas with maritime and semi-continental climates. In Bulgaria, losses in grain yield due to powdery mildew range from 10 to 30%, and sometimes-higher percentages depending on the resistance of the variety and the degree of attack. Utilization of resistant cultivars is the most effective and environmentally safe means of controlling powdery mildew. The objectives of our study were: (1) identify the resistance of breeding lines, introduced and Bulgarian wheat varieties to a set of isolates; (2) identify age resistance in these cultivars based on field trials. Of the 69 wheat cultivars and lines tested, 42 were susceptible to all isolates. 27 wheat lines and cultivars were found to contain at least one or more resistance genes. The most frequently tested lines and cultivars responded with a persistent response to isolates with marked avirulence with respect to genes Pm 4a and Pm 4b, followed by Pm 8 and Pm 2. Out of 42 selection lines and cultivars showed susceptibility to all isolates on B. graminis. f. sp. tritici in the young phase, 29 respond with a sustained response under field conditions.

Temporal dynamics of N-hydroxypipecolic acid and salicylic acid pathways in the disease response to powdery mildew in wheat

Wheat (Triticum aestivum) is a major staple crop worldwide, and its yields are significantly threatened by wheat powdery mildew (Blumeria graminis f. sp. tritici). Enhancing disease resistance in wheat is crucial for meeting global food demand. This study investigated the disease response in wheat, focusing on the bioactive small molecules salicylic acid (SA), pipecolic acid (Pip), and N-hydroxypipecolic acid (NHP), to provide new insights for molecular breeding. We found that endogenous levels of SA, Pip, and NHP significantly increased in infected plants, with Pip and NHP levels rising earlier than those of SA. Notably, the rate of increase of NHP was substantially higher than that of SA. The gene expression levels of SARD1 and CBP60g, which are transcription factors for SA, Pip, and NHP biosynthesis, increased significantly during the early stages of infection. We also found that during the later stages of infection, the expression of ALD1, SARD4, and FMO1, which encode enzymes for Pip and NHP biosynthesis, dramatically increased. Additionally, ICS1, which encodes a key enzyme involved in SA biosynthesis, also showed increased expression during the later stages of infection. The temporal changes in ICS1 transcription closely mirrored the behavior of endogenous SA levels, suggesting that the ICS pathway is the primary route for SA biosynthesis in wheat. In conclusion, our results suggest that the early accumulation of Pip and NHP cooperates with SA in the disease response against wheat powdery mildew infection.

Bioefficacy of Novel Chemical Fungicides for Management of Mango Powdery Mildew

Mango (Mangifera indica L.), the king of the fruits, is considered the most important fruit among millions of people worldwide, particularly in India. Among all diseases, powdery mildew caused by Oidium mangiferae is one of the most common, wide spread and serious diseases throughout the world causing significant yield losses. In this study experiments were conducted for two seasons by using new fungicides to control the disease along with some old ones. Among all fungicides tested Tebuconazole 50% + Trifloxystrobin 25% WG reduced the disease severity significantly. In both the seasons (pooled) Tebuconazole 50% + Trifloxystrobin 25% WG worked significantly by reducing the disease with PDI of 3.33 per cent and per cent disease reduction over control of 87.51.

Pan-Genome Analysis of TRM Gene Family and Their Expression Pattern under Abiotic and Biotic Stresses in Cucumber

Cucumber (Cucumis sativus L.) is a vital economic vegetable crop, and the TONNEAU1 Recruiting Motif (TRM) gene plays a key role in cucumber organ growth. However, the pan-genomic characteristics of the TRM gene family and their expression patterns under different stresses have not been reported in cucumber. In this study, we identified 29 CsTRMs from the pan-genomes of 13 cucumber accessions, with CsTRM29 existing only in PI183967. Most CsTRM proteins exhibited differences in sequence length, except five CsTRMs having consistent protein sequence lengths among the 13 accessions. All CsTRM proteins showed amino acid variations. An analysis of CsTRM gene expression patterns revealed that six CsTRM genes strongly changed in short-fruited lines compared with long-fruited lines. And four CsTRM genes strongly responded to salt and heat stress, while CsTRM14 showed responses to salt stress, powdery mildew, gray mold, and downy mildew. Some CsTRM genes were induced or suppressed at different treatment timepoints, suggesting that cucumber TRM genes may play different roles in responses to different stresses, with expression patterns varying with stress changes. Remarkably, the expression of CsTRM21 showed considerable change between long and short fruits and in responses to abiotic stresses (salt stress and heat stress), as well as biotic stresses (powdery mildew and gray mold), suggesting a dual role of CsTRM21 in both fruit shape determination and stress resistance. Collectively, this study provided a base for the further functional identification of CsTRM genes in cucumber plant growth and stress resistance.

In-silico identification of putatively functional intergenic small open reading frames in the cucumber genome and their predicted response to biotic and abiotic stresses.

