title: Structural and Functional Characterization of the VQ Protein Family and VQ Protein Variants from Soybean.
abstract: Proteins containing the FxxxVQxhTG or VQ motif interact with WRKY transcription factors. Although VQ proteins have been reported in several plants, knowledge about their structures, functions and evolution is still very limited. Here, we report structural and functional analysis of the VQ protein family from soybean. Like Arabidopsis homologues, soybean VQ proteins bind only Group I and IIc WRKY proteins and a substantial number of their genes are responsive to stress-associated phytohormones. Overexpression of some soybean VQ genes in Arabidopsis had strong effects on plant growth, development, disease resistance and heat tolerance. Phylogenetic analysis, sequence alignment and site-directed mutagenesis revealed that the region immediately upstream of the FxxxVQxhTG motif also affects binding to WRKY proteins. Consistent with a larger WRKY-binding VQ domain, soybean VQ22 protein from cultivated soybean contains a 4-amino acid deletion in the region preceding its VQ motif that completely abolishes its binding to WRKY proteins. By contrast, the 4-amino acid deletion is absent in the VQ22 protein from wild soybean species (Glycine soja). Overexpression of wild soybean VQ22 in cultivated soybean inhibited growth, particularly after cold treatment. Thus, the mutation of soybean VQ22 is associated with advantageous phenotypes and may have been positively selected during evolution.
authors.affiliation: Department of Horticulture, Zijingang Campus, 866 Yuhangtang Road, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Horticulture, Zijingang Campus, 866 Yuhangtang Road, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Horticulture, Zijingang Campus, 866 Yuhangtang Road, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Xinjian
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Horticulture, Zijingang Campus, 866 Yuhangtang Road, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Yingjun
authors.initials: Y
authors.lastname: Chi
authors.affiliation: Department of Botany and Plant Pathology, 915 W. State Street, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Baofang
authors.initials: B
authors.lastname: Fan
authors.affiliation: Department of Horticulture, Zijingang Campus, 866 Yuhangtang Road, Zhejiang University, Hangzhou, 310058, China.|Department of Botany and Plant Pathology, 915 W. State Street, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Zhixiang
authors.initials: Z
authors.lastname: Chen
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites; D020171:Botrytis / Q000472:pathogenicity / Q000502:physiology; D060467:Disease Resistance / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D010937:Plant Growth Regulators / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013025:Glycine max / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D015534:Trans-Activators / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D010937:Plant Growth Regulators; D010940:Plant Proteins; D015534:Trans-Activators; D014157:Transcription Factors