Ecophysiological Adaptation Characteristic Of Halophytes In Xingjiang Province And The Mechanisms Of Silicon To Salt Resistance

The content and distribution of silica .activity and location of POD on the leaves of rice and cucumber were studied by means of localization and quantitlive analysis.The content of Si and activity of POD were higher from +Si leaves than that from -Si leaves in these plants.and that in creased with the ages of leaves. In rices Si were observed distributed densely on the older leaves.from the base to the top of blades,the denity of Si increased. In cucumber, there were obviously Si depoist on the older leaves from +Si plant, Si can't be observed on the younger leaves from + Si plant.There were no silicon distribtion on the -Si leaves .by analzing EDX map of silicon ,it was showed that,in the leaf blades of rices ,Si exsisted in the form,of fan-shaped and dumbbell-shaped .There were many trichomes which contained Si on the surfaces of leave and stems on cucumber. The results of cytochemical localization of silicon demonstrated that there were fan-shaped silica bodies and cyliner shape silica deposit ,and high activity of POD were observed in fan-shaped silica bodies. The base of trichomes consisted of large quantity of cells.. The number of cell increased with the age of leaves. The silicon and POD accumulated on the base of trichomes .The results of externalexperiment demonstrated that POD is essential for Silica deposit, Addition of Omm,0.5mM and 2mM HsSiO4 to reaction systems had no effect on the activity of POD. But activity of POD was inhibited by 5mm and 10mm HsSiOi .Therefore, though the shape and location of Si on the leaves of rice and cucumber were so different. There were correlation between the position of Si and POD. It was suggest that the amount,location and shape of silicon desopit may be affected by the activity of POD.