Premium
APETALA 2 antagonizes the transcriptional activity of AGAMOUS in regulating floral stem cells in Arabidopsis thaliana
Author(s) -
Huang Zhigang,
Shi Ting,
Zheng Binglian,
Yumul Rae Eden,
Liu Xigang,
You Chenjiang,
Gao Zhihong,
Xiao Langtao,
Chen Xuemei
Publication year - 2017
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14151
Subject(s) - agamous , biology , sepal , petal , mutant , transcription factor , microbiology and biotechnology , arabidopsis thaliana , arabidopsis , genetic screen , stem cell , genetics , gentiana , homeotic gene , gene , botany , pollen , stamen
SummaryAPETALA 2 ( AP 2 ) 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 AP 2 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 AP 2 . While AG is known to shut down the expression of the stem cell maintenance gene WUSCHEL ( WUS ) to terminate floral stem cell fate, AP 2 promotes the expression of WUS . AP 2 does not repress the transcription of AG in the inner two whorls, but instead counteracts AG activity.