Genome-wide analysis of the XTH gene family and functional analysis of DlXTH23.5/25 during early longan somatic embryogenesis

作者：Xiangwei Ma, Yan Chen, Mengyu Liu, Xiaodong Xue, Xueying Zhang, Luzhen Xu, Zhongxiong Lai, Yu‐Ling Lin · 发表于：Frontiers in Plant Science · 年份：2022 · DOI：10.3389/fpls.2022.1043464 · 被引用次数：10 · 研究领域：Polysaccharides and Plant Cell Walls、Plant tissue culture and regeneration、Plant Molecular Biology Research

Introduction: Xyloglucan endotransglucosylase (XET)/hydrolase (XTH) is a cell wall-modifying protein that affects cell expansion and loosening of the cell wall. Results: This study focused on the regulatory mechanism of DlXTH genes during early somatic embryogenesis (SE) and the heat stress response in longan. Mining of the available D. longan genome sequence yielded 25 putative XTH genes. Transcript profiles based on RNA sequencing (RNA-seq) data showed that most of the 17 detected DlXTH genes were highly expressed in the embryogenic callus (EC) (8) and globular embryo (GE) (8), and 13 of them responded significantly to heat stress. The assay for transposase-accessible chromatin sequencing (ATAC-seq) data analysis showed that in terms of chromatin accessibility, 22 of the 25 DlXTH genes were open during early SE, and most of the peak DlXTH genes with transcription differences during early SE were associated with high levels of H3K4me1. The most differentially expressed genes, DlXTH23.5 and DlXTH25, were selected for analysis. According to subcellular localization and quantitative real-time PCR (qRT-PCR) analysis, DlXTH23.5/25, which encode cell membrane-localized proteins, were expressed at the highest level in the GE and significantly responded to heat stress. Dual-luciferase assays and transient transformation showed that the transcription factors (TFs) DlWRKY31, DlERF1, and DlERF5 might bind to the DlXTH23.5/25 promoters to activate gene transcription. Transient overexpre...