As a common post-translational modification pathway, glycosylation plays important roles in maintaining proteins’ inherent conformations and normal functions. The contribution of core N-glycans formed in endoplasmic reticulum (ER) to plant tolerance against salt stress has been well-studied; however, the knowledge about the involvement of complex N-glycans synthesized in Golgi apparatus is limited. Here, we report that a pepper N-acetylglucosaminyl-transferase III gene CaGnT-III, which takes part in the maturation of complex N-glycans, can respond to heat, salt, and drought stress. Furthermore, silencing of CaGnT-III compromises pepper tolerance and its overexpression enhances Arabidopsis tolerance, to the above abiotic stresses. Under stressed conditions, compared to those in the control with empty vector, in CaGnT-III silenced pepper seedlings, the increase of MDA (malondialdehyde) accumulation and the decrease of total chlorophyll content were aggravated, while the enhancement of proline content, CAT (catalase) and APX (ascorbate peroxidase) activities, and stress-related genes expression were weakened. On the contrary, overexpression of CaGnT-III in Arabidopsis presented the opposite results. Therefore, we speculate that CaGnT-III gene positively regulates the formation of plants tolerance to abiotic stress by enhancing antioxidant ability.

作为常见的翻译后修饰途径，糖基化在维持蛋白质的固有构象和正常功能中起着重要作用。已经深入研究了内质网（ER）中形成的核心N-聚糖对植物抗盐胁迫的贡献。但是，关于在高尔基体中合成的复杂的N-聚糖的参与的知识是有限的。在这里，我们报道了一个辣椒N-乙酰氨基葡萄糖基转移酶III基因CaGnT-III，它参与复杂的N-聚糖的成熟，可以响应热量，盐分和干旱胁迫。此外，CaGnT-III沉默降低了辣椒的耐性，其过表达增强了拟南芥对上述非生物胁迫的耐受性。在胁迫条件下，与空载体对照相比，CaGnT-III沉默的辣椒幼苗中，MDA（丙二醛）积累的增加和总叶绿素含量的减少加剧，而脯氨酸含量CAT（过氧化氢酶）的增加）和APX（抗坏血酸过氧化物酶）活性，以及​​与压力相关的基因表达均被削弱。相反，在拟南芥中CaGnT-III的过表达表现出相反的结果。因此，我们推测CaGnT-III基因通过增强抗氧化能力来积极调节植物对非生物胁迫的耐受性。