Genome-wide identification of bHLH transcription factors: Discovery of a candidate regulator related to flavonoid biosynthesis in Erigeron breviscapus

Qingqing Gao; Wanling Song; Xia Li; Chunfan Xiang; Geng Chen; Guisheng Xiang; Xiangyu Liu; Guanghui Zhang; Xiaoning Li; Shengchao Yang; Chenxi Zhai; Yan Zhao

doi:10.3389/fpls.2022.977649

Genome-wide identification of bHLH transcription factors: Discovery of a candidate regulator related to flavonoid biosynthesis in Erigeron breviscapus

Front Plant Sci. 2022 Sep 14:13:977649. doi: 10.3389/fpls.2022.977649. eCollection 2022.

Authors

Qingqing Gao^{1

2}, Wanling Song^{1

2}, Xia Li^{1

2}, Chunfan Xiang^{1

2}, Geng Chen^{1

2}, Guisheng Xiang¹, Xiangyu Liu¹, Guanghui Zhang¹, Xiaoning Li¹, Shengchao Yang¹, Chenxi Zhai³, Yan Zhao^{1

2}

Affiliations

¹ Key Laboratory of Medicinal Plant Biology of Yunnan Province, National and Local Joint Engineering Research Center on Germplasms Innovation and Utilization of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, China.
² College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China.
³ Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, United States.

Abstract

Erigeron breviscapus is a Compositae plant, and its rich flavonoids have shown strong preventative and curative effects in the treatment of cardio- and cerebrovascular diseases. bHLH genes play a crucial role in plant growth and development. There are 116 EbbHLH genes in E. breviscapus, and each gene has been named based on its chromosome location. Our phylogenetic analysis divided these genes into 18 subfamilies. To further investigate its function, EbbHLH80 was isolated from E. breviscapus leaves. Next, transcriptomic and metabolomic analyses of tobacco leaves were performed. Among 421 differentially accumulated compounds, 98 flavonoids were identified. In addition, differentially expressed genes were identified using RNA-seq, and further analysis suggested that EbbHLH80-OE could not only regulate the expression of some structural genes in the flavonoid biosynthesis pathway to achieve flavonoid accumulation but also be involved in the regulation of a series of downstream pathways, such as stress response, ABA and ethylene signal transduction, to affect plant growth and development. The results of our analysis provide new insights into the function of EbbHLH80 and lay the foundation for future functional studies on E. breviscapus.

Keywords: EbbHLH80; Erigeron breviscapus; anthocyanins; bHLH transcription factors; flavonoids.