Hirai N, Yoshida R, Todoroki Y, Ohigashi H
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Japan.
Biosci Biotechnol Biochem. 2000 Jul;64(7):1448-58. doi: 10.1271/bbb.64.1448.
The biosynthetic pathways to abscisic acid (ABA) were investigated by feeding [1-(13)C]-D-glucose to cuttings from young tulip tree shoots and to two ABA-producing phytopathogenic fungi. 13C-NMR spectra of the ABA samples isolated showed that the carbons at 1, 5, 6, 4', 7' and 9' of ABA from the tulip tree were labeled with 13C, while the carbons at 2, 4, 6, 1', 3', 5', 7', 8' and 9' of ABA from the fungi were labeled with 13C. The former corresponds to C-1 and -5 of isopentenyl pyrophosphate, and the latter to C-2, -4 and -5 of isopentenyl pyrophosphate. This finding reveals that ABA was biosynthesized by the non-mevalonate pathway in the plant, and by the mevalonate pathway in the fungi. 13C-Labeled beta-carotene from the tulip tree showed that the positions of the labeled carbons were the same as those of ABA, being consistent with the biosynthesis of ABA via carotenoids. Lipiferolide of the tulip tree was also biosynthesized by the non-mevalonate pathway.
通过给年轻郁金香树嫩枝的插条以及两种产生脱落酸（ABA）的植物病原真菌饲喂[1-(13)C]-D-葡萄糖，研究了ABA的生物合成途径。分离得到的ABA样品的13C-NMR光谱显示，来自郁金香树的ABA的1、5、6、4'、7'和9'位的碳被13C标记，而来自真菌的ABA的2、4、6、1'、3'、5'、7'、8'和9'位的碳被13C标记。前者对应于异戊烯基焦磷酸的C-1和-5，后者对应于异戊烯基焦磷酸的C-2、-4和-5。这一发现表明，植物中ABA是通过非甲羟戊酸途径生物合成的，而在真菌中是通过甲羟戊酸途径生物合成的。来自郁金香树的13C标记的β-胡萝卜素表明，标记碳的位置与ABA的相同，这与通过类胡萝卜素生物合成ABA一致。郁金香树的脂化醇也通过非甲羟戊酸途径生物合成。
