EIN3/EIL1 cooperate with PIF1 to prevent photo-oxidation and to promote greening of Arabidopsis seedlings

• DOI: 10.1073/pnas.0907670106
• Publication Date: 2009-12-01T03:19:59Z
• Authors: Shangwei Zhong; Mantong Zhao; Tianying Shi; Hui Shi; Fengying An; Qiong Zhao; Hongwei Guo
• Keywords: Etiolation; Photomorphogenesis; Protochlorophyllide; Phytochrome

The ability to switch from skotomorphogenesis photomorphogenesis is essential for seedling development and plant survival. Recent studies revealed that COP1 phytochrome-interacting factors (PIFs) are key regulators of this transition by repressing the photomorphogenic responses and/or maintaining skotomorphogenic state etiolated seedlings. Here we report hormone ethylene plays a crucial role in facilitating greening seedlings upon light irradiation. Activation EIN3/EIL1 both necessary sufficient ethylene-induced enhancement greening, as well repression accumulation protochlorophyllide, phototoxic intermediate chlorophyll synthesis. were found induce gene expression two enzymes synthesis pathway, protochlorophyllide oxidoreductase A B (PORA/B). ChIP EMSA assays demonstrated EIN3 directly binds specific elements present PORA PORB promoters. Genetic function cooperation with PIF1 preventing photo-oxidative damage promoting cotyledon greening. Moreover, activation reverses blockage triggered cop1 mutation or far-red Consistently, acts downstream its protein enhanced but decreased light. Taken together, represent new class transcriptional along optimize de-etiolation Arabidopsis Our study highlights enhancing survival through protecting against damage.