芥菜AGL18家族成员与开花整合子SOC1的互作分析

为阐明芥菜开花抑制因子AGL18与开花整合子SOC1间的互作调控机制,在芥菜‘QJ’的开花期克隆了AGL18-1,幼苗期克隆了AGL18-2和AGL18-3,它们分别编码257、257和258个氨基酸,为AGL18家族的3个成员。序列比对表明,芥菜AGL18家族成员与十字花科芜菁和油菜同源性均高达90%。酵母双杂交和BiFC试验表明:芥菜AGL18-1、AGL18-2和AGL18-3蛋白与SOC1不会发生蛋白相互作用。酵母单杂交和Dual-Glo~ Luciferase试验表明:AGL18-1、AGL18-2和AGL18-3中仅有花期AGL18-1蛋白与SOC1启动子间存在互作。为进一步筛选AGL18-1/SOC1的互作区域,分别截取了AGL18-1蛋白的M域和IKC域,发现仅M域与SOC1启动子存在相互作用,说明M域是介导花期AGL18-1蛋白与SOC1启动子互作的关键区域。这为深入研究AGL18与SOC1互作的分子机制及其对开花时间的调控奠定了基础。

Analysis of Interactions Between AGL18 Family Members and Flowering Time Integrator Factor SOC1 in Brassica juncea

AGAMOUS-LIKE 18 (AGL18) is a key regulatory factor in flowering time control of Brassicajuncea.In order to clarify the regulatory mechanism of AGL18 protein interact with SOC1 in flowering pathways,AGL18-1 gene from reproductive shoots as well as AGL18-2 and AGL18-3 from vegetative shoots in ‘QJ’ germplasm of Brassicajuncea,were cloned respcetively.AGL18-1,AGL18-2 and A GL18-3 were members of AGL 18 family and respectively encoded 257,257 and 258 amino acids.Sequences analysis showed that they were more than 90％ similar to Brassica rapa and Brassica napus.Both Yeast two hybrid and BiFC showed that SOC1 protein could not interact with AGL18-1,AGL18-2 or AGL18-3.Yeast one hybrid and Dual-Glo(R) Luciferase assays indicated that SOC1 promoter could interact with AGL 18-1 but not AGL 18-2 and AGL 18-3.To screen the interaction regions of AGL 18-1/SOC1,the M-domain and IKC-domain truncations of AGL18-1 protein were separated and found that only the M-domain truncation could interact with SOC1 promoter.It suggested that M-domain was the key region that mediated the interaction between AGL18-1 and SOC1 promoter.The work provided valuable information for in-depth studies on the molecular mechanisms of AGL18 protein with SOC1 and the flowering time in Brassicajuncea.