The main polysaccharide of the gel present in the leaves of or Aloe vera Burm.F., (Aloe barbadensis Miller) a xerophytic crassulacean acid metabolism (CAM) plant, is an acetylated glucomannan named acemannan. This polysaccharide is responsible for the succulence of the plant, helping it to retain water. In this study we determined using polysaccharide analysis by carbohydrate gel electrophoresis (PACE) that the acemannan is a glucomannan without galactose side branches. We also investigated the expression of the gene responsible for acemannan backbone synthesis, encoding a glucomannan mannosyltransferase (GMMT, EC 2.4.1.32), since there are no previous reports on GMMT expression under water stress in general and specifically in Aloe vera. It was found by in silico analyses that the GMMT gene belongs to the cellulose synthase-like A type-9 (CSLA9) subfamily. Using RT-qPCR it was found that the expression of GMMT increased significantly in Aloe vera plants subjected to water stress. This expression correlates with an increase of endogenous ABA levels, suggesting that the gene expression could be regulated by ABA. To corroborate this hypothesis, exogenous ABA was applied to non-water-stressed plants, resulting in a significant increase of GMMT expression after 48 h of ABA treatment.

中文翻译：

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缺水和脱落酸处理增加了芦荟中葡甘露聚糖甘露糖基转移酶基因 (GMMT) 的表达。F。

Aloe vera Burm.F. (Aloe barbadensis Miller) 是一种旱生景天菜酸代谢 (CAM) 植物，其叶子中存在的凝胶的主要多糖是一种乙酰化葡甘露聚糖，称为乙酰甘露聚糖。这种多糖负责植物的多汁性，帮助它保持水分。在这项研究中，我们通过碳水化合物凝胶电泳 (PACE) 使用多糖分析确定乙酰甘露聚糖是一种没有半乳糖侧枝的葡甘露聚糖。我们还研究了负责乙酰甘露聚糖骨架合成的基因的表达，该基因编码葡甘露聚糖甘露糖基转移酶（GMMT，EC 2.4.1.32），因为之前没有关于一般水分胁迫下特别是芦荟中 GMMT 表达的报告。通过计算机分析发现GMMT基因属于纤维素合酶样A型9(CSLA9)亚家族。使用 RT-qPCR 发现，在遭受水分胁迫的芦荟植物中，GMMT 的表达显着增加。这种表达与内源性 ABA 水平的增加相关，表明基因表达可能受 ABA 调节。为了证实这一假设，将外源 ABA 应用于非水分胁迫的植物，导致 ABA 处理 48 小时后 GMMT 表达显着增加。