Search

Abstract Background The C2H2-type zinc finger proteins (C2H2-ZFPs) are one of major classes of transcription factors that play important roles in plant growth, development and stress responses. Limit information about the C 2 H 2 -ZF genes hinders the molecular breeding in bread wheat (Triticum aestivum). Results In this study, 457 C2H2-ZFP proteins (including 253 splice variants), which contain four types of conserved domain (named Q, M, Z, and D), could be further classified into ten subsets. They were identified to be distributed in 21 chromosomes in T. aestivum. Subset-specific motifs, like NPL-, SFP1-, DL- (EAR-like-motif), R-, PL-, L- and EK-, might make C2H2-ZFP diverse multifunction. Interestingly, NPL- and SFP1-box were firstly found to be located in C2H2-ZFP proteins. Synteny analyses showed that only 4 pairs of C2H2 family genes in T. aestivum, 65 genes in B. distachyon, 66 genes in A. tauschii, 68 genes in rice, 9 genes in Arabidopsis, were syntenic relationships respectively. It indicated that TaZFPs were closely related to genes in Poaceae. From the published transcriptome data, totally 198 of 204 TaC 2 H 2 -ZF genes have expression data. Among them, 25 TaC 2 H 2 -ZF genes were certificated to be significantly differentially expressed in 5 different organs and 15 different development stages by quantitative RT-PCR. The 18 TaC 2 H 2 -ZF genes were verified in response to heat, drought, and heat & drought stresses. According to expression pattern analysis, several TaZFPs, like Traes_5BL_D53A846BE.1, were not only highly expressed in L2DAAs, RTLS, RMS, but also endowed tolerance to drought and heat stresses, making them good candidates for molecular breeding. Conclusions This study systematically characterized the TaC2H2-ZFPs and their potential roles in T. aestivum. Our findings provide new insights into the C 2 H 2 -ZF genes in T. aestivum as well as a foundation for further studies on the roles of TaC 2 H 2 -ZF genes in T. aestivum molecular breeding.

Sugars and phytohormones co-regulate various common responses and development processes in plants. The previous studies reveal that the cross-talk between sugar and phytohormone signaling affects cellular elongation in root and hypocotyl. The elongation of hypocotyl is vital for the initial growth and development of seedlings during the transit from skotomorphogenesis to photomorphogenesis. Here, we found that LecRK-Ⅷ.2 gene regulated hypocotyl elongation involving in cross-talk between sugar and BR signaling. The results showed that sugar treatment could partly recover the defect of brassinosteroid (BR) response in bak1 mutant. LecRK-Ⅷ.2 gene regualted hypocotyl elongation by integrating the signaling cross-talk among BR, sucrose, glucose and fructose. Expression analysis of BR signaling related genes in response to exogenous sugar and BR suggested that LecRK-Ⅷ.2 may play essential roles in regulating hypocotyl growth. We also studied the roles of sugar transporter genes (STP1 and STP13) during hypocotyl elongation in the lecrk-Ⅷ.2 mutants in response to sugar/BR. The results showed that STP1 and STP13 expression in lecrk-Ⅷ.2-1 mutants were higher than that of Col-0 plant under sugar-free conditions. The expressions of STP1 in lecrk-Ⅷ.2 mutants were down-regulated compared to Col-0 under glucose treatments. The expressions of STP13 in lecrk-Ⅷ mutants were up-regulated compared to Col-0 under sucrose treatments. Altogether, our work indicated that LecRK-Ⅷ.2 regulated hypocotyl elongation by mediating the signaling cross-talk among sucose, glucose and BR.