Effects Of Exogenous ALA On Physiological Characteristics Of Jujube Under NaCl Stress

In order to reveal the effect of spraying exogenous ALA on Zan Huang Jujube and wild Jujube physiological indexes under NaCl stress.There were four NaCl treatments(0,4,8,12 g·kg^-1)and three ALA treatments(0,75,150 mg·L^-1),in all 12 treatments in this study,.Through the determination of photosynthetic characteristics,physiological and biochemical indicators,protective enzyme activities and related indicators of ASA-GSH recycling system to reveal the effect of ALA on NaCl stress and dressing by screening the suitable ALA concentration.The results as;1.Effects of exogenous ALA on photosynthesis in Jujube under NaCl stress: with the increase of NaCl stress concentration,the contents of Pn,Ci,Gs,Tr and total chlorophyll in wild Jujube and Zan Huang Jujube showed a downward trend.Under different concentrations of NaCl stress,exogenous ALA could improve the net photosynthetic rate（Pn）,intercellular carbon dioxide concentration（Ci）,stomatal conductance（Gs）,transpiration rate（Tr）and chlorophyll content of wild Jujube and Zan Huang Jujube.Under different NaCl stress concentration,spraying 75 mg·L^-1 concentration of ALA could only increased wild Jujube and Zan Huang Jujube Tr significantly under 4 and 8 g·kg^-1 NaCl concentration,while spraying 150 mg·L^-1 ALA could improve Pn,Ci and Tr significantly under different NaCl stress concentration.Stress in severe salt(12 g·kg^-1),spraying 150 mg·L^-1 ALA improve chlorophyll content significantly under all NaCl concentration,while spraying 75 mg·L^-1 ALA had no significant increased in total chlorophyll content of Jujube leaves.In all NaCl stress,spraying 150 mg·L^-1 ALA had better effect on Jujube photosynthesis.2.Effects of exogenous ALA on physiological and biochemical indexes and activities of protective enzymes in Jujube under NaCl stress: with the increase of NaCl concentration,the relative conductivity and MDA content of Jujube leaves showed an increasing trend,the results showed that under NaCl stress,Jujube membrane system was damaged,and the content of NaCl more serious the content of MDA were higher,and the proline content increased,the results showed that under NaCl stress,the proline content of Jujube could regulat alleviate NaCl injury,different concentrations of ALA could reduce the relative conductivity and MDA content of Jujube leaves and improve the content of proline in response to osmotic stresses,including 150 mg·L^-1 ALA was remarkable;the activity of wild Jujube and Zan Huang Jujube SOD,POD and CAT increased with the concentration of NaCl stress increased,but under severe NaCl stress the activity can not continue to rise,spraying ALA can continue to improve three kinds of enzyme activity under NaCl stress,so as to alleviate the NaCl stress,the 150 mg·L^-1 ALA effect is remarkable.3.Effects of exogenous spraying ALA on ASA-GSH circulatory system of Jujube under NaCl stress: under the NaCl stress,the activity of wild Jujube and Zan Huang Jujube GR and APX increased,but with the increase of NaCl concentration,the activity increased slowly,but spraying ALA could improve NaCl tolerance of Jujube throught improve the activity of GR and APX;with the increase of NaCl concentration,the content of Jujube ASA,DHA GSH,and GSSG was decreased,it showed that the ASA-GSH circulation system of Jujube was affected by NaCl stress,exogenous ALA increased the content of Jujube ASA,DHA,GSH and GSSG significantly,and in the content of 150 mg·L^-1 ALA could improve ASA,DHA,GSH and GSSG to alleviate the NaCl stress,the 150 mg·L^-1 ALA had better relief effects.