Physiological And Biochemical Mechanisms Of Salt, Mustard And Arabidopsis Salt

We adopted two model plants of halophyte and glycophyte, that is Thellungiella halophila and Arabidopsis thaliana as materials. Some data, that were relevant to salt stress, including the variations of activity of antioxidant enzymes electrbphoresis zymogram of isoxymes, the variations of water potential and yield, and the variations of soluble sugar etc., were measured respectively. By analyzing and studying the mechanism of salt resistance in physiology and biochemistry of T. halophila and A. thaliana in different stages, we hoped to get the basic data in physiology and biochemistry reaction in order to discuss the mechanism of salt tolerance in both plants, and find the essential genes that were correlative with salt resistance.Some data under salt stress of T. halophila and A. thaliana in different stages were studied in the thesis and some conclusions are shown as follows:A. thaliana in strong sprout and bulting stage were treated with different salt concentration, and the variations of activity of antioxidant enzymes were measured. The effects of salt stress on antioxidant enzymes of A. thaliana in strong sprout and bulting stage were different, and it indicated the variations of activity of SOD,POD and CAT were different in different stages. Both have the same change tendency in POD, and also have the same basic activity in different developmental stages under salt stress;the change tendency of activity of CAT was opposite; the activity of SOD in strong sprout was far bigger than that of in bulting stage.The activity of antioxidant enzymes of T. halophila in seedling and strong sprout under salt stress were different, and the activity of antioxidant enzymes in seedling was far bigger than in strong sprout. It suggested that SOD, POD of T. halophila in seedling played more important roles under salt stress, compared with that in strong spouts, because of its perfect system in protection .Analyzing the zymogram of isoxymes of leaves and roots in A. thaliana in different stages under salt stress, the number of POD zymogram of isoxymes was identical, so was the mobility. The POD zymogram of isoxymes were stable verymuch in leaves and roots. There were 2 bands of SOD zymogram of isoxymes in leaves of A. thaliana in strong sprout and bulting stage, and it can be seen that the SOD zymogram of isoxymes was stable in the specific organ in different developmental stages. Moreover, the SOD zymogram of isoxymes of A. thaliana in strong sprouts of were brighter than that of in bulting stage, which was consistent with the activity of SOD. There were 3 SOD bands in roots of A. thaliana, and one of them was the same band, comparing with the leaves. It was special for the expression of SOD in different organ in A. thaliana.At the same time, we analyzed the POD zymogram of isoxymes of T. halophila in seedling and strong sprout. There were 3 bands in roots but there was only one band that was the same Rf. The number of bands of SOD of T. halophila root in seedling was more than that of in strong sprout, so was the brightness. And the results were consistent with the activities of SOD. The activities of SOD and POD in T. halophila in different developmental stages were different.There were 2 bands of SOD in roots and 3 bands in leaves, for T. halophila in strong sprout, which two of them have the same Rf. It can be inferred that there was an organization organ peculiarity for SOD in T. halophila in same stage.Studying of zymogram of isoxymes in T. halophila and A. thaliana, the POD isoxymes of T. halophila were unstable and different in special organ, the leaves of T. halophila in different developmental stage produced the same number but the different kinds of zymogram of isoxymes. It inferred that it was the way of halophyte plant that adjusted to the changes of environment. But the POD isoxymes of A. thaliana were stable and similar in special organ, and there were the same bands in different developmental stage. There were special bands of SOD in T. halophila and A. thaliana under salt stress, but POD was very stable. It inferred that the SOD response to AOS was at first under salt stress, so the gene expression of SOD was stronger than that of POD.By WP4-T (Water Potential Measurement) and PAM-2100 (Chlorophy II fluorescence instrument), we measured the water potential and Yield in T. halophila and A. thaliana under salt stress, both of them were decrease gradually along with thesalinity increasing. The dropping scope in A. thaliana was bigger than that of in T. halophila, especially the Yield. The level at 100mM NaCl in A. thaliana was equal to that of at 500 mM NaCl in T. halophila, according to the data of Yield.Besides, the soluble sugar of leaves in T. halophila and A. thaliana were measured separately. The level of soluble sugar in A. thaliana increased, along with the enhancement of salt stress, so did in T. halophila. The basic level of soluble sugar in A. thaliana was higher than that of in T. halophila. It suggested that the soluble sugar played a role in osmotic adjustment under salt stress for both of plants.There were differences in mechanism of salt resistance between T. halophila and A. thaliana, including T. halophila in its different developmental stages and A. thaliana in its different developmental stages.