title: Ectopic expression of a wheat WRKY transcription factor gene TaWRKY71-1 results in hyponastic leaves in Arabidopsis thaliana.
abstract: Leaf type is an important trait that closely associates with crop yield. WRKY transcription factors exert diverse regulatory effects in plants, but their roles in the determination of leaf type have not been reported so far. In this work, we isolated a WRKY transcription factor gene TaWRKY71-1 from a wheat introgression line SR3, which has larger leaves, superior growth capacity and higher yield than its parent common wheat JN177. TaWRKY71-1 specifically expressed in leaves, and produced more mRNA in SR3 than in JN177. TaWRKY71-1 localized in the nucleus and had no transcriptional activation activity. TaWRKY71-1 overexpression in Arabidopsis resulted in hyponastic rosette leaves, and the hyponastic strength was closely correlative with the transcription level of the transgene. The spongy mesophyll cells at abaxial side of leaves were drastically compacted by TaWRKY71-1 overexpression. In TaWRKY71-1 overexpression Arabidopsis, the expression of IAMT1 that encodes a methyltransferase converting free indole-3-acetic acid (IAA) to methyl-IAA ester (MeIAA) to alter auxin homeostatic level was induced, and the induction level was dependent on the abundance of TaWRKY71-1 transcripts. Besides, several TCP genes that had found to be restricted by IAMT1 had lower expression levels as well. Our results suggest that TaWRKY71-1 causes hyponastic leaves through altering auxin homeostatic level by promoting the conversion of IAA to MeIAA.
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Jinan, Shandong, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Qin
authors.forename: Hongjun
authors.initials: H
authors.lastname: Lv
authors.forename: Xinlei
authors.initials: X
authors.lastname: Zhu
authors.forename: Chen
authors.initials: C
authors.lastname: Meng
authors.forename: Taiyong
authors.initials: T
authors.lastname: Quan
authors.forename: Mengcheng
authors.initials: M
authors.lastname: Wang
authors.forename: Guangmin
authors.initials: G
authors.lastname: Xia
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014157:Transcription Factors / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D014908:Triticum / Q000145:classification / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D010940:Plant Proteins; C560908:TCP4 protein, Arabidopsis; D014157:Transcription Factors; C030737:indoleacetic acid; C507996:IAMT1 protein, Arabidopsis; D008780:Methyltransferases