A Brassica miRNA Regulates Plant Growth and Immunity through Distinct Modes of Action
A Brassica miRNA Regulates Plant Growth and Immunity through Distinct Modes of Action
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芸苔属 miRNA 通过不同的作用模式调节植物生长和免疫
DOI：
10.1016/j.molp.2019.11.010
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发表时间：
2020-02-03
期刊：
影响因子：
27.5
通讯作者：
Duan, Cheng-Guo
中科院分区：
文献类型：
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作者：
Cui, Chen;Wang, Jing-Jing;Duan, Cheng-Guo
在植物中，高抗病性常常导致产量降低。因此，培育产量和抗病性平衡的作物已成为一项重大挑战。最近，微小RNA（miRNA）介导的R基因周转已被证明是植物在缺乏病原体的情况下防止自身免疫的保护机制。然而，这些miRNAs是否在植物生长中发挥作用，以及miRNAs介导的R基因周转如何响应病原体感染很少被探索。在这里，我们发现芸苔属miRNA，miR 1885，靶向免疫受体基因和发育相关基因，通过不同的作用模式进行负调控。MiR 1885直接沉默TIR-NBS-LRR类R基因BraTNL 1，但通过靶向反式作用沉默（TAS）基因BraTIR 1进行反式作用小干扰RNA（tasiRNA）介导的沉默来抑制光合作用相关基因BraCP 24的表达。我们发现，在自然条件下，miR 1885保持在低水平以维持正常发育和基础免疫，但在开花过渡期间达到峰值以促进开花。有趣的是，在芜菁花叶病毒（TuMV）感染，miR 1885依赖的反式作用沉默的BraCP 24被增强，以加快花的转变，而miR 1885介导的R基因周转被克服TuMV诱导的BraTNL 1表达，反映了精确的调节植物和病原体之间的军备竞赛。总的来说，我们的研究结果表明，一个单一的芸苔属miRNA动态调节先天免疫和植物生长，并响应病毒感染，揭示芸苔属植物已经开发出一个复杂的机制，在调节生长，免疫和病原体感染之间的相互作用。
In plants, high disease resistance often results in a reduction of yield. Therefore, breeding crops with balanced yield and disease resistance has become a major challenge. Recently, microRNA (miRNA)-mediated R gene turnover has been shown to be a protective mechanism used by plants to prevent autoimmunity in the absence of pathogens. However, whether these miRNAs play a role in plant growth and how miRNA-mediated R gene turnover responds to pathogen infection have rarely been explored. Here, we found that a Brassica miRNA, miR1885, targets both an immune receptor gene and a development-related gene for negative regulation through distinct modes of action. MiR1885 directly silences the TIR-NBS-LRR class of R gene BraTNL1 but represses the expression of the photosynthesis-related gene BraCP24 by targeting the Trans-Acting Silencing (TAS) gene BraTIR1 for trans-acting small interfering RNAs (tasiRNAs)-mediated silencing. We found that, under natural conditions, miR1885 was kept at low levels to maintain normal development and basal immunity but peaked during the floral transition to promote flowering. Interestingly, upon Turnip mosaic virus (TuMV) infection, miR1885-dependent trans-acting silencing of BraCP24 was enhanced to speed up the floral transition, whereas miR1885-mediated R gene turnover was overcome by TuMV-induced BraTNL1 expression, reflecting precise regulation of the arms race between plants and pathogens. Collectively, our results demonstrate that a single Brassica miRNA dynamically regulates both innate immunity and plant growth and responds to viral infection, revealing that Brassica plants have developed a sophisticated mechanism in modulating the interplay between growth, immunity, and pathogen infection.