Lysine crotonylation of proteins is a recently identified post-translational modification (PTM) in plants. However, the function of lysine-crotonylated proteins in response to abiotic stress in plants has not been reported. In this study, we identified a temperature-induced lipocalin-1-like gene (DgTIL1) from chrysanthemum and showed that it was notably induced in response to cold stress. Overexpression of DgTIL1 enhanced cold tolerance in transgenic chrysanthemum. Ubiquitin membrane yeast two-hybrid (MYTH) system and bimolecular fluorescence complementation (BIFC) assays showed that DgTIL1 interacts with a nonspecific lipid transfer protein (DgnsLTP), which can promote peroxidase (POD) gene expression and POD activity to reduce the accumulation of reactive oxygen species (ROS) and improve resistance to cold stress in DgnsLTP transgenic chrysanthemum. In addition, we found that DgTIL1 was lysine crotonylated at K72 in response to low temperature in chrysanthemum. Moreover, lysine crotonylation of DgTIL1 prevented DgnsLTP protein degradation in tobacco and chrysanthemum. Inhibition of DgnsLTP degradation by lysine crotonylation of DgTIL1 further enhanced POD expression and POD activity, reduced the accumulation of ROS under cold stress in DgTIL1 transgenic chrysanthemum, thus promoting the cold resistance of chrysanthemum.

中文翻译：

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DgTIL1 在 K72 处的赖氨酸巴豆酰化通过增强菊花中 DgnsLTP 的稳定性来调节耐冷性


蛋白质的赖氨酸巴豆酰化是最近在植物中发现的一种翻译后修饰（PTM）。然而，赖氨酸巴豆酰化蛋白响应植物非生物胁迫的功能尚未见报道。在这项研究中，我们从菊花中鉴定出一种温度诱导的脂质运载蛋白-1 样基因 ( DgTIL1 )，并表明该基因是针对冷应激而显着诱导的。 DgTIL1的过表达增强了转基因菊花的耐冷性。泛素膜酵母双杂交（MYTH）系统和双分子荧光互补（BIFC）检测表明，DgTIL1与非特异性脂质转移蛋白（DgnsLTP）相互作用，可以促进过氧化物酶（ POD ）基因表达和POD活性，从而减少反应性的积累氧物种（ROS）并提高DgnsLTP转基因菊花的抗冷应激能力。此外，我们发现 DgTIL1 在 K72 处被赖氨酸巴豆酰化以响应菊花的低温。此外，DgTIL1 的赖氨酸巴豆酰化可防止烟草和菊花中的 DgnsLTP 蛋白降解。 DgTIL1赖氨酸巴豆酰化抑制DgnsLTP降解进一步增强DgTIL1转基因菊花POD表达和POD活性，减少冷胁迫下ROS的积累，从而促进菊花的抗寒性。