Department of Vegetable Sciences, Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, China Agricultural University, Beijing, 100193, China.
Department of Vegetable Sciences, Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, China Agricultural University, Beijing, 100193, China.
Biochem Biophys Res Commun. 2018 May 5;499(2):307-313. doi: 10.1016/j.bbrc.2018.03.153. Epub 2018 Mar 26.
Cucumber is an important vegetable with indeterminate growth habit which is beneficial to its yield. In this study, we cloned the TFL1 homolog CsTFL1b in cucumber. CsTFL1b shares highly sequence similarity to TFL1 from Arabidopsis and has conservative histidine amino acid residue which is necessary for TFL1 function. However, phylogenetic analysis suggested that cucurbits TFL1s (CsTFL1b of cucumber and CmTFL1 of melon) formed a subclade which is far from the AtTFL1 in Arabidopsis or CEN in Antirrhinum. CsTFL1b was highest expressed in male flower but barely expressed in SAM which was different from TFL1 in Arabidopsis with highly transcription accumulation in SAM and CsTFL1b was located in nucleus and cytoplasm. Upon ectopic expression of CsTFL1b in Arabidopsis, the flowering time of transgenic plants was significantly delayed in both wild type and tfl1-11 mutant background but the terminal flower phenotype of tfl1-11 mutant was partially rescued. These results may underlie the discrepant function of CsTFL1b in cucumber from that in Arabidopsis.
黄瓜是一种具有无限生长习性的重要蔬菜，这有利于其产量。本研究在黄瓜中克隆了 TFL1 同源基因 CsTFL1b。CsTFL1b 与拟南芥中的 TFL1 具有高度的序列相似性，并且具有保守的组氨酸氨基酸残基，这对于 TFL1 的功能是必需的。然而，系统发育分析表明，葫芦科的 TFL1 （黄瓜的 CsTFL1b 和甜瓜的 CmTFL1）形成了一个亚分支，远离拟南芥中的 AtTFL1 或金鱼草中的 CEN。CsTFL1b 在雄花中表达量最高，但在 SAM 中几乎不表达，这与拟南芥中的 TFL1 不同，TFL1 在 SAM 中高度转录积累，而 CsTFL1b 位于细胞核和细胞质中。在拟南芥中异位表达 CsTFL1b 后，转基因植株的开花时间在野生型和 tfl1-11 突变体背景下均显著延迟，但 tfl1-11 突变体的顶花表型部分得到挽救。这些结果可能解释了 CsTFL1b 在黄瓜中的功能与在拟南芥中的功能不一致。
