title: Arabidopsis DET1 degrades HFR1 but stabilizes PIF1 to precisely regulate seed germination.
abstract: Seed is an essential propagation organ and a critical strategy adopted by terrestrial flowering plants to colonize the land. The ability of seeds to accurately respond to light is vital for plant survival. However, the underlying mechanism is largely unknown. In this study, we reveal a circuit of triple feed-forward loops adopted by Arabidopsis seeds to exclusively repress germination in dark conditions and precisely initiate germination under diverse light conditions. We identify that de-etiolated 1 (DET1), an evolutionarily conserved protein, is a central repressor of light-induced seed germination. Genetic analysis demonstrates that DET1 functions upstream of long hypocotyl in far-red 1 (HFR1) and phytochrome interacting factor 1 (PIF1), the key positive and negative transcription regulators in seed germination. We further find that DET1 and constitutive photomorphogenic 10 (COP10) target HFR1 for protein degradation by assembling a COP10-DET1-damaged DNA binding protein 1-cullin4 E3 ligase complex. Moreover, DET1 and COP10 directly interact with and promote the protein stability of PIF1. Computational modeling reveals that phytochrome B (phyB)-DET1-HFR1-PIF1 and phyB-DET1-Protease-PIF1 are new signaling pathways, independent of the previously identified phyB-PIF1 pathway, respectively mediating the rapid and time-lapse responses to light irradiation. The model-simulated results are highly consistent with their experimental validations, suggesting that our mathematical model captures the essence of Arabidopsis seed germination networks. Taken together, this study provides a comprehensive molecular framework for light-regulated seed germination, improving our understanding of how plants respond to changeable environments.
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, The Peking-Tsinghua Center for Life Sciences, School of Advanced Agricultural Sciences and School of Life Sciences, Peking University, Beijing 100871, China; Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520;
authors.forename: Hui
authors.initials: H
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, The Peking-Tsinghua Center for Life Sciences, School of Advanced Agricultural Sciences and School of Life Sciences, Peking University, Beijing 100871, China; Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520;
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Mo
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, The Peking-Tsinghua Center for Life Sciences, School of Advanced Agricultural Sciences and School of Life Sciences, Peking University, Beijing 100871, China; Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, The Peking-Tsinghua Center for Life Sciences, School of Advanced Agricultural Sciences and School of Life Sciences, Peking University, Beijing 100871, China; Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520; xingwang.deng@yale.edu shangwei.zhong@pku.edu.cn.
authors.forename: Shangwei
authors.initials: S
authors.lastname: Zhong
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, The Peking-Tsinghua Center for Life Sciences, School of Advanced Agricultural Sciences and School of Life Sciences, Peking University, Beijing 100871, China; Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520; xingwang.deng@yale.edu shangwei.zhong@pku.edu.cn.
authors.forename: Xing Wang
authors.initials: XW
authors.lastname: Deng
mesh_terms: D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000502:physiology*; D051792:Basic Helix-Loop-Helix Proteins / Q000502:physiology*; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D004268:DNA-Binding Proteins / Q000502:physiology*; D017353:Gene Deletion; D005838:Genotype; D018525:Germination; D047908:Intracellular Signaling Peptides and Proteins; D009154:Mutation; D009687:Nuclear Proteins / Q000502:physiology*; D010641:Phenotype; D012639:Seeds / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; C088435:DET1 protein, Arabidopsis; C414438:At1g02340 protein, Arabidopsis; C508068:At2g20180 protein, Arabidopsis
keywords: CDD-CUL4; DET1-COP10; HFR1-PIF1; phyB; seed germination