Comparison Of Na Roles In Responding To Drought Stress Between Zygophyllum Xanthoxylum And Arabidopsis Thaliana

Drought is a main factor which seriously affects plants growth. The great majority of crop plants cultivated under good conditions, thus the drought resistance capacity of such plants is quite weak. However, Zygophyllum xanthoxylum, as a succulent xerophyte species, grow in arid regions, which has formed multiple adaptive ways to harsh conditions over evolutionary time. Our previous investigations showed that absorbing a great quantity of Na from low salinity soil through roots and transport Na to leaves is one of the effective strategies for Z. xanthoxylum adapting to drought conditions. However, limited research result is acquired on suitable Na involved in Arabidopsis thaliana in response to drought, especially, effects of suitable Na on element characteristics in A. thaliana under osmotic stress. Therefore, to further confirm the roles of suitable Na on Z. xanthoxylum and A. thaliana in response to drought conditions, element characteristics of these two different species were studied in my work. The main findings and conclusions are as follows:1. Compared with control, the addition of 50 mmol/L NaCl had deleterious impacts on the growth of A. thaliana. However, 5 mmol/L NaCl treatment showed no effect on its growth. The above results indicated that the addition of 5 mmol/L NaCl is suitable to the growth of A. thaliana.2. Under -0.5 MPa osmotic stress, the addition of 50 mmol/L NaCl can stimulate the growth of Z. xanthoxylum, whereas there is no positive correlation between 5 mmol/L NaCl and the growth of A. thaliana. These results showed that, compared with A. thaliana, suitable Na played important roles in Z. xanthoxylum when adapting to drought conditions.3. Compared with control, K concentrations in all tissues of Z. xanthoxylum maintained relatively stable under osmotic stress, but in A. thaliana, K concentrations in shoot significantly decreased by 36%. These datum suggested that it should be another significant water stress resistance mechanism of Z. xanthoxylum to remain absorbing K under drought stress.4. Under -0.5 MPa osmotic stress, the content of Ca, Mg, N, P in A. thaliana remarkably decreased. Furthermore, the addition of 5 mmol/L NaCl can not alleviate such negative effect of osmotic stress on element characteristics in A. thaliana. These results further confirmed that suitable Na showed no impact on increasing the drought tolerance of A. thaliana plants.In conclusion, our results demonstrated that, compared with A. thaliana, suitable Na played important roles in Z. xanthoxylum when adapting to drought conditions.