Wound-response plant growth restriction requires the synthesis of potent mediators called jasmonates (JAs). Four 13-lipoxygenases (13-LOXs) produce JA precursors in Arabidopsis (Arabidopsis thaliana) leaves, but the 13-LOXs responsible for growth restriction have not yet been identified. Through loss-of-function genetic analyses, we identified LOX3 and LOX4 as the principal 13-LOXs responsible for vegetative growth restriction after repetitive wounding. Additional genetic studies were carried out in the gain-of-function fatty acid oxygenation 2 (fou2) mutant that, even when undamaged, shows JA-dependent leaf growth restriction. The fou2 lox3 lox4 triple mutant suppressed the fou2 JA-dependent growth phenotype, confirming that LOX3 and LOX4 function in leaf growth restriction. The fou2 mutation affects the TWO PORE CHANNEL1 (TPC1) ion channel. Additional genetic approaches based on this gene were used to further investigate LOX3 function in relation to leaf growth. To activate LOX3-dependent JA production in unwounded plants, we employed hyperactive TPC1 variants. Expression of the TPC1Ca_i variant in phloem companion cells caused strongly reduced rosette growth in the absence of wounding. Summarizing, in parallel to their established roles in male reproductive development in Arabidopsis, LOX3 and LOX4 control leaf growth rates after wounding. The process of wound-response growth restriction can be recapitulated in unwounded plants when the LOX3 pathway is activated genetically using a hyperactive vacuolar cation channel.

伤口反应植物生长限制需要合成称为茉莉酸 (JAs) 的有效介质。四种 13-脂氧合酶 (13-LOX) 在拟南芥 ( Arabidopsis thaliana ) 叶子中产生 JA 前体，但负责生长限制的 13-LOX 尚未确定。通过功能丧失遗传分析，我们确定 LOX3 和 LOX4 是导致反复受伤后营养生长受限的主要 13-LOX。在功能获得性脂肪酸氧化 2 ( fou2 ) 突变体中进行了额外的遗传研究，该突变体即使未受损，也显示出 JA 依赖性叶片生长限制。 fou2 lox3 lox4三重突变体抑制了fou2 JA 依赖性生长表型，证实了 LOX3 和 LOX4 在叶片生长限制中的功能。 fou2突变影响双孔通道 1 (TPC1) 离子通道。基于该基因的其他遗传方法被用来进一步研究 LOX3 与叶子生长相关的功能。为了激活未受伤植物中 LOX3 依赖性 JA 的产生，我们采用了高度活跃的 TPC1 变体。在没有受伤的情况下，韧皮部伴随细胞中TPC1Ca变体的表达导致玫瑰花结的生长大大减少。总而言之，LOX3 和 LOX4 与它们在拟南芥雄性生殖发育中的既定作用同时控制着受伤后的叶片生长速率。当使用高度活跃的液泡阳离子通道从基因上激活 LOX3 途径时，可以在未受伤的植物中重现伤口反应生长限制的过程。