MoARG1, MoARG5,6 and MoARG7 involved in arginine biosynthesis are essential for growth, conidiogenesis, sexual reproduction, and pathogenicity in Magnaporthe oryzae.
Arginine is one of the most versatile amino acids in eukaryote cells, which plays important roles in a multitude of processes such as protein synthesis, nitrogen metabolism, nitric oxide (NO) and urea biosynthesis. The de novo arginine biosynthesis pathway is conserved among fungal kingdom, but poorly understood in plant pathogenic fungi. Here, we characterized the functions of three synthetic enzyme-encoding genes MoARG1, MoARG5,6, and MoARG7, which involved the seventh step, second-third step and fifth step of arginine biosynthesis in Magnaporthe oryzae, respectively. Deletion of MoARG1 or MoARG5,6, resulted in arginine auxotrophic mutants, which had a strict requirement for arginine on minimal medium (MM). Both ΔMoarg1 and ΔMoarg5,6 severely reduced in aerial hyphal growth, pigmentation, conidiogenesis, sexual reproduction and pathogenicity. Interestingly, like Saccharomyces cerevisiae, deletion of MoARG7 caused a leaky arginine auxotrophy, and attenuated pathogenicity. Limited appressorium-mediated penetration and restricted invasive hyphae growth in host cells are responsible for the severely attenuated pathogenicity of the Arg(-) mutants. Additionally, we monitored the NO generation during conidial germination and appressorial formation in both Arg(-) mutants and wild type, and demonstrated that NO generation may not occur via arginine-dependent pathway in M. oryzae. In summary, MoARG1, MoARG5,6, and MoARG7 are required for growth, conidiogenesis, sexual reproduction, and pathogenicity in M. oryzae.
State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310058, China; Quzhou Municipal Plant Protection and Quarantine Station, Quzhou Municipal Bureau of Agriculture, Quzhou 324000, China.
Yong
Y
Zhang
State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310058, China.
Huanbin
H
Shi
State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310058, China.
Shuang
S
Liang
State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310058, China.
Guoao
G
Ning
Quzhou Municipal Plant Protection and Quarantine Station, Quzhou Municipal Bureau of Agriculture, Quzhou 324000, China.
Nanchang
N
Xu
College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Jianping
J
Lu
State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310058, China. Electronic address: xhliu@zju.edu.cn.
Xiaohong
X
Liu
State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310058, China; China Tobacco Gene Research Center, Zhengzhou Tobacco Institute of CNTC, Zhengzhou 450001, China. Electronic address: fuchenglin@zju.edu.cn.
Fucheng
F
Lin
D000445:Aldehyde Oxidoreductases / Q000235:genetics / Q000378:metabolism; D001119:Arginase / Q000235:genetics / Q000378:metabolism; D001120:Arginine / Q000096:biosynthesis* / Q000235:genetics; D053898:Biosynthetic Pathways; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D020082:Magnaporthe / Q000201:enzymology* / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology*; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009569:Nitric Oxide / Q000096:biosynthesis; D012275:Oryza / Q000382:microbiology*; D017851:Phosphotransferases (Carboxyl Group Acceptor) / Q000235:genetics / Q000378:metabolism; D010858:Pigmentation / Q000235:genetics; D010935:Plant Diseases / Q000382:microbiology*; D017384:Sequence Deletion; D014774:Virulence
D005656:Fungal Proteins; D009097:Multienzyme Complexes; D009569:Nitric Oxide; D001120:Arginine; D000445:Aldehyde Oxidoreductases; D017851:Phosphotransferases (Carboxyl Group Acceptor); D001119:Arginase
Arginine biosynthesis; Auxotrophy; Magnaporthe oryzae; Nitric oxide; Pathogenicity