不同浓度盐胁迫对红砂渗透调节物质及抗氧化酶活性的影响

[Objective]To investigate the effects of different concentrations of salt stress on osmoregulatory substances and antioxidant enzyme activities of the desert shrub Reaumuria soongorica,and to enrich the study of salt tolerance mechanism of Reaumuria soongorica,in order to provide a reference basis for ecological restoration of arid and semi-arid desert areas.[Method]Red sand seedlings of the current year were used as test materials for potting experiment,which was set up by using different concentration gradients of NaCl solution(0,0.1,0.2,0.3,0.4,0.5 mol/L)to water the red sand seedlings.Seedlings were sampled at 0,3,6,and 9d of the treatments,respectively,and physiological indexes such as proline,soluble protein,Na+,K+ content,and SOD enzyme activity were determined.[Result]The results showed that compared with the control treatment group without NaCl solution,different concentrations of salt stress could increase the content of osmoregulatory substances and SOD enzyme activity of red sand to different degrees.The Na+ content of red sand root system showed a trend of decreasing and then increasing under the same concentration of NaCl solution treatment for different time,while the opposite was true for K+ content.At 9d 0.5mol/L NaCl treatment,the Na+ content of aboveground part and root system of red sand reached the maximum,while the K+ content was the minimum,and the difference was significant compared with the control.Proline content showed an increasing trend under the treatment of 0.1mol/L NaCl solution,which first increased and then decreased under the remaining concentrations,and reached the maximum at 3d 0.4mol/L NaCl treatment,and the rest of the osmoregulatory substances showed an increasing trend.soluble protein content reached the maximum at 9d 0.2mol/L NaCl treatment.When the concentration of NaCl solution was 0.1 mol/L,the SOD enzyme activity showed an increasing pattern.0.2 mol/L and 0.3 mol/L NaCl treatment,the SOD enzyme activity showed an increasing and then decreasing pattern.When the concentration of NaCl solution was 0.4 mol/L and 0.5 mol/L,the SOD enzyme activity showed a decreasing pattern.The proline content showed an increasing trend under the treatment of different concentrations of NaCl solution at the same time.At the 9th d treatment,the soluble protein content first increased and then decreased,and the differences between the treatment concentrations and the control were significant.With the increase of NaCl solution concentration,SOD enzyme activity showed the law of increasing first and then decreasing,and SOD was the largest when the concentration of NaCl solution was 0.2 mol/L,and the difference was significant compared with other concentrations,and the SOD was the smallest when the concentration was 0.5 mol/L.[Conclusion]In summary,it is concluded that different concentrations of salt stress will have different degrees of influence on the osmoregulatory substances and antioxidant enzyme activities of the desert shrub red sand.When the shrub was subjected to low salt concentration(0.1 mol/L,0.2 mol/L),NaCl could promote the growth of red sand seedlings and increase the activities of osmoregulators and antioxidant enzymes,so as to improve its adaptability to the salt-stressed environment;when subjected to high salt concentration(0.4 mol/L,0.5 mol/L),NaCl could inhibit the growth of red sand seedlings and increase the activity of osmoregulators and antioxidant enzymes,so as to improve its adaptability to the salt-stressed environment;when subjected to high salt concentration(0.4 mol/L,0.5 mol/L),NaCl could inhibit the growth of red sand seedlings,so as to improve its adaptability to the salt-stressed environment.When subjected to high salt concentration(0.4mol/L,0.5mol/L),NaCl could inhibit the growth of red sand seedlings and reduce the content of osmoregulatory substances and antioxidant enzymes,and then the adaptive ability to the salt stress environment was weakened.