Fusarium pseudograminearum (F. pseudograminearum) is the main causal agent of Fusarium Crown Rot (FCR) posing a severe threat to wheat yield. Effectors, as one class of weapons of phytopathogens, help pathogens infect their hosts by disturbing plant immunity. In this study, we identified a secreted effector, FpECIR, which has no functional domains, suppresses INF1-triggered cell death in Nicotiana benthamiana. Once translocated into wheat cells, FpECIR (without signal peptide) interacts with TaPLATZ2B, and silencing TaPLATZ2B and its alleles makes wheat more susceptible to F. pseudograminearum. Deletion of residues 29-35 of FpECIR disrupted its interaction with TaPLATZ2B, and eliminated its ability to suppress INF1-induced cell death. The pathogenicity of deletion mutants ΔFpecir on wheat coleoptiles was significantly reduced. Analysis of transcriptome data showed that infection with the ΔFpecir strain triggered the upregulation of defense-related genes in wheat coleoptiles, many of which were functionally enriched in hormone signaling pathways. qRT-PCR results revealed that FpECIR suppressed the expression of TaPLATZ2B and of genes related to ethylene signaling pathway. Furthermore, EMSA experiment result proved that FpECIR can inhibit the ability of TaPLATZ2B binding with the promoter region of ethylene response factors (TaERF020L). Suppressing the transcription levels of genes related to ethylene biosynthesis made the wheats more susceptible to FCR. Overall, the results showed that FpECIR plays an important role in the pathogenicity of F. pseudograminearum, and that the integrity of FpECIR is necessary for its interaction with TaPLATZ2B and for its suppression of INF1-induced cell death. Additionally, FpECIR not only affects the expression of TaPLATZ2B but also inhibits the function of TaPLATZ2B to regulate plant defense response through ethylene signaling pathways.

Fusarium pseudograminearum, the dominant causal agent of Fusarium crown rot (FCR), secretes numerous effectors to modulate host immunity during infection, but the functions of most remain unknown. In this study, we identified FpSP5, an effector from F. pseudograminearum, as a pathogen-associated molecular pattern (PAMP) that triggers plant immunity. FpSP5 induces cell death, oxidative burst, and PTI in Nicotiana benthamiana, conferring resistance against multiple pathogens. Furthermore, its perception specifically depends on the coreceptor BAK1 in N. benthamiana. Interestingly, FpSP5 is not only conserved among fungi and capable of activating defense responses in different plants but also essential for the full virulence of F. pseudograminearum on wheat. Collectively, these findings enhance our understanding of how F. pseudograminearum effectors modulate host immunity and contribute to pathogenicity, laying a foundation for developing targeted strategies to control FCR.

BACKGROUND:Suitable nano-pesticide carriers play a crucial role in enhancing the utilization efficiency of pesticides. Among these, mesoporous silica nanoparticles (MSNs) are the most promising candidates for large-scale and safe pesticide applications. RESULTS:In the present work, functionalized MSNs were demonstrated to be effective mitochondrial-targeted carriers for delivering strobilurin fungicides (mitochondrial respiratory chain inhibitors). MSNs were bi-functionalized with carboxymethyl chitosan (CMC), which is pH-responsive, and (4-carboxybutyl) triphenylphosphonium bromide (TPP), which is mitochondrial targeting. The loading capacity of the model pesticide pyraclostrobin (Py) on the carrier reached 32%. In vitro release experiments of Py demonstrated the sustained release performance of the carriers. Co-localization of the mitochondria and the carrier confirmed that mitochondria targeting by the nanoparticle carrier. Bioactivity assays showed superior antifungal activity of bi-functionalized Py@MSNs-CMC-TPP compared to mono-functionalized MSNs and commercial Py suspension products. Moreover, even when the concentrations of Py@MSNs-CMC and Py commercial suspension were increased by 200% relative to Py@MSNs-CMC-TPP, inhibition remained lower. This indicates that the bi-functionalized carrier reduced the required amount of Py while enhancing its utilization efficiency. CONCLUSION:With the large-scale application of mitochondrial-targeted pesticides, such as methoxyacrylates and succinate dehydrogenase inhibitors, functionalized MSNs have significant potential to emerge as promising, environmentally friendly fungicide formulation. © 2025 Society of Chemical Industry.

