APETALA2 antagonizes the transcriptional activity of AGAMOUS in regulating floral stem cells in Arabidopsis thaliana.
APETALA2 antagonizes the transcriptional activity of AGAMOUS in regulating floral stem cells in Arabidopsis thaliana.
复制标题
DOI：
10.1111/nph.14151
复制
发表时间：
2017-08
期刊：
影响因子：
--
通讯作者：
Chen X
中科院分区：
文献类型：
--
作者：
Huang Z;Shi T;Zheng B;Yumul RE;Liu X;You C;Gao Z;Xiao L;Chen X
APETALA 2（AP 2）最为人所知的是其在外部两个花轮中的功能，其中它通过将AGAMOUS（AG）的表达限制在拟南芥的内部两个花轮中来指定萼片和花瓣的身份。在这里，我们描述了AP 2在促进维持花干细胞命运中的作用，不是通过抑制AG转录，而是通过拮抗花中心的AG活性。我们用表现出弱花决定性缺陷的ag-10植物进行了遗传筛选，并分离出具有强花决定性缺陷的突变体。发现该突变体在AG中具有另一个突变，并将其命名为ag-11。我们在ag-11背景下进行了遗传筛选，以分离抑制花决定性缺陷的突变。两个抑制突变体被发现在AP 2中具有突变。虽然已知AG关闭干细胞维持基因WUSCHEL（WUS）的表达以终止花干细胞命运，但AP 2促进WUS的表达。 AP 2不抑制内两轮中AG的转录，而是抵消AG活性。
APETALA2 (AP2) is best known for its function in the outer two floral whorls, where it specifies the identities of sepals and petals by restricting the expression of AGAMOUS (AG) to the inner two whorls in Arabidopsis thaliana. Here, we describe a role of AP2 in promoting the maintenance of floral stem cell fate, not by repressing AG transcription, but by antagonizing AG activity in the center of the flower. We performed a genetic screen with ag‐10 plants, which exhibit a weak floral determinacy defect, and isolated a mutant with a strong floral determinacy defect. This mutant was found to harbor another mutation in AG and was named ag‐11. We performed a genetic screen in the ag‐11 background to isolate mutations that suppress the floral determinacy defect. Two suppressor mutants were found to harbor mutations in AP2. While AG is known to shut down the expression of the stem cell maintenance gene WUSCHEL (WUS) to terminate floral stem cell fate, AP2 promotes the expression of WUS. AP2 does not repress the transcription of AG in the inner two whorls, but instead counteracts AG activity.