School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.
School of Design, Shanghai Jiao Tong University, Shanghai, China.
Plant Cell Environ. 2021 Aug;44(8):2580-2592. doi: 10.1111/pce.14075. Epub 2021 Jun 9.
Plants monitor environmental cues to balance their vegetative and productive growth by optimizing their inflorescence architecture. TERMINAL FLOWER 1 (TFL1) and its orthologs regulate the inflorescence structure in cucumber, yet the mechanisms underlying their responses to environmental factors and the formation of terminal flowers remain elusive. Here, we performed map-based cloning to identify the gene that controls a season-dependent determinate growth phenotype and found that it was caused by the complete deletion of CsTFL1 in the genome of cucumber line WI1983Hde. In the CsTFL1 deletion plants (CsTFL1 ), determinate growth could be partially rescued by high-temperature and long-day conditions. The expressions of CsTFL1 and its ortholog CsTFL1d could be upregulated by long-day and high-temperature signals. Knockdown of CsTFL1d resulted in determinate growth and the formation of terminal flowers in WT. These results indicate that the induction of CsTFL1d expression by long-day and high-temperature might partially rescue determinate growth of CsTFL1 . Furthermore, biochemical analyses showed that CsTFL1d interacts directly with CsNOT2a, which indicated that CsTFL1d and CsTFL1 function via similar regulatory mechanism. Our data suggest that CsTFL1 and CsTFL1d co-contribute to inhibit determinate growth by responding to temperature and photoperiod signals. It provides mechanistic insights into how environmental cues sculpt the inflorescence architecture of cucumber.
植物通过优化花序结构来监测环境线索，从而平衡其营养生长和生殖生长。TERMINAL FLOWER 1（TFL1）及其同源物调节黄瓜的花序结构，但它们对环境因素的响应机制和顶端花的形成机制仍不清楚。在这里，我们通过图位克隆鉴定了控制黄瓜 WI1983Hde 品系季节依赖性定长表型的基因，发现它是由黄瓜 CsTFL1 基因在基因组中的完全缺失引起的。在 CsTFL1 缺失植物（CsTFL1）中，高温和长日照条件可以部分挽救定长生长。CsTFL1 和其同源物 CsTFL1d 的表达可以被长日照和高温信号上调。CsTFL1d 的敲低导致 WT 中定长生长和顶端花的形成。这些结果表明，长日照和高温诱导 CsTFL1d 表达可能部分挽救 CsTFL1 的定长生长。此外，生化分析表明 CsTFL1d 与 CsNOT2a 直接相互作用，这表明 CsTFL1d 和 CsTFL1 通过类似的调控机制发挥作用。我们的数据表明，CsTFL1 和 CsTFL1d 通过响应温度和光周期信号共同抑制定长生长。它为环境线索如何塑造黄瓜花序结构提供了机制上的见解。
