DELLA-mediated PIF degradation contributes to coordination of light and gibberellin signalling in Arabidopsis.
Light and gibberellins (GAs) antagonistically regulate hypocotyl elongation in plants. It has been demonstrated that DELLAs, which are negative regulators of GA signalling, inhibit phytochrome-interacting factors 3 and 4 (PIF3 and PIF4) by sequestering their DNA-recognition domains. However, it is unclear whether there are other mechanisms of regulatory crosstalk between DELLAs and PIFs. Here, we demonstrate that DELLAs negatively regulate the abundance of four PIF proteins through the ubiquitin-proteasome system. Reduction of PIF3 protein abundance by DELLAs correlates closely with reduced hypocotyl elongation. Both sequestration and degradation of PIF3 by DELLAs contribute to a reduction in PIF3 binding to its target genes. Thus, we show that promotion of PIF degradation by DELLAs is required to coordinate light and GA signals, and the dual regulation of transcription factors by DELLAs by both sequestration and degradation may be a general mechanism.
State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Advanced Agriculture Sciences, and School of Life Sciences, Peking University, Beijing 100871, China.
Kunlun
K
Li
State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Advanced Agriculture Sciences, and School of Life Sciences, Peking University, Beijing 100871, China.
Renbo
R
Yu
State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Advanced Agriculture Sciences, and School of Life Sciences, Peking University, Beijing 100871, China.
Liu-Min
LM
Fan
Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520, USA.
Ning
N
Wei
State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Advanced Agriculture Sciences, and School of Life Sciences, Peking University, Beijing 100871, China.
Haodong
0000-0001-7228-6341
H
Chen
State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Advanced Agriculture Sciences, and School of Life Sciences, Peking University, Beijing 100871, China.
Xing Wang
XW
Deng
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D002940:Circadian Rhythm / Q000528:radiation effects; D003624:Darkness; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D005875:Gibberellins / Q000378:metabolism*; D018546:Hypocotyl / Q000033:anatomy & histology / Q000528:radiation effects; D008027:Light; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D059748:Proteolysis / Q000528:radiation effects; D015398:Signal Transduction; D025801:Ubiquitin / Q000378:metabolism
D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D005875:Gibberellins; D046988:Proteasome Endopeptidase Complex; D025801:Ubiquitin; C116162:PIF3 protein, Arabidopsis