CNR ExploRA

Articolo in rivista, 2020, ENG, 10.1104/pp.20.00037

DRT111/SFPS splicing factor controls ABA sensitivity during seed development and germination

Paola Punzo, Alessandra Ruggiero, Marco Possenti, Giorgio Perrella, Roberta Nurcato, Antonello Costa, Giorgio Morelli, Stefania Grillo and Giorgia Batelli

National Research Council of Italy, Institute of Biosciences and Bioresources (CNR-IBBR), Via Università 133, Portici (NA), Italy (P.P., A.R., R.N., A.C., S.G., G.B.); Research Centre for Genomics and Bioinformatics, Council for Agricultural Research and Economics (CREA-GB) , Via Ardeatina 546, 00178 Rome, Italy (M.P., G.M.); ENEA Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Trisaia Research Center, S.S. 106 14 Ionica, km 419+500 - 75026 Rotondella (MT), Italy (G.P.).

RNA splicing is a fundamental mechanism contributing to the definition of the cellular protein population in any given environmental condition. DNA-DAMAGE REPAIR/TOLERATION PROTEIN 111/ SPLICING FACTOR FOR PHYTOCHROME SIGNALING (DRT111/SFPS) is a splicing factor previously shown to interact with phytochrome B and characterized for its role in splicing of pre-mRNAs involved in photomorphogenesis. Here, we show that DRT111 interacts with Arabidopsis thaliana Splicing Factor 1 (SF1), involved in 3? splicing site recognition. Double and triple mutant analysis shows that DRT111 controls splicing of ABI3 and acts upstream of the splicing factor SUPPRESSOR OF ABI3-5 (SUA). DRT111 is highly expressed in seeds and stomata of Arabidopsis and is induced by long-term treatments of polyethylene glycol and abscisic acid (ABA). DRT111 knock-out mutants are defective in ABA-induced stomatal closure and are hypersensitive to ABA during seed germination. Conversely, DRT111 over-expressing plants show ABA-hyposensitive seed germination. RNAseq experiments show that in dry seeds, DRT111 controls expression and splicing of genes involved in osmotic-stress and ABA responses, light signaling, and mRNA splicing, including targets of ABSCISIC ACID INSENSITIVE3 (ABI3) and PHYTOCHROME INTERACTING FACTORs (PIFs). Consistently, expression of the germination inhibitor SOMNUS, induced by ABI3 and PIF1, is up-regulated in imbibed seeds of drt111-2 mutants. Together, these results indicate that DRT111 controls sensitivity to ABA during seed development, germination, and stomatal movements, and integrates ABA- and light-regulated pathways to control seed germination.

Plant physiology (Online) 183 , pp. 793–807