The Effect Of Flavonoids On Fiber Development

In flavonoid metabolic pathway, interplay of Flavonoid-3-hydroxylase(F3H) and Flavonoid-3’-hydroxylase (F3’H) might elucidate total NAR content, because these two genes share the common substrate.To implement the idea,2 DP A ovules of YZ1 were cultured with five different kinds of flavonoids and two flavonoids Naringenin, Dihydrokaempferol significantly retarded fiber growth development as expected. However, a highly significant effect was noticed in ERI treated ovules in comparison with the control.To further verify significant effect of ERI on fiber development the effect of ERI was compared with control (no ERI) at three different time point integrations. The results clearly depicted an obvious phenotypic change in fiber length and quality in ERI treated ovules as compared to control.Collectively, it can be suggested that ERI is positively associated with fiber development and that the metabolism regulated by F3’H might be important in fiber development. In order to further comprehend the relationship between F3H and F3’Hgenes, cotton F3’H genes were further examined in petal and 5DPA fiber tissues of F3H silence and overexpression lines by using semi quantitative PCR.The results clearly indicated that transcripts of three GrF3’H candidate genes GrF3’H-3, GrF3’H-4 and GrF3’H-8 were up regulated in petals of F3H RNAi lines while in 5DPA fiber the transcription level was not detected. However, these genes were down regulated in petals F3H overexpression lines.Real time PCR was performed and expression pattern of F3’H genes in different YZ1 tissues.These results demonstrated the transcript levels of GhF3’H3 were high in fiber development stages, indicate thatGrF3’H3 could be significantly involved in regulating fiber development in cotton and might have a determining role to play in fiber length and quality parameters. Moreover, development of GhF3’HI and GrF3’H8 transgenic lines will further validate results and provide further insights into flavonoid metabolic pathway, we have isolated two F3’H genes and GhF3’HI and GrF3’H8 cDNAs from upland cotton which showed 98% protein sequence identity and 99% nucleotide sequence identity (Gene Bank GU062185 and Gorai.008G198200).After hybridization and Southern blotting, three to four independent GhF3’H1 RNAi lines with low copy number were selected for T1 generation.