In Arabidopsis (Arabidopsis thaliana), overproduction of salicylic acid (SA) increases disease resistance and abiotic stress tolerance but penalizes growth. This growth–defense trade-off has hindered the adoption of SA-based disease management strategies in agriculture. However, investigation of how SA inhibits plant growth has been challenging because many SA-hyperaccumulating Arabidopsis mutants have developmental defects due to the pleiotropic effects of the underlying genes. Here, we heterologously expressed a bacterial SA synthase gene in Arabidopsis and observed that elevated SA levels decreased plant growth and reduced the expression of cold-regulated (COR) genes in a dose-dependent manner. Growth suppression was exacerbated at below-ambient temperatures. Severing the SA-responsiveness of individual COR genes was sufficient to overcome the growth inhibition caused by elevated SA at ambient and below-ambient temperatures while preserving disease- and abiotic-stress-related benefits. Our results show the potential of decoupling SA-mediated growth and defense trade-offs for improving crop productivity.

中文翻译：

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改变冷调控基因表达使拟南芥中的水杨酸-生长权衡脱钩


在拟南芥 （Arabidopsis thaliana） 中，水杨酸 （SA） 的过量产生会增加抗病性和非生物胁迫耐受性，但会损害生长。这种生长-防御权衡阻碍了农业中基于 SA 的疾病管理策略的采用。然而，对 SA 如何抑制植物生长的研究一直具有挑战性，因为许多 SA 过度积累的拟南芥突变体由于潜在基因的多效性效应而存在发育缺陷。在这里，我们在拟南芥中异源表达细菌 SA 合酶基因，并观察到升高的 SA 水平降低了植物生长，并以剂量依赖性方式降低了冷调节 （COR） 基因的表达。在低于环境温度下，生长抑制加剧。切断单个 COR 基因的 SA 反应性足以克服在环境和低于环境温度下 SA 升高引起的生长抑制，同时保留与疾病和非生物胁迫相关的益处。我们的结果表明，解耦 SA 介导的生长和防御权衡有助于提高作物生产力的潜力。