The APETALA2-MYBL2 module represses proanthocyanidin biosynthesis by affecting formation of the MBW complex in seeds of Arabidopsis thaliana.

ABSTRACT: Proanthocyanidins (PAs) are the second most abundant plant phenolic natural products. PA biosynthesis is regulated by the well-documented MYB/bHLH/WD40 (MBW) complex, but how this complex itself is regulated remains ill defined. Here, in situ hybridization and β-glucuronidase staining show that APETALA2 (AP2), a well-defined regulator of flower and seed development, is strongly expressed in the seed coat endothelium, where PAs accumulate. AP2 negatively regulates PA content and expression levels of key PA pathway genes. AP2 activates MYBL2 transcription and interacts with MYBL2, a key suppressor of the PA pathway. AP2 exerts its function by directly binding to the AT-rich motifs near the promoter region of MYBL2. Molecular and biochemical analyses revealed that AP2 forms AP2-MYBL2-TT8/EGL3

SUBMITTER: Jiang W 

PROVIDER: S-EPMC10943577 | biostudies-literature | 2024 Mar

REPOSITORIES: biostudies-literature