两种圆柏属植物叶绿体膜脂肪酸组成和ATP酶活力的季节变化特征与比较

Seasonal variation characteristics and comparison in chloroplast membrane fatty acid composition and ATPase activity in two Sabina trees

以2种常绿的祁连圆柏(Sabina przewalskii Kom.)和圆柏(Sabina chinensis(Lin)Ant.)为材料,测定叶绿体膜脂脂肪酸组分及膜功能蛋白活力的季节变化,比较分析2种植物的种间差异.结果表明:祁连圆柏和圆柏叶绿体膜脂中不饱和脂肪酸亚油酸(18∶2)、亚麻酸(18∶3)与月平均气温呈显著负相关,而饱和脂肪酸棕榈酸(16∶0)和硬脂酸(18∶0)与月平均气温呈显著正相关;K^+Na^+-ATPase和Ca^(2+)Mg^(2+)-ATPase的活性也与月平均气温呈显著负相关.抗寒性强的祁连圆柏叶绿体膜脂中亚麻酸含量显著低于抗寒性弱的圆柏,而其饱和脂肪酸花生四烯酸含量显著高于圆柏.可见,季节性变化中不饱和脂肪酸的比例提高有利于圆柏属植物抗寒性增强,但不饱和脂肪酸含量高低并不是物种间抗寒性强弱的决定因素.

Taking leaves of Sabina przewalskii Kom. and Sabina chinensis （Lin） Ant as materials, chloroplast membrane fatty acid components and seasonal variation in membrane protein activity were measured to compare the inter-specific difference. The results showed that there was negative correlation between unsaturated fatty acid including linoleic acid （18：2） and linolenic acid （18：3） in chloroplast membrane lipid and monthly average temperature（MAT）in S. przewalskii and S. chinensis. However the satu- rated fatty acid, such as palmitic acid （16：0） and stearic acid （18：0） were significantly positive correlated with MAT. The activity of K＋ Na＋-ATPase and Ca2＋ Mg2＋-ATPase in chloroplasts also appeared significantly negative correlation with MAT in both Sabina trees. Compared with S. chinensis characterized by weak cold-resistance,S, przewalskii had significant lower linolenie acid and higher arachidonic acid. Therefore,increase of unsaturated fatty acids ratios in seasonal cold help Sabina trees to improve cold-resistance, while the content of unsaturated fatty acid is not determinant of cold-resistance for different tree species.