AUTHOR=Li Yongtai , Song Shenglong , Chen Bin , Zhang Yong , Sun Tiange , Ma Xiaohu , Li Yanjun , Sun Jie , Zhang Xinyu 

TITLE=Deleting an xylosidase-encoding gene VdxyL3 increases growth and pathogenicity of Verticillium dahlia

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1428780

DOI=10.3389/fmicb.2024.1428780

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p><italic>Verticillium dahliae</italic> causes a devastating Verticillium wilt disease on hundreds of plant species worldwide, including cotton. Understanding the interaction mechanism between <italic>V. dahliae</italic> and its hosts is the prerequisite for developing effective strategies for disease prevention.</p></sec><sec><title>Methods</title><p>Here, based on the previous observation of an xylosidase-encoding gene (<italic>VdxyL3</italic>) in <italic>V. dahliae</italic> being obviously up-regulated after sensing root exudates from a cotton variety susceptible to this pathogen, we investigated the function of <italic>VdxyL3</italic> in the growth and pathogenesis of <italic>V. dahliae</italic> by generating its deletion-mutant strains (<italic>ΔVdxyL3</italic>).</p></sec><sec><title>Results</title><p>Deleting <italic>VdxyL3</italic> led to increased colony expansion rate, conidial production, mycelial growth, carbon and nitrogen utilization capacities, and enhanced stress tolerance and pathogenicity of <italic>V. dahliae</italic>. <italic>VdxyL3</italic> is a secretory protein; however, <italic>VdxyL3</italic> failed to induce cell death in <italic>N. benthamiana</italic> based on transient expression experiment. Transcriptomic analysis identified 1300 genes differentially expressed (DEGs) between wild-type (Vd952) and <italic>ΔVdxyL3</italic> during infection, including 348 DEGs encoding secretory proteins, among which contained 122 classical secreted proteins and 226 non-classical secreted proteins. It was notable that of the 122 classical secretory proteins, 50 were carbohydrate-active enzymes (CAZymes) and 58 were small cysteine rich proteins (SCRPs), which were required for the pathogenicity of <italic>V. dahliae</italic>.</p></sec><sec><title>Conclusion</title><p>The RNA-seq data thus potentially connected the genes encoding these proteins to the pathogenesis of <italic>V. dahliae</italic>. This study provides an experimental basis for further studies on the interaction between <italic>V. dahliae</italic> and cotton and the pathogenic mechanism of the fungus.</p></sec>