Extracellular ATP-induced defense transcriptome in Arabidopsis thaliana

Adenosine 5’-triphosphate (ATP) is not only an essential metabolite of cellular biochemistry, but also acts as a signal in the extracellular milieu. In Arabidopsis thaliana, extracellular ATP is monitored by the lectin receptor kinase P2K1, also known as DORN1. Recent studies have revealed that extracellular ATP acts as a damage associated molecular pattern in plants and its signaling through P2K1 is important for mounting an effective defense response against various pathogenic microorganisms. Biotrophic and necrotrophic pathogens attack plants using different strategies, for which plants respond accordingly with salicylate-based and jasmonate/ethylene-based defensive signaling, respectively. Defense mediated by P2K1 is effective against pathogens of both lifestyles, raising the question of the level of interplay between extracellular ATP signaling and that of jasmonate, ethylene, and salicylate. To address this idea, we analyzed ATP-induced transcriptomes in wild-type Arabidopsis seedlings and mutant seedlings defective in essential components in the signaling pathways of jasmonate, ethylene, and salicylate, classic defense hormones, as well as a mutant and a overexpression line of the P2K1 receptor.

腺苷三磷酸（ATP）不仅是细胞生物化学的必需代谢物，亦在细胞外基质中扮演信号分子的角色。在拟南芥（Arabidopsis thaliana）中，细胞外ATP的监测由凝集素受体激酶P2K1，亦称DORN1，负责。近期研究揭示了细胞外ATP在植物中作为一种损伤相关分子模式的作用，其通过P2K1的信号传导对于有效抵御多种病原微生物的防御反应至关重要。生物寄生物和坏死性病原体以不同的策略攻击植物，植物则分别以水杨酸盐和茉莉酸/乙烯为基础的防御信号进行应答。由P2K1介导的防御机制对两种生活方式的病原体均有效，从而引发了细胞外ATP信号与茉莉酸、乙烯和水杨酸盐之间的相互作用水平的问题。为探讨此观点，我们对野生型拟南芥幼苗及其在茉莉酸、乙烯和水杨酸盐信号通路中关键组分缺失的突变体幼苗，以及P2K1受体的突变体和过表达系，分析了由ATP诱导的转录组。