Shen Hongyan, Tan Qiuping, Zhao Wenzhe, Zhang Mengdan, Qin Cunhao, Liu Zhaobing, Wang Xinsheng, An Sendi, An Hailong, Wu Hongyu
College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an 271018, China.
National Center of Technology Innovation for Saline-Alkali Tolerant Rice in Sanya, Sanya 572000, China.
Int J Mol Sci. 2025 Aug 1;26(15):7457. doi: 10.3390/ijms26157457.
Xyloglucan endotransglucosylase/hydrolases (XTHs) are a class of cell wall-associated enzymes involved in the construction and remodeling of cellulose/xyloglucan crosslinks. However, knowledge of this gene family in the model monocot is limited. A total of 29 genes were identified from the whole genome, and these were further divided into three subgroups (Group I/II, Group III, and the Ancestral Group) through evolutionary analysis. Gene structure and protein motif analyses indicate that closely clustered genes are relatively conserved within each group. A highly conserved amino acid domain (DEIDFEFLG) responsible for catalytic activity was identified in all BdXTH proteins. We detected three pairs of segmentally duplicated genes and five groups of tandemly duplicated genes, which played vital roles in the expansion of the gene family. -elements related to hormones, growth, and abiotic stress responses were identified in the promoters of each gene, and when roots were treated with two abiotic stresses (salinity and drought) and four plant hormones (IAA, auxin; GA3, gibberellin; ABA, abscisic acid; and BR, brassinolide), the expression levels of many genes changed significantly. Transcriptional analyses of the genes in 38 tissue samples from the publicly available RNA-seq data indicated that most genes have distinct expression patterns in different tissues and at different growth stages. Overexpressing the gene in led to reduced root length in transgenic plants, which exhibited higher cellulose levels but lower hemicellulose levels compared to wild-type plants. Our results provide valuable information for further elucidation of the biological functions of genes in the model grass .
木葡聚糖内转糖基酶/水解酶（XTHs）是一类与细胞壁相关的酶，参与纤维素/木葡聚糖交联的构建和重塑。然而，在模式单子叶植物中对该基因家族的了解有限。从全基因组中总共鉴定出29个基因，并通过进化分析将它们进一步分为三个亚组（I/II组、III组和祖先组）。基因结构和蛋白质基序分析表明，紧密聚类的基因在每组中相对保守。在所有BdXTH蛋白中鉴定出一个负责催化活性的高度保守氨基酸结构域（DEIDFEFLG）。我们检测到三对片段重复基因和五组串联重复基因，它们在基因家族的扩展中发挥了重要作用。在每个基因的启动子中鉴定出与激素、生长和非生物胁迫反应相关的元件，当用两种非生物胁迫（盐度和干旱）和四种植物激素（IAA，生长素；GA3，赤霉素；ABA，脱落酸；和BR，油菜素内酯）处理根时，许多基因的表达水平发生了显著变化。对公开可用RNA-seq数据中38个组织样本中的基因进行转录分析表明，大多数基因在不同组织和不同生长阶段具有不同的表达模式。在中过表达该基因导致转基因植物根长缩短，与野生型植物相比，转基因植物表现出更高的纤维素水平但更低的半纤维素水平。我们的结果为进一步阐明模式禾本科植物中基因的生物学功能提供了有价值的信息。
