Chang Yung-Jin, Kim Bo-Ra, Kim Soo-Un
School of Agricultural Biotechnology, Seoul National University, 151-742, Seoul, Korea.
Biotechnol Lett. 2005 Sep;27(18):1375-80. doi: 10.1007/s10529-005-3684-7.
Relative transcript levels of eight rice diterpene cyclases at the branch points of gibberellins and phytoalexins biosynthesis pathway were measured by reverse transcription quantitative PCR. Metabolic flux analysis by the distribution ratio of common substrate showed that UV-irradiation of etiolated rice seedlings decreased the flux for primary metabolism of gibberellins biosynthesis by half (from 62 to 27%) and 41% of geranylgeranyl pyrophosphate was used for induction of pimaradiene intermediate as the major phytoalexin. In comparison, light-illumination used almost all geranylgeranyl pyrophosphate (96%) for gibberellin biosynthesis to stimulate the plant growth and strongly repressed the metabolic flux for phytoalexins biosynthesis.
通过逆转录定量PCR测定了赤霉素和植物抗毒素生物合成途径分支点处8种水稻二萜环化酶的相对转录水平。通过共同底物的分配比进行的代谢通量分析表明，对黄化水稻幼苗进行紫外线照射会使赤霉素生物合成初级代谢的通量降低一半（从62%降至27%），并且41%的香叶基香叶基焦磷酸用于诱导作为主要植物抗毒素的半日花二烯中间体。相比之下，光照几乎将所有香叶基香叶基焦磷酸（96%）用于赤霉素生物合成以刺激植物生长，并强烈抑制植物抗毒素生物合成的代谢通量。
