Transcription factor GLK1 promotes anthocyanin biosynthesis via an MBW complex‐dependent pathway in Arabidopsis thaliana

• Published in: Journal of integrative plant biology 2023-06, Vol.65 (6), p.1521-1535
• Main Authors: Li, Yan, Lei, Wei, Zhou, Zuxu, Li, Yanlin, Zhang, Dawei, Lin, Honghui
• Format: Article
• Language: English
• Subjects: Accumulation; anthocyanin biosynthesis; Anthocyanins; Biosynthesis; Distribution patterns; GLK1; MYB75; Photoinhibition; Pigments; Plant growth; Plants (botany); Protein interaction; Proteins; Regulatory mechanisms (biology); Spatial distribution; Transcription activation; Transcription factors; transcriptional activation activity
• ISSN: 1672-9072; 1744-7909
• DOI: 10.1111/jipb.13471

ABSTRACT Anthocyanins are important natural plant pigments and play diverse roles in plant growth and adaptation. Anthocyanins function as screens to protect photosynthetic tissues from photoinhibition. However, the regulatory mechanisms underlying the biosynthesis and spatial accumulation pattern of anthocyanins remain some unresolved issues. Here, we demonstrate that the GARP‐type transcription factor GOLDEN2‐LIKE 1 (GLK1) functions as a positive factor in anthocyanin accumulation. GLK1 enhances the transcriptional activation activities of MYB75, MYB90, and MYB113 via direct protein‐protein interactions to increase the expression of anthocyanin‐specific biosynthetic genes. Anthocyanins accumulate in an acropetal manner in Arabidopsis. We also found that the expression pattern of GLK1 overall mimicked the accumulation pattern of anthocyanin from the base of the main stem to the shoot apex. Based on these findings, we established a working model for the role of GLK1 in anthocyanin accumulation and propose that GLK1 mediates the spatial distribution pattern of anthocyanins by affecting the transcriptional activation activities of MYB75, MYB90, and MYB113. Anthocyanins are important natural plant pigments that play diverse roles in plant growth, such as affecting pollination and seed distribution, and protecting against UV light. The GARP‐type transcription factor GLK1 positively regulates anthocyanin accumulation.