UV-B promotes flavonoid biosynthesis in Ginkgo biloba by inducing the GbHY5-GbMYB1-GbFLS module

Abstract

Ginkgo biloba (ginkgo) leaves have medicinal value due to their high levels of secondary metabolites, such as flavonoids. We found that the flavonoid content in ginkgo leaves increases significantly at high altitudes (Qinghai-Tibet Plateau). Considering that high UV-B radiation is among the key environmental characteristics of the Qinghai-Tibet Plateau, we carried out simulated UV-B treatments on ginkgo seedlings and found that the flavonoid content of the leaves increased significantly following the treatments. Combined with results from our previous studies, we determined that the transcription factor GbHY5 may play a key role in responses to UV-B radiation. Overexpression of GbHY5 significantly promoted the accumulation of flavonoids in both ginkgo callus and Arabidopsis thaliana. Furthermore, yeast two-hybrid and real-time quantitative PCR showed that GbHY5 promoted the expression of GbMYB1 by interacting with GbMYB1 protein. Overexpression of GbMYB1 in ginkgo callus and A. thaliana also significantly promoted flavonoid biosynthesis. GbFLS encodes a key enzyme in flavonoid biosynthesis, and its promoter has binding elements of GbHY5 and GbMYB1. A dual-luciferase reporter assay indicated that while GbHY5 and GbMYB1 activated the expression of GbFLS individually, their co-expression achieved greater activation. Our analyses reveal the molecular mechanisms by which the UV-B-induced GbHY5-GbMYB1-GbFLS module promotes flavonoid biosynthesis in ginkgo, and they provide insight into the use of UV-B radiation to enhance the flavonoid content of ginkgo leaves.

Metabolomic Profiling of Floccularia luteovirens from Different Geographical Regions Proposes a Novel Perspective on Their Antioxidative Activities

“…Consequently, species inhabiting high altitudes necessitate the adoption of multiple strategies to effectively acclimate to harsh environmental conditions. Numerous previous studies suggested that environmental factors have a significant effect on the growth and development of organisms, especially on the accumulation of their flavonoid metabolites [39][40][41]. Environmental factors contribute to the flavonoid biosynthesis of many organisms and generate economic value.…”

Identification of One O-Methyltransferase Gene Involved in Methylated Flavonoid Biosynthesis Related to the UV-B Irradiation Response in Euphorbia lathyris

“…When plants receive high doses of UV-B radiation, the plant leaves show severe wilting and curling. In addition, certain doses of UV-B radiation cause dwarfism in plants [26,27]. The damage caused by UV-B radiation to plants is mainly caused by the accumulation of reactive oxygen species (ROS), which harm cells by damaging proteins and DNA [28,29].…”

Metabolome and Transcriptome Analysis Provide Insights into Flower Bud Color Variation in the Adaptation to UV-B Radiation of Litchi

“…In this present study, LcFLS and UGTs were significantly upregulated in the flower buds of EEM cultivars compared to MLM cultivars. FLS is an important enzyme responsible for the production of flavonols and has been proven to play vital roles in flower coloration [55,56] and response to UV-B radiation [17,57]. FLS competes with DFR for the common substrate dihydroflavonols, leading to the production of flavonols and anthocyanins, respectively [58].…”

“…Flavonoids have been demonstrated as the major UV-absorbing compound that protects plants from the detrimental effects of UV-B radiation [15][16][17]. A previous study revealed that the concentration of flavone aglycones was elevated because of increasing UV-B radiation in an Antarctic moss, Bryum argenteum [18].…”