Fusarium crown rot, caused by Fusarium pseudograminearum (F. pseudograminearum), poses a significant threat to wheat production in China. Growing evidence suggests that Fusarium secretes a large number of effectors into host, but the biological function of these effectors remains poorly understood. Additionally, the effectors in F. pseudograminearum have not been reported. In this study, we elucidate the role of F. pseudograminearum Cell Death-induced Protein 1 (FpCDP1) from the secretome of F. pseudograminearum, in triggering plant immunity by inducing cell death, oxidative burst and PTI response. FpCDP1 emerges as a conserved pathogen-associated molecular pattern (PAMP) across various fungi, eliciting immune responses in different plants. Moreover, we demonstrated that FpCDP1 elicits intercellular defence responses in a BAK1-dependent manner in Nicotiana benthamiana. Furthermore, we identified a 21-amino-acid peptide capable of stimulating plant immune responses. Interestingly, while FpCDP1 induces plant immunity, it is also indispensable for the full virulence of F. pseudograminearum infecting wheat. These findings contribute to a deeper understanding of the interaction mechanism between F. pseudograminearum and wheat.

Fusarium crown rot (FCR), caused by Fusarium pseudograminearum, is a devastating wheat disease leading to significant yield losses worldwide. However, the pathogenic mechanism of F. pseudograminearum and its resistance to fungicides remain poorly understood. In this study, we identified a hypothetical gene encoding GPI-anchored protein, designated FpPer1, by screening a T-DNA insertion mutant library of F. pseudograminearum for tebuconazole resistance. The ΔFpper1 mutant exhibited increased sensitivity to the triazole antifungal drugs and fludioxonil. Additionally, the deletion of FpPER1 impaired fungal growth, conidiation, and pathogenicity in barley leaves and wheat coleoptiles. Furthermore, the ΔFpper1 mutant displayed enhanced susceptibility to various environmental stresses, including NaCl, CR, sorbitol, H2O2, and SDS. The mutant also showed reduced penetration peg formation and impaired reactive oxygen species (ROS) scavenging ability during infection. Subcellular localization analysis revealed that FpPer1-GFP co-localized with the endoplasmic reticulum (ER) marker RFP-HDEL in both conidia and hyphae, indicating its localization in the ER. In summary, our findings demonstrate that FpPER1 plays an important role in pathogenicity and fungicide resistance in F. pseudograminearum. This study not only provides a theoretical foundation for understanding fungal virulence mechanisms but also offers practical insights for developing novel fungicide strategies.

Fusarium pseudograminearum is a devastating pathogen that causes Fusarium crown rot (FCR) in wheat and poses a significant threat to wheat production in terms of grain yield and quality. However, the mechanism by which F. pseudograminearum infects wheat remains unclear. In this study, we aimed to elucidate these mechanisms by constructing a T-DNA insertion mutant library for the highly virulent strain WZ-8A of F. pseudograminearum. By screening this mutant library, we identified nine independent mutants that displayed impaired pathogenesis in barley leaves. Among these mutants, one possessed a disruption in the gene FpRCO1 that is an ortholog of Saccharomyces cerevisiae RCO1, encoding essential component of the Rpd3S histone deacetylase complex in F. pseudograminearum. To further investigate the role of FpRCO1 in F. pseudograminearum, we employed a splitmarker approach to knock out FpRCO1 in F. pseudograminearum WZ-8A. FpRCO1 deletion mutants exhibit reduced vegetative growth, conidium production, and virulence in wheat coleoptiles and barley leaves, whereas the complementary strain restores these phenotypes. Moreover, under stress conditions, the FpRCO1 deletion mutants exhibited increased sensitivity to NaCl, sorbitol, and SDS, but possessed reduced sensitivity to H2O2 compared to these characteristics in the wild-type strain. RNA-seq analysis revealed that deletion of FpRCO1 affected gene expression (particularly the downregulation of TRI gene expression), thus resulting in significantly reduced deoxynivalenol (DON) production. In summary, our findings highlight the pivotal role of FpRCO1 in regulating vegetative growth and development, asexual reproduction, DON production, and pathogenicity of F . pseudograminearum. . This study provides valuable insights into the molecular mechanisms underlying F . pseudograminearum infection in wheat and may pave the way for the development of novel strategies to combat this devastating disease.

