Pre-mRNA splicing repression triggers abiotic stress signaling in plants.
Alternative splicing (AS) of precursor RNAs enhances transcriptome plasticity and proteome diversity in response to diverse growth and stress cues. Recent work has shown that AS is pervasive across plant species, with more than 60% of intron-containing genes producing different isoforms. Mammalian cell-based assays have discovered various inhibitors of AS. Here, we show that the macrolide pladienolide B (PB) inhibits constitutive splicing and AS in plants. Also, our RNA sequencing (RNA-seq) data revealed that PB mimics abiotic stress signals including salt, drought and abscisic acid (ABA). PB activates the abiotic stress- and ABA-responsive reporters RD29A::LUC and MAPKKK18::uidA in Arabidopsis thaliana and mimics the effects of ABA on stomatal aperture. Genome-wide analysis of AS by RNA-seq revealed that PB perturbs the splicing machinery and leads to a striking increase in intron retention and a reduction in other forms of AS. Interestingly, PB treatment activates the ABA signaling pathway by inhibiting the splicing of clade A PP2C phosphatases while still maintaining to some extent the splicing of ABA-activated SnRK2 kinases. Taken together, our data establish PB as an inhibitor and modulator of splicing and a mimic of abiotic stress signals in plants. Thus, PB reveals the molecular underpinnings of the interplay between stress responses, ABA signaling and post-transcriptional regulation in plants.
Laboratory for Genome Engineering, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
Yu
Y
Ling
Laboratory for Genome Engineering, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
Sahar
S
Alshareef
Laboratory for Genome Engineering, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
Haroon
H
Butt
Instituto de Biologia Molecular y Celular de Plantas, Consejo Superior de Investigaciones Cientificas-Universidad Politecnica de Valencia, ES-46022, Valencia, Spain.
Jorge
J
Lozano-Juste
Laboratory for Genome Engineering, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
Lixin
L
Li
Department of Biology and Biotechnology Graduate Program, American University in Cairo, New Cairo, 11835, Egypt.
Aya A
AA
Galal
Department of Biology and Biotechnology Graduate Program, American University in Cairo, New Cairo, 11835, Egypt.
Ahmed
A
Moustafa
Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
Afaque A
AA
Momin
Laboratory for Genome Engineering, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
Manal
M
Tashkandi
Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156, Oeiras, Portugal.
Dale N
DN
Richardson
Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20014, Turku, Finland.
Hiroaki
H
Fujii
Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
Stefan
S
Arold
Instituto de Biologia Molecular y Celular de Plantas, Consejo Superior de Investigaciones Cientificas-Universidad Politecnica de Valencia, ES-46022, Valencia, Spain.
Pedro L
PL
Rodriguez
Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156, Oeiras, Portugal.
Paula
P
Duque
Laboratory for Genome Engineering, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
Magdy M
MM
Mahfouz
D000040:Abscisic Acid / Q000378:metabolism / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D055864:Droughts; D004852:Epoxy Compounds / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D007438:Introns; D020930:MAP Kinase Kinase Kinases / Q000235:genetics / Q000378:metabolism; D018942:Macrolides / Q000494:pharmacology*; D054046:Plant Stomata / Q000187:drug effects; D030821:Plants, Genetically Modified; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism; D012326:RNA Splicing / Q000187:drug effects*; D012333:RNA, Messenger / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics*; D013312:Stress, Physiological / Q000235:genetics*
D029681:Arabidopsis Proteins; D004852:Epoxy Compounds; D018942:Macrolides; C520629:RD29a protein, Arabidopsis; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C483303:SR45 protein, Arabidopsis; C492978:SnRK2 protein, Arabidopsis; C522342:pladienolide B; D000040:Abscisic Acid; D017346:Protein Serine-Threonine Kinases; D020930:MAP Kinase Kinase Kinases; C000598433:MAPKKK18 protein, Arabidopsis
abiotic stress responses; abscisic acid; alternative splicing; pladienolide B; serine/arginine-rich proteins; splicing inhibitors