AtDREB2G is involved in the regulation of riboflavin biosynthesis in response to low-temperature stress and abscisic acid treatment in Arabidopsis thaliana

• Published in: Plant science (Limerick) Vol. 347; p. 112196
• Main Authors: Namba, Junya, Harada, Miho, Shibata, Rui, Toda, Yuina, Maruta, Takanori, Ishikawa, Takahiro, Shigeoka, Shigeru, Yoshimura, Kazuya, Ogawa, Takahisa
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.10.2024
• Subjects: Abscisic Acid - metabolism; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; cofactor; Cold Temperature; Cold-Shock Response - genetics; environmental stress; flavin; Gene Expression Regulation, Plant; regulatory factor; Riboflavin - biosynthesis; Riboflavin - metabolism; Transcription Factors - genetics; Transcription Factors - metabolism; vitamin B2; ABA; environmental stress; RF; vitamin B2; FMN; cofactor; FAD; DREB; flavin; regulatory factor; vitamin B
• ISSN: 0168-9452; 1873-2259; 1873-2259
• DOI: 10.1016/j.plantsci.2024.112196

Riboflavin (RF) serves as a precursor to flavin mononucleotide and flavin adenine dinucleotide, which are crucial cofactors in various metabolic processes. Strict regulation of cellular flavin homeostasis is imperative, yet information regarding the factors governing this regulation remains largely elusive. In this study, we first examined the impact of external flavin treatment on the Arabidopsis transcriptome to identify novel regulators of cellular flavin levels. Our analysis revealed alterations in the expression of 49 putative transcription factors. Subsequent reverse genetic screening highlighted a member of the dehydration-responsive element binding (DREB) family, AtDREB2G, as a potential regulator of cellular flavin levels. Knockout mutants of AtDREB2G (dreb2g) exhibited reduced flavin levels and decreased expression of RF biosynthetic genes compared to wild-type plants. Conversely, conditional overexpression of AtDREB2G led to an increase in the expression of RF biosynthetic genes and elevated flavin levels. In wild-type plants, exposure to low temperatures and abscisic acid treatment stimulated enhanced flavin levels and upregulated the expression of RF biosynthetic genes, concomitant with the induction of AtDREB2G. Notably, these responses were significantly attenuated in dreb2g mutants. Our findings establish AtDREB2G is involved in the positive regulation of flavin biosynthesis in Arabidopsis, particularly under conditions of low temperature and abscisic acid treatment. ●We identified AtDREB2G as a potential regulator of cellular flavin levels.●dreb2g mutants exhibit reduced flavin levels and decreased expression of RF biosynthetic genes.●The AtDREB2G expression is significantly induced by low-temperature stress and ABA treatment.●AtDREB2G enhances RF biosynthesis in response to low-temperature stress and ABA treatment.