Common Nat | 历经十余载，邓兴旺院士南科大团队揭示光-COP1-剪接体调控植物光形态建成的新机制
Light is the material basis on which living things depend. Light is not only an important source of energy for plant growth and development, but also a direct participant in the regulation of plant growth and development. The process of photoregulation of plant growth and development is called photomorphogenesis (in Arabidopsis, it is manifested by inhibition of hypocotyl elongation, loss of apical hooks, chloroplast development, etc.). COP1 (CONSTITUTIVE PHOTOMORPHOGENIC 1) IS A CORE NEGATIVE REGULATOR OF PLANT PHOTOMORPHOGENESIS. COP1 acts as an E3 ubiquitination ligase that inhibits photomorphogenesis by ubiquitinating and degrading a series of substrates. In addition, COP1 also widely participates in and regulates a series of processes such as flowering, stomatal development, and biological rhythm of plants. Therefore, the normal functioning of COP1 is essential for the growth and development of plants. In order to identify more pathways for COP1 signaling, the researchers performed EMS mutagenesis on cop1-6 mutants (weak mutants) to screen for genetic suppressors that could restore the constitutive photomorphogenesis phenotype of cop1-6 mutants under dark conditions. The 13 dominant COP1-6 inhibitors were mapped and resequenced throughout the genome, and 6 dominant COP1-6 inhibitor genes (DCS1-DCS6) were cloned. The results have recently been published in the internationally renowned journal Nature Communications.
Intron retention (IR) is the most common alternative splicing event in plants. IR plays an important role in the regulation of gene expression. It has been found that intron-retained transcripts (IRTs) are retained in the nucleus to avoid being translated into new proteins or degraded, and these IRTs stored in the nucleus can be cleaved and processed into proteins when stimulated by external signals or changes in developmental stages, so as to quickly respond to external signals to coordinate plant growth and development by controlling the cleavage of IRT at the post-transcriptional level.
This study suggests that COP1 is involved in light-mediated mRNA alternative splicing (mainly IR) processes to coordinate the photomorphological development of Arabidopsis thaliana seedlings. Light enables fine control of photomorphogenesis in Arabidopsis thaliana seedlings through the regulation of IR of genes encoding genes (e.g., PIF4, RVE1, and ABA3) of optical pathway members, which is COP1-dependent and regulated by the splice complex. The DCS1-DCS6 proteins identified in this study are all components of the Arabidopsis spliceosome. COP1 regulates the functional state of the splice complex by directly interacting with and degrading the ubiquitination of DCS1, a plant spliceosome-specific component protein. Therefore, this study revealed a novel molecular mechanism by which the light-COP1-spliceosome module regulates photomorphogenesis in plants.
Research Assistant Professor Zhou Hua of Southern University of Science and Technology is the first author of this paper, and Academician Deng Xingwang is the corresponding author. Southern University of Science and Technology is the first author's institution. Professor Wei Ning of Southwest University, Professor Xu Dongqing and Associate Professor Chen Sunlu of Nanjing Agricultural University, Professor Lin Fang of Lanzhou University, Researcher Qin Guochen of the Institute of Modern Agriculture of Peking University, Associate Professor Li Jian of Nanjing Normal University, Associate Professor Heng Yueqin of South China Agricultural University, Dr. Zhao Xianhai of Brookhaven National Laboratory in the United States, Dr. Yan Tingting of Hainan Academy of Agricultural Sciences, Zeng Haiyue, a doctoral student working at the Institute of Modern Agriculture of Peking University, and Fu Ying, a research assistant, also participated in the research work. The research was supported by the National Natural Science Foundation of China, the Peking University-Tsinghua Joint Center for Life Sciences, the Southern University of Science and Technology, and the Shenzhen Science and Technology Program.
Paper Links:
https://www.nature.com/articles/s41467-024-49571-9