Xyloglucan endotransglucosylase/hydrolases (XTHs) are cell wall modifying enzymes that function in response to multiple abiotic stresses by promoting cell wall reinforcement in plants. However, it is elusive whether plays a role in cold stress tolerance in upland cotton ( L.). In this study, we found that ( (L.) Heynh) transgenic lines overexpressing exhibit clearly increased cold tolerance compared with wild type (WT). Moreover, cold stress results in markable enhancements in the activities of catalase (CAT) and peroxidase (POD), cell wall rigidity, and the expression of cold responsive genes, as well as a notable reduction in malondialdehyde (MDA) levels in the overexpression (OE) lines compared with those in WT plants. Consistently, silencing by virus-induced gene silencing (VIGS) method causes markedly decreases in cold stress tolerance in upland cotton. Additionally, by electrophoretic mobility shift assay (EMSA) and dual-luciferase assay, it was confirmed that GhMYB44 activate the expression of by binding to AACNG motif on the promoter and silencing the expression of can decrease the cold resistance of cotton. In summary, this study systematically confirmed the cold resistance function of and discovered the upstream regulating gene of , providing gene resources for cold resistance and enriching the knowledge on the mechanism of cold resistance.

中文翻译：

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木葡聚糖内转葡糖基酶水解酶 22 正向调节陆地棉 (Gossypium hirsutum L.) 的冷应激反应


木葡聚糖内转葡糖基酶/水解酶 (XTH) 是细胞壁修饰酶，通过促进植物细胞壁强化来响应多种非生物胁迫。然而，其是否在陆地棉（L.）的冷胁迫耐受性中发挥作用尚不清楚。在这项研究中，我们发现（（L.）Heynh）转基因品系过度表达，与野生型（WT）相比，耐冷性明显增强。此外，冷应激导致过氧化氢酶（CAT）和过氧化物酶（POD）的活性、细胞壁刚性和冷响应基因的表达显着增强，以及过度表达的丙二醛（MDA）水平显着降低。 OE) 品系与 WT 植物中的品系进行比较。一致地，通过病毒诱导基因沉默（VIGS）方法进行的沉默会导致陆地棉的冷胁迫耐受性显着降低。此外，通过电泳迁移率变动分析（EMSA）和双荧光素酶分析，证实GhMYB44通过与启动子上的AACNG基序结合激活 的表达，并沉默 的表达可以降低棉花的抗寒性。综上所述，本研究系统证实了 的抗寒功能，发现了 的上游调控基因，为抗寒提供了基因资源，丰富了抗寒机制的认识。