SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) and AGAMOUS-LIKE 24 (AGL24) are pivotal flowering signal integrators, which respectively, belong to TM3/SOC1 and STMADS11 clades of MIKC-type MADS-box family. AGAMOUS-LIKE 19 (AGL19), one member of TM3/SOC1 clade family, acts as an activator of flowering time. Previous studies have suggested that AGL19 together with AGL24 and SOC1 coordinately regulate flowering time. However, it remains unknown how AGL19 interacts with SOC1 and AGL24 in Brassica juncea. Here, an AGL19-like (BjuAGL19) was cloned from B. juncea, which was expressed in roots, stems, leaves, buds and flowers. Furthermore, both yeast one-hybrid and Dual-Glo Luciferase assays confirmed that BjuAGL19 protein could not target the promoters of BjuSOC1 and BjuAGL24. Interestingly, based on yeast two-hybrid and pull-down assays, BjuAGL19 protein directly interacted with BjuAGL24 protein, instead of BjuSOC1 protein. It is speculated that BjuAGL19 can bind to BjuAGL24 to form protein complex of BjuAGL19-BjuAGL24 and thus regulates flowering time in B. juncea. The results are very helpful for further elucidating the molecular mechanism of BjuAGL19 in flowering time control.

CONSTANS1（SOC1）和Agamous-Like 24（AGL24）的过表达抑制物是关键的开花信号整合子，分别属于MIKC型MADS-box系列的TM3 / SOC1和STMADS11进化枝。TM3 / SOC1进化枝家族的成员之一AGAMOUS-LIKE 19（AGL19）是开花时间的激活剂。先前的研究表明，AGL19与AGL24和SOC1协同调节开花时间。但是，目前还不清楚如何AGL19相互作用与SOC1和AGL24在雪里蕻。在这里从芥菜芽孢杆菌（B.juncea）克隆AGL19样（BjuAGL19），其在根，茎，叶，芽和花中表达。此外，酵母一杂交和双Glo荧光素酶测定均证实BjuAGL19蛋白不能靶向BjuSOC1和BjuAGL24的启动子。有趣的是，基于酵母双杂交和下拉分析，BjuAGL19蛋白直接与BjuAGL24蛋白相互作用，而不是与BjuSOC1蛋白相互作用。推测BjuAGL19可以结合BjuAGL24形成BjuAGL19-BjuAGL24的蛋白复合物，从而调节芥菜中的开花时间。该结果对于进一步阐明BjuAGL19在开花时间控制中的分子机制非常有帮助。