Constructing Sense And Anti-sense AtNOS1 Gene Plant Expressing Systems And Physiological Responses Of AtNOS1 Mutant To Salinity Stress

First of all, nitric oxide synthase(NOS) gene was cloned from wild type Arabidopsis thanliana (WT) by PT-PCR and PCR, and then sense and anti-sense AtNOSl gene expressing vectors were constructed and transferred into wild type Arabidopsis by Agrobacterium tumefaciens. After primary selecting on Kan resistant medium, successfully transformed plants were got. Meanwhile, in order to study the biochemical functions of AtNOSl in plants, AtNOSl antibody was raised. These works were all prepared for the further study of the functions of NO acting as a signal in plants which were under different environmental stresses such as salinity or drought.Further more, in order to study the functions of NO in plant salt tolerance, AtNOSl mutant and wild type Arabidopsis were used as experimental materials, and we found that:1. Compared with wild type Arabidopsis, AtNOSl mutant was much more sensitive to salt stress including: root elongation, seed germination and anti-oxidative system. Under salt stress condition, the root elongation of WT and AtNOSl mutant were both inhibited, but AtNOSl mutant was inhibited much more seriously. Treatments with L-NNA and PTIO applied to WT plants found that inhibit NO production or clear the NO in plants can increase the slat stress effects on plants.2. In normal conditions, the seed germination speed of AtNOSl mutant was slower than WT. In salt stress conditions, the seed germination rate and speed of AtNOS1 mutant and WT both decreased but they decreased much more rapidly in AtNOSl mutant.3. Salinity stress resulted in increasing production of H₂O₂ and lipid peroxidation in both plants, the extent was higher in the mutant. It is indicate that H₂O₂ accumulation was a main factor which can cause lipid peroxidation. The activities of enzymes in the anti-oxidative system also change dramaticly, especially the activities of SOD and POD and they increase much rapidly in AtNOSl mutant compared with WT.