title: The thioredoxin MoTrx2 protein mediates reactive oxygen species (ROS) balance and controls pathogenicity as a target of the transcription factor MoAP1 in Magnaporthe oryzae.
abstract: We have shown previously that the transcription factor MoAP1 governs the oxidative response and is important for pathogenicity in the rice blast fungus Magnaporthe oryzae. To explore the underlying mechanism, we have identified thioredoxin MoTrx2 as a target of MoAP1 in M. oryzae. Thioredoxins are highly conserved 12-kDa oxidoreductase enzymes containing a dithiol-disulfide active site, and function as antioxidants against free radicals, such as reactive oxygen species (ROS). In yeast and fungi, thioredoxins are important for oxidative stress tolerance and growth. To study the functions of MoTrx2, we generated ΔMotrx2 mutants that exhibit various defects, including sulfite assimilation, asexual and sexual differentiation, infectious hyphal growth and pathogenicity. We found that ΔMotrx2 mutants possess a defect in the scavenging of ROS during host cell invasion and in the active suppression of the rice defence response. We also found that ΔMotrx2 mutants display higher intracellular ROS levels during conidial germination, but lower peroxidase and laccase activities, which contribute to the attenuation in virulence. Given that the function of MoTrx2 overlaps that of MoAP1 in the stress response and pathogenicity, our findings further indicate that MoTrx2 is a key thioredoxin protein whose function is subjected to transcriptional regulation by MoAP1 in M. oryzae.
authors: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China.
authors: Jingzhen
authors: J
authors: Wang
authors: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China.
authors: Ziyi
authors: Z
authors: Yin
authors: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China.
authors: Wei
authors: W
authors: Tang
authors: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China.
authors: Xingjia
authors: X
authors: Cai
authors: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China.
authors: Chuyun
authors: C
authors: Gao
authors: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China.
authors: Haifeng
authors: H
authors: Zhang
authors: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China.
authors: Xiaobo
authors: X
authors: Zheng
authors: Departments of Pediatrics and Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA.
authors: Ping
authors: P
authors: Wang
authors: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China.
authors: Zhengguang
authors: Z
authors: Zhang
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D020082:Magnaporthe / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013879:Thioredoxins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D000975:Antioxidants; D005656:Fungal Proteins; D017382:Reactive Oxygen Species; D014157:Transcription Factors; D013879:Thioredoxins
keywords: Magnaporthe oryzae; MoAP1; ROS balance; pathogenicity; sulfite assimilation; thioredoxin