title: Seedlings Transduce the Depth and Mechanical Pressure of Covering Soil Using COP1 and Ethylene to Regulate EBF1/EBF2 for Soil Emergence.
abstract: The survival of seed plants in natural environments requires the successful emergence from the soil. In this process, the ethylene signaling pathway is utilized by plants to sense and respond to the mechanical resistance of the soil. Here, we report that constitutive photomorphogenesis 1 (COP1), a central repressor of light signaling, is a key component required for seedlings to sense the depth of soil overlay. Mutation in COP1 causes severe defects in penetrating soil, due to decreased level of EIN3, a master transcription factor in ethylene pathway that mediates seedling emergence. We show that COP1 directly targets the F box proteins EBF1 and EBF2 for ubiquitination and degradation, thus stabilizing EIN3. As seedlings grow toward the surface, the depth of soil overlay decreases, resulting in a gradual increase of light fluences. COP1 channels the light signals, while ethylene transduces the information on soil mechanical conditions, which cooperatively control EIN3 protein levels to promote seedling emergence from the soil. The COP1-EBF1/2-EIN3 module reveals a mechanism by which plants sense the depth to surface and uncovers a novel regulatory paradigm of an ubiquitin E3 ligase cascade.
authors.affiliation: Peking-Yale Joint Center for Plant Molecular Genetics and Agro-biotechnology, 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.
authors.forename: Hui
authors.initials: H
authors.lastname: Shi
authors.affiliation: Peking-Yale Joint Center for Plant Molecular Genetics and Agro-biotechnology, 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.
authors.forename: Renlu
authors.initials: R
authors.lastname: Liu
authors.affiliation: Peking-Yale Joint Center for Plant Molecular Genetics and Agro-biotechnology, 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.
authors.forename: Chang
authors.initials: C
authors.lastname: Xue
authors.affiliation: Peking-Yale Joint Center for Plant Molecular Genetics and Agro-biotechnology, 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.
authors.forename: Xing
authors.initials: X
authors.lastname: Shen
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA.
authors.forename: Ning
authors.initials: N
authors.lastname: Wei
authors.affiliation: Peking-Yale Joint Center for Plant Molecular Genetics and Agro-biotechnology, 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. Electronic address: deng@pku.edu.cn.
authors.forename: Xing Wang
authors.initials: XW
authors.lastname: Deng
authors.affiliation: Peking-Yale Joint Center for Plant Molecular Genetics and Agro-biotechnology, 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. Electronic address: shangwei.zhong@pku.edu.cn.
authors.forename: Shangwei
authors.initials: S
authors.lastname: Zhong
mesh_terms: D029681:Arabidopsis Proteins / Q000378:metabolism*; D005030:Ethylenes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D009687:Nuclear Proteins / Q000378:metabolism*; D011312:Pressure; D036226:Seedlings / Q000235:genetics*; D012987:Soil
chemical_list: D029681:Arabidopsis Proteins; D005030:Ethylenes; D009687:Nuclear Proteins; D012987:Soil
keywords: COP1; EBF1 and EBF2; EIN3; ethylene signaling; seedling emergence