水分胁迫对小麦叶绿体果糖——1.6—双磷酸酯酶活性的影响

A Study of Water Stress on Activity of Chloroplastic Stromal Fructose-1, 6-biphosphatase of Wheat Seedling

在PEG溶液处理所引起的水分胁迫下,小麦幼苗叶片的相对含水量、净光合速率、蒸腾速率、气孔导度、细胞间隙二氧化碳浓度降低。在轻度水分胁迫下,叶片叶绿体果糖—1.6—双磷酸酯酶(E.C.3.1.3.11)活性没有受影响,而严重水分胁迫可使此酶活性显著降低,这是此时叶片净光合速率下降的原因之一。叶片轻微失水时,其内淀粉含量有一定上升,但继续失水则含量下降。水分胁迫使小麦叶片蔗糖含量降低。

Under water stress induced by PEG (6000) solution, the relative water content, net photosynthesis rate, transpiration rate, stomatal conductance and intercellular carbon dioxide concentration of leaves of wheat seedling were obviously decreased. The activity of chloroplastic stromal fructose—1, 6-biphosphatase (E. C. 3. 1. 3. 11) of wheat leaves appeared not to be apparently affected by mild water stress (LRWC decreased by 8%～10%), but serious water stress (LRWC decreased more than 20%) significantly reduced the activity of this enzyme. The starch content of stressed leaves increased to a certain extent while the leaves lossing little water. As the LRWC continually decreased, the starch content changed less. The Sucrose content of wheat leaves, however, was decreased by water stress.