Fusarium crown rot (FCR) in wheat is a prevalent soil-borne disease worldwide and poses a significant threat to the production of wheat (Triticum aestivum) in China, with F. pseudograminearum being the dominant pathogen. Currently, there is a shortage of biocontrol resources to control FCR induced by F. pseudograminearum, along with biocontrol mechanisms. In this study, we have identified 37 strains of biocontrol bacteria displaying antagonistic effects against F. pseudograminearum from over 8000 single colonies isolated from soil samples with a high incidence of FCR. Among them, QY43 exhibited remarkable efficacy in controlling FCR. Further analysis identified the isolate QY43 as Pseudomonas aeruginosa, based on its colony morphology and molecular biology. In vitro, QY43 significantly inhibited the growth, conidial germination, and the pathogenicity of F. pseudograminearum. In addition, QY43 exhibited a broad spectrum of antagonistic activities against several plant pathogens. The genomics analysis revealed that there are genes encoding potential biocontrol factors in the genome of QY43. The experimental results confirmed that QY43 secretes biocontrol factor siderophores and pyocyanin. In summary, QY43 exhibits a broad spectrum of antagonistic activities and the capacity to produce diverse biocontrol factors, thereby showing substantial potential for biocontrol applications to plant disease.

Cucumber Fusarium wilt caused by Fusarium oxysporum f. sp. cucumerium (FOC), is a prevalent soil-borne disease. In this study, Bacillus subtilis JNF2, isolated from the high incidence area of cucumber Fusarium wilt in Luoyang, demonstrated significant inhibitory effects on FOC and promoted cucumber seedling growth. The biocontrol mechanism of strain JNF2 were elucidated through morphological observation, physiological and biochemical experiments, and whole genome sequence analysis. Pot experiments revealed an 81.33 ± 0.21% control efficacy against Fusarium wilt, surpassing the 64.10 ± 0.06% efficacy of hymexazol. Seedlings inoculated with JNF2 exhibited enhanced stem thickness and leaf area compared to control and hymexazol-treated plants. Physiological tests confirmed JNF2’s production of indole-3-acetic acid (IAA), siderophores, and hydrolytic enzymes, such as β-1,3-glucanase, amylase, and protease, which inhibited FOC growth and promoted plant development. Genome analysis identified genes encoding antimicrobial peptides and hydrolases, as well as a novel glycocin synthetic gene cluster. These findings underscore B. subtilis JNF2’s potential as a biocontrol agent for sustainable cucumber cultivation.

Falcarindiol is active against phytopathogenic fungi. In the present study, racemic falcarindiol analogs (8a-8q) were designed, synthesized, and tested for their activities against eight economically significant phytopathogenic fungal species. The compound 8o displayed the best antifungal activities and up to 54.6-fold in vitro potency improvement against Phytophthora capsici than the natural product stipudiol. Its half-maximum effective concentrations ranged from 4 to 23 μg/mL against all tested fungal species. Racemic 8o was 195-fold more potent than the fungicide carbendazim against P. capsici in vitro. The isomer (1S, 6S)-8o exhibited an EC50 of 1.10 and 2.70 μg/mL against Monilia fructigena and P. capsici, respectively, which was 47 and 11 times lower than (1R, 6S)-8o and (1S, 6R)-8o. In addition, in vivo bioassay results showed that (1S, 6S)-8o had high antifungal activity against infection of M. fructigena and P. capsici to apricot and pepper fruits and pepper plants, which the efficacy was similar or better than carbendazim. The high potency and selectivity of 8o stereoisomers against the phytopathogens warrant an interest in elucidating the molecular target for fungicide development.

Fusarium pseudograminearum is one of the major fungal pathogens that cause Fusarium crown rot (FCR) worldwide and can lead to a substantially reduced grain yield and quality. Transcription factors play an important role in regulating growth and pathogenicity in plant pathogens. In this study, we identified a putative Zn(II)2Cys6 fungal-type domain-containing transcription factor and named it FpUme18. The expression of FpUME18 was induced during the infection of wheat by F. pseudograminearum. The ΔFpume18 deletion mutant showed defects in growth, conidial production, and conidial germination. In the responses to the cell wall, salt and oxidative stresses, the ΔFpume18 mutant inhibited the rate of mycelial growth at a higher rate compared with the wild type. The staining of conidia and mycelia with lipophilic dye FM4-64 revealed a delay in endocytosis when FpUME18 was deleted. FpUME18 also positively regulated the expression of phospholipid-related synthesis genes. The deletion of FpUME18 attenuated the pathogenicity of wheat coleoptiles. FpUME18 also participated in the production of the DON toxin by regulating the expression of TRI genes. Collectively, FpUme18 is required for vegetative growth, conidiation, stress response, endocytosis, and full virulence in F. pseudograminearum.

