Identification of the WRKY gene family and the functional analysis of DoWRKY71 in yam (Dioscorea opposita Thunb.)

Abstract

Abstract Background:Dioscorea opposita Thunb. is one of the top 10 most important edible tuber and root plants worldwide, have been widely cultivated for nutritional and medicinal purposes. Yam is susceptible to various biological and abiotic stresses that will affect the yield and quality of the tubers. The WRKY gene family are widely distributed in plants growth and respond to abiotic stresses. However, current information on WRKY characteristics in yam is limited. Results: This study identifed 22 DoWRKYgenes from transcriptome of Dioscorea spp., which were divided into 6 clades based on phylogenetic analysis. Analysis of conserved motifs showed that there were 10 conserved motifs, with lengths ranging between 17 and 50 amino acids. Expression pattern analysis showed DoWRKYgenes are expressed in different growth and development stages and responsed to a variety of abiotic stress. DoWRKY71 was up-regulated in the late stage of tuber expansion, and it was differentially expressed in cold and ABA stress. Therefore, further study indicated that DoWRKY71 protein was localized in the nucleus. Overexpression of DoWRKY71 enhanced the cold tolerance of transgenic tobacco, promoted abscisic acid-mediated stomatal closure. Conclusions: This paper is the first systematic analysis the WRKY gene family in Dioscorea spp., and provide a new insight for further studying WRKY transcription factors in Dioscorea spp.. The functional study of DoWRKY71 laid a theoretical foundation for further exploring the regulatory function of DoWRKY71 gene in the growth and development related signaling pathway of yam.