Evolutionarily Conserved DELLA-mediated Gibberellin Signaling in Plants

Gibberellins (GAs) play important roles in many essential plant growth and development processes. A family of nuclear growth-repressing DELLA proteins is the key component in GA signaling. GA perception is mediated by GID1, and the key event of GA signaling is the degradation of DELLA proteins via the 26S proteasome pathway. DELLA proteins integrating other plant hormones signaling and environmental cue modulating plant growth and development have been revealed. GA turning on the de-DELLA-repressing system is conserved, and independently establishes step-by-step recruitment of GA- stimulated GID1-DELLA interaction and DELLA growth-repression functions during land plant evolution. These discoveries open new prospects for the understanding of GA action and DELLA-mediated signaling in plants.