Botanical Institute, University of Cologne, Otto-Fischer-Str. 6, 50674, Cologne, Germany.
Planta. 2010 Mar;231(4):825-33. doi: 10.1007/s00425-009-1088-y. Epub 2009 Dec 30.
The COP1/SPA complex and DET1 function to suppress photomorphogenesis in dark-grown Arabidopsis seedlings. Additionally, they inhibit flowering under non-inductive short-day conditions. The COP1/SPA complex and DET1, as part of the CDD complex, represent distinct high-molecular-weight complexes in Arabidopsis. Here, we provide genetic evidence that these complexes co-act in regulating plant development. We report the isolation of a spa1 enhancer mutation that represents a novel, very weak allele of det1. This det1 ( esp1 ) mutation caused no detectable mutant phenotype in the presence of wild-type SPA1, but showed strongly synergistic genetic interaction with the spa1 mutation in the control of seedling photomorphogenesis, anthocyanin accumulation, plant size as well as flowering time. On the biochemical level, the det1 ( esp1 ) spa1 double mutant showed higher HY5 protein levels than either single mutant or the wild type. The genetic interaction of spa1 and det1 mutations was further confirmed in the spa1 det1-1 double mutant which carries a strong allele of det1. Taken together, these results show that SPA1 and DET1 act together to control photomorphogenesis throughout plant development. Hence, this suggests that COP1/SPA complexes and the CDD complex co-act in controlling the protein stability of COP1/SPA target proteins.
COP1/SPA 复合体和 DET1 抑制暗培养拟南芥幼苗中的光形态发生。此外，它们还抑制非诱导短日照条件下的开花。COP1/SPA 复合体和 DET1 作为 CDD 复合体的一部分，代表拟南芥中不同的高分子量复合物。在这里，我们提供了遗传证据，证明这些复合物共同作用于调节植物发育。我们报告了 spa1 增强子突变的分离，这是 det1 的一个新的、非常弱的等位基因。在存在野生型 SPA1 的情况下，这种 det1 (esp1) 突变没有表现出可检测的突变表型，但在控制幼苗光形态发生、花青素积累、植株大小和开花时间方面与 spa1 突变表现出强烈的协同遗传相互作用。在生化水平上，det1 (esp1) spa1 双突变体的 HY5 蛋白水平高于任何单个突变体或野生型。spa1 和 det1 突变的遗传相互作用在携带 det1 强等位基因的 spa1 det1-1 双突变体中得到了进一步证实。总之，这些结果表明 SPA1 和 DET1 共同作用于控制整个植物发育过程中的光形态发生。因此，这表明 COP1/SPA 复合物和 CDD 复合物共同作用于控制 COP1/SPA 靶蛋白的稳定性。
