Sequence tag analysis of gene expression during pathogenic growth and microsclerotia development in the vascular wilt pathogen Verticillium dahliae

2003 ◽  
Vol 38 (1) ◽  
pp. 54-62 ◽  
Author(s):  
M Neumann
2013 ◽  
Vol 26 (2) ◽  
pp. 249-256 ◽  
Author(s):  
Parthasarathy Santhanam ◽  
Bart P. H. J. Thomma

The ascomycete fungus Verticillium dahliae causes vascular wilt diseases in hundreds of dicotyledonous plant species. However, thus far, only few V. dahliae effectors have been identified, and regulators of pathogenicity remain unknown. In this study, we investigated the role of the V. dahliae homolog of Sge1, a transcriptional regulator that was previously implicated in pathogenicity and effector gene expression in Fusarium oxysporum. We show that V. dahliae Sge1 (VdSge1) is required for radial growth and production of asexual conidiospores, because VdSge1 deletion strains display reduced radial growth and reduced conidia production. Furthermore, we show that VdSge1 deletion strains have lost pathogenicity on tomato. Remarkably, VdSge1 is not required for induction of Ave1, the recently identified V. dahliae effector that activates resistance mediated by the Ve1 immune receptor in tomato. Further assessment of the role of VdSge1 in the induction of the nine most highly in-planta-induced genes that encode putative effectors revealed differential activity. Although the expression of one putative effector gene in addition to Ave1 was not affected by VdSge1 deletion, VdSge1 appeared to be required for the expression of six putative effector genes, whereas two of the putative effectors genes were found to be negatively regulated by VdSge1. In conclusion, our data suggest that VdSge1 differentially regulates V. dahliae effector gene expression.


2021 ◽  
Vol 22 (14) ◽  
pp. 7328
Author(s):  
Yang Chen ◽  
Mi Zhang ◽  
Lei Wang ◽  
Xiaohan Yu ◽  
Xianbi Li ◽  
...  

Verticillium wilt, caused by Verticillium dahliae, is a devastating disease for many important crops, including cotton. Kiwellins (KWLs), a group of cysteine-rich proteins synthesized in many plants, have been shown to be involved in response to various phytopathogens. To evaluate genes for their function in resistance to Verticillium wilt, we investigated KWL homologs in cotton. Thirty-five KWL genes (GhKWLs) were identified from the genome of upland cotton (Gossypium hirsutum). Among them, GhKWL1 was shown to be localized in nucleus and cytosol, and its gene expression is induced by the infection of V. dahliae. We revealed that GhKWL1 was a positive regulator of GhERF105. Silencing of GhKWL1 resulted in a decrease, whereas overexpression led to an increase in resistance of transgenic plants to Verticillium wilt. Interestingly, through binding to GhKWL1, the pathogenic effector protein VdISC1 produced by V. dahliae could impair the defense response mediated by GhKWL1. Therefore, our study suggests there is a GhKWL1-mediated defense response in cotton, which can be hijacked by V. dahliae through the interaction of VdISC1 with GhKWL1.


2013 ◽  
Vol 13 (3) ◽  
pp. 367-378 ◽  
Author(s):  
Helen H. Tai ◽  
Claudia Goyer ◽  
H. W. (Bud) Platt ◽  
David De Koeyer ◽  
Agnes Murphy ◽  
...  

BMC Genomics ◽  
2014 ◽  
Vol 15 (1) ◽  
pp. 324 ◽  
Author(s):  
Dianguang Xiong ◽  
Yonglin Wang ◽  
Jie Ma ◽  
Steven J Klosterman ◽  
Shuxiao Xiao ◽  
...  

1996 ◽  
Author(s):  
Randall C. Rowe ◽  
Jaacov Katan ◽  
Talma Katan ◽  
Leah Tsror

Verticillium dahliae is an economically important pathogen causing vascular wilt on over 160 plant species. In North America, potato early dying is a significant disease of potato, especially in the midwest and Pacific northwest states. This disease is caused by the fungus Verticillium dahliae and in some cases involves a synergistic interaction with root-lesion nematodes, primarily Pratylenchus penetrans. In Israel, Verticillium wilt occurs in many regions and inflicts serious losses in potato, cotton, and other crops. Objectives of this project were to establish a large collection of isolates of Verticillium dahliae from potato (USA) and several host plants (Israel) and to characterize and compare the isolates with regard to morphology, vegetative compatibility group (VCG), and pathogenic capabilities on several hosts. Isolations were made from 224 commercial lots of certified potato seed tubers from across N. America and 87 potato fields located in the Columbia Basin of Oregon and Washington. A large collection of isolates from central U.S. states already existed. In Israel, 47 field sites were sampled and isolates of Verticillium dahliae were recovered from 13 host plant species and from soil. Potato isolates from N. America were tested for vegetative compatibility and all found to be in VCG 4 with about 2/3 in VCG 4A and the rest in VCG 4B. VCG 4A isolates were significantly more aggressive on potato than VCG 4B isolates and were more likely to interact synergistically with P. penetrans. The Israeli isolates fell into three vegetative compatibility groups. Nearly all (> 90%) VCG2B and VCG 4B isolates were recovered from the northern and southern parts of Israel, respectively, with some overlap in central areas. Several pathotypes were defined in cotton, using cotton and eggplant together as differentials. All VCG 2B isolates from cotton caused severe disease in cotton, while VCG 2A and VCG 4B isolates from several crops were much less aggressive to cotton. When Israeli isolates of VCGs 2A, 2B and 4B were inoculated to potato and tomato, VCG 4B isolates caused much more severe disease on potato and VCG 2A isolates caused much more severe disease in tomato. Differential patterns of pathogenicity and aggressiveness of these VCGs on potato and tomato were consistent regardless of the host plant of origin. Isolates of the same VCG resembled one another more than isolates from different VCGs based on colony and microsclerotial morphology, temperature responses and, partially, in pathogenicity. Vegetative compatibility grouping of V. dahliae in Israel appears closely associated with specific pathogenicity and other phenotypic traits. The absence of VCG 4A in Israel is significant. VCG patterns among Verficillium populations are useful to predict relatedness and pathogenic potential in both countries.  


