【摘要】 以葡萄品种京秀(VitisviniferaL.cv.Jingxiu)一年生扦插苗为试材,40℃高温处理30min,并以25℃为对照,采用体外底物磷酸化方法对叶片中蛋白激酶的活性进行了测定。结果表明,热胁迫处理后,叶片中蛋白激酶在底物髓鞘碱性蛋白(myelinbasicprotein,MBP)浓度为0.5mg·ml-1时,其活性达到最大(7678.7cpm),而后随底物浓度的进一步增加,其活性下降。Mg2+浓度为5mmol·L-1时,蛋白激酶活性达到最大(8165.8cpm)。Ca2+对蛋白激酶活性的影响极弱,Mn2+对蛋白激酶活性的激活没有影响。ATP浓度为50μmol·L-1时,蛋白激酶的活性最大(7900.9cpm),比对照高4.7倍。在以组蛋白-III(histone-III)为底物时,蛋白激酶的活性很微弱,且Mg2+和Ca2+对蛋白激酶有极弱的激活作用。更多还原

【Abstract】 One-year-old grape plants (Vitis vinifera L. cv. Jingxiu) by cuttage were used as experimental materials. The activity of protein kinase in grape leaves after treatment of heat stress (40℃) was measured through substrate phosphorylation in vitro. The results showed that the activity of protein kinase in leaves after heat stress reached a peak value(7 678.7 cpm) as MBP concentration was 0.5 mg·ml-1, and then the activity of protein kinase decreased slightly as MBP concentration increased continuously. The activity of protein kinase exhibited a maximum value as Mg2+concentration was 5 mmol·L-1in reaction system with MBP substrate, and then, the activity of protein kinase decreased. Stimulation by Ca2+ to the activity of protein kinase was extremely weak. Mn2+ had no stimulative effect on the activity of protein kinase. Phosphorylation of protein kinase to histone-III was weak in reaction system with histone-III substrate. Mg2+ and Ca2+ displayed extremely weak effect on kinase activity in the reaction system with histone-III substrate. The activity of protein kinase reached a peak value (7 900.9 cpm) as ATP concentration was 50μmol·L-1, then, the activity of protein kinase decreased gradually as ATP concentration increased continuously .更多还原