Leaf-derived ABA regulates rice seed development via a transporter-mediated and temperature-sensitive mechanism.

ABSTRACT: Long-distance transport of the phytohormone abscisic acid (ABA) has been studied for ~50 years, yet its mechanistic basis and biological significance remain very poorly understood. Here, we show that leaf-derived ABA controls rice seed development in a temperature-dependent manner and is regulated by defective grain-filling 1 (DG1), a multidrug and toxic compound extrusion transporter that effluxes ABA at nodes and rachilla. Specifically, ABA is biosynthesized in both WT and dg1 leaves, but only WT caryopses accumulate leaf-derived ABA. Our demonstration that leaf-derived ABA activates starch synthesis genes explains the incompletely filled and floury seed phenotypes in dg1 Both the DG1-mediated long-distance ABA transport efficiency and grain-filling phenotypes are temperatu

SUBMITTER: Qin P 

PROVIDER: S-EPMC7810376 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature