Drought stress and lateral branch are both important factors affecting crop yield. Cucumber is a widely planted vegetable crop that requires a large amount of water during its production and prefers varieties with few lateral branches. However, the mechanism regulating cucumber drought tolerance and lateral branch development remain largely unclear. The MADS-box transcription factor AGAMOUS-LIKE 16 (CsAGL16) was recently found to be a key positive regulator in cucumber shoot branching through stimulating ABA catabolism. In this study, we demonstrated that cucumber TCP interactor containing EAR motif protein 1 (CsTIE1) directly interacts with CsAGL16 at protein level and promotes lateral branch outgrowth through the CsAGL16-CsCYP707A4 mediated ABA pathway in cucumber. Additionally, mutation of CsAGL16 resulted in decreased drought tolerance, while overexpression of CsAGL16 significantly enhanced drought tolerance in cucumber. Similarly, the drought resistance of Cstie1 mutants was significantly reduced. However, overexpression of CsAGL16 can enhance the drought tolerance of Cstie1 mutants and promote their lateral branch outgrowth. These results indicated that the CsTIE1-CsAGL16 module was crucial for both lateral branch development and drought response, providing a strategy for cultivating drought tolerant cucumber varieties with appropriate branch outgrowth.

中文翻译：

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CsTIE1-CsAGL16模块调节黄瓜侧枝生长和耐旱性


干旱胁迫和侧枝都是影响作物产量的重要因素。黄瓜是一种广泛种植的蔬菜作物，在生产过程中需要大量的水，并且偏爱侧枝较少的品种。然而，调节黄瓜耐旱性和侧枝发育的机制仍不清楚。最近发现 MADS-box 转录因子 AGAMOUS-LIKE 16 (CsAGL16) 通过刺激 ABA 分解代谢而成为黄瓜芽分枝的关键正调节因子。在这项研究中，我们证明了含有 EAR 基序蛋白 1 (CsTIE1) 的黄瓜 TCP 相互作用子在蛋白质水平上直接与 CsAGL16 相互作用，并通过 CsAGL16-CsCYP707A4 介导的黄瓜 ABA 途径促进侧枝生长。此外，CsAGL16的突变导致黄瓜的耐旱性下降，而CsAGL16的过表达显着增强了黄瓜的耐旱性。同样，Cstie1突变体的抗旱性也显着降低。然而，CsAGL16的过表达可以增强Cstie1突变体的耐旱性并促进其侧枝生长。这些结果表明，CsTIE1-CsAGL16模块对于侧枝发育和干旱响应都至关重要，为培育具有适当枝条生长的耐旱黄瓜品种提供了策略。