Little impacts on transcriptome and secondary metabolites of transgenic rice by resveratrol synthase gene

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a stilbenoid that displays a wide range of biological effects, notably as a cardioprotective, antitumor, or neuroprotective agent, as well as an antifungal or antibacterial compound. Obtaining resveratrol safely from the daily diet will contribute to disease prevention and life extension. In this study, the microarray-based transcriptome profiles of two transgenic resveratrol rice lines, Iksan515 (I515) and Iksan526 (I526) were compared with those of the isogenic DJ variety and a non-transgenic common variety Nagdong (ND) as a reference strain, in order to identify the unpredictable effects of gene insertion. Only five genes were differentially expressed in both transgenic lines, suggesting that the impact of insertion of RS on the transcriptome was minimal. No gene up- or down-stream from the RS insertion showed more than 2-fold change in expression, implying that overexpression of RS could occur without causing activation of any unexpected gene networks in secondary metabolic pathways. Three up-stream and one down-stream metabolites from RS, viz., ρ-coumaric, acid, vanillin, chlorogenic acid, and biochanin A, demonstrated similar levels between transgenic lines and their counterpart however, a difference in naringenin level was observed on transgenic line I515 compared to those of I526, DJ, and ND.