Blanco-Touriñán Noel, Legris Martina, Minguet Eugenio G, Costigliolo-Rojas Cecilia, Nohales María A, Iniesto Elisa, García-Leόn Marta, Pacín Manuel, Heucken Nicole, Blomeier Tim, Locascio Antonella, Černý Martin, Esteve-Bruna David, Díez-Díaz Mόnica, Brzobohatý Břetislav, Frerigmann Henning, Zurbriggen Matίas D, Kay Steve A, Rubio Vicente, Blázquez Miguel A, Casal Jorge J, Alabadí David
Instituto de Biologίa Molecular y Celular de Plantas, Consejo Superior de Investigaciones Cientίficas, Universidad Politécnica de Valencia, 46022 Valencia, Spain.
Fundaciόn Instituto Leloir, Instituto de Investigaciones Bioquίmicas de Buenos Aires, Consejo Nacional de Investigaciones Cientίficas y Técnicas, 1405 Buenos Aires, Argentina.
Proc Natl Acad Sci U S A. 2020 Jun 16;117(24):13792-13799. doi: 10.1073/pnas.1907969117. Epub 2020 May 29.
DELLA transcriptional regulators are central components in the control of plant growth responses to the environment. This control is considered to be mediated by changes in the metabolism of the hormones gibberellins (GAs), which promote the degradation of DELLAs. However, here we show that warm temperature or shade reduced the stability of a GA-insensitive DELLA allele in Furthermore, the degradation of DELLA induced by the warmth preceded changes in GA levels and depended on the E3 ubiquitin ligase CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1). COP1 enhanced the degradation of normal and GA-insensitive DELLA alleles when coexpressed in DELLA proteins physically interacted with COP1 in yeast, mammalian, and plant cells. This interaction was enhanced by the COP1 complex partner SUPRESSOR OF 1 (SPA1). The level of ubiquitination of DELLA was enhanced by COP1 and COP1 ubiquitinated DELLA proteins in vitro. We propose that DELLAs are destabilized not only by the canonical GA-dependent pathway but also by COP1 and that this control is relevant for growth responses to shade and warm temperature.
DELLA转录调节因子是植物对环境生长反应控制中的核心组成部分。这种控制被认为是由促进DELLA降解的赤霉素（GA）代谢变化介导的。然而，我们在此表明，温暖温度或遮荫会降低GA不敏感DELLA等位基因的稳定性。此外，温暖诱导的DELLA降解先于GA水平的变化，且依赖于E3泛素连接酶组成型光形态建成1（COP1）。当在[具体细胞类型未给出]中共表达时，COP1增强了正常和GA不敏感DELLA等位基因的降解。DELLA蛋白在酵母、哺乳动物和植物细胞中与COP1发生物理相互作用。这种相互作用被COP1复合体伙伴抑制子1（SPA1）增强。COP1增强了DELLA的泛素化水平，并且COP1在体外使DELLA蛋白泛素化。我们提出，DELLA不仅通过经典的GA依赖途径而不稳定，而且还受COP1影响，并且这种控制与对遮荫和温暖温度的生长反应相关。
