海藻酸钠寡糖对菜心类囊体膜组成及特性的影响

Effects of Alginate-derived Oligosaccharides on Composition and Characteristic of Thylakoid Membrane of Brassica chinensis

采用溶液培养,研究海藻酸钠寡糖对菜心(Brassica chinensis L.)类囊体膜组成和特性的影响。结果表明:海藻酸钠寡糖处理可不同程度提高细胞色素b559、细胞色素b563和光系统Ⅱ浓度,从而提高光合电子传递效率。海藻酸钠寡糖处理还可提高亚油酸(C18∶2)含量,降低棕榈酸(C16∶1)和硬脂酸(C18∶0)含量,从而增加膜脂的不饱和度,有利于维持类囊体膜的流动性和稳定性。此外,海藻酸钠寡糖处理的菜心希尔反应活力在第2、4、6和8天时,分别为对照的2.91、3.88、2.48和2.18倍。Mg2+-ATP酶和Ca2+-ATP酶活性也有不同程度的提高。海藻酸钠寡糖提高植物光合效率可能归因于其对类囊体膜结构的改变和功能的改善。

Hydroponic experiments were conducted to study the effects of alginate-derived oligosaccharides（ADO）on the composition and properties of thylakoid membranes in Brassica chinensis.The results showed that ADO increased the concentrations of cytochrome b559 and cytochrome b563 as well as photosystemⅡ（PSⅡ）,thereby improved photosynthetic electron transport efficiency.ADO raised linoleic acid（C18∶2）content,and reduced the contents of palmitic acid（C16∶1）and stearic acid（C18∶0）,thereby increased unsaturation of membrane lipids to maintain the fluidity and stability of the membranes.Moreover,Hill reaction activity under the ADO treatment was 2.91,3.88,2.48 and 2.18 times of those in the control plants on day 2,4,6and 8,respectively.The activity of Mg2＋-ATPase and Ca2＋-ATPase in the chloroplast were also increased after the ADO treatment.The improvement of photosynthetic efficiency caused by ADO could be attributed to changes in the composition of lipids,pigment-protein complex and the improvement in the function of the thylakoid membrane.