title: Alternative Splicing of Rice WRKY62 and WRKY76 Transcription Factor Genes in Pathogen Defense.
abstract: The WRKY family of transcription factors (TFs) functions as transcriptional activators or repressors in various signaling pathways. In this study, we discovered that OsWRKY62 and OsWRKY76, two genes of the WRKY IIa subfamily, undergo constitutive and inducible alternative splicing. The full-length OsWRKY62.1 and OsWRKY76.1 proteins formed homocomplexes and heterocomplexes, and the heterocomplex dominates in the nuclei when analyzed in Nicotiana benthamiana leaves. Transgenic overexpression of OsWRKY62.1 and OsWRKY76.1 in rice (Oryza sativa) enhanced plant susceptibility to the blast fungus Magnaporthe oryzae and the leaf blight bacterium Xanthomonas oryzae pv oryzae, whereas RNA interference and loss-of-function knockout plants exhibited elevated resistance. The dsOW62/76 and knockout lines of OsWRKY62 and OsWRKY76 also showed greatly increased expression of defense-related genes and the accumulation of phytoalexins. The ratio of full-length versus truncated transcripts changed in dsOW62/76 plants as well as in response to pathogen infection. The short alternative OsWRKY62.2 and OsWRKY76.2 isoforms could interact with each other and with full-length proteins. OsWRKY62.2 showed a reduced repressor activity in planta, and two sequence determinants required for the repressor activity were identified in the amino terminus of OsWRKY62.1. The amino termini of OsWRKY62 and OsWRKY76 splice variants also showed reduced binding to the canonical W box motif. These results not only enhance our understanding of the DNA-binding property, the repressor sequence motifs, and the negative feedback regulation of the IIa subfamily of WRKYs but also provide evidence for alternative splicing of WRKY TFs during the plant defense response.
authors.affiliation: Key Laboratory of Plant Pathology, MOA, China Agricultural University, Beijing 100193, China (Jiq.L., X.C., X.L., X.Z., F.Y., Jia.L., Z.G.); andHoward Hughes Medical Institute, Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824 (S.Y.H.).
authors.forename: Jiqin
authors.identifier: 0000-0002-2697-1919
authors.initials: J
authors.lastname: Liu
authors.affiliation: Key Laboratory of Plant Pathology, MOA, China Agricultural University, Beijing 100193, China (Jiq.L., X.C., X.L., X.Z., F.Y., Jia.L., Z.G.); andHoward Hughes Medical Institute, Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824 (S.Y.H.).
authors.forename: Xujun
authors.initials: X
authors.lastname: Chen
authors.affiliation: Key Laboratory of Plant Pathology, MOA, China Agricultural University, Beijing 100193, China (Jiq.L., X.C., X.L., X.Z., F.Y., Jia.L., Z.G.); andHoward Hughes Medical Institute, Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824 (S.Y.H.).
authors.forename: Xiaoxing
authors.identifier: 0000-0003-4253-1662
authors.initials: X
authors.lastname: Liang
authors.affiliation: Key Laboratory of Plant Pathology, MOA, China Agricultural University, Beijing 100193, China (Jiq.L., X.C., X.L., X.Z., F.Y., Jia.L., Z.G.); andHoward Hughes Medical Institute, Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824 (S.Y.H.).
authors.forename: Xiangui
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Plant Pathology, MOA, China Agricultural University, Beijing 100193, China (Jiq.L., X.C., X.L., X.Z., F.Y., Jia.L., Z.G.); andHoward Hughes Medical Institute, Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824 (S.Y.H.).
authors.forename: Fang
authors.initials: F
authors.lastname: Yang
authors.affiliation: Key Laboratory of Plant Pathology, MOA, China Agricultural University, Beijing 100193, China (Jiq.L., X.C., X.L., X.Z., F.Y., Jia.L., Z.G.); andHoward Hughes Medical Institute, Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824 (S.Y.H.).
authors.forename: Jia
authors.identifier: 0000-0001-7648-9816
authors.initials: J
authors.lastname: Liu
authors.affiliation: Key Laboratory of Plant Pathology, MOA, China Agricultural University, Beijing 100193, China (Jiq.L., X.C., X.L., X.Z., F.Y., Jia.L., Z.G.); andHoward Hughes Medical Institute, Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824 (S.Y.H.).
authors.forename: Sheng Yang
authors.identifier: 0000-0003-1308-498X
authors.initials: SY
authors.lastname: He
authors.affiliation: Key Laboratory of Plant Pathology, MOA, China Agricultural University, Beijing 100193, China (Jiq.L., X.C., X.L., X.Z., F.Y., Jia.L., Z.G.); andHoward Hughes Medical Institute, Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824 (S.Y.H.) guozj@cau.edu.cn.
authors.forename: Zejian
authors.identifier: 0000-0001-7210-2370
authors.initials: Z
authors.lastname: Guo
mesh_terms: D017398:Alternative Splicing / Q000187:drug effects / Q000235:genetics*; D003517:Cyclopentanes / Q000494:pharmacology; D060467:Disease Resistance / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D055786:Gene Knockout Techniques; D017343:Genes, Plant; D020082:Magnaporthe / Q000187:drug effects / Q000502:physiology; D009154:Mutation / Q000235:genetics; D012275:Oryza / Q000235:genetics* / Q000276:immunology* / Q000382:microbiology; D054883:Oxylipins / Q000494:pharmacology; D000069452:Pathogen-Associated Molecular Pattern Molecules / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D057865:Plant Immunity / Q000187:drug effects / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D012097:Repressor Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014974:Xanthomonas / Q000187:drug effects / Q000502:physiology
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D000069452:Pathogen-Associated Molecular Pattern Molecules; D010940:Plant Proteins; D020033:Protein Isoforms; D012097:Repressor Proteins; D014157:Transcription Factors; C011006:jasmonic acid