Screening Of Dinerential Proteins And Expression Of Related Ion Transport Genes In Lycium Barbarum L.under Salt Stress

As aggravation of soil salinization.the effects of salt stress on plant growth and development will become more and more seriously.As a kind of halophyte,Lvcium barbarum L.not only has the characteristics of salt-tolerant and barren-resistant,but also is one of the pioneer plants for improving saline-alkali land.Therefore,It is helpful to study the physiological and molecular mechanism of Lycium barbarum L.to salt tolerance and to saline-alkali land improvement.In this study."Ningxia No.I" of Lycium barbarum L.was used as a test material,proteomics,physiology,the expression of related ion transport genes,osmotic adjustment and antioxidant protection system were investigated with different NaCl(0,100,200,300 mmol L-1)treatment by TMT quantitative technique and qRT-PCR technique.The main findings are as follows:1.Through TMT technology.5305 proteins were identified under NaCl stress.4631 quantitating of proteome were obtained.The proteins were analyzed by two-sample two-tailed T-test(p-value<0.05).A total of 885 differently expressed proteins were identified,of which 600 were up-regulated and 285 were down-regulated.175 differential proteins were identified with 100 mmol·L-1 NaCl treatment compared with control.Among them,117 proteins were up-regulated.and 58 proteins were down-regulated.Under 200 mmol· L-1 NaCl treatment.378 proteins were up-regulated and 212 proteins were down-regulated among identified 590 proteins compared with control;During 300 mmol·L-1 NaCl,120 proteins were identified,105 proteins were up-regulated,and 15 proteins were down-regulated.2.GO function and KEGG pathway significant enrichment analysis found that differently expressed proteins are mainly involved in important biological processes such as carbon metabolism,energy metabolism,antioxidant metabolism and ion transport.3.The results of physiological and biochemical indexes of roots in salt stress show ed that with the increase of salt concentration,the permeability of root plasma membrane increased gradually,and the content of MDA increased gradually.SOD.POD and CAT increased at 100 mmol·L-1 NaCl.Then continuous decreasing trend were observed under 200mmol·L-1 and 300mmol·L-1 NaCl treatments;H2O2 contents and O2-production rate increased with the increase of salt stress concentration;Proline content increased gradually with the increase of salt stress concentration;The soluble sugar content increased then decreased and finally increased with different NaCl treatments.The soluble protein content increased firstly,when it was 200mmol·L-1 NaCl,300 mmo·L-1 NaCl treatment,It showed a continuous decreasing trend;The content of Na+ increased with the increase of stress concentration,and the K+content increased firstly and then decreased.K+ content was the highest under 100 mmol L-1 NaCI,and Ma+/K+increased with the increase of salt stress concentration4.The expression levels of LbSOS1 and LbHA1 genes in plasma membrane Na+/H+ transporter and H+-ATPase enzymes increased with the increase of salt concentration.The expression level of LbNHX1 gene in vacuolar membrane Na+/H+ transporter decreased firstly then increased with NaCl concentration increasing.However,the expression level of LbVHA-C1 in vacuolar membrane H+-ATPase enzyme increased then decreased and finally increased with different NaCl treatments.Meanwhile,the expression level of LbHKTl gene decreased firstly then increased.There was a certain correlation between the five ion transport genes and the Na+ concentration,and some reached a significant or extremely significant positive correlation.The expression of LbNHX1 gene and LbHA1 was significantly positively correlated with the content of Na+.The LbSOS1 gene was significantly correlated with Na+ content.The expression levels of LbVHA-C1 and HKT1 genes were positively correlated with Na+ content.