Aspartate Transaminase AST2 Involved in Sporulation and Necrotrophic Pathogenesis in the Hemibiotrophs Magnaporthe oryzae and Colletotrichum graminicola

作者：Penghui Zhang, Zhenyu Fang, Yanyue Song, Shaowei Wang, Lina Bao, Mingyu Liu, Yuejia Dang, Yi Wei, Shihong Zhang · 发表于：Frontiers in Microbiology · 年份：2022 · DOI：10.3389/fmicb.2022.864866 · 被引用次数：4 · 研究领域：Plant Pathogens and Fungal Diseases、Plant-Microbe Interactions and Immunity、Plant Pathogens and Resistance

Aspartate family includes five additional amino acids other than aspartate, among which most except aspartate have been reported for their action in pathogenesis by amino acid biosynthesis. However, how aspartate, the initial substrate of this family metabolic pathway, is involved in pathogenesis remains unknown. Here, we focused on aspartate transaminase (AST) that catalyzes transamination reaction between glutamate-aspartate in Magnaporthe oryzae . Three MoAST genes were bioinformatically analyzed, of which MoAST2 was uniquely upregulated when invasive hyphae switched to necrotrophic pathogenesis. MoAST2 deletion (Δ Moast2 ) caused a drastic reduction in conidiogenesis and appressorium formation. Particularly, Δ Moast2 was observed to be proliferated at the biotrophic phase but inhibited at the necrotrophic stage, and with invisible symptoms detected, suggesting a critical role in necrotrophic phase. Glutamate family restored the Δ Moast2 defects but aspartate family did not, inferring that transamination occurs from aspartate to glutamine. MoAST2 is cytosolic and possessed H 2 O 2 stress tolerance. In parallel, Colletotrichum graminicola AST2, CgAST2 was proven to be a player in necrotrophic anthracnose development. Therefore, conserved AST2 is qualified to be a drug target for disease control.