Main content area

Molecular characterization of 26 cotton WRKY genes that are expressed differentially in tissues and are induced in seedlings under high salinity and osmotic stress

Zhou, Li, Wang, Na-Na, Kong, Lu, Gong, Si-Ying, Li, Yang, Li, Xue-Bao
Plant cell, tissue, and organ culture 2014 v.119 no.1 pp. 141-156
corolla, seedlings, phylogeny, genes, mannitol, plant response, roots, hypocotyls, Gossypium hirsutum, data collection, gene expression regulation, leaves, transcription factors, Arabidopsis, osmotic stress, anthers, sodium chloride, acid treatment, cotton, salinity, reverse transcriptase polymerase chain reaction, cotyledons, abscisic acid
WRKY proteins that contain highly conserved WRKYGQK sequence and zinc-finger-like motif belong to a large transcription factor family in plants. In this study, 26 genes encoding putative WRKY proteins were identified in cotton (Gossypium hirsutum). On the basis of their conserved WRKY domain sequences, all of the GhWRKY proteins can be assigned to the previously defined groups I–III. Among 26 members of cotton WRKY family, five with two WRKY domains belong to group I, sixteen contribute to group II, and five containing C₂HC zinc-finger pattern fall into group III. Phylogenetic analysis of GhWRKY proteins with Arabidopsis WRKYs revealed that they were indeed classified into three groups, and also their relative distance can be used as clues to confer their putative functions. Quantitative RT-PCR analysis showed that the isolated GhWRKY genes were expressed differentially in different tissues (such as leaves, roots, cotyledons, petals, anthers, or/and fibers), suggesting they may have an impact on cotton development. Under NaCl, mannitol and abscisic acid treatments, expressions of the GhWRKY genes are up-regulated in roots, cotyledons and/or hypocotyls of cotton seedlings, suggesting that the isolated GhWRKY genes may take part in plant response to abiotic stress during cotton development. Thus, our results may provide a valuable reference data set as the basis for further studying the roles of these WRKY genes in cotton.