The Effcts Of Downregulation Of Leaf Flavin Content On Flowering Time And Disease Resistance In Arabidopsis

Riboflavin is the forebody of flavin mononucleotide?FMN?and flavin adenine dinucleotide?FAD?,indispensable cofactors for many metabolic enzymes that catalyze all kinds of biochemical responses.Plants can compound riboflavin while the standards change widely in diverse organs and during diverse phases of development,indicating that varies in riboflavin phases may induce physiological influences.The well-demonstrated developmental role of oviparous riboflavin-binding protein?RfBP?in riboflavin binding and redistribution inspired the idea to manipulate plant riboflavin content by engineering with the turtle RfBP.Its activity in riboflavin binding permits for the function in regulating free flavin content in transgenic plants.On this basis,in this study we have illuminated the accidental effect of the RfBP protein in impactting flowering time after again expression in Arabidopsis.In the present study,Arabidopsis RfBP+ and RfBP-lines were investigated in comparison with the WT plant.RfBP-displayed the role of inducing downregulation of free flavin concentrations in leaves,accompanied by the early flowering phenotype.Externally treating plants with riboflavin caused significant reduction in the expression of the florigen gene FT and floral promoting photoperiod genes in leaves,in the expression of the FD gene encoding bZIP transcription factor FD essential for flowering time control and the floral meristem identity gene API in the shoot apex.In this case,flavin concentrations were brought back to the constituitive levels inside plants.RfBP-causced early flowering was correlated with elevated expression of floral promoting photoperiod genes and FT in leaves but not related to genes join in vernalization pathways,gibberellin pathways and autonomous regulation pathways which offer flowering adjustion mechanisms.Moreover,numerous studies show that the reactive oxygen?ROS?participates in the control of plant responses to pathogen resistance.Riboflavin mediated biological processes related with H₂O₂,a cellular signal that can control defense responses.Additional data in this study suggested that ectopic expression of RfBP lead to an increase of the intrinsic H₂O₂ level in association with enhanced resistance to a bacterial pathogen.