Bipolaris sorokiniana, one of the most devastating hemibiotrophic fungal pathogens, causes root rot, crown rot, leaf blotching, and black embryos of gramineous crops worldwide, posing a serious threat to global food security. However, the host-pathogen interaction mechanism between B. sorokiniana and wheat remains poorly understood. To facilitate related studies, we sequenced and assembled the genome of B. sorokiniana LK93. Nanopore long reads and next generation sequencing short reads were applied in the genome assembly, and the final 36.4-Mb genome assembly contains 16 contigs with the contig N50 of 2.3 Mb. Subsequently, we annotated 11,811 protein-coding genes. Of these, 10,620 were functional genes, 258 of which were identified as secretory proteins, including 211 predicted effectors. Additionally, the 111,581-bp mitogenome of LK93 was assembled and annotated. The LK93 genomes presented in this study will facilitate research in the B. sorokiniana–wheat pathosystem for better control of crop diseases. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

假禾谷镰孢(Fusarium pseudograminearum,Fp)是我国黄淮麦区小麦茎基腐病(Fusarium crown rot of wheat)的优势病原菌,目前该病害呈不断蔓延和为害加重的趋势.本研究从五月中旬小麦灌浆期至玉米收获期,在河南开封和焦作田间调查采集小麦茎基腐病样,对13份小麦茎秆和小麦残茬上带子囊壳的病样在室内进行单子囊孢子分离培养,获得纯化菌株327个,用形态学和分子生物学方法鉴定均为假禾谷镰孢,交配型MAT1-1和MAT1-2各有164株和163株.对国外报道的有性态诱导方法进行了改进和优化,用不同交配型菌株在Sachs合成固体培养基配以水稻茎节对峙培养,在黑光灯和冷白光灯交替光照及22℃条件下,温箱培养60 d左右,KF86×KF73组合在水稻茎节处产生大量子囊壳和成熟子囊孢子.本研究利用假禾谷镰孢子囊孢子后代进行室内有性杂交实验,通过改进诱导子囊壳产生的培养条件,获得高育性菌株,为今后假禾谷镰孢基因功能的有性生殖阶段研究提供材料和方法.

RNAi(RNA干扰)是指由诱导分子siRNA(小干扰RNA)、miRNA(微小RNA)或piRNA(P转座子诱导互作RNA)特异性降解或者抑制同源mRNA,引起靶标基因沉默的现象.RNAi技术具有操作简便、特异性和选择性强等显著特点,是目前农业生命科学领域最有可能应用于病虫害防控的新技术之一.本文通过综述近年来RNAi在农业病虫害防控领域应用的最新研究成果,并对RNAi技术在新靶标基因筛选、高效dsRNA载体开发、与传统农药相结合以及拓宽应用范围等诸多方面的发展前景进行了展望,同时还针对RNAi干扰效率、稳定性、成本控制、抗性发展及抗性治理等方面所面临的挑战进行了深入探讨,提出了合理建议.基于RNAi技术的病虫害防控策略将继续焕发新的活力,为综合防控提供新理念.

Tup1, a conserved transcriptional repressor, plays a critical role in the growth and development of fungi. Here, we identified a BsTup1 gene from the plant pathogenic fungus Bipolaris sorokiniana. The expression of BsTup1 showed a more than three-fold increase during the conidial stage compared with mycelium stage. Deletion of BsTup1 led to decrease hyphal growth and defect in conidia formation. A significant difference was detected in osmotic, oxidative, or cell wall stress responses between the WT and ΔBsTup1 strains. Pathogenicity assays showed that virulence of the ΔBsTup1 mutant was dramatically decreased on wheat and barely leaves. Moreover, it was observed that hyphal tips of the mutants could not form appressorium-like structures on the inner epidermis of onion and barley coleoptile. Yeast two-hybrid assays indicated that BsTup1 could interact with the BsSsn6. RNAseq revealed significant transcriptional changes in the ΔBsTup1 mutant with 2369 genes down-regulated and 2962 genes up-regulated. In these genes, we found that a subset of genes involved in fungal growth, sporulation, cell wall integrity, osmotic stress, oxidation stress, and pathogenicity, which were misregulated in the ΔBsTup1 mutant. These data revealed that BsTup1 has multiple functions in fungal growth, development, stress response and pathogenesis in B. sorokiniana.