Author(s):  
Edgar A. Chavarro-Carrero ◽  
Jasper P. Vermeulen ◽  
David E. Torres ◽  
Toshiyuki Usami ◽  
Henk J. Schouten ◽  
...  

SUMMARYPlant pathogens secrete effector molecules during host invasion to promote host colonization. However, some of these effectors become recognized by host receptors, encoded by resistance genes, to mount defense response and establish immunity. Recently, a novel resistance was identified in tomato, mediated by the single dominant V2 locus, to control strains of the soil-borne vascular wilt fungus Verticillium dahliae that belong to race 2. We performed comparative genomics between race 2 strains and resistance-breaking race 3 strains to identify the avirulence effector that activates V2 resistance, termed Av2. We identified 277 kb of race 2-specific sequence comprising only two genes that encode predicted secreted proteins, both of which are expressed by V. dahliae during tomato colonization. Subsequent functional analysis based on genetic complementation into race 3 isolates confirmed that one of the two candidates encodes the avirulence effector Av2 that is recognized in V2 tomato plants. The identification of Av2 will not only be helpful to select tomato cultivars that are resistant to race 2 strains of V. dahliae, as the corresponding V2 resistance gene has not yet been mapped, but also to monitor adaptations in the V. dahliae population to deployment of V2-containing tomato cultivars in agriculture.


2021 ◽  
Author(s):  
Jasper P. Vermeulen ◽  
Katharina Hanika ◽  
Bart P.H.J. Thomma ◽  
Yuling Bai ◽  
Henk J Schouten

Abstract Verticillium dahliae is a soil-borne fungal pathogen that causes vascular wilt disease in numerous plant species. The only described qualitative resistances against V. dahliae are the Ve1 gene and the V2 locus in tomato. These resistances have been overcome by virulent strains. We tried to identify additional resistances. Out of the methods we tested, comparing the canopy area of V. dahliae-inoculated plants with mock-inoculated plants yielded the best discriminative power in resistance tests. Out of six wild tomato accessions that were previously reported to possess some resistance, Solanum pimpinellifolium G1.1596 and S. cheesmanii G1.1615 displayed the lowest stunting and the least colonization by V. dahliae. Recombinant inbred line (RIL) populations were developed of both populations. No QTLs were identified in the G1.1596 RIL population. In the G1.1615 population, four small-effect QTLs were associated with reduced stunting. Many studies in other hosts also failed to discover major resistance genes against V. dahliae. We hypothesize that the scarcity of major resistance genes against V. dahliae is caused by its endophytic behaviour in nature. The limited damage in nature would not lead to evolutionary pressure to evolve major resistances. However, in agriculture V. dahliae can behave more pathogenic, leading to serious damage.


2019 ◽  
Vol 32 (5) ◽  
pp. 622-634 ◽  
Author(s):  
Dimei Yu ◽  
Yulin Fang ◽  
Chen Tang ◽  
Steven J. Klosterman ◽  
Chengming Tian ◽  
...  

Verticillium dahliae is a soilborne fungus and the primary causal agent of vascular wilt diseases worldwide. The fungus produces melanized microsclerotia that are crucially important for the survival and spread of V. dahliae. There are no fungicides available that are both effective and environmentally friendly to suppress the fungus. Previously, Bacillus subtilis C232 was isolated from soil and was demonstrated to suppress microsclerotia formation in V. dahliae. In this study, liquid chromatography coupled with mass spectrometry revealed that the antifungal substance is actually a mixture of lipopeptides. Exposure of V. dahliae to these lipopeptides resulted in hyphal swelling, cell lysis, and downregulation of melanin-related genes. RNA sequencing analyses of the lipopeptide-suppressed transcriptome during microsclerotial development revealed that 5,974 genes (2,131 upregulated and 3,843 downregulated) were differentially expressed versus nonsuppressive conditions. Furthermore, gene ontology enrichment analyses revealed that genes involved in response to stress, cellular metabolic processes, and translation were significantly enriched. Additionally, the lipopeptides inhibited expression of genes associated with secondary metabolism, protein catabolism, and the high-osmolarity glycerol response signaling pathway. Together, these findings provide evidence for the mechanism by which B. subtilis lipopeptides suppress microsclerotia formation. The transcriptomic insight garnered here may facilitate the development of biological agents to combat Verticillium wilt.


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