The Study On Molecular Mechanism For Salt Tolerance Of Wild Jujube With Mycorrhizal Fungi

Wild jujube (Zizyphus spinosus Hu), one kind of old fruit trees belong to the Rhamnaceae family and the Zizyphus Mill. genus, originated from China, is the elementary morphism species of Chinese jujube. Arbuscular mycorrhiza is a product of the adaptive coevolution with arbuscular mycorrhizal fungi in the long-term life process, and is a kind of beneficial symbiont of plants. It can promote the resistance ability of plants to poor surroundings, and accelerate plant growth. The seedlings of wild jujube were used as materials in this research. Total RNA was extracted from wild jujube seedlings inoculated with AMF and/or treated by NaCl stress, and then the purity of RNA was tested. After getting cDNA by reverse transcription, some researches were carried out on salt-resistance related gene expression by cDNA-AFLP technique. The purpose of this study was to lay a solid foundation for further molecular biology research for Chinese jujube, select and clone gene fragments related to drought resistance and salt-tolerant of wild jujube with mycorrhizal fungi, reveal the molecular mechanism of drought resistance and salt-tolerant of wild jujube with mycorrhizal fungi.Under cDNA-AFLP analysis, the related gene expression of wild jujube which was infected by mycorrhizal fungi and treated with salt-stress was mainly researched. The following results were obtained:1. The modified CTAB can isolate high quality RNA from wild jujube seedlings. After exorcizing DNA from RNA by DNase I, the cDNA fragment synthesized with M-MLV reverse transcriptase was 100bp to 1500bp, satisfied to the requirement of cDNA-PCR.2. The 96 pairs of primers which were combined by 9 Mse I and 12 EcoR I random primers were screened. The results showed that 23 pairs of primers with the excellent expansion effect were found, and 6 cDNA-AFLP display types were observed.3. No.1 difference band (E41/LM1) in the first cDNA-AFLP display type was recycled and re-amplified, and its sequence was tested and analyzed. Finally get a 437bp's expression sequence, and analyzed it on NCBI with BALASTN comparatively analysis. The result shows that, the 437bp's expression sequence, being no homology with other plants' salt-resistance related gene sequences and all plant gene sequences already existed, is merely homologous to CX943087.1 sequence, an expression sequence in algae, with which the homologous rate is 96%. It may be from a new special gene which is con-elated with salt-resistance ability of wild jujube with mycorrhizal fungi.