The availability of high-throughput sequencing technologies increased our understanding of different genomes. However, the genomes of all living organisms still have many unidentified coding sequences. The increased number of missing small open reading frames (sORFs) is due to the length threshold used in most gene identification tools, which is true in the genic and, more importantly and surprisingly, in the intergenic regions. Scanning the cucumber genome intergenic regions revealed 420 723 sORF. We excluded 3850 sORF with similarities to annotated cucumber proteins. To propose the functionality of the remaining 416 873 sORF, we calculated their codon adaptation index (CAI). We found 398 937 novel sORF (nsORF) with CAI ≥ 0.7 that were further used for downstream analysis. Searching against the Rfam database revealed 109 nsORFs similar to multiple RNA families. Using SignalP-5.0 and NLS, identified 11 592 signal peptides. Five predicted proteins interacting with Meloidogyne incognita and Powdery mildew proteins were selected using published transcriptome data of host-pathogen interactions. Gene ontology enrichment interpreted the function of those proteins, illustrating that nsORFs' expression could contribute to the cucumber's response to biotic and abiotic stresses. This research highlights the importance of previously overlooked nsORFs in the cucumber genome and provides novel insights into their potential functions.

Endophytes infection increased the disease resistance of host Achnatherum sibiricum and non-symbiotic neighbours to pathogenic fungi

Epichloë infection can affect the fungal disease resistance of host grasses. However, few studies have been reported on the effects of endophyte infection on non-symbiotic neighbours. We surveyed the plant diseases in natural grassland, and compared differences of total disease index between neighboring and non-neighboring plants of Achnatherum sibiricum. Then laboratory experiments were conducted to investigate the effects of endophyte on the growth of four pathogen species as well as the brown patch of the host and its neighboring plants. The results of plant disease investigation in natural grassland showed that the major epidemic diseases of grasses were spot blight, rust disease and powdery mildew in Hulunbuir natural grassland. Among common herbages, the total disease index of endophyte-infected A. sibiricum was the lowest. Compared with non-neighboring plants, the brown patch disease index of Leymus chinensis, Stipa baicalensis and Agropyron cristatum was significantly reduced when neighbouring with A. sibiricum. The laboratory experiments results showed that the culture filtration of both Epichloë gansuensis and Epichloë sibiricum significantly restrained the growth of Curvularia lunata, Bipolaris sorokiniana, Sclerotinia sclerotiorum and Sclerotinia trifoliorum. The two species of endophytes could reduce lesion area of detached host leaves. In vivo plant experiments, the endophyte reduced the disease resistance of both the host and its neighbor grasses L. chinensis to C. lunata and B. sorokiniana. This study first verified that the endophytes in A. sibiricum have a positive effect on disease resistance of neighbor grasses to brown patch. The study contributes to the understanding of endophyte-host interactions and suggests potential applications of endophytes in biological control strategies for grassland management.

TaNAC1 boosts powdery mildew resistance by phosphorylation-dependent regulation of TaSec1a and TaCAMTA4 via PP2Ac/CDPK20.

The integrity of wheat (Triticum aestivum) production is increasingly jeopardized by the fungal pathogen Blumeria graminis f. sp. tritici (Bgt), particularly amid the vicissitudes of climate change. Here, we delineated the role of a wheat transcription factor, TaNAC1, which precipitates cellular apoptosis and fortifies resistance against Bgt. Utilizing BiFC, co-immunoprecipitation, protein quantification, luciferase report assays, we determined that cytoplasmic TaNAC1-7A undergoes phosphorylation at the S184/S258 sites by TaCDPK20, facilitating its nuclear translocation. This migration appears to prime further phosphorylation by TaMPK1, thereby enhancing transcriptional regulatory activity. Notably, the apoptotic activity of phosphorylated TaNAC1-7A is negatively modulated by the nuclear protein phosphatase PP2Ac. Furthermore, activation of TaNAC1 phosphorylation initiates transcription of downstream genes TaSec1a and TaCAMTA4, through binding to the C[T/G]T[N7]A[A/C]G nucleic acid motif. Suppression of TaNAC1, TaCDPK20, and TaMPK1 in wheat compromises its resistance to Bgt strain E09, whereas overexpression of TaNAC1 and silencing of PP2Ac markedly elevate resistance levels. Our results reveal the pivotal role of TaNAC1 in basal resistance which is mediated by its effects on homotypic fusion, vacuolar protein sorting, and the expression of defense-related genes. The findings highlight the potential through targeting TaNAC1 and its regulators as a strategy for improving wheat's resistance to fungal pathogens.

Metabolome and Mycobiome of Aegilops tauschii Subspecies Differing in Susceptibility to Brown Rust and Powdery Mildew Are Diverse.

The present study demonstrated the differences in the seed metabolome and mycobiome of two Aegilops tauschii Coss accessions with different resistance to brown rust and powdery mildew. We hypothesized that the seeds of resistant accession k-1958 Ae. tauschii ssp. strangulata can contain a larger number of metabolites with antifungal activity compared with the seeds of susceptible Ae. tauschii ssp meyeri k-340, which will determine differences in the seed fungal community. Our study emphasizes the differences in the seed metabolome of the studied Ae. tauschii accessions. The resistant accession k-1958 had a higher content of glucose and organic acids, including pyruvic, salicylic and azelaic acid, as well as pipecolic acids, galactinol, glycerol and sitosterol. The seeds of Ae. tauschii-resistant accession k-1958 were found to contain more active substances with antifungal activity. The genera Cladosporium and Alternaria were dominant in the seed mycobiome of the resistant accession. The genera Alternaria, Blumeria and Cladosporium dominated in seed mycobiome of susceptible accession k-340. In the seed mycobiome of the resistant k-1958, a higher occurrence of saprotrophic micromycetes was found, and many of the micromycetes were biocontrol agents. It was concluded that differences in the seed metabolome of Ae. tauschii contributed to the determination of the differences in mycobiomes.