FtbZIP85 Is Involved in the Accumulation of Proanthocyanidin by Regulating the Transcription of FtDFR in Tartary Buckwheat

Abstract

As a drought-tolerant crop, Tartary buckwheat survives under adverse environmental conditions, including drought stress. Proanthocyanidins (PAs) and anthocyanins are flavonoid compounds, and they participate in the regulation of resistance to both biotic and abiotic stresses by triggering genes’ biosynthesis of flavonoids. In this study, a basic leucine zipper, basic leucine zipper 85 (FtbZIP85), which was predominantly expressed in seeds, was isolated from Tartary buckwheat. Our study shows that the expressions of FtDFR, FtbZIP85 and FtSnRK2.6 were tissue-specific and located in both the nucleus and the cytosol. FtbZIP85 could positively regulate PA biosynthesis by binding to the ABA-responsive element (ABRE) in the promoter of dihydroflavonol 4-reductase (FtDFR), which is a key enzyme in the phenylpropanoid biosynthetic pathway. Additionally, FtbZIP85 was also involved in the regulation of PA biosynthesis via interactions with FtSnRK2.6 but not with FtSnRK2.2/2.3. This study reveals that FtbZIP85 is a positive regulator of PA biosynthesis in TB.

FlbZIP12 gene enhances drought tolerance via modulating flavonoid biosynthesis in Fagopyrum leptopodum

“…Indeed, accumulation of the phytohormone abscisic acid (ABA) triggers multiple physiological responses through ABA signaling ( Soma et al., 2023 ), such as inhibiting seed germination and promoting stomatal closure to decrease transpiration. In addition, plants produce a variety of pigments, such as flavonoids, carotenoids, and anthocyanins ( Liu et al., 2023 ; Mishra, 2023 ). These strategies are not exclusive and multiple strategies can be employed simultaneously to enhance drought tolerance.…”