Fujihara S, Yamaguchi M
Department of Agricultural Chemistry, College of Agriculture, University of Osaka Prefecture, 4-cho, Mozuumemachi, Sakai, Osaka 591, Japan.
Plant Physiol. 1978 Jul;62(1):134-8. doi: 10.1104/pp.62.1.134.
Some studies on the effects of xanthine oxidase inhibitor allopurinol [4-hydroxypyrazolo(3,4-d)pyrimidine] on allantoin metabolism of soybean plants (Glycine max cv. Tamanishiki) are reported. Soybean seedlings, aseptically germinated for 96 hours on agar containing 1 millimolar allopurinol, contained only slight amounts of allantoin, allantoic acid, and urea as compared with controls. Analysis of purines and pyrimidines of the allopurinol-treated seedlings showed marked accumulation of xanthine both in the cotyledons and seedling axes. No hypoxanthine accumulation was found. Xanthine accumulation due to allopurinol treatment was relatively low after the cotyledons had fallen. For nodulated plants, allopurinol caused a significant drop in allantoin (+allantoic acid) in the stems and nodules, accompanied by a striking accumulation of xanthine in the nodules. The xanthine concentration in the nodules far exceeded that in the germinated seedlings. Allopurinol at a concentration of 50 micromolar strongly inhibited xanthine oxidase prepared from soybean nodules.The results suggested that the main pathway of allantoin formation in soybean plants was through purine decomposition, via xanthine-uric acid. It was specially noted that a very active purine-decomposing system existed in soybean nodules.
本文报道了关于黄嘌呤氧化酶抑制剂别嘌呤醇[4-羟基吡唑并(3,4-d)嘧啶]对大豆植株（大豆品种玉锦）尿囊素代谢影响的一些研究。在含有1毫摩尔别嘌呤醇的琼脂上无菌萌发96小时的大豆幼苗，与对照相比，仅含有少量的尿囊素、尿囊酸和尿素。对用别嘌呤醇处理过的幼苗的嘌呤和嘧啶进行分析表明，在子叶和幼苗轴中黄嘌呤均有明显积累。未发现次黄嘌呤积累。子叶脱落后，别嘌呤醇处理导致的黄嘌呤积累相对较低。对于结瘤植株，别嘌呤醇导致茎和根瘤中尿囊素（+尿囊酸）显著下降，同时根瘤中黄嘌呤显著积累。根瘤中的黄嘌呤浓度远远超过萌发幼苗中的浓度。50微摩尔浓度的别嘌呤醇强烈抑制从大豆根瘤中制备的黄嘌呤氧化酶。结果表明，大豆植株中尿囊素形成的主要途径是通过嘌呤分解，经由黄嘌呤-尿酸。特别值得注意的是，大豆根瘤中存在非常活跃的嘌呤分解系统。
