GmCHS8 and GmIFS2 Gene Co-Determine Accumulation of Isoflavonoid in Soybean

Soybean isoflavonoids (isoFLVs) are natural secondary componds produced in Phenylpropanol metabolism Pathway. In past ten years, the isoFLVs were proved with anti-cancer activity to human health and therefore intensively included in nowadays food industry. However, the low content in natural soybean germplasm is a major limit to be weed in desired population. Herein we report that expression patterns of 18 362 genes were monitored by using Microarray between 30 to 70 days after pollination (DAP) during the soybean seed development. The expression profile of CHS8 and IFS2 revealed by both Microarray and RT-PCR indicated these two genes may play critical roles in determination of the accumulation of isoFLV in soybean seeds. According to Agrobacterium rhizogenes transformation system, over-expression of individuals of CHS8 and IFS2 resulted in 65.9% and 34.4% isoFLV increase respectively, but not significant in Duncan’s multiple test at the 0.05 probability level. However, co-expression of CHS8+ IFS2 significantly increased (P0.0001) the isoFLV content up to 82.3% when comparing to non-transgenic control. Conclusively, both IFS2 and CHS8 gene co-determine the accumulation of isoFLV in soybean.