ERF.D2 negatively controls drought tolerance through synergistic regulation of abscisic acid and jasmonic acid in tomato.

Plants inevitably encounter a diverse array of constantly changing environmental stresses, and drought stands out as one of the most severe threats to plants. Abscisic acid (ABA) and jasmonic acid (JA) work synergistically to increase plant drought tolerance, but their interplay during drought response remains elusive. Here, we uncovered that ABA induced the degradation of a negative transcription regulator, ethylene responsive factor (ERF.D2), in tomato drought tolerance. We identified that ERF.D2 was phosphorylated at Ser-52 by calcium-dependent protein kinase 27 (CPK27) in an ABA-dependent manner and underwent subsequent PUB22-mediated ubiquitination. Degradation of ERF.D2 leads to the increase of the transcript levels of JA biosynthesis genes, allene oxide cyclase (AOC) and 12-oxophytodienoic acid reductase 3 (OPR3), and endogenous concentration of JA, thus enhancing tomato plant drought tolerance. These findings demonstrate a novel insight into the molecular mechanism of ABA-JA synergistic interaction during tomato drought tolerance.