The succinate dehydrogenase PsSDHB is involved in hyphal morphology, chemical stress response and pathogenicity of Phytophthora sojae

Soybean blight caused by Phytophthora sojae is a serious disease that may occur during any developmental stage of soybean. Many proteins participate in the process of pathogenetic, like the existence of a set of preset perfect procedures that command these proteins to perform their duties at the appropriate time and space, such as necrosis-inducing proteins. In this study, we investigated the function of the PsSDHB gene by constructing the PsSDHB-silencing vector (pTOR-PsSDHB) and transforming this vector into P. sojae protoplasts using polyethylene glycol (PEG)-mediated protoplast transformation. After the transformation, two silenced mutants (B1 and B2) with good inhibitory effects were obtained from the screening. Further experiments indicated that both of the silenced mutants showed slower mycelial growth. The growth of P. sojae in medium containing NaCl, H2O2, and Congo Red (sodium salt of 3,3′-bis) showed that silenced mutants had a lower resistance than the wild-type (WT) strain to stress conditions. Moreover, pathogenicity assays showed that both of the silenced mutants showed significantly reduced pathogenicity compared with the WT strain. Our experimental results may help improve our understanding of the energy supply chain of P. sojae and provide a theoretical basis for the prevention of disease.