A Genome-Wide Identification and Expression Analysis of the Xyloglucan Endotransglucosylase/Hydrolase Gene Family in Melon (<i>Cucumis melo</i> L.)

Abstract

The xyloglucan endotransglucosylase/hydrolase (XTH) family is an important multigene family in plants that plays a key role in cell wall reconstruction and stress tolerance. However, the specific traits of XTH genes and their expression patterns under different stresses have not been systematically studied in melon. In this study, based on the genomic data of Cucumis melon, 29 XTH genes were identified; most of these genes contain two conserved domains (Glyco_hydro_16 and XET_C domains). Based on neighbor-joining phylogenetic analysis, the CmXTHs were divided into four subfamilies, I/II, IIIA, and IIIB, which are distributed across nine chromosomes of melon. Collinearity analysis showed that the melon XTH genes have an evolutionary history consistent with three species: Arabidopsis, tomato, and cucumber. The promoter regions of the CmXTH genes contain numerous cis-acting elements, which are associated with plant growth, hormonal response, and stress responses. RNA-Seq analysis indicated that CmXTH genes exhibit different expression patterns under drought and salt stress treatments, suggesting that this gene family plays an important role under abiotic stress. This study provides a theoretical basis for further studies on the molecular function of XTH genes in melon.

Keywords

• <i>Cucumis melo</i>
• xyloglucan endotransglucosylases/hydrolase (<i>XTH</i>) gene family
• gene-wide identification