Abstract Apple cuticular waxes have important functions in responses to mechanical injury, pathogen invasion, low temperatures, drought, salinity, and other stresses. In recent years, AP2/EREBP-type transcription factors have been shown to play an important role in cuticular wax biosynthesis. However, it remains unclear whether the apple AP2/EREBP-type transcription factor WRI4 has a similar function, and the molecular mechanisms of its regulation have not been characterized. In this study, we identified an AP2/EREBP-type transcription factor, MdWRI4, from apple and demonstrated that it was localized in the nucleus. The MdWRI4 gene was highly expressed in the pericarp, and heterologous expression of MdWRI4 in Arabidopsis caused increased cuticular wax biosynthesis in stems and leaves. MdWRI4 transgenic Arabidopsis exhibited reduced epidermal permeability, water loss, and chlorophyll leaching rate, as well as improved drought and salt resistance. Finally, we predicted the protein interaction network of the MdWRI4 protein in order to clarify potential pathways by which MdWRI4 regulates the response to environmental stress.

中文翻译：

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苹果 AP2/EREBP 型转录因子 MdWRI4 通过增加表皮蜡负荷增强植物对非生物胁迫的抗性

摘要 苹果表皮蜡在应对机械损伤、病原体入侵、低温、干旱、盐度和其他胁迫方面具有重要作用。近年来，AP2/EREBP 型转录因子已被证明在角质层蜡生物合成中发挥重要作用。然而，苹果AP2/EREBP型转录因子WRI4是否具有类似功能尚不清楚，其调控的分子机制尚未明确。在这项研究中，我们从苹果中鉴定了一种 AP2/EREBP 型转录因子 MdWRI4，并证明它位于细胞核中。MdWRI4 基因在果皮中高表达，而 MdWRI4 在拟南芥中的异源表达导致茎和叶中表皮蜡生物合成增加。MdWRI4 转基因拟南芥表现出降低的表皮渗透性、水分流失和叶绿素浸出率，以及提高的抗旱性和抗盐性。最后，我们预测了 MdWRI4 蛋白的蛋白质相互作用网络，以阐明 MdWRI4 调节对环境压力反应的潜在途径。