Effect