RESULTS: In this study, we identified a total of 135 XTH genes in wheat, which were clustered into three evolutionary groups. These TaXTHs were unevenly distributed on 21 chromosomes of wheat with a majority of TaXTHs located on homelogous groups 2, 3 and 7. Gene duplication analysis revealed that segmental and tandem duplication were the main reasons for the expansion of XTH family in wheat. Interaction network predictions indicated that TaXTHs could interact with multiple proteins, including three kinases, one methyltransferase and one gibberellin-regulated protein. The promoters of the TaXTH genes harbored various cis-acting elements related to stress and hormone responses. RNA-seq data analyses showed that some TaXTH genes were induced by salt and drought stresses. Furthermore, we verified that TaXTH17 was induced by abiotic stresses and phytohormone treatments, and demonstrated that TaXTH17 was localized in the secretory pathway and cell wall. Functional analyses conducted in heterologous expression systems and in wheat established that TaXTH17 plays a negative role in plant resistance to salt and drought.
CONCLUSIONS: We identified 135 XTH genes in wheat and conducted comprehensive analyses of their phylogenetic relationships, gene structures, conserved motifs, gene duplication events, chromosome locations, interaction networks, cis-acting elements and gene expression patterns. Furthermore, we provided solid evidence supporting the notion that TaXTH17 plays a negative role in plant resistance to salt and drought stresses. Collectively, our results provide valuable insights into understanding wheat XTHs, particularly their involvement in plant stress responses, and establish a foundation for further functional and mechanistic studies of TaXTHs.
结果:在这项研究中,我们在小麦中鉴定出135个XTH基因,它们被分成三个进化组。这些TaXTH在小麦的21条染色体上分布不均匀,大多数TaXTH位于同源组2、3和7上。基因重复分析表明,节段性和串联重复是小麦XTH家族扩展的主要原因。相互作用网络预测表明,TaXTHs可以与多种蛋白质相互作用,包括三种激酶,一个甲基转移酶和一个赤霉素调节蛋白。TaXTH基因的启动子含有与胁迫和激素反应相关的各种顺式作用元件。RNA-seq数据分析表明,盐和干旱胁迫诱导了一些TaXTH基因。此外,我们验证了TaXTH17是由非生物胁迫和植物激素处理诱导的,并证明TaXTH17定位于分泌途径和细胞壁中。在异源表达系统和小麦中进行的功能分析确定TaXTH17在植物对盐和干旱的抗性中起负面作用。
结论:我们在小麦中鉴定了135个XTH基因,并对它们的系统发育关系进行了综合分析,基因结构,保守的图案,基因复制事件,染色体位置,互动网络,顺式作用元件和基因表达模式。此外,我们提供了确凿的证据支持TaXTH17在植物对盐和干旱胁迫的抗性中起负面作用的观点。总的来说,我们的结果为理解小麦XTHs提供了有价值的见解,特别是它们参与植物应激反应,为进一步研究TaXTHs的功能和机理奠定了基础。