Abscisic acid inhibits hypocotyl elongation acting on gibberellins, DELLA proteins and auxin

Riccardo Lorrai; Alessandra Boccaccini; Veronica Ruta; Marco Possenti; Paolo Costantino; Paola Vittorioso

doi:10.1093/aobpla/ply061

Abscisic acid inhibits hypocotyl elongation acting on gibberellins, DELLA proteins and auxin

AoB Plants. 2018 Oct 5;10(5):ply061. doi: 10.1093/aobpla/ply061. eCollection 2018 Oct.

Authors

Riccardo Lorrai¹, Alessandra Boccaccini¹, Veronica Ruta¹, Marco Possenti², Paolo Costantino¹, Paola Vittorioso¹

Affiliations

¹ Department of Biology and Biotechnology, Sapienza University of Rome, Laboratory affiliated to Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Rome, Italy.
² Research Centre for Genomics and Bioinformatics, Council for Agricultural Research and Economics (CREA), Rome, Italy.

Abstract

Hypocotyl elongation of Arabidopsis seedlings is influenced by light and numerous growth factors. Light induces inhibition of hypocotyl elongation (photomorphogenesis), whereas in the dark hypocotyl elongation is promoted (skotomorphogenesis). Abscisic acid (ABA) plays a major role in inhibition of hypocotyl elongation, but the molecular mechanism remains unclear. We investigated the effect of ABA during photo- and skotomorphogenesis, making use of appropriate mutants, and we show that ABA negatively controls hypocotyl elongation acting on gibberellin (GA) metabolic genes, increasing the amount of the DELLA proteins GAI and RGA, thus affecting GA signalling, and (ultimately) repressing auxin biosynthetic genes.

Keywords: ABA; Arabidopsis; DELLA proteins; GA; PIF proteins; auxin; hypocotyl elongation.