Liquid-liquid phase separation (LLPS) has emerged as an important strategy for plant stress resistance, yet its dynamic regulation during plant-pathogen interaction remains poorly understood. Here, we demonstrate that the stripe rust fungus Puccinia striiformis f. sp. tritici (Pst) deploys effector Hasp170 (one haustorial secreted protein) to subvert wheat immunity by directly disrupting host LLPS. Hasp170 targets the intrinsically disordered region (IDR1) of the wheat nuclear protein TaPSTE (phase separation protein targeted by effector), which forms LLPS-dependent biomolecular condensates. Within these condensates, TaPSTE recruits the transcription factor TaNF-YC, thereby activating the expression of genes driving reactive oxygen species burst and Ca2+ influx, key components for disease resistance. By binding TaPSTE's IDR1, Hasp170 impairs condensate formation and prevents TaNF-YC recruitment, consequently suppressing host immunity and facilitating fungal parasitism. This reveals a virulence strategy where pathogens directly manipulate host biomolecular condensates to evade immune responses.

Wheat powdery mildew poses a significant threat to global wheat yield and is considered as one of the most destructive diseases in agriculture. Early detection of the causal pathogen enables timely fungicide application, reduces chemical usage, and supports sustainable disease management. In this study, we developed a rapid one-pot detection method, termed ORCas12a-Bgt (one-pot RPA-CRISPR/Cas12a platform), for the wheat powdery mildew fungus, Blumeria graminis f. sp. tritici (Bgt). This assay integrates RPA with CRISPR/Cas12a by combining all reaction components in a single tube. This closed-tube design eliminates the risk of aerosol contamination and avoids the sensitivity loss inherent in sequential tube-opening protocols. The entire assay can be completed at 37 °C, with a detection limit of 3 × 100 copies/μL (corresponding to 6 copies per 20-μL reaction) of Bgt genomic DNA, which represents a 1000-fold increase in sensitivity compared to conventional PCR. Specificity tests confirmed that the assay could detect both Bgt and Blumeria graminis f. sp. poae (Bgp), while with no cross-reactivity against common wheat-associated pathogens, including Fusarium graminearum, F. pseudograminearum, and Cladosporium sphaerospermum. Notably, the method successfully detected Bgt in inoculated wheat leaves as early as 1 day post-inoculation (dpi), preceding the development of visible symptoms at 3-7 dpi. Overall, the ORCas12a-Bgt assay provides a rapid, simple, highly sensitive detection tool that is specific for B. graminis at the species level, with minimal equipment requirements. Application of the ORCas12a assay to growth chamber-grown wheat samples produced results in complete agreement with conventional PCR, confirming the robustness of this equipment-minimal platform and its potential for field deployment following validation with naturally infected field samples and a broader set of Bgt isolates.

Wheat is a major staple crop worldwide, and with the ongoing changes in dietary patterns, the demand for improved nutritional quality in wheat has been increasing. Black-grained wheat is a promising germplasm rich in nutrients. Agropyron cristatum (2n = 4x = 28, PPPP) is a wild relative of wheat that carries several desirable genes for genetic improvement. Here, we identified black-grained lines PB31334 and PB31340 from wheat—A. cristatum derivatives, which exhibited significantly higher anthocyanin content and possibly increased amino acid content compared with common wheat. These lines were identified as wheat—A. cristatum 6P (6A) disomic substitution lines, with the alien chromosome 6P from A. cristatum responsible for the black grain trait, as revealed by genetic analysis of four segregated populations created by crossing PB31334 and PB31340 with Fukuho and Xinong979. Additionally, three lines were identified, including telosomic lines carrying the short arm (6PS) and the long arm (6PL) of alien chromosome 6P, as well as a 6PL-deletion line lacking a partial segment of the long arm (bin 6–17). The line with 6PL displayed the black grain trait, whereas the other two did not. The gene was localized to the 6PL (bin 6–17) region without affecting the grain number per spike or thousand-grain weight. Notably, the total anthocyanin content increased in 6PL telosomic line and was positively correlated with grain coloration. The newly identified 6PL chromosomal region is a valuable resource rich in anthocyanins, offering a promising avenue for increasing the nutritional content of wheat.

