Bertoldi Daniela, Tassoni Annalisa, Martinelli Lucia, Bagni Nello
Department of Biology e.s. and Interdepartmental Centre for Biotechnology, University of Bologna, Via Irnerio 42, 40126, Bologna, Italy.
Physiol Plant. 2004 Apr;120(4):657-666. doi: 10.1111/j.0031-9317.2004.0282.x.
Polyamine content and activities of enzymes of polyamine biosynthesis were assayed during somatic embryogenesis in Vitis vinifera callus cultures of Chardonnay and Brachetto 'a grappolo lungo' (Brachetto g.l.) cultivars. The analyses were carried out on embryogenic callus samples, embryos at different stages and developing plants. Polyamine content, both in the free and PCA-soluble conjugated form, was higher in Brachetto g.l. than in Chardonnay, and putrescine was present at higher concentrations than the other polyamines. In all samples of both cultivars, ornithine decarboxylase activity (ODC, EC 4.1.1.17) was higher than arginine decarboxylase (ADC, EC 4.1.1.19), with a maximum in developing plant roots. S-Adenosylmethionine decarboxylase (SAMDC, EC 4.1.1.50) activity displayed a similar trend. The activities of all three enzymes were detected both in the supernatant and pellet fractions, indicating for the first time the presence of SAMDC activity in the particulate fraction. Particularly in the Chardonnay cultivar, an increase in the mRNAs expression patterns of ODC and SAMDC during morphogenesis from small embryos to plantlets was detected by northern blot, suggesting a direct correlation with enzymatic activities.
在霞多丽（Chardonnay）和布拉凯托“长串葡萄”（Brachetto 'a grappolo lungo'，简称Brachetto g.l.）葡萄品种的葡萄愈伤组织培养物体细胞胚胎发生过程中，对多胺含量和多胺生物合成酶的活性进行了测定。分析在胚性愈伤组织样品、不同阶段的胚以及发育中的植株上进行。无论是游离形式还是PCA可溶性结合形式，Brachetto g.l.中的多胺含量均高于霞多丽，且腐胺的浓度高于其他多胺。在两个品种的所有样品中，鸟氨酸脱羧酶活性（ODC，EC 4.1.1.17）均高于精氨酸脱羧酶（ADC，EC 4.1.1.19），在发育中的植株根中达到最高。S-腺苷甲硫氨酸脱羧酶（SAMDC，EC 4.1.1.50）活性呈现类似趋势。所有这三种酶的活性在上清液和沉淀组分中均被检测到，首次表明在颗粒组分中存在SAMDC活性。特别是在霞多丽品种中，通过Northern印迹检测到从小胚到植株形态发生过程中ODC和SAMDC的mRNA表达模式增加，表明与酶活性直接相关。
