Servettaz O, Cortesi F, Longo C P
Istituto di Scienze Botaniche dell'Università, Centro di Studio del Consiglio Nazionale delle Ricerche per la Biologia Cellulare e Molecolare delle Piante, 20133 Milano, Italy.
Plant Physiol. 1976 Oct;58(4):569-72. doi: 10.1104/pp.58.4.569.
Benzyladenine (BA) increases the rate of expansion of dark-grown sunflower (Helianthus annuus L.) cotyledons. The hormone slightly enhances the development of the two glyoxysomal enzymes, isocitrate lyase and malate synthetase, during the first 3 days of germination and greatly accelerates their decay in the 2 following days. The levels of the peroxisomal enzymes, glycolate oxidase and glyoxylate reductase, are enhanced by BA more than those of the two glyoxysomal enzymes. These effects of BA on microbody enzymes are very similar to those of white light. Mitochondrial enzyme activities are increased to a varying extent by BA: the increase is minimal for fumarase, and maximal for cytochrome oxidase. The level of cytochrome oxidase is enhanced 346% at the 5th day of germination. Also, the rate of O(2) consumption is increased by BA, but the time course of this increased O(2) consumption does not match with that of cytochrome oxidase. Fusicoccin, a fungal toxin, mimics the effect of BA on cotyledon expansion, but fails to duplicate its action on microbody enzymes. This suggests that the effect of BA on microbody enzymes is not closely linked with the mechanism of growth promotion.
苄基腺嘌呤（BA）可提高暗中生长的向日葵（Helianthus annuus L.）子叶的扩展速率。在萌发的前3天，该激素略微增强了两种乙醛酸循环体酶（异柠檬酸裂解酶和苹果酸合成酶）的发育，并在随后的2天极大地加速了它们的降解。BA对过氧化物酶体酶（乙醇酸氧化酶和乙醛酸还原酶）水平的提高幅度大于对两种乙醛酸循环体酶水平的提高幅度。BA对微体酶的这些作用与白光的作用非常相似。BA不同程度地提高了线粒体酶的活性：对延胡索酸酶的提高最小，对细胞色素氧化酶的提高最大。在萌发第5天时，细胞色素氧化酶的水平提高了346%。此外，BA增加了氧气消耗速率，但这种增加的氧气消耗的时间进程与细胞色素氧化酶的不同。真菌毒素藤霉素模拟了BA对子叶扩展的作用，但未能复制其对微体酶的作用。这表明BA对微体酶的作用与生长促进机制没有紧密联系。
