Jae-Hyun Kim

The resveratrol-producing rice (Oryza sativaL.) inbred lines, Iksan 515 (I.515) and Iksan 526 (I.526), developed by the expression of the groundnut (Arachis hypogaea)resveratrol synthase 3(AhRS3) gene in thejaponicarice cultivar Dongjin, accumulated both resveratrol and its glucoside, piceid, in seeds. Here, we investigated the effect of theAhRS3transgene on the expression of endogenous piceid biosynthesis genes (UGTs) in the developing seeds of the resveratrol-producing rice inbred lines. Ultra-performance liquid chromatography (UPLC) analysis revealed that I.526 accumulates significantly higher resveratrol and piceid in seeds than those in I.515 seeds and, in I.526 seeds, the biosynthesis of resveratrol and piceid reached peak levels at 41 days after heading (DAH) and 20 DAH, respectively. Furthermore, RNA-seq analysis showed that the expression patterns ofUGTgenes differed significantly between the 20 DAH seeds of I.526 and those of Dongjin. Quantitative real-time PCR (RT-qPCR) analyses confirmed the data from RNA-seq analysis in seeds of Dongjin, I.515 and I.526, respectively, at 9 DAH, and in seeds of Dongjin and I.526, respectively, at 20 DAH. A total of 245UGTs, classified into 31 UGT families, showed differential expression between Dongjin and I.526 seeds at 20 DAH. Of these, 43UGTs showed more than 2-fold higher expression in I.526 seeds than in Dongjin seeds. In addition, the expression of resveratrol biosynthesis genes (PAL,C4Hand4CL) was also differentially expressed between Dongjin and I.526 developing seeds. Collectively, these data suggest thatAhRS3altered the expression pattern ofUGTgenes, andPAL,C4Hand4CLin developing rice seeds.

The purpose of this study was to investigate alcohol content of commercial Korean fermented sources and to analyze the quality parameters such as titratable acidity, pH, salinity, reducing sugar, alcohol and yeast cell count. Eighty-seven samples of Doenjang, 68 samples of Kanjang and 57 samples of Kochujang were collected and divided into conventional and improved products depending on manufacturing method. As a result, the titratable acidities of conventional Doenjang, Kanjang and Kochujang were 1.72, 1.23 and 1.25%, and those of the improved products were 1.87, 1.80, and 1.00%, respectively. The pH values of conventional Doenjang and Kochujang were lower than those of the corresponding improved products and the pH of conventional Kanjang was higher than improved products. The salinities of the conventional products were higher than the improved products, and an the reducing sugar and alcohol content of the conventional products were lower than the improved products. The detection rate of alcohol (above 1%) in conventional Doenjang, Kanjang, and Kochujang were 6, 10 and 39%, respectively while the corresponding improved products showed much higher rates of 100, 76 and 100%, respectively. There was no significant difference in the yeast cell count between the alcohol-containing products and the alcohol-free products. Accordingly, further study is necessary to develop a manufacturing method using non-degradable sugar and salt control to reduce the production of alcohol in Korean source.