Genome-Wide Identification of Direct Targets of the TTG1-bHLH-MYB Complex in Regulating Trichome Formation and Flavonoid Accumulation in Arabidopsis Thaliana

• Published in: International journal of molecular sciences 2019-10, Vol.20 (20), p.5014
• Main Authors: Wei, Zelou, Cheng, Yalong, Zhou, Chenchen, Li, Dong, Gao, Xin, Zhang, Shuoxin, Chen, Mingxun
• Format: Article
• Language: English
• Subjects: Abiotic stress; Accumulation; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; arabidopsis thaliana; Basic Helix-Loop-Helix Transcription Factors - genetics; Basic Helix-Loop-Helix Transcription Factors - metabolism; Biological activity; Biosynthesis; Chromatin; flavonoid accumulation; Flavonoids; Flavonoids - biosynthesis; Flavonoids - genetics; Fusion protein; Gene expression; Gene Expression Regulation, Plant; Genes; Genes, Plant - genetics; Genomes; Glucocorticoids; Immunoprecipitation; mbw complex; Plant Leaves - metabolism; Plant Shoots - metabolism; Plants, Genetically Modified - genetics; Post-translation; Proteins; Regulatory proteins; Seeds; Sequence Analysis, RNA; Transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism; trichome formation; Trichomes - genetics; Trichomes - metabolism; ttg1; WD40 Repeats
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms20205014

Extensive studies have shown that the MBW complex consisting of three kinds of regulatory proteins, MYB and basic helix-loop-helix (bHLH) transcription factors and a WD40 repeat protein, TRANSPARENT TESTA GLABRA1 (TTG1), acts in concert to promote trichome formation and flavonoid accumulation in . TTG1 functions as an essential activator in these two biological processes. However, direct downstream targets of the TTG1-dependent MBW complex have not yet been obtained in the two biological processes at the genome-wide level in . In the present study, we found, through RNA sequencing and quantitative real-time PCR analysis, that a great number of regulatory and structural genes involved in both trichome formation and flavonoid accumulation are significantly downregulated in the young shoots and expanding true leaves of plants. Post-translational activation of a TTG1-glucocorticoid receptor fusion protein and chromatin immunoprecipitation assays demonstrated that these downregulated genes are directly or indirectly targeted by the TTG1-dependent MBW complex in vivo during trichome formation and flavonoid accumulation. These findings further extend our understanding of the role of TTG1-dependent MBW complex in the regulation of trichome formation and flavonoid accumulation in .