Abscisic Acid Has a Key Role in Modulating Diverse Plant-Pathogen Interactions
Abscisic Acid Has a Key Role in Modulating Diverse Plant-Pathogen Interactions
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DOI：
10.1104/pp.109.137943
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发表时间：
2009-08-01
期刊：
影响因子：
7.4
通讯作者：
Lamb, Chris
中科院分区：
文献类型：
--
作者：
Fan, Jun;Hill, Lionel;Lamb, Chris
我们分离了一个激活标记的拟南芥（Arabidopsis thaliana）系，组成型疾病易感性2- 1d (cds2-1D)，当受到各种丁香假单胞菌菌株的攻击时，细菌生长增强。全身获得性耐药和全身发病机制相关的GENE1诱导也在cds2-1D中受损。编码脱落酸（ABA）生物合成酶NCED的6个基因之一的9 -顺式-环氧类胡萝卜素dioxygenoid ase5 （NCED5）附近的T-DNA插入导致转录物水平大量增加，ABA水平提高了2倍。NCED基因的过表达重现了增强的疾病易感性表型。诱导NCED2、NCED3和NCED5， ABA在相容性丁香假单胞菌感染后大量积累。ABA生物合成突变体aba3-1对强毒紫丁香假单胞菌的敏感性降低，ABA无论是通过外源施用还是内源积累应对轻度水分胁迫，都能在强毒紫丁香假单胞菌攻毒后促进细菌生长，表明ABA抑制了对紫丁香假单胞菌的抗性。同样，ABA的积累也削弱了拟南芥对生物营养性卵菌的抗性，而在cds2-1D植物中增强了对真菌十字花科菌的抗性，而在aba3-1植物中则减弱了对十字花科菌的抗性，这表明ABA促进了对这种坏死性菌的抗性。通过比较野生型、cds2-1D和aba3-1植株水杨酸和茉莉酸的积累，发现ABA促进了茉莉酸的积累，并与水杨酸表现出复杂的拮抗关系。我们的研究结果提供了遗传证据，表明非生物胁迫信号ABA在调节多种植物与病原体的相互作用中也起着深远的作用，至少部分是通过与茉莉酸和水杨酸的生物胁迫信号通路的串扰介导的。
We isolated an activation-tagged Arabidopsis (Arabidopsis thaliana) line, constitutive disease susceptibility2-1D (cds2-1D), that showed enhanced bacterial growth when challenged with various Pseudomonas syringae strains. Systemic acquired resistance and systemic PATHOGENESIS- RELATED GENE1 induction were also compromised in cds2-1D. The T-DNA insertion adjacent to NINE-CIS-EPOXYCAROTENOID DIOXYGENASE5 (NCED5), one of six genes encoding the abscisic acid (ABA) biosynthetic enzyme NCED, caused a massive increase in transcript level and enhanced ABA levels >2-fold. Overexpression of NCED genes recreated the enhanced disease susceptibility phenotype. NCED2, NCED3, and NCED5 were induced, and ABA accumulated strongly following compatible P. syringae infection. The ABA biosynthetic mutant aba3-1 showed reduced susceptibility to virulent P. syringae, and ABA, whether through exogenous application or endogenous accumulation in response to mild water stress, resulted in increased bacterial growth following challenge with virulent P. syringae, indicating that ABA suppresses resistance to P. syringae. Likewise ABA accumulation also compromised resistance to the biotrophic oomycete Hyaloperonospora arabidopsis, whereas resistance to the fungus Alternaria brassicicola was enhanced in cds2-1D plants and compromised in aba3-1 plants, indicating that ABA promotes resistance to this necrotroph. Comparison of the accumulation of salicylic acid and jasmonic acid in the wild type, cds2-1D, and aba3-1 plants challenged with P. syringae showed that ABA promotes jasmonic acid accumulation and exhibits a complex antagonistic relationship with salicylic acid. Our findings provide genetic evidence that the abiotic stress signal ABA also has profound roles in modulating diverse plant-pathogen interactions mediated at least in part by cross talk with the jasmonic acid and salicylic acid biotic stress signal pathways.