APETALA2 antagonizes the transcriptional activity of AGAMOUS in regulating floral stem cells in Arabidopsis thaliana. Issue 3 (8th September 2016)

• Record Type: Journal Article
• Authors: Huang, Zhigang; Shi, Ting; Zheng, Binglian; Yumul, Rae Eden; Liu, Xigang; You, Chenjiang; Gao, Zhihong; Xiao, Langtao; Chen, Xuemei
• Is Part Of: New phytologist. Volume 215:Issue 3(2017)
• Page Start: 1197
• Page End: 1209
• Publication Date: 2016-09-08
• Subjects: AGAMOUS -- APETALA2 -- floral determinacy -- floral stem cells -- KNUCKLES -- WUSCHEL; Botany -- Periodicals; 580
• DOI: 10.1111/nph.14151
• Languages: English
• ISSNs: 0028-646X

Abstract

Summary: 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.