Characterization, expression patterns and functional analysis of PcMPK12 gene in Phytophthora capsici

• Published in: European journal of plant pathology Vol. 164; no. 4; pp. 525 - 537
• Main Authors: Zhu, Tong-tong, Xiang, Sheng-han, Yang, Lei, Tang, Fang, Li, Wei, Liu, Ying-bao, Sun, Wen-xiu
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.12.2022; Springer Nature B.V
• Subjects: Agriculture; Biomedical and Life Sciences; Capsicum annuum; Cysts; Detoxification; Ecology; Economic importance; Functional analysis; Genomes; Inoculation; Kinases; Life Sciences; MAP kinase; Pathogenicity; Pathogens; Peppers; Phytophthora capsici; Plant Pathology; Plant Sciences; Protein kinase; RNA-mediated interference; Sequence analysis; Stresses; Pathogenicity; Encystment; MAPK; Oomycete
• ISSN: 0929-1873; 1573-8469
• DOI: 10.1007/s10658-022-02576-w

Phytophthora capsici is a pathogen of several economically important crops, including pepper ( Capsicum annuum ). The infection process of P. capsici involves several key developmental steps. This study was conducted to reveal the association between mitogen-activated protein kinases and P. capsici pathogenicity. The PcMPK12 gene was screened by retrieving the P. capsici genome database using the well-characterized Saccharomyces cerevisiae MAPKs as queries. The results of sequence analysis showed that the PcMPK12 gene shared high identity with Phytophthora oomycete MAPKs. It was demonstrated that PcMPK12 was transcribed in each detected stage with higher expression during the zoospore and cyst stages by using qRT-PCR. Pathogen inoculation shows that the PcMPK12 contributed to pathogenicity. Tthe specific segment of PcMPK12 was successfully silenced via RNAi, and transformants displayed deficiency in vegetative growth, oospore production, zoospore release, and tolerance to abiotic stresses. No transformants could infect pepper leaves. Furthermore, DAB stain proved that silenced lines exhibited weakened ability to scavenge ROS at the infected sites. Finally, we proposed that PcMPK12 is a highly conserved MAP kinase signal transducer that is not only required for cyst, zoospore release, and responses to various stresses, but also for ROS detoxification and pathogenicity of P. capsici.