Transcriptome-wide identification of salt-responsive members of the WRKY gene family in Gossypium aridum

• Published in: PloS one 2015-05, Vol.10 (5), p.e0126148-e0126148
• Main Authors: Fan, Xinqi, Guo, Qi, Xu, Peng, Gong, YuanYong, Shu, Hongmei, Yang, Yang, Ni, Wanchao, Zhang, Xianggui, Shen, Xinlian
• Format: Article
• Language: English
• Subjects: Abiotic stress; Agriculture; Arabidopsis; Bioinformatics; Chromosome Mapping; Cotton; Cotton (Plant); Crop diseases; Crops; Deoxyribonucleic acid; Developmental stages; DNA; Drought; Environmental aspects; Gene expression; Gene Expression Regulation, Plant; Genes; Genes, Plant; Genetic aspects; Genetic improvement; Genomes; Genomics; Gossypium; Gossypium - genetics; Laboratories; Multigene Family; Orthology; Oryza; Phylogeny; Plant biology; Plant ecophysiology; Plants, Genetically Modified; Polymerase chain reaction; Proteins; Ribonucleic acid; Rice; RNA; Roots; Salinity; Salinity tolerance; Salt stress (Botany); Salt tolerance; Salts; Stress; Stress response; Stresses; Transcription factors; Transcriptome; Transgenic; Zinc; Zinc finger proteins
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0126148

WRKY transcription factors are plant-specific, zinc finger-type transcription factors. The WRKY superfamily is involved in abiotic stress responses in many crops including cotton, a major fiber crop that is widely cultivated and consumed throughout the world. Salinity is an important abiotic stress that results in considerable yield losses. In this study, we identified 109 WRKY genes (GarWRKYs) in a salt-tolerant wild cotton species Gossypium aridum from transcriptome sequencing data to elucidate the roles of these factors in cotton salt tolerance. According to their structural features, the predicted members were divided into three groups (Groups I-III), as previously described for Arabidopsis. Furthermore, 28 salt-responsive GarWRKY genes were identified from digital gene expression data and subjected to real-time quantitative RT-PCR analysis. The expression patterns of most GarWRKY genes revealed by this analysis are in good agreement with those revealed by RNA-Seq analysis. RT-PCR analysis revealed that 27 GarWRKY genes were expressed in roots and one was exclusively expressed in roots. Analysis of gene orthology and motif compositions indicated that WRKY members from Arabidopsis, rice and soybean generally shared the similar motifs within the same subgroup, suggesting they have the similar function. Overexpression-GarWRKY17 and -GarWRKY104 in Arabidopsis revealed that they could positively regulate salt tolerance of transgenic Arabidopsis during different development stages. The comprehensive data generated in this study provide a platform for elucidating the functions of WRKY transcription factors in salt tolerance of G. aridum. In addition, GarWRKYs related to salt tolerance identified in this study will be potential candidates for genetic improvement of cultivated cotton salt stress tolerance.