假禾谷镰孢(Fusarium pseudograminearum,Fp)是引起小麦茎基腐病的优势病原菌,但关于该病原菌致病机理的研究报道很少.三角状五肽重复蛋白(Pentatricopeptide repeat protein,Ppr)为一类核编码的RNA结合蛋白,通过结合特定的RNA序列调控靶标基因RNA的成熟过程,参与线粒体基因组转录和翻译.Ppr蛋白在植物、动物(包括人)及酵母中有一些研究报道,但在丝状真菌特别是植物病原真菌中鲜见报道.为了明确假禾谷镰孢中PPR基因家族的特征,本研究通过全基因组Blastp分析,共鉴定出8个PPR候选基因序列FpPPR1～FpPPR8,主要分布在1号、3号、4号染色体上,基本不含有内含子.理化性质与功能预测显示,Ppr为亲水性蛋白,氨基酸长度510～1 353 aa,分子量59.09～152.23 kDa,等电点为5.23～9.69,其中FpPpr3和FpPpr7为稳定蛋白,其他6个蛋白为不稳定蛋白.亚细胞定位预测显示,Ppr蛋白主要位于线粒体.FpPpr1、FpPpr3、FpPpr5、FpPpr6和FpPpr7的3D结构预测形成明显的超螺旋结构.在假禾谷镰孢营养阶段和侵染过程的转录组数据中分析了 8个基因表达模式,通过qRT-PCR进行验证,FpPPR1、FpPPR3、FpPPR5在菌丝阶段高表达,FpPPR1、FpPPR5在侵染后期显著下调.本研究结果为进一步研究假禾谷镰孢中PPRs基因的生物学功能奠定基础.

Homeobox transcription factors have been implicated in filamentous growth, conidia formation and virulence in fungal pathogens. However, the presence of the homeobox gene family and their potential influence on pathogenesis in Fusarium pseudograminearum have not been investigated. F. pseudograminearum is an important plant pathogen that causes wheat and barley crown rot. In this study, we performed a genome-wide survey for F. pseudograminearum homeobox genes, and 11 FpHtfs were identified and characterized. Domain analyses revealed that all of these proteins contain a complete homeobox domain that contains three helices. Expression profiles of FpHtf genes at different pathogen stages showed that six FpHtf genes were induced during infection. Further, we generated and characterized FpHtf3 deletion mutants in F. pseudograminearum, showing it was essential for virulence. These results indicated that members of the homeobox gene family are likely involved in F. pseudograminearum pathogenicity. Our work also provides a useful foundation for further studies on the complexity and function of the homeobox gene family in F. pseudograminearum.

Fusarium crown rot (FCR) and Fusarium head blight (FHB) are caused by Fusarium pseudograminearum and are newly emerging diseases of wheat in China. In this study, we characterized FpPPR1, a gene that encodes a protein with 12 pentatricopeptide repeat (PPR) motifs. The radial growth rate of the ΔFpppr1 deletion mutant was significantly slower than the wild type strain WZ-8A on potato dextrose agar plates and exhibited significantly smaller colonies with sector mutations. The aerial mycelium of the mutant was almost absent in culture tubes. The ΔFpppr1 mutant was able to produce spores, but spores of abnormal size and altered conidium septum shape were produced with a significant reduction in sporulation compared to wild type. ΔFpppr1 failed to cause disease on wheat coleoptiles and barley leaves using mycelia plugs or spore suspensions. The mutant phenotypes were successfully restored to the wild type levels in complemented strains. FpPpr1-GFP signals in spores and mycelia predominantly overlapped with Mito-tracker signals, which substantiated the mitochondria targeting signal prediction of FpPpr1. RNAseq revealed significant transcriptional changes in the ΔFpppr1 mutant with 1,367 genes down-regulated and 1,333 genes up-regulated. NAD-binding proteins, thioredoxin, 2Fe-2S iron-sulfur cluster binding domain proteins, and cytochrome P450 genes were significantly down-regulated in ΔFpppr1, implying the dysfunction of mitochondria-mediated reductase redox stress in the mutant. The mating type idiomorphic alleles MAT1-1-1, MAT1-1-2, and MAT1-1-3 in F. pseudograminearum were also down-regulated after deletion of FpPPR1 and validated by real-time quantitative PCR. Additionally, 21 genes encoding putative heterokaryon incompatibility proteins were down-regulated. The yellow pigmentation of the mutant was correlated with reduced expression of PKS12 cluster genes. Taken together, our findings on FpPpr1 indicate that this PPR protein has multiple functions in fungal asexual development, regulation of heterokaryon formation, mating-type, and pathogenesis in F. pseudograminearum.

