Perea-Resa Carlos, Carrasco-López Cristian, Catalá Rafael, Turečková Veronika, Novak Ondrej, Zhang Weiping, Sieburth Leslie, Jiménez-Gómez José Manuel, Salinas Julio
Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, 28040 Madrid, Spain.
Laboratory of Growth Regulators, Institute of Experimental Botany Academy of Sciences of the Czech Republic, v.v.i. & Palacký University, 78371 Olomouc, Czech Republic.
Plant Cell. 2016 Feb;28(2):505-20. doi: 10.1105/tpc.15.00867. Epub 2016 Jan 13.
In eukaryotes, the decapping machinery is highly conserved and plays an essential role in controlling mRNA stability, a key step in the regulation of gene expression. Yet, the role of mRNA decapping in shaping gene expression profiles in response to environmental cues and the operating molecular mechanisms are poorly understood. Here, we provide genetic and molecular evidence that a component of the decapping machinery, the LSM1-7 complex, plays a critical role in plant tolerance to abiotic stresses. Our results demonstrate that, depending on the stress, the complex from Arabidopsis thaliana interacts with different selected stress-inducible transcripts targeting them for decapping and subsequent degradation. This interaction ensures the correct turnover of the target transcripts and, consequently, the appropriate patterns of downstream stress-responsive gene expression that are required for plant adaptation. Remarkably, among the selected target transcripts of the LSM1-7 complex are those encoding NCED3 and NCED5, two key enzymes in abscisic acid (ABA) biosynthesis. We demonstrate that the complex modulates ABA levels in Arabidopsis exposed to cold and high salt by differentially controlling NCED3 and NCED5 mRNA turnover, which represents a new layer of regulation in ABA biosynthesis in response to abiotic stress. Our findings uncover an unanticipated functional plasticity of the mRNA decapping machinery to modulate the relationship between plants and their environment.
在真核生物中，去帽机制高度保守，在控制mRNA稳定性方面发挥着至关重要的作用，而mRNA稳定性是基因表达调控中的关键一步。然而，mRNA去帽在响应环境线索塑造基因表达谱方面的作用以及其运作的分子机制仍知之甚少。在此，我们提供了遗传和分子证据，表明去帽机制的一个组成部分，即LSM1-7复合体，在植物对非生物胁迫的耐受性中起关键作用。我们的结果表明，根据胁迫情况，来自拟南芥的该复合体与不同的选定胁迫诱导转录本相互作用，将它们靶向去帽并随后降解。这种相互作用确保了靶转录本的正确周转，从而确保了植物适应所需的下游胁迫响应基因表达的适当模式。值得注意的是，LSM1-7复合体选定的靶转录本中包括编码NCED3和NCED5的转录本，这两种是脱落酸（ABA）生物合成中的关键酶。我们证明，该复合体通过差异控制NCED3和NCED5 mRNA的周转来调节暴露于寒冷和高盐环境下的拟南芥中的ABA水平，这代表了响应非生物胁迫时ABA生物合成中的新调控层面。我们的发现揭示了mRNA去帽机制在调节植物与其环境之间关系方面意想不到的功能可塑性。
