An FYVE-Domain-Containing Protein, PsFP1, Is Involved in Vegetative Growth, Oxidative Stress Response and Virulence of <i>Phytophthora sojae</i>

• Main Authors: Jinhui Zhang, Xiaoran Du, Xin Zhou, Duo Jin, Jianqiang Miao, Xili Liu
• Format: Article
• Language: English
• Published: MDPI AG 2021-06-01
• Series: International Journal of Molecular Sciences
• Subjects: FYVE; PX; <i>Phytophthora sojae</i>; CRISPR/Cas9; gene knockout; pathogenicity
• Online Access: https://www.mdpi.com/1422-0067/22/12/6601
• ISSN: 1661-6596; 1422-0067

Proteins that contain the FYVE zinc-finger domain are recruited to PtdIns3P-containing membranes, participating in numerous biological processes such as membrane trafficking, cytoskeletal regulation, and receptor signaling. However, the genome-wide distribution, evolution, and biological functions of FYVE-containing proteins are rarely reported for oomycetes. By genome mining of <i>Phytophthora sojae</i>, two proteins (PsFP1 and PsFP2) with a combination of the FYVE domain and the PX domain (a major phosphoinositide binding module) were found. To clarify the functions of PsFP1 and PsFP2, the CRISPR/Cas9-mediated gene replacement system was used to knock out the two genes respectively. Only heterozygous deletion mutants of <i>PsFP1</i> were recovered, and the expression level of <i>PsFP1</i> in the heterozygous knockout transformants was significantly down-regulated. These <i>PsFP1</i> mutants showed a decrease in mycelial growth and pathogenicity and were more sensitive to hydrogen peroxide. These phenotypes were recovered to the level of wild-type by overexpression <i>PsFP1</i> gene in the PsFP1 heterozygous knockout transformant. In contrast, deletion of <i>PsFP2</i> had no significant effect on vegetative growth, asexual and sexual reproduction, pathogenicity, or oxidative stress sensitivity. PsFP1 was primarily localized in vesicle-like structures and both the FYVE and PX domains are important for its localization. Overall, our results indicate that <i>PsFP1</i> plays an important role in the vegetative growth and virulence of <i>P. sojae</i>.