Division of Pharmacognosy, Section Metabolomics, Institute of Biology, Leiden University, Leiden, The Netherlands.
J Plant Physiol. 2010 Dec 15;167(18):1525-32. doi: 10.1016/j.jplph.2010.06.022. Epub 2010 Aug 11.
Metabolome analysis by 1-dimensional proton nuclear magnetic resonance (¹H NMR) coupled with multivariate data analysis was carried out in Brassica rapa plants transformed with a gene encoding bacterial isochorismate synthase (ICS). Partial least square-discrimination analysis (PLS-DA) on selected signals suggested that the resonances that were dominant in the transgenic plants corresponded to a glucosinolate (neoglucobrassicin), phenylpropanoids (sinapoyl malate, feruloyl malate, caffeoyl malate), organic acids (succinic acid and fumaric acid) and sugars (α- and β-glucose). In contrast, amino acids alanine threonine, valine, leucine were dominant in the untransformed controls. In addition, HPLC data showed that the transgenic plant accumulated salicylic acid (SA) at significantly higher levels than the control plants, whereas the phylloquinone levels were not affected. The results suggest that the expression of the bacterial isochorismate synthase gene in B. rapa does not affect fluxes into pathways to other groups of secondary metabolites through competition for the same precursor. On the contrary, the biosynthesis of isochorismate-derived products (SA) seems to induce the competitive pathways via phenylalanine (phenylpropanoids) and tryptophan (IAA and indole glucosinolates).
利用 1 维质子核磁共振（¹H NMR）结合多元数据分析对转化了编码细菌异分支酸合酶（ICS）基因的油菜进行代谢组学分析。对选定信号的偏最小二乘判别分析（PLS-DA）表明，在转基因植物中占主导地位的共振对应于硫代葡萄糖苷（新葡糖异硫氰酸盐）、苯丙素类（芥子酰苹果酸、阿魏酰苹果酸、咖啡酰苹果酸）、有机酸（琥珀酸和富马酸）和糖（α-和β-葡萄糖）。相比之下，在未转化的对照中，氨基酸丙氨酸、苏氨酸、缬氨酸和亮氨酸占主导地位。此外，HPLC 数据表明，转基因植物中水杨酸（SA）的积累水平明显高于对照植物，而生育醌水平不受影响。结果表明，在油菜中表达细菌异分支酸合酶基因不会通过竞争相同的前体而影响其他次级代谢物途径的通量。相反，异分支酸衍生产物（SA）的生物合成似乎通过苯丙氨酸（苯丙素类）和色氨酸（IAA 和吲哚硫代葡萄糖苷）诱导竞争途径。
