Arabidopsis thaliana plants differentially modulate auxin biosynthesis and transport during defense responses to the necrotrophic pathogen Alternaria brassicicola
Arabidopsis thaliana plants differentially modulate auxin biosynthesis and transport during defense responses to the necrotrophic pathogen Alternaria brassicicola
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拟南芥植物在对坏死性病原体黑斑病菌的防御反应过程中差异调节生长素的生物合成和运输
DOI：
10.1111/j.1469-8137.2012.04208.x
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发表时间：
2012-09-01
期刊：
影响因子：
9.4
通讯作者：
Li, Chuanyou
中科院分区：
文献类型：
--
作者：
Qi, Linlin;Yan, Jiao;Li, Chuanyou
虽然生长素在活体营养型致病机理中的作用已被广泛研究，但对其在植物抗坏死营养型中的作用知之甚少。在生长素途径的不同方面有缺陷的拟南芥突变体通常比野生型植物更容易受到坏死型病原体芸苔链格孢的影响。我们证明了A.芸苔属侵染上调了受侵染植物的生长素生物合成并下调了受侵染植物的生长素运输能力，这些作用部分依赖于JA信号传导。我们还证明了A.芸苔属侵染共同导致宿主植物中生长素反应增强。IAA和MeJA的共同应用协同诱导防御标记基因PDF1.2（植物防御素1.2）和HEL（HEVEIN-LIKE）的表达，这表明JA依赖的防御信号的增强可能是植物生长素介导的防御机制的一部分，参与对坏死型病原体的抗性。我们的研究结果提供了分子证据支持的假设，JA和生长素相互作用，积极调节植物对坏死性病原体的抗性，JA激活生长素信号可能有助于植物对坏死性病原体的抗性。
Although the role of auxin in biotrophic pathogenesis has been extensively studied, relatively little is known about its role in plant resistance to necrotrophs. Arabidopsis thaliana mutants defective in different aspects of the auxin pathway are generally more susceptible than wild-type plants to the necrotrophic pathogen Alternaria brassicicola. We show that A. brassicicola infection up-regulates auxin biosynthesis and down-regulates the auxin transport capacities of infected plants, these effects being partially dependent on JA signaling. We also show that these effects of A. brassicicola infection together lead to an enhanced auxin response in host plants. Application of IAA and MeJA together synergistically induces the expression of defense marker genes PDF1.2 (PLANT DEFENSIN 1.2) and HEL (HEVEIN-LIKE), suggesting that enhancement of JA-dependent defense signaling may be part of the auxin-mediated defense mechanism involved in resistance to necrotrophic pathogens. Our results provide molecular evidence supporting the hypothesis that JA and auxin interact positively in regulating plant resistance to necrotrophic pathogens and that activation of auxin signaling by JA may contribute to plant resistance to necrotrophic pathogens.