Wild tomatoes, which are the natural ancestors of the tomato genus, exhibit a wide range of genetic diversity and adaptability. They possess unique characteristics in terms of their ability to withstand cold stress, which sets them apart from cultivated tomatoes. However, the specific mechanisms underlying the differences in cold tolerance between wild and cultivated tomatoes remain unclear. Studies have shown that the expression of , a gene involved in the synthesis of spermidine (Spd), significantly increases in both wild tomato () LA1777 and cultivated tomato () AC after exposure to cold stress. Additionally, the content of Spd also increases significantly in these materials, particularly in wild tomato LA1777. Further analysis, involving the use of exogenous Spd and the polyamine synthesis inhibitor MGBG under cold stress conditions, has revealed that the application of exogenous Spd enhances the plant’s cold tolerance by increasing the endogenous Spd content, while the use of MGBG inhibits Spd accumulation and reduces the plant’s cold tolerance. By comparing the -acting regulatory elements in the promoter of both materials, we discovered that wild tomato LA1777 possesses an extra W-box compared to cultivated tomato AC. Through yeast one-hybrid, EMSA, and dual-luciferase assays, we demonstrated that ShWRKY55 can target the promoter of and regulate its upregulation expression. Our study suggests that the stronger cold resistance observed in wild tomato LA1777, as compared to cultivated tomato AC, can be attributed to the regulation of expression through ShWRKY55 after exposure to cold stress, which leads to higher Spd accumulation. However, this regulatory mechanism is absent in cultivated tomatoes. This research contributes to our understanding of the distinct adaptation mechanisms of wild and cultivated tomatoes to cold stress and provides novel insights and strategies for improving the cold tolerance of cultivated tomatoes.

中文翻译：

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ShWRKY55通过调控参与多胺合成的关键基因ShSAMDC2的表达增强野生番茄LA1777的抗寒性

野生番茄是番茄属的自然祖先，表现出广泛的遗传多样性和适应性。它们在承受冷应激的能力方面具有独特的特征，这使它们有别于栽培番茄。然而，野生番茄和栽培番茄耐冷性差异的具体机制仍不清楚。研究表明，在暴露于冷胁迫后，野生番茄（LA1777）和栽培番茄（AC）中参与亚精胺合成的基因（Spd）的表达显着增加。此外，这些材料中的 Spd 含量也显着增加，特别是在野生番茄 LA1777 中。进一步分析，在冷胁迫条件下使用外源Spd和多胺合成抑制剂MGBG，发现外源Spd的施用通过增加内源Spd含量来增强植物的耐冷性，而MGBG的使用抑制Spd积累并减少植物的抗寒能力。植物的耐寒性。通过比较两种材料启动子中的作用调控元件，我们发现野生番茄LA1777比栽培番茄AC拥有额外的W-box。通过酵母单杂交、EMSA和双荧光素酶测定，我们证明ShWRKY55可以靶向其启动子并调节其上调表达。我们的研究表明，与栽培番茄 AC 相比，在野生番茄 LA1777 中观察到的更强的耐寒性可归因于暴露于冷胁迫后通过 ShWRKY55 的表达调节，从而导致更高的 Spd 积累。然而，栽培番茄中不存在这种调节机制。这项研究有助于我们了解野生和栽培番茄对冷胁迫的不同适应机制，并为提高栽培番茄的耐冷性提供新的见解和策略。