Yoneda Yuki, Nakashima Hiroshi, Miyasaka Juro, Ohdoi Katsuaki, Shimizu Hiroshi
Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
Phytochemistry. 2017 May;137:57-65. doi: 10.1016/j.phytochem.2017.02.002. Epub 2017 Feb 16.
Stevia rebaudiana (Bertoni) Bertoni is a plant that biosynthesizes a group of natural sweeteners that are up to approximately 400 times sweeter than sucrose. The sweetening components of S. rebaudiana are steviol glycosides (SGs) that partially share their biosynthesis pathway with gibberellins (GAs). However, the molecular mechanisms through which SGs levels can be improved have not been studied. Therefore, transcription levels of several SG biosynthesis-related genes were analyzed under several light treatments involved in GA biosynthesis. We detected higher transcription of UGT85C2, which is one of the UDP-glycosyltransferases (UGTs) involved in catalyzing the sugar-transfer reaction, under red/far-red (R/FR) 1.22 light-emitting diodes (LEDs) and blue LEDs treatment. In this study, it was demonstrated that transcription levels of SG-related genes and the SGs content are affected by light treatments known to affect the GA contents. It is expected that this approach could serve as a practical way to increase SG contents using specific light treatments.
甜叶菊（Stevia rebaudiana (Bertoni) Bertoni）是一种能生物合成一组天然甜味剂的植物，这些甜味剂的甜度比蔗糖高约400倍。甜叶菊的甜味成分是甜菊糖苷（SGs），其生物合成途径与赤霉素（GAs）部分共享。然而，尚未研究提高SGs水平的分子机制。因此，在参与GA生物合成的几种光照处理下，分析了几个与SG生物合成相关基因的转录水平。我们发现在红/远红（R/FR）1.22发光二极管（LED）和蓝色LED处理下，参与催化糖基转移反应的尿苷二磷酸糖基转移酶（UGTs）之一UGT85C2的转录水平更高。在本研究中，已证明SG相关基因的转录水平和SGs含量受已知影响GA含量的光照处理的影响。预计这种方法可作为一种利用特定光照处理增加SG含量的实用方法。
