AUTHOR=Wang Shaowei , Li Guihua , Wei Yi , Wang Gang , Dang Yuejia , Zhang Penghui , Zhang Shi-Hong 

TITLE=Involvement of the Mitochondrial Protein Tyrosine Phosphatase PTPM1 in the Promotion of Conidiation, Development, and Pathogenicity in Colletotrichum graminicola

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.605738

DOI=10.3389/fmicb.2020.605738

ISSN=1664-302X

ABSTRACT=<p>The phosphorylation status of proteins, which is determined by protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs), governs many cellular actions. In fungal pathogens, phosphorylation-mediated signal transduction has been considered to be one of the most important mechanisms in pathogenicity. <italic>Colletotrichum graminicola</italic> is an economically important corn pathogen. However, whether phosphorylation is involved in its pathogenicity is unknown. A mitochondrial protein tyrosine phosphatase gene, designated <italic>CgPTPM1</italic>, was deduced in <italic>C. graminicola</italic> through the use of bioinformatics and confirmed by enzyme activity assays and observation of its subcellular localization. We then created a <italic>CgPTPM1</italic> deletion mutant (Δ<italic>CgPTPM1</italic>) to analyze its biological function. The results indicated that the loss of <italic>CgPTPM1</italic> dramatically affected the formation of conidia and the development and differentiation into appressoria. However, the colony growth and conidial morphology of the Δ<italic>CgPTPM1</italic> strains were unaffected. Importantly, the Δ<italic>CgPTPM1</italic> mutant strains exhibited an obvious reduction of virulence, and the delayed infected hyphae failed to expand in the host cells. In comparison with the wild-type, Δ<italic>CgPTPM1</italic> accumulated a larger amount of H<sub>2</sub>O<sub>2</sub> and was sensitive to exogenous H<sub>2</sub>O<sub>2</sub>. Interestingly, the host cells infected by the mutant also exhibited an increased accumulation of H<sub>2</sub>O<sub>2</sub> around the infection sites. Since the expression of the <italic>CgHYR1</italic>, <italic>CgGST1</italic>, <italic>CgGLR1</italic>, <italic>CgGSH1</italic> and <italic>CgPAP1</italic> genes was upregulated with the H<sub>2</sub>O<sub>2</sub> treatment, our results suggest that the mitochondrial protein tyrosine phosphatase PTPM1 plays an essential role in promoting the pathogenicity of <italic>C. graminicola</italic> by regulating the excessive <italic>in vivo</italic> and <italic>in vitro</italic> production of H<sub>2</sub>O<sub>2</sub>.</p>