Powdery mildew poses a significant threat to global wheat production and most cloned and deployed resistance genes for wheat breeding encode nucleotide-binding and leucine-rich repeat (NLR) immune receptors. Although two genetically linked NLRs function together as an NLR pair have been reported in other species, this phenomenon has been relatively less studied in wheat. Here, we demonstrate that two tightly linked NLR genes, RXL and Pm5e, arranged in a head-to-head orientation, function together as an NLR pair to mediate powdery mildew resistance in wheat. The resistance function of the RXL/Pm5e pair is validated by mutagenesis, gene silencing, and gene-editing assays. Interestingly, both RXL and Pm5e encode atypical NLRs, with RXL possessing a truncated NB-ARC (nucleotide binding adaptor shared by APAF-1, plant R proteins and CED-4) domain and Pm5e featuring an atypical coiled-coil (CC) domain. Notably, RXL and Pm5e lack an integrated domain associated with effector recognition found in all previously reported NLR pairs. Additionally, RXL and Pm5e exhibit a preference for forming hetero-complexes rather than homo-complexes, highlighting their cooperative role in disease resistance. We further show that the CC domain of Pm5e specifically suppresses the hypersensitive response induced by the CC domain of RXL through competitive interaction, revealing regulatory mechanisms within this NLR pair. Our study sheds light on the molecular mechanism underlying RXL/Pm5e-mediated powdery mildew resistance and provides a new example of an NLR pair in wheat disease resistance.

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is a continuous threat to global wheat production. In 2021, the epidemic of wheat stripe rust in China affected approximately 4.5 million hectares, resulting in severe yield losses. When confronted with the epidemic, tracing the sources of the pathogen can offer valuable insights for disease prevention and control. This study was conducted to analyze the genetic structure, aerodynamics, geographical features, and cultivation practices of the pathogen population in various wheat-producing regions and to further reveal the spread patterns of the stripe rust pathogens in China. The findings indicated an overall trend of the pathogen dissemination from the west to the east. The pathogen was primarily spread from the northwestern region to the Huang-Huai-Hai region through the Guanzhong Plain and the NanXiang Plain. Meanwhile, the pathogen also spread eastward from the southwestern region to the lower reaches of the Yangtze River, using the Jianghan Plain as a bridge and the Yangtze River Valley in southwestern Anhui as the main pathway. Furthermore, the pathogen spread northward into Shandong under the driving force of the southeast winds. The findings of this study may provide valuable insights for the integrated management of wheat stripe rust in China.

Wheat powdery mildew caused by Blumeria graminis f. sp tritici (Bgt), an obligate biotrophic fungal pathogen, is a destructive disease world-wide, particularly severe in China. However, the molecular mechanisms underlying virulence variation and pathogenesis of Chinese Bgt isolates remain poorly understood. Here, we constructed a chromosome-level genome assembly (136.19 Mb) of Chinese isolate 21-2, with repetitive element expansion (predominantly retrotransposons), by integrating Illumina, PacBio, Nanopore, and Hi-C sequencing technologies. The genome was predicted to contain 9215 protein-coding genes, of which 1569 were assessed as pathogenicity-related genes. This included 998 effectors, 371 involved in pathogen-host interactions (PHI), 223 CAZymes-encoding with plant cell wall degrading capacity, and 79 lipase-coding implicated in pathogenic infection. Compared to Swiss isolate 96224, isolate 21-2 displayed a distinct virulence pattern on 21 wheat differential lines. Comparative genomics analysis revealed that variations in composition and sequence of effector genes between the two isolates resulted in different virulence spectra (e.g., AvrPm1a, AvrPm3a 2/f2, AvrPm3b2/c2, AvrPm3d3 ). Transcriptome analysis of 21-2 revealed 64 effector genes exhibiting preferential expression during haustorial development, suggesting their potential involvement in pathogenesis. Among them, one can bind a defence-related protein of wheat and may play a key role in suppressing host immune responses and promoting disease progression. This study provides comprehensive genomic and transcriptomic insights into Chinese Bgt isolate 21-2, and reveals virulence determinants and their variants fundamental to pathogenesis. Future functional analysis of such genes will enhance our understanding of pathogenic mechanisms of powdery mildews.

IntroductionTetrastigma hemsleyanum Diels et Gilg is a medicinal plant known for its diverse pharmacological effects, including anti-inflammatory, anti-tumor, anti-hepatocellular carcinoma, and antipyretic activities. To explore the medicinal components from different parts of the plant and to fully utilize T. hemsleyanum, this study investigated the mechanisms underlying the differential accumulation of metabolites in its tuberous roots, fibrous roots, and leaves.MethodsThis study employed a combination of metabolomics and transcriptomics to analyze the metabolic profiles of T. hemsleyanum. Using LC-MS/MS technology in positive ion mode, metabolites were identified and quantified in the tuberous roots, fibrous roots, and leaves. Key metabolic pathways were analyzed to understand the spatial distribution of bioactive compounds.ResultsA total of 65 metabolites were identified in the tuberous roots, 203 in the fibrous roots, and 235 in the leaves. The main compounds identified included flavonoids, alkaloids, terpenoids, glycosides, ketones, and amino acids and their derivatives. Flavonoids, glycosides, alkaloids, and terpenoids were strongly accumulated in the tuberous roots, while flavonoid alcohols, glycosides, alkaloids, and terpenoids were predominant in the leaves and fibrous roots. The phenylpropanoid biosynthesis pathway and isoflavonoid biosynthesis were found to play a major role in the pharmacological effects of T. hemsleyanum. The glucosinolate pathway and ABC transporters were also identified as key contributors to tissue-specific metabolic accumulation.DiscussionThese results elucidate the molecular mechanisms behind the differential accumulation of metabolites in different parts of T. hemsleyanum. The findings provide important insights into the spatial distribution of its bioactive components and their biosynthetic pathways, offering a foundation for further development and utilization of this medicinal plant.

Cereal powdery mildews, which are caused by Blumeria graminis, are economically important diseases that are distributed throughout the world. To successfully evade the host defence mechanism, the wheat powdery mildew pathogen known as B. graminis f. sp. tritici (Bgt) secretes an array of effectors into plant cells to interfere with host immunity and promote fungal invasion and colonisation during the infection process. However, little is known about the functions of the vast majority of these effectors in immune manipulation. In this study, we identified an effector-coding gene known as BgtE-20069a from Bgt. This gene encodes a short protein carrying an N-terminal signal peptide with a secretory function and is highly upregulated in the early stage of Bgt infection in wheat. We observed that transient expression of BgtE-20069a in Nicotiana benthamiana suppressed programmed cell death (PCD) induced by both the proapoptotic protein Bax and the elicitor PAMP INF1 from Phytophthora infestans. The mature form of BgtE-20069a (which lacks a signal peptide) is localised to the cytoplasm and nucleus of plant cells. Moreover, the knockdown of BgtE-20069a resulted in reduced virulence towards wheat, with significantly decreased conidia production and a decreased haustorial formation rate being observed. Together, these results suggest that BgtE-20069a is a vital virulence factor that is required for Bgt infection in wheat; moreover, the results indicate that it can suppress plant immunity and increase Bgt virulence. Our findings broaden the current understanding of the role of effectors in promoting Bgt infection by manipulating host immunity, thereby providing new insights into the molecular mechanism of Bgt pathogenesis.

Crop wild relatives offer natural variations of disease resistance for crop improvement. Here, we report the isolation of broad-spectrum powdery mildew resistance gene Pm36, originated from wild emmer wheat, that encodes a tandem kinase with a transmembrane domain (WTK7-TM) through the combination of map-based cloning, PacBio SMRT long-read genome sequencing, mutagenesis, and transformation. Mutagenesis assay reveals that the two kinase domains and the transmembrane domain of WTK7-TM are critical for the powdery mildew resistance function. Consistently, in vitro phosphorylation assay shows that two kinase domains are indispensable for the kinase activity of WTK7-TM. Haplotype analysis uncovers that Pm36 is an orphan gene only present in a few wild emmer wheat, indicating its single ancient origin and potential contribution to the current wheat gene pool. Overall, our findings not only provide a powdery mildew resistance gene with great potential in wheat breeding but also sheds light into the mechanism underlying broad-spectrum resistance. Powdery mildew is a fungal leaf disease that reduces yield and grain quality in susceptible wheat varieties. Here, the authors report the cloning of the wild emmer wheat originated powdery mildew resistance gene Pm36 as a membrane associated tandem kinase and its possible resistance mechanism.

