title: WRKY transcription factor genes in wild rice Oryza nivara.
abstract: The WRKY transcription factor family is one of the largest gene families involved in plant development and stress response. Although many WRKY genes have been studied in cultivated rice (Oryza sativa), the WRKY genes in the wild rice species Oryza nivara, the direct progenitor of O. sativa, have not been studied. O. nivara shows abundant genetic diversity and elite drought and disease resistance features. Herein, a total of 97 O. nivara WRKY (OnWRKY) genes were identified. RNA-sequencing demonstrates that OnWRKY genes were generally expressed at higher levels in the roots of 30-day-old plants. Bioinformatic analyses suggest that most of OnWRKY genes could be induced by salicylic acid, abscisic acid, and drought. Abundant potential MAPK phosphorylation sites in OnWRKYs suggest that activities of most OnWRKYs can be regulated by phosphorylation. Phylogenetic analyses of OnWRKYs support a novel hypothesis that ancient group IIc OnWRKYs were the original ancestors of only some group IIc and group III WRKYs. The analyses also offer strong support that group IIc OnWRKYs containing the HVE sequence in their zinc finger motifs were derived from group Ia WRKYs. This study provides a solid foundation for the study of the evolution and functions of WRKY genes in O. nivara.
authors.affiliation: School of Life Sciences, Shandong University of Technology, Zibo 255000, Shandong Province, People's Republic of China School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA.
authors.forename: Hengjian
authors.initials: H
authors.lastname: Xu
authors.affiliation: School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA.
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Watanabe
authors.affiliation: School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA.
authors.forename: Liyuan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA jeffery.shen@unlv.edu.
authors.forename: Qingxi J
authors.initials: QJ
authors.lastname: Shen
mesh_terms: D055864:Droughts; D018506:Gene Expression Regulation, Plant; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D013312:Stress, Physiological; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016335:Zinc Fingers
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors
keywords: Genome; Oryza nivara; WRKY transcription factors; Wild rice