Quantitative real-time pcr
Cotton flowers were harvested at different time points for flavonoind gene expression analysis. Rna extraction war performed following the procedure of spectrum plant total rna kit of sigma-aldrich(usa), cdna synthesis and Qrt-pgr were performed as previously described (48), with cotton ubiquitin gene ubq7 as the reference gene 49 . flavonoid gene sequences were obtained from the public NCBI unigene data bank and the cotton d genome sequence (http://www.phytozome.com/).
The expression of all genes was normalized to ubq7. Three biological replicates were performed.
The error bars represent the standard deviations (sd). All primers are listed in table SI. Superscript
III reverse transcription kits were from invitrogen (garlsbad,USA).reagents(iTaq SYBR Green supermix with ROX) for real time PCR were from bio-rad (foster City, USA).