Functional Characterization of Two Cell Wall Integrity Pathway Components of the MAPK Cascade in Phomopsis longicolla

• Published in: Molecular plant-microbe interactions Vol. 36; no. 1; pp. 47 - 58
• Main Authors: Zhang, Chen, Zhang, Haifeng, Zheng, Xiaobo, Wang, Yuanchao, Ye, Wenwu
• Format: Journal Article
• Language: English
• Published: United States American Phytopathological Society 01.01.2023; The American Phytopathological Society
• Subjects: abiotic stress; Ascomycota - genetics; Blight; Cell Wall - metabolism; Cell walls; Crop production; Diaporthe; Diaporthe longicolla; fungal pathogen; gene targeting; Genes; Genetic transformation; genomics; growth and development; Growth rate; Hyphae; Integrity; Kinases; MAP kinase; MAPK; mitogen-activated protein kinase; mitogen-activated protein kinase kinase; Pathogenesis; Pathogenicity; Pathogens; Phomopsis; Phomopsis longicolla; Pigmentation; Plant diseases; polyethylene; Polyethylene glycol; protoplasts; Sensitivity enhancement; soybean disease; Soybeans; Sporulation; Stem blight; Stem canker; stem cankers; Stems; Virulence; virulent strains; fungal pathogen; genetic transformation; MAPK; Phomopsis longicolla; Diaporthe; soybean disease
• ISSN: 0894-0282; 1943-7706; 1943-7706
• DOI: 10.1094/MPMI-07-22-0156-R

The pathogenic fungus Phomopsis longicolla causes numerous plant diseases, such as Phomopsis seed decay, pod and stem blight, and stem canker, which seriously affect the yield and quality of soybean production worldwide. Because of a lack of technology for efficient manipulation of genes for functional genomics, understanding of P. longicolla pathogenesis is limited. Here, we developed an efficient polyethylene glycol–mediated protoplast transformation system in P. longicolla that we used to characterize the functions of two genes involved in the cell wall integrity (CWI) pathway of the mitogen-activated protein kinase (MAPK) cascade, including PlMkk1, which encodes MAPK kinase, and its downstream gene PlSlt2, which encodes MAPK. Both gene knockout mutants ΔPlMkk1 and ΔPlSlt2 displayed a reduced growth rate, fragile aerial hyphae, abnormal polarized growth and pigmentation, defects in sporulation, inadequate CWI, enhanced sensitivity to abiotic stress agents, and significant deficiencies in virulence, although there were some differences in degree. The results suggest that PlMkk1 and PlSlt2 are crucial for a series of growth and development processes as well as pathogenicity. The developed transformation system will be a useful tool for additional gene function research and will aid in the elucidation of the pathogenic mechanisms of P. longicolla. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .