Cloning and expression of the FtWRKY28 gene from Fagopyrum tataricum under low phosphorus and hormone treatment

Abstract

Abstract [Objective] WRKY transcription factors are involved in response to low phosphorus stress in plants. Based on transcriptome data of Tartary buckwheat (Fagopyrum tataricum ) under low phosphorus stress, the aim of this study is to isolate FtWRKY28 gene, to predict the structure of the gene and its deduced protein, to analyze the subcellular localization and transcription-activating activity, and to investigate gene expression in different organs under low phosphorus stress and hormone application, providing a basis for function identification of the gene. [Methods] Primer sequences were designed according to the Tartary buckwheat genome sequence. RT-PCR was used to amplify the CDS of FtWRKY28 from the RNAs generated from Tartary buckwheat roots at low phosphorus. Bioinformatical tools were employed to analyze the structure of the gene and protein and the phylogenetic relationship of the homologous proteins. qRT-PCR was used to investigate gene expression pattern. Transient expression system of the Arabidopsis protoplast was used to analyze the subcellular localization of the protein. Yeast-one-hybrid was employed to analyze the transcription-activating activity of the protein. [Results] The obtained CDS of Ft- WRKY28 was 876 bp in length, encoding a polypeptide of 291 amino acid residues consisting of one conserved WRKY domain with a zinc finger motif of C2H2, belonging to WRKY group Ⅱ. FtWRKY28 was predominantly localized in nucleus, which had transcription-activating activity. The transcript abundance of FtWRKY28 was relatively higher in roots, and was induced by low phosphorus and hormones such as indole acetic acid, gibberellin 3, and 6-benzylamino purine. [Conclusion] FtWRKY28 has basic structural and biochemical characteristics of a putative transcription factor, and involves in response to low phosphorus, which may crosstalk with auxin, gibberellin, and cytokinin signaling networks.

Keywords

• fagopyrum tataricum gaertn.
• low phosphorus stress
• wrky gene
• gene expression
• structure prediction
• biochemical characteristics