Flowering time is an important agricultural trait of the oil crop Brassica juncea (B. juncea), as accelerated flowering enables avoidance of terminal drought leading to increased yields. One gene known to control flowering time is TERMINAL FLOWER 1 (TFL1), which belongs to a family of phosphatidylethanolamine binding proteins, which can either repress or promote flowering time. Here, a TFL1 homolog, named BjTFL1, has been isolated from B. juncea, which shared 95% amino acid identity with TFL1 from Arabidopsis thaliana. Sequence analysis predicts the BjTFL1 protein contains the ligand-binding site, conserved motifs and other amino acid residues that are critical for TFL1 function. Confirming this as a functional TFL1 orthologue, overexpression of BjTFL1 under the control of the constitutive 35S promoter in Arabidopsis delayed flowering time. As a proof-of-concept to investigate its utility to shorten flowering time, an RNAi construct containing a partial sequence of BjTFL1 was transformed into Arabidopsis. Transcript analysis demonstrated the downregulation of endogenous AtTFL1. Moreover, the RNAi BjTFL1 transgenic lines were early flowering and had fewer rosette and cauline leaves compared to wild-type. Therefore, this BjTFL1 RNAi transgene could be used as a biotechnological tool to reduce flowering time in Brassica juncea in a bid to improve agricultural performance.

中文翻译：

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芥菜TERMINAL FLOWER 1同源物的序列和功能分析：用于调节开花时间的推定生物技术工具。

开花时间是油菜芸苔（B. juncea）的重要农业特性，因为加速开花可以避免终末干旱，从而提高产量。已知可以控制开花时间的一个基因是TERMINAL FLOWER 1（TFL1），该基因属于磷脂酰乙醇胺结合蛋白家族，可以抑制或促进开花时间。在这里，已经从芥菜芽胞杆菌中分离了一个名为BjTFL1的TFL1同源物，该菌株与拟南芥中的TFL1具有95％的氨基酸同一性。序列分析预测BjTFL1蛋白含有配体结合位点，保守的基序和其他对TFL1功能至关重要的氨基酸残基。确认这是功能性TFL1直向同源物，拟南芥中组成型35S启动子控制下BjTFL1的过度表达延迟了开花时间。作为研究其缩短开花时间效用的概念验证，将包含BjTFL1部分序列的RNAi构建体转化为拟南芥。笔录分析表明内源性AtTFL1的下调。而且，与野生型相比，RNAi BjTFL1转基因品系早开花，花环和茎生叶较少。因此，该BjTFL1 RNAi转基因可用作减少芥菜开花时间的生物技术工具，以提高农业生产性能。与野生型相比，RNAi BjTFL1转基因品系早开花，花环和茎生叶较少。因此，该BjTFL1 RNAi转基因可用作减少芥菜开花时间的生物技术工具，以提高农业生产性能。与野生型相比，RNAi BjTFL1转基因品系早开花，花环和茎生叶较少。因此，该BjTFL1 RNAi转基因可用作减少芥菜开花时间的生物技术工具，以提高农业生产性能。