Two recessive powdery mildew resistance loci pmAeCIae8_2DS and pmAeCIae8_7DS from Aegilops tauschii were mapped and two synthesized hexaploid wheat lines were developed by distant hybridization. Wheat powdery mildew (Pm), one of the worldwide destructive fungal diseases, causes significant yield loss up to 30

Light-harvesting chlorophyll a/b binding proteins are encoded by nucleus genes and widely involve in capturing light energy, transferring energy, and responding to various stresses. However, their roles in wheat photosyn-thesis and stress tolerance are largely unknown. Here, Triticum aestivum light-harvesting chlorophyll a/b binding protein TaLhc2 was identified. It showed subcellular localization in chloroplast, contained light responsive cis -elements, and highly expressed in green tissues and down-regulated by multiple stresses. TaLhc2 promoted the colonization of hemi-biotrophic pathogen; further analysis showed that TaLhc2 strengthened BAX-induced cell death, enhanced the ROS accumulation, and up-regulated pathogenesis-related genes; those results suggested that TaLhc2 has adverse influence on host immunity and function as a susceptible gene, thus host decreased its expression when faced with pathogen infection. RT-qPCR results showed that TaLhc2 was down-regulated by drought and salt stresses, while TaLhc2 improved the ROS accumulation under the two stresses, suggesting TaLhc2 may participate in wheat responding to abiotic stress. Additionally, TaLhc2 can increase the content of total chlorophyll and carotenoid by 1.3 % and 2.9 %, increase the net photosynthetic rate by 18 %, thus promote plant photosynthesis. Conclusively, we preliminarily deciphered the function of TaLhc2 in biotic/abiotic stresses and photosynthesis, which laid foundation for its usage in wheat breeding.

为建立简便、快速和灵敏的小麦白粉菌Blumeria graminis f.sp.tritici(Bgt)分子检测技术体系,基于环介导等温扩增(loop-mediated isothermal amplification,LAMP)技术,以 BGT96224V316_LOCUS1725 基因(GenBank:VCU40465.1)为靶标序列,设计并筛选特异性引物,建立小麦白粉菌的LAMP检测方法,并对其特异性、灵敏度和应用效果进行测定.结果表明,基于筛选出的1套特异性引物建立的LAMP方法能够从8种白粉菌属菌株和1种腐生菌中特异性地检测到小麦白粉菌;对小麦白粉菌DNA样品的检测灵敏度可达到300 fg/μL;对发病叶片的检测显示该LAMP方法能从人工接种的小麦叶片中准确检测出小麦白粉菌,检出时间为接种4 h及以上.综上,本研究建立了一种小麦白粉菌的LAMP检测方法,具有简便快捷、灵敏度高等特点,丰富了小麦白粉菌的检测体系.

为了明晰小麦白粉菌BgtVosA、BgtVelB、BgtBrlA基因的序列特点及它们在白粉菌产孢过程中的表达动态,为解析velvet蛋白在调控白粉菌无性繁殖中的作用提供理论依据,采用基于 RNA-seq数据的克隆测序技术获得BgtVosA、BgtVelB、BgtBrlA基因的CDS序列,用生物信息学方法分析它们编码的蛋白质序列特征和空间结构,用RT-qPCR监测它们在白粉菌分生孢子形成时期的表达模式.结果表明,BgtVosA、BgtVelB、BgtBrlA基因的ORF长度依次为1470、1341、1143bp,分别编码489、446、380个氨基酸,分子量在54.0～48.0ku,属于碱性、亲水性、热不稳定蛋白质,均含有核定位信号,不含跨膜螺旋和信号肽,空间结构呈现出近球形.BgtVosA、BgtVelB、BgtBrlA分别与其他真菌来源的VosA、VelB、BrlA蛋白具有同源性,且与白粉菌同源蛋白具有更近的亲缘关系,氨基酸序列在白粉菌自然群体中均高度保守.BgtVosA、BgtVelB属于典型的velvet蛋白家族成员,可能通过分子互作形成复合物,但其结构与构巢曲霉同源蛋白复合物存在明显差异.在小麦白粉菌无性繁殖阶段,BgtVosA、BgtVelB基因均显著上调(P＜0.01),BgtBrlA表达水平没有显著变化(P＞0.05).DNA结合区域分析推测BgtVosA-BgtVelB复合物不能靶向BgtBrlA启动子,调控其BgtBrlA的表达.BgtVosA、BgtVelB基因在调控白粉菌无性生殖中起重要作用.

