AUTHOR=Ding Yijuan , Chen Yangui , Yan Baoqin , Liao Hongmei , Dong Mengquan , Meng Xinran , Wan Huafang , Qian Wei 

TITLE=Host-Induced Gene Silencing of a Multifunction Gene Sscnd1 Enhances Plant Resistance Against Sclerotinia sclerotiorum

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.693334

DOI=10.3389/fmicb.2021.693334

ISSN=1664-302X

ABSTRACT=<p><italic>Sclerotinia sclerotiorum</italic> is a devastating necrotrophic fungal pathogen and has a substantial economic impact on crop production worldwide. Magnaporthe appressoria-specific (MAS) proteins have been suggested to be involved in the appressorium formation in <italic>Magnaporthe oryzae</italic>. <italic>Sscnd1</italic>, an MAS homolog gene, is highly induced at the early infection stage of <italic>S. sclerotiorum</italic>. Knock-down the expression of <italic>Sscnd1</italic> gene severely reduced the virulence of <italic>S. sclerotiorum</italic> on intact rapeseed leaves, and their virulence was partially restored on wounded leaves. The <italic>Sscnd1</italic> gene-silenced strains exhibited a defect in compound appressorium formation and cell integrity. The instantaneous silencing of <italic>Sscnd1</italic> by tobacco rattle virus (TRV)-mediated host-induced gene silencing (HIGS) resulted in a significant reduction in disease development in tobacco. Three transgenic HIGS <italic>Arabidopsis</italic> lines displayed high levels of resistance to <italic>S. sclerotiorum</italic> and decreased <italic>Sscnd1</italic> expression. Production of specific <italic>Sscnd1</italic> siRNA in transgenic HIGS <italic>Arabidopsis</italic> lines was confirmed by stem-loop qRT-PCR. This study revealed that the compound appressorium<italic>-</italic>related gene <italic>Sscnd1</italic> is required for cell integrity and full virulence in <italic>S. sclerotiorum</italic> and that Sclerotinia stem rot can be controlled by expressing the silencing constructs of <italic>Sscnd1</italic> in host plants.</p>