PDF(Pubmed)
Abstract：
Correct flower organ formation at the right timing is one of the most important strategies for plants to achieve reproductive success. Ectopic overexpression of LATE FLOWERING (LATE) is known to induce late flowering, partly through suppressing expression of the florigen-encoding gene FLOWERING LOCUS T (FT) in Arabidopsis. LATE is one of the C2H2 zinc finger transcription factors, and it has a canonical transcriptional repression domain called the ethylene-responsive element-binding factor-associated amphiphilic repression (EAR) motif at the end of its C terminus. Therefore, LATE is considered a transcriptional repressor, but its molecular function remains unclear. Our genome-edited late mutants exhibited no distinct phenotype, even in flowering, indicating the presence of redundancy from other factors. To reveal the molecular function of LATE and factors working with it, we investigated its transcriptional activity and interactions with other proteins. Transactivation activity assay showed that LATE possesses transcriptional repression ability, which appears to be attributable to both the EAR motif and other sequences. Yeast two-hybrid assay showed the EAR motif-mediated interaction of LATE with TOPLESS, a transcriptional corepressor. Moreover, LATE could also interact with CRABS CLAW (CRC), one of the most important regulators of floral meristem determinacy, through sequences in LATE other than the EAR motif. Our findings demonstrated the possibility that LATE can form a transcriptional repression complex with CRC for floral meristem determinacy.
摘要：
在正确的时机正确的花器官形成是植物实现繁殖成功的最重要策略之一。晚期开花(LATE)的异位过表达已知能诱导晚期开花,部分通过抑制拟南芥中荧光素编码基因FLOWERINGLOCUST（FT）的表达。LATE是C2H2锌指转录因子之一，并且它在其C末端具有一个经典的转录抑制域，称为乙烯响应元件结合因子相关的两亲性抑制（EAR）基序。因此,LATE被认为是转录抑制因子，但其分子功能尚不清楚。我们的基因组编辑的晚期突变体没有表现出明显的表型，即使在开花时，表明存在来自其他因素的冗余。为了揭示LATE的分子功能和与之相关的因素，我们研究了它的转录活性和与其他蛋白质的相互作用。反式激活活性测定表明LATE具有转录抑制能力，这似乎可归因于EAR基序和其他序列。酵母双杂交试验显示了EAR基序介导的LATE与TOPLESS的相互作用，转录辅抑制因子。此外，Late还可以与CRABSCLAW（CRC）进行交互，花卉分生组织决定的最重要的调节剂之一，通过耳基序以外的晚期序列。我们的发现证明了LATE可以与CRC形成花分生组织确定性的转录抑制复合物的可能性。