This study aimed to evaluate the impact of stripe rust on different wheat cultivars with varying resistance levels.Five main cultivars with different resistance levels to wheat stripe rust were selected as the experimental materials in Hubei province(Lankao 198,highly susceptible;Fumai 368,moderately susceptible;Huamai 1168,moderately susceptible;Xiangmai 46,moderately resistant,Emai DH16,highly resistant).Artificial inoculation of stripe rust was carried out in the field to assess the damage caused by the disease.Different doses of fluconazole were applied to create varying incidence levels of stripe rust.The damage loss rates of five cultivars under different levels of disease incidence were studied,and the relationship between varietal resistance and plant protection contribution was analyzed.The economic thresholds for prevention and control of different resistant cultivars were established through quadratic polynomial regression analysis.The study found a significant positive correlation between the damage loss rate of different cultivars and the degree of disease occurrence.Additionally,the contribution of plant protection was correlated with the resistance of cultivars,with weaker resistance resulting in a higher contribution rate of plant protection.The economic thresholds for controlling stripe rust were determined for cultivars Lankao 198,Fumai 368,Huamai 1168,Xiangmai 46,and Emai DH16 during the heading and flowering stage,with the corresponding values of 5.443,4.819,3.994,3.376,and 5.150.These findings serve as a valuable theoretical foundation for utilizing wheat cultivars in stripe rust management.

Wheat powdery mildew caused by Blumeria graminis f. sp. tritici is one of the most serious foliar diseases of wheat, causing grain yield and quality degradation by affecting plant photosynthesis. It is an effective method to improve the disease resistance of wheat plants by molecular breeding. With the continuous development of sequencing technology, long intergenic noncoding RNAs (lincRNAs) have been discovered in many eukaryotes and act as key regulators of many cellular processes. In this study, 12 sets of RNA-seq data from wheat leaves pre- and post-pathogen infection were analyzed and 2,266 candidate lincRNAs were identified. Consistent with previous findings, lincRNA has shorter length and fewer exons than mRNA. The results of differential expression analysis showed that 486 DE-lincRNAs were selected as lincRNAs that could respond to powdery mildew stress. Since lincRNAs may be functionally related to their adjacent target genes, the target genes of these lincRNAs were predicted, and the GO and KEGG functional annotations of the predicted target genes were performed. Integrating the functions of target genes and the biological processes in which they were involved uncovered 23 lincRNAs that may promote or inhibit the occurrence of wheat powdery mildew. Co-expression patterns of lincRNAs with their adjacent mRNAs showed that some lincRNAs showed significant correlation with the expression patterns of their potential target genes. These suggested an involvement of lincRNAs in pathogen stress response, which will provide a further understanding of the pathogenic mechanism of wheat powdery mildew.

2018-2023年,在湖北省开展了抗(耐)性品种筛选、多粘芽孢杆菌拌种、植物诱抗剂(或植物生长调节剂)拌种+拔节—抽穗期喷雾,以及高效低风险农药筛选等多项小麦赤霉病全生育期综合防控关键技术研究,并于2021-2023年在小麦主产区松滋市、公安县、荆州区、钟祥市、枝江市、仙桃市、天门市、安陆市、襄州区、宜城市、随县等地进行了技术集成示范.结果表明:示范区取得明显的经济、社会和生态效益.示范区赤霉病平均防效为86.0％,比农民自防区(71.9％)提高14.1个百分点;示范区平均病粒率为0.1％,比农民 自防区(0.3％)降低0.2个百分点,比对照区(1.2％)降低1.0个百分点;示范区平均产量为381.6 kg/667m2,比自防区(354.8 kg/667m2)增长7.5％,比赤霉病对照区增产11.8％;示范区比对照区新增收益53.0元/667m2,比农民 自防区新增收益54.8元/667m2;示范区比农民 自防区农药减量13.4％,天敌增加42.3％;示范区赤霉菌呕吐毒素均控制在国家标准1 000μg/kg以下,质量合格率达100.0％.

