The LSM1-7 Complex Differentially Regulates Arabidopsis Tolerance to Abiotic Stress Conditions by Promoting Selective mRNA Decapping

• Published in: The Plant cell Vol. 28; no. 2; pp. 505 - 520
• Main Authors: Perea-Resa, Carlos, Carrasco-López, Cristian, Catalá, Rafael, Turečková, Veronika, Novak, Ondrej, Zhang, Weiping, Sieburth, Leslie, Jiménez-Gómez, José Manuel, Salinas, Julio
• Format: Journal Article
• Language: English
• Published: United States American Society of Plant Biologists 01-02-2016; American Society of Plant Biologists (ASPB)
• Subjects: Abscisic Acid - metabolism; Adaptation, Physiological; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Chemical and Process Engineering; Cold Temperature; Endoribonucleases - genetics; Endoribonucleases - metabolism; Engineering Sciences; Food engineering; Gene Expression Regulation, Plant; Genes, Reporter; Life Sciences; Models, Biological; Plant Growth Regulators - metabolism; Plants, Genetically Modified; RNA, Messenger - genetics; RNA, Messenger - metabolism; Sodium Chloride - metabolism; Stress, Physiological; Vegetal Biology
• ISSN: 1040-4651; 1532-298X
• DOI: 10.1105/tpc.15.00867

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 stressresponsive 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.