College of Agronomy, Hunan Agricultural University, Changsha 410128, China.
Hunan Provincial Engineering Research Center for Grass Crop Germplasm Innovation and Utilization, Changsha 410128, China.
Int J Mol Sci. 2022 Dec 17;23(24):16104. doi: 10.3390/ijms232416104.
Xyloglucan endotransglycosylase/hydrolase (XTH) genes play an important role in plant resistance to abiotic stress. However, systematic studies of the response of (ramie) genes () to cadmium (Cd) stress are lacking. We sought to identify the -family genes in ramie through bioinformatics analyses and to investigate their responses to Cd stress. We identified 19 members of the gene family from the ramie genome, referred to as , among which and were located on no chromosomes and the remaining genes were unevenly distributed across 11 chromosomes. The 19 members were divided into four groups, Groups I/II/IIIA/IIIB, according to their phylogenetic relationships, and these groups were supported by analyses of intron-exon structure and conserved motif composition. A highly conserved catalytic site (HDEIDFEFLG) was observed in all BnXTH proteins. Additionally, three gene pairs (-, -, and -) were obtained with a fragment and tandem-repeat event analysis of the ramie genome. An analysis of cisregulatory elements revealed that expression might be regulated by multiple hormones and abiotic and biotic stress responses. In particular, 17 cisregulatory elements related to abiotic and biotic stress responses and 11 cisregulatory elements related to hormone responses were identified. We also found that most genes responded to Cd stress, and , , , and were most likely to contribute to the Cd tolerance of ramie, as evidenced by the substantial increases in expression under Cd treatment. Heterologous expression of , , and significantly enhanced the Cd tolerance of transgenic yeast cells. These results suggest that the gene family is involved in Cd stress responses, laying a theoretical foundation for functional studies of genes and the innovative breeding of Cd-tolerant ramie.
木葡聚糖内转糖基酶/水解酶(XTH)基因在植物抗非生物胁迫中发挥着重要作用。然而,关于 (苎麻) 基因对镉(Cd)胁迫响应的系统研究还很缺乏。我们通过生物信息学分析,试图从苎麻基因组中鉴定 XTH 家族基因,并研究它们对 Cd 胁迫的响应。我们从苎麻基因组中鉴定出 19 个 基因家族成员,称为 ,其中 和 位于非染色体上,其余基因不均匀分布在 11 条染色体上。19 个成员根据系统发育关系分为四个组,即 I/II/IIIA/IIIB 组,这些组通过内含子-外显子结构和保守基序组成分析得到支持。所有 BnXTH 蛋白都观察到高度保守的催化位点(HDEIDFEFLG)。此外,通过对苎麻基因组的片段和串联重复事件分析,获得了三个基因对(-、-和-)。顺式调控元件分析表明, 表达可能受到多种激素和非生物及生物胁迫反应的调控。特别是,鉴定出与非生物和生物胁迫反应以及与激素反应相关的 17 个顺式调控元件和 11 个顺式调控元件。我们还发现,大多数 基因对 Cd 胁迫有响应,在 Cd 处理下表达显著上调的 、 、 和 极有可能对苎麻的 Cd 耐受性做出贡献。 、 和 的异源表达显著增强了转基因酵母细胞的 Cd 耐受性。这些结果表明,XTH 基因家族参与 Cd 胁迫响应,为 XTH 基因的功能研究和 Cd 耐受型苎麻的创新育种奠定了理论基础。