Brassinosteroids Suppress Rice Defense Against Root-Knot Nematodes Through Antagonism With the Jasmonate Pathway
Brassinosteroids Suppress Rice Defense Against Root-Knot Nematodes Through Antagonism With the Jasmonate Pathway
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DOI：
10.1094/mpmi-05-12-0108-fi
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发表时间：
2013-01-01
影响因子：
3.5
通讯作者：
Gheysen, Godelieve
中科院分区：
文献类型：
--
作者：
Nahar, Kamrun;Kyndt, Tina;Gheysen, Godelieve
植物激素平衡的重要性越来越被认为是植物病原体相互作用的结果的核心。油菜素甾醇（BR）除了具有众所周知的发育作用外，最近还被发现参与植物先天免疫。在这项研究中，我们研究了BR在水稻感染根际线虫草间根结线虫（Meloidogyne graminicola）期间先天免疫中的作用，并研究了与茉莉酸（JA）途径的相互关系。外源表油菜素（BL）供应在低浓度诱导的易感性，而高浓度的BL加强对这种线虫的系统防御。在高外源BL供应的地上部，定量逆转录聚合酶链反应（qRT-PCR）证实了强烈的反馈抑制作用，导致减少BR生物合成的根。此外，我们证明BR的免疫抑制作用至少部分是由于与JA途径的负面串扰。BR生物合成或信号传导途径中的突变体积累了略高水平的直接JA-前体12-氧代-植物二烯酸，qRT-PCR数据表明，BR和JA途径在水稻根中相互拮抗。总的来说，这些结果表明，BR和JA途径之间的平衡是一个有效的调节水稻M。禾生菌相互作用
The importance of phytohormone balance is increasingly recognized as central to the outcome of plant pathogen interactions. Next to their well-known developmental role, brassinosteroids (BR) were recently found to be involved in plant innate immunity. In this study, we examined the role of BR in rice (Oryza sativa) innate immunity during infection with the root-knot nematode Meloidogyne graminicola, and we studied the inter-relationship with the jasmonate (JA) pathway. Exogenous epibrassinolide (BL) supply at low concentrations induced susceptibility in the roots whereas high concentrations of BL enforced systemic defense against this nematode. Upon high exogenous BL supply on the shoot, quantitative reverse-transcription polymerase chain reaction (qRT-PCR) confirmed a strong feedback inhibitory effect, leading to reduced BR biosynthesis in the root. Moreover, we demonstrate that the immune suppressive effect of BR is at least partly due to negative cross-talk with the JA pathway. Mutants in the BR biosynthesis or signaling pathway accumulate slightly higher levels of the immediate JA-precursor 12-oxo-phytodienoic acid, and qRT-PCR data showed that the BR and JA pathway are mutually antagonistic in rice roots. Collectively, these results suggest that the balance between the BR and JA pathway is an effective regulator of the outcome of the rice M. graminicola interaction.