Wang Bin, Wang Guang, Zhu Shijiang
Guangdong Province Key Laboratory of Postharvest Science of Fruits and Vegetables/Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in South China, Ministry of Agriculture, College of Horticulture, South China Agricultural University, Guangzhou, China.
College of Ying-Tong Agricultural Science and Engineering, Shaoguan University, Shaoguan, China.
Front Plant Sci. 2020 Jan 24;10:1723. doi: 10.3389/fpls.2019.01723. eCollection 2019.
Chilling stress can cause cellular DNA damage, affecting the faithful transmission of genetic information. Cold acclimation enhances chilling tolerance, but it is not clear that the process of cold adaption involves DNA damage responses, as cold acclimation does not form real chilling stress. Here we showed with cucumber fruit that pre-storage cold acclimation (PsCA) reduces chilling injury and upregulates DNA damage inducible protein1 (), suggesting that the chilling tolerance induced by cold acclimation involves transcription. Application of nitric oxide (NO), abscisic acid (ABA) or HO biosynthesis inhibitor before PsCA treatment downregulates and aggravates chilling injury, while HO generation inhibition plus exogenous NO or ABA application before PsCA treatment restores chilling tolerance, but does not restore expression, suggesting HO plays a crucial role in triggering cold adaption. overexpression lines show faster growth, stronger chilling tolerance, lower reactive oxygen species levels, enhanced catalase and superoxide dismutase activities and higher expression of nine other defense genes under chilling stress, suggesting strengthens defenses against chilling stress by enhancing antioxidant defense system. Taken together, positively regulates chilling tolerance induced by cold acclimation in cucumber. In addition, HO is involved in initiation of cold acclimation. While upregulation requires HO as a key signaling molecule, the upregulation of activates an antioxidant system to reduce biotoxic accumulation of HO and helps in DNA repair.
低温胁迫会导致细胞DNA损伤，影响遗传信息的准确传递。冷驯化可增强耐寒性，但由于冷驯化不会形成真正的低温胁迫，因此尚不清楚冷适应过程是否涉及DNA损伤反应。在这里，我们以黄瓜果实为材料表明，采前冷驯化（PsCA）可减轻冷害并上调DNA损伤诱导蛋白1（），这表明冷驯化诱导的耐寒性涉及转录。在PsCA处理前施用一氧化氮（NO）、脱落酸（ABA）或HO生物合成抑制剂会下调并加重冷害，而在PsCA处理前抑制HO生成并外加施用NO或ABA可恢复耐寒性，但不能恢复表达，这表明HO在触发冷适应中起关键作用。过表达系在低温胁迫下表现出更快的生长速度、更强的耐寒性、更低的活性氧水平、增强的过氧化氢酶和超氧化物歧化酶活性以及其他九个防御基因的更高表达，这表明通过增强抗氧化防御系统来加强对低温胁迫的防御。综上所述，在黄瓜中正向调节冷驯化诱导的耐寒性。此外，HO参与冷驯化的启动。虽然的上调需要HO作为关键信号分子，但的上调会激活抗氧化系统以减少HO的生物毒性积累并有助于DNA修复。
