缺磷胁迫对小麦幼苗地上部分膜脂组成的影响

Effects of Phosphate Deprivation on the Lipid Composition of Wheat Shoots

磷脂酰甘油(PG)是类囊体膜中唯一的磷脂。本研究以小麦为试验材料,研究了缺磷胁迫对小麦幼苗地上部分的膜脂组成及光合功能的影响。结果表明,缺磷导致PG含量下降和双半乳糖甘油二酯(DGDG)及硫代异鼠李糖甘油二酯(SQDG)含量上升。但各种甘油酯的脂肪酸组成变化不显著。尽管缺磷使小麦地上部分的PG含量下降了49%,但其光合气体交换能力与PSⅡ最大光化学效率都没有受到显著影响,表明磷脂含量的降低可为其它不含磷的膜脂含量的升高(SQDG)所弥补,从而保证了植物体在磷缺乏状态下也可维持光合作用的正常进行。

PG is the sole phospholipid in thylakoid membranes. Under phosphate deprivation conditions, the lipid composition of wheat （Triticum aestivum） shoot obviously changed by decreasing the relative proportion of PG. In addition, the increase of SQDG and DGDG were also observed. Although the decrease of PG was up to 49%, the photosynthesis characters and the arnximal efficiency of PS 11 photochemistry of shoot grown in phosphate-deficient conditions were similar to those of controls. These results suggested that the decrease of PG could be substituted for the increase of SQDG and accordingly kept normal photosynthesis. On the other hand, effects of phosphate deprivation on the composition of fatty acid of MGDG, DGDG, SQDG and PG were slight.