Glycosyltransferases (GTs) constitute a diverse family of synthetic polysaccharides with important roles in plant growth and development. This study characterized the GT14 family gene BpGT14;6 of birch (Betula platyphylla Suk.). BpGT14;6 was highly expressed in the xylem and stem of birch plants. Subcellular localization analysis suggested that BpGT14;6 was located in the Golgi apparatus. RNA interference (RNAi) silencing of BpGT14;6 revealed lower lignin, hemicellulose, and pectin contents compared to wild type (WT) plants. Following treatment with abscisic acid (ABA), compared to WT plants, RNAi-BpGT14;6 plants were more sensitive to ABA, suffered more membrane lipid damage, and accumulated more reactive oxygen species. The inhibition of BpGT14;6 expression narrowed the birch xylem and thinned the cell wall, and increased the expression of multiple ABA pathway-related genes in birch under ABA treatment. Compared to WT plants, RNAi-BpGT14;6 plants showed increased tolerance to drought stress. Promoter analysis revealed that BpGT14;6 is involved in hormone regulation and adaptation to adversity. Using the 1156 bp BpGT14;6 promoter as bait, two potential transcription factors, BpWRKY1 and BpARF2, were identified through Y1H screening that may regulate its expression. EMSA confirmed that BpWRKY1 and BpARF2 can directly bind to the W-BOX and AuxRE cis-acting elements on the BpGT14;6 promoter, respectively. The collective results suggest that BpGT14;6 affects birch xylem and cell wall development by affecting lignin, hemicellulose, and pectin synthesis, and participates in birch adversity adaptation.

中文翻译：

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白桦 glucosyltransferase BpGT14;6 对于细胞壁发育和应激反应至关重要


糖基转移酶 （GTs） 构成了一个多样化的合成多糖家族，在植物生长和发育中起重要作用。本研究表征了 GT14 家族基因 BpGT14;6 棵桦树 （Betula platyphylla Suk.）。BPGT14;6 在桦树植物的木质部和茎中高表达。亚细胞定位分析表明，BpGT14;6 位于高尔基体中。BpGT14 的 RNA 干扰 （RNAi） 沉默;6 显示与野生型 （WT） 植物相比，木质素、半纤维素和果胶含量较低。用脱落酸 （ABA） 处理后，与 WT 植物相比，RNAi-BpGT14;6 株植物对 ABA 更敏感，膜脂质损伤更多，积累活性氧更多。抑制 BpGT14;6 表达使白桦木质部变窄，使细胞壁变薄，并在 ABA 处理下增加了白桦中多个 ABA 通路相关基因的表达。与 WT 植物相比，RNAi-BpGT14;6 株植物对干旱胁迫的耐受性增强。启动子分析显示 BpGT14;6 参与荷尔蒙调节和适应逆境。使用 1156 bp BpGT14;6 启动子作为诱饵，通过 Y1H 筛选鉴定了两个潜在的转录因子 BpWRKY1 和 BpARF2，可能调节其表达。EMSA 证实 BpWRKY1 和 BpARF2 可以直接与 BpGT14 上的 W-BOX 和 AuxRE 顺式作用元件结合;6 个启动子。集体结果表明，BpGT14;6 通过影响木质素、半纤维素和果胶合成来影响桦木质部和细胞壁发育，并参与桦树逆境适应。