You Jin Lima, Ho Young Jeongb, Chan Saem Gila, Soon-Jae Kwonc, Jong Kuk Nad, Chanhui Leeb,*, Seok Hyun Eoma,*
a Department of Horticultural Biotechnology, College of Life Sciences, Kyung Hee University, Yongin 17104, Republic of Korea
b Department of Plant & Environmental New Resources, College of Life Sciences, Kyung Hee University, Yongin 17104, Republic of Korea
c Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 56212, Republic of Korea
d Department of Controlled Agriculture, College of Lifelong Learning, Kangwon National University, Chunchon 24341, Republic of Korea
*Corresponding author : Chanhui Lee, Seok Hyun Eom
This study investigated the effects of persistent ultraviolet B (UV-B) irradiation on isoflavone accumulation in soybean sprouts. Three malonyl isoflavones were increased by UV-B. Malonylgenistin specifically accumulated upon UV-B exposure, whereas the other isoflavones were significantly increased under both dark conditions and UV-B exposure. The results of isoflavone accumulation to UV-B irradiation time were observed as following: acetyl glycitin rapidly increased and then gradually decreased; malonyl daidzin and malonyl genistin were highly accumulated within an intermediate period; genistein and daidzin were gradually maximized; daidzin, glycitin, genistein, and malonyl glycitin did not increase; and glycitin, acetyl daidzin, and acetyl genistin exhibited trace amounts. Transcriptional analysis of isoflavonoid biosynthetic genes demonstrated that most metabolic genes were highly activated in response to UV-B 24 and UV-B 36 treatments. In particular, it was found that GmCHS6, GmCHS7, and GmCHS8 genes among the eight known genes encoding chalcone synthase were specifically related to UV-B response.
Keywords : Isoflavone; Metabolic gene expression; Nitric oxide; Soybean sprouts