Wheat root rot, caused byBipolaris sorokiniana, has led to severe losses of wheat products worldwide. To evaluate the pathogenicity and genetic variation ofB.sorokiniana, diseased wheat samples were collected from 97 locations in the Huanghuai floodplain of China in 2014 and 2015 for analysis. A total of 673 isolates were obtained, 262 of which were identified asB.sorokiniana. Pathogenicity analysis of the isolates revealed variation in pathogenicity, which was not directly correlated with geographic region. Large variations in pathogenicity were also found within geographic groups. To determine the genetic structure of the populations, PCR was performed with universal rice primers (URP). Cluster analysis based on amplification patterns showed that the classified groups were correlated with geographical regions. Thus, analysis of the genetic diversity of the population indicated a negative correlation with geographic origin, that is, the greater the distance between sites, the lower the genetic variation similarity coefficient. Identification of wheat germplasm resistance showed that resistant cultivars accounted for a low percentage, while susceptible and highly susceptible cultivars were in the majority. Overall, these results are meaningful for developing strategies to prevent and control wheat root rot.

Phagocytosis and autophagy play critical roles in immune defense. The human fungal pathogen Cryptococcus neoformans (Cn) subverts host autophagy-initiation complex (AIC)-related proteins, to promote its phagocytosis and intracellular parasitism of host cells. The mechanisms by which the pathogen engages host AIC-related proteins remain obscure. Here, we show that the recruitment of host AIC proteins to forming phagosomes is dependent upon the activity of CD44, a host cell surface receptor that engages fungal hyaluronic acid (HA). This interaction elevates intracellular Ca2+ concentrations and activates CaMKKβ and its downstream target AMPKα, which results in activation of ULK1 and the recruitment of AIC components. Moreover, we demonstrate that HA-coated beads efficiently recruit AIC components to phagosomes and CD44 interacts with AIC components. Taken together, these findings show that fungal HA plays a critical role in directing the internalization and productive intracellular membrane trafficking of a fungal pathogen of global importance.

AbstractThe hemibiotrophic pathogen Bipolaris sorokiniana causes root rot, leaf blotching, and black embryos in wheat and barley worldwide, resulting in significant yield and quality reductions. However, the mechanism underlying the host–pathogen interactions between B. sorokiniana and wheat or barley remains unknown. The B. sorokiniana genome encodes a large number of uncharacterized putative effector proteins. In this study, we identified a putative secreted protein, CsSp1, with a classic N‐terminal signal peptide, that is induced during early infection. A split‐marker approach was used to knock out CsSP1 in the Lankao 9‐3 strain. Compared with the wild type, the deletion mutant ∆Cssp1 displayed less radial growth on potato dextrose agar plates and produced fewer spores, and complementary transformation completely restored the phenotype of the deletion mutant to that of the wild type. The pathogenicity of the deletion mutant in wheat was attenuated even though appressoria still penetrated the host. Additionally, the infectious hyphae in the deletion mutant became swollen and exhibited reduced growth in plant cells. The signal peptide of CsSp1 was functionally verified through a yeast YTK12 secretion system. Transient expression of CsSp1 in Nicotiana benthamiana inhibited lesion formation caused by Phytophthora capsici. Moreover, CsSp1 localized in the nucleus and cytoplasm of plant cells. In B. sorokiniana‐infected wheat leaves, the salicylic acid‐regulated genes TaPAL, TaPR1, and TaPR2 were down‐regulated in the ∆Cssp1 strain compared with the wild‐type strain under the same conditions. Therefore, CsSp1 is a virulence effector and is involved in triggering host immunity.