Abstract:

The protein kinases were identified at different developmental stages of apple (Malus domestica L. Borth. cv. Red Starking) and grape (Vitis vinifera L. × V.lubrusca L. cv. Kyoho) fruit, and these protein kinases were found to be greatly activated by Ca2+. This demonstrated that calcium-dependent protein kinase plays an important role in apple and grape fruits. The results also showed that calmodulin (CaM) had no stimulation effect, but the CaM antagonists, such as calmidazolium, W7 and trifluoroacetic acid (TFA), had some inhibitory effects on the activities of this kind of protein kinase in both fruits, indicating that the detected protein kinases may be a kind of calmodulin-like domain protein kinase or calcium-dependent protein kinase (CDPK). There were distinct differences between apple and grape fruits, both in the characteristics and in the activity evolution patterns of the protein kinases during fruit development. The activity of calcium-dependent protein kinase was little changed in the three stages of apple fruit development, while in grape fruit the activity of this protein kinase was much higher in stage Ⅱ than those in stage Ⅰ and stage Ⅲ. The calcium-dependent protein kinase in apple fruits was strongly activated by Mn2+, and it was sensitive to heat treatment, but in grape fruits it was neither stimulated by Mn2+ nor sensitive to high temperature. Besides, phosphatidyl-serine (PS) had little effect on the activities of calcium-dependent protein kinase in grape fruits, but had stimulative effects in apple fruits. It was thus proposed that there might be a kind of calcium- and phosphatide-activated protein kinase, i.e., PKC, in apple fruits. The differences among the kinds, characteristics and the activity evolution patterns of protein kinases during apple and grape fruit development, suggest that the protein kinases may be involved in the process of fruit development.

苹果和葡萄果实发育过程中蛋白激酶特性的比较研究
梁小娥 张大鹏*   贾文锁
（中国农业大学果树分子发育生物学实验室，北京100094）

摘要：在苹果 (MalusdomesticaL .Borkh .cv .RedStarking)和葡萄 (VitisviniferaL .×V .lubruscaL .cv .Kyoho)的不同发育阶段均检测到蛋白激酶活性 ,它们可被Ca2 + 强烈激活 ,表明依赖钙的蛋白激酶是苹果和葡萄果实中一类非常重要的蛋白激酶。钙调素 (CaM)对苹果和葡萄果实蛋白激酶没有激活作用 ,同时CaM拮抗剂calmidazolium、W7及三氟乙酸 (TFA)均可不同程度地抑制其活性 ,表明依赖钙的蛋白激酶中可能有含类似钙调素结构域的蛋白激酶(CDPK)的存在。在苹果和葡萄果实发育中 ,依赖钙的蛋白激酶无论在其活性变化还是特性上都存在着显著差异 :苹果果实发育的不同阶段依赖钙的蛋白激酶活性无明显变化 ,而葡萄果实在发育的第Ⅱ期蛋白激酶活性大大高于第Ⅰ、Ⅲ期 ;苹果果实依赖钙的蛋白激酶可被Mn2 + 强烈激活并对热敏感 ,而葡萄果实依赖钙的蛋白激酶却不受Mn2 + 及热处理的影响 ;此外 ,葡萄果实蛋白激酶活性不受磷脂酰丝氨酸 (PS)的影响 ,而苹果果实蛋白激酶可被PS激活 ,表明苹果果实中还可能有钙和磷脂激活的蛋白激酶即PKC的存在。苹果和葡萄果实发育中蛋白激酶种类、特性及其活性变化的不同 ,暗示了这两种果实发育调控的差异 ,也意味着苹果和葡萄果实发育调控可能与蛋白激酶密切相关。

关键词： 苹果；葡萄；果实发育；依赖钙的蛋白激酶

Key words: apple, grape, fruit development, calcium-dependent protein kinase