Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA.
Department of Genetics, University of Georgia, Athens, GA 30602, USA.
Plant Cell. 2024 Oct 3;36(10):4293-4308. doi: 10.1093/plcell/koae210.
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.
在拟南芥（Arabidopsis thaliana）中，水杨酸（SA）的过量产生会增加对疾病的抵抗力和非生物胁迫的耐受性，但会损害生长。这种生长-防御权衡关系阻碍了基于 SA 的疾病管理策略在农业中的应用。然而，由于许多 SA 超积累拟南芥突变体由于基础基因的多效性而存在发育缺陷，因此调查 SA 如何抑制植物生长一直具有挑战性。在这里，我们在拟南芥中异源表达了一个细菌 SA 合酶基因，观察到升高的 SA 水平以剂量依赖的方式降低了植物的生长，并降低了冷调节（COR）基因的表达。在低于环境温度下，生长抑制作用加剧。单独 COR 基因的 SA 反应性的切断足以克服在环境和低于环境温度下升高的 SA 引起的生长抑制，同时保持与疾病和非生物胁迫相关的益处。我们的结果表明，分离 SA 介导的生长和防御权衡关系以提高作物生产力具有潜力。