Silica nanoparticles (SiNPs) have been demonstrated to have beneficial effects on plant growth and development, especially under biotic and abiotic stresses. However, the mechanisms of SiNPs-mediated plant growth strengthening are still unclear, especially under field condition. In this study, we evaluated the effect of SiNPs on the growth and sugar and hormone metabolisms of wheat in the field. SiNPs increased tillers and elongated internodes by 66.7% and 27.4%, respectively, resulting in a larger biomass. SiNPs can increase the net photosynthetic rate by increasing total chlorophyll contents. We speculated that SiNPs can regulate the growth of leaves and stems, partly by regulating the metabolisms of plant hormones and soluble sugar. Specifically, SiNPs can increase auxin (IAA) and fructose contents, which can promote wheat growth directly or indirectly. Furthermore, SiNPs increased the expression levels of key pathway genes related to soluble sugars (SPS, SUS, and α-glucosidase), chlorophyll (CHLH, CAO, and POR), IAA (TIR1), and abscisic acid (ABA) (PYR/PYL, PP2C, SnRK2, and ABF), whereas the expression levels of genes related to CTKs (IPT) was decreased after SiNPs treatment. This study shows that SiNPs can promote wheat growth and provides a theoretical foundation for the application of SiNPs in field conditions.

为评价灰霉病菌对氟啶胺的敏感性及抗药性风险,本试验于2020年-2021年在吉林、江西、湖北、山东、北京、湖南等地区的草莓、辣椒、四季豆、茄子和番茄上采集病叶、病茎、病花和病果,经单孢分离获得117个灰葡萄孢Botrytis cinerea菌株,采用菌丝生长速率法测定其对氟啶胺的敏感性.结果表明:有4株灰葡萄孢BJ14、BJ45、BJ46和BJ47对氟啶胺的敏感性显著降低,EC50在0.113 7～0.394 6 μg/mL,抗性倍数为4.7～16.3,MIC值＞4 μg/mL.其余113个菌株对氟啶胺的平均EC5.为0.025 1 μg/mL.敏感性降低的4个菌株继代培养10代后,抗药性状稳定.交互抗性测定结果表明,对氟啶胺敏感性下降的菌株对腐霉利和咯菌腈2种杀菌剂表现为敏感,氟啶胺与腐霉利或咯菌腈没有交互抗性.生物学性状研究表明,4株敏感性下降菌株在PDA平板上的生长速率和在番茄果实上的致病力都显著低于敏感菌株,而菌丝生物量、产孢量和孢子萌发率与敏感菌株无显著差异.以上研究结果表明,田间已存在对氟啶胺敏感性降低的菌株,鉴于灰葡萄孢属于高风险抗性菌株,建议氟啶胺在防治灰霉病的使用中需谨慎.

Stripe rust, caused by Puccinia striifomis f. sp. tritici (Pst), is one of the most destructive wheat diseases in China. Understanding the interregional dispersal of Pst inoculum is important for controlling the disease. In the present study, wheat stripe rust samples collected from the winter spore production and oversummering regions in November 2018 to March 2019 were studied through virulence testing and molecular characterization. From 296 isolates, 96 races were identified using a set of 19 Chinese wheat cultivars and 111 races were identified using 18 Yr single-gene lines as differentials. The isolates from Hubei province in the winter spore production area had the highest similarity in virulence with those from eastern Yunnan in the oversummering area. Molecular characterization using 13 simple-sequence repeat and 43 Kompetitive allele specific PCR-single nucleotide polymorphism markers supported the conclusion that the Pst populations in the winter spore production regions were from Guizhou and eastern Yunnan, key oversummering areas in the southwest. Furthermore, an analysis of wind movement at the 700-hPa high altitude also supported the conclusion of spore dispersal from the southwestern oversummering region to the south-central winter spore production region. The results of this study provide an epidemiological basis for deploying various effective resistance genes in different regions to control stripe rust.