title: The bZIP transcription factor PfZipA regulates secondary metabolism and oxidative stress response in the plant endophytic fungus Pestalotiopsis fici.
abstract: The bZIP transcription factors are conserved in all eukaryotes and play critical roles in organismal responses to environmental challenges. In filamentous fungi, several lines of evidence indicate that secondary metabolism (SM) is associated with oxidative stress mediated by bZIP proteins. Here we uncover a connection with a bZIP protein and oxidative stress induction of SM in the plant endophytic fungus Pestalotiopsis fici. A homology search of the P. fici genome with the bZIP protein RsmA, involved in SM and the oxidative stress response in Aspergillus nidulans, identified PfZipA. Deletion of PfzipA resulted in a strain that displayed resistant to the oxidative reagents tert-butylhydroperoxide (tBOOH), diamide, and menadione sodium bisulfite (MSB), but increased sensitivity to H2O2 as compared to wild type (WT). Secondary metabolite production presented a complex pattern dependent on PfzipA and oxidative reagents. Without oxidative treatment, the ΔPfzipA strain produced less isosulochrin and ficipyroneA than WT; addition of tBOOH further decreased production of iso-A82775C and pestaloficiol M in ΔPfzipA; diamide treatment resulted in equivalent production of isosulochrin and ficipyroneA in the two strains; MSB treatment further decreased production of RES1214-1 and iso-A82775C but increased pestaloficiol M production in the mutant; and H2O2 treatment resulted in enhanced production of isosulochrin, RES1214-1 and pestheic acid but decreased ficipyroneA and pestaloficiol M in ΔPfzipA compared to WT. Our results suggest that PfZipA regulation of SM is modified by oxidative stress pathways and provide insights into a possible role of PfZipA in mediating SM synthesis in the endophytic lifestyle of P. fici.
authors.affiliation: Department of Plant Pathology and the Ministry of Agriculture Key Laboratory for Plant Pathology, China Agricultural University, Beijing 100193, China; State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Xiuna
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Xingzhong
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Toxicology & Medical Countermeasures, Beijing Institute of Pharmacology & Toxicology, AMMS, Beijing 100850, China.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Che
authors.affiliation: Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, WI, United States.
authors.forename: Nancy P
authors.initials: NP
authors.lastname: Keller
authors.affiliation: Department of Plant Pathology and the Ministry of Agriculture Key Laboratory for Plant Pathology, China Agricultural University, Beijing 100193, China. Electronic address: ppguo@cau.edu.cn.
authors.forename: Liyun
authors.initials: L
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: yinwb@im.ac.cn.
authors.forename: Wen-Bing
authors.initials: WB
authors.lastname: Yin
mesh_terms: D001233:Aspergillus nidulans / Q000235:genetics; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D001565:Benzoates / Q000378:metabolism; D060026:Endophytes / Q000235:genetics / Q000502:physiology; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D006843:Hydrocarbons, Chlorinated / Q000378:metabolism; D016877:Oxidants / Q000633:toxicity; D018384:Oxidative Stress; D010647:Phenyl Ethers / Q000378:metabolism; D010944:Plants / Q000382:microbiology; D064210:Secondary Metabolism; D017385:Sequence Homology; D013312:Stress, Physiological; D013098:Xylariales / Q000235:genetics* / Q000502:physiology*
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D001565:Benzoates; D006843:Hydrocarbons, Chlorinated; D016877:Oxidants; D010647:Phenyl Ethers; C588350:pestheic acid; C562277:isosulochrin
keywords: Endophytic fungi; Oxidative stress; Pestalotiopsis fici; Secondary metabolism; bZIP transcription factor