title: Carbamoyl Phosphate Synthetase Subunit MoCpa2 Affects Development and Pathogenicity by Modulating Arginine Biosynthesis inMagnaporthe oryzae.
abstract: Arginine is a semi-essential amino acid that affects physiological and biochemical functions. TheCPA2gene in yeast encodes a large subunit of arginine-specific carbamoyl phosphate synthetase (CPS) and is involved in arginine biosynthesis. Here, an ortholog of yeastCPA2was identified in the rice blast fungusMagnaporthe oryzae, and was namedMoCPA2. MoCpa2 is an 1180-amino acid protein which contains an ATP grasp domain and two CPSase domains. Targeted deletion ofMoCPA2supported its role inde novoarginine biosynthesis inM. oryzaeas mutant phenotypes were complemented by arginine but not ornithine. The ΔMocpa2mutant exhibited defects in asexual development and pathogenicity but not appressorium formation. Further examination revealed that the invasive hyphae of the ΔMocpa2mutant were restricted mainly to the primary infected cells. In addition, the ΔMocpa2mutant was unable to induce a plant defense response and had the ability to scavenge ROS during pathogen-plant interactions. Structure analysis revealed that the ATP grasp domain and each CPS domain were indispensable for the proper localization and full function of MoCpa2. In summary, our results indicate that MoCpa2 plays an important role in arginine biosynthesis, and affects growth, conidiogenesis, and pathogenicity. These results suggest that research into metabolism and processes that mediate amino acid synthesis are valuable for understandingM. oryzaepathogenesis.
authors.affiliation: Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University Nanjing, China.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University Nanjing, China.
authors.forename: Yongchao
authors.initials: Y
authors.lastname: Cai
authors.affiliation: Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University Nanjing, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University Nanjing, China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University Nanjing, China.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University Nanjing, China.
authors.forename: Zhengguang
authors.initials: Z
authors.lastname: Zhang
keywords: Magnaporthe oryzae; arginine biosynthesis; carbamoyl phosphate synthetase; conidiation; pathogenicity