Stress Tolerance Function Analysis Of ThNAC7 Gene From Tamarix Hispida

Drought, high salt or ABA can induce NAC gene to express, gene overexpression can significantly enhance the drought tolerance of transgenic plants. Research has shown that NAC gene is involved in the regulation of plant cell resilience and many biological processes. However, its specific biological function is unclear. This research thoroughly discusses the resistance mechanism of the NAC7 gene of Tamarix hispida.Under various abiotic stresses, including salt, drought and ABA stresses, we use real time quantitative PCR analysises the expression mode of ThNAC7 gene, in leaves and roots. The experimental results demonstrate that ThNAC7 gene can be up-regulated by NaCl, PEG and ABA. The plasmids of overexpressed vector (pROK2-ThNAC7), inhibit expression vector (ThNAC7-RNAi) and the control vector pBI121 were transfected into the Agrobacterium tumefaciens(EHA105) by method of electroporation. We have built the Instantaneous infection system, and improved it by three methods, following we detected the GUS gene respectively. Plant tissue, with pBI121 vector in it, have GUS genes expressed in of which. Further speculate that overexpression vector and inhibit expression vector also transferred into Tamarix plants. By GUS staining analysis, a transformation method 1 is superior to the method 2 and 3. In method 1, GUS gene could be detected in the seventh weeks after the infection. We performed real-time quantitative PCR for transgenic Tamarix hispida, and the results show that the overexpression plant of NAC7 gene increased five-fold, the control plants within 2-fold increase, and the inhibit expression plants’ ThNAC7 gene was significantly inhibited. We further use staining, including NBT, DAB and Evans blue, to analysis the ability of scavenging active oxygen and the extent of cell death. Under normal circumstances, staining of the three (Overexpression, inhibited expression and control transgenic seedlings) almost the same. The degree of inhibited expression seedlings staining is deeper than Overexpression transgenic seedlings under stress. The color of the control seedlings was between the two. Then, we determined water loss rate, electrolyte leakage, chlorophyll content and MDA content of the three kind transgenic seedlings. Water loss rate of Overexpression transgenic seedlings were the lowest, but under stress, chlorophyll content was the highest, electrolyte leakage and the MDA content was the lowest. Control plants of four kinds of physiological indicators are centered. Cell water loss rate of inhibit expression transgenic seedlings was the highest, chlorophyll content was the lowest, electrolyte leakage and the MDA content was the highest under stress. Consequently, ThNAC7 gene can response to abiotic stress, overexpression of this gene can enhance the plant’s ability to withstand adversity. Further demonstrates ThNAC7 gene has resilience function.