WRKY proteins, comprising one of the largest transcription factor families in plant kingdom, play crucial roles in the plant development and stress responses. Despite several studies on WRKYs in wheat (Triticum aestivum L.) were investigated, functional annotation information about wheat WRKYs was limited. Here, 171 TaWRKY transcription factors (TFs) were identified from the whole wheat genome and compared with proteins from other 19 species representing nine major plant lineages. A phylogenetic analysis, coupled with gene structure analysis and motif determination, divided these TaWRKYs into seven subgroups (Group I, IIa-e, III). Chromosomal location showed that the most TaWRKY genes were enriched on four chromosomes, especially on chromosome 3B, and 85 (49.7%) genes were either tandem (5) or segmental duplication (80), which suggested that though tandem duplication has contributed to the expansion of TaWRKY family, segmental duplication probably played a more pivotal role. The cis-acting elements analysis revealed putative functions of WRKYs in wheat during development as well as under numerous biotic and abiotic stresses. Finally, the expression of TaWRKY genes in flag leaves, glumes and lemmas under water stress were analyzed, and we found different TaWRKY genes preferentially express in specific tissue during the grain-filling stage. Our results provide a more extensive knowledge on TaWRKYs, which helps to complete the information of WRKY gene family in wheat, and also contribute to screen more candidate genes for further investigation on function characterization of WRKYs under various stresses.
Evidences of organic acids exudation in aluminium stress responses of two Madeiran wheat (Triticum aestivum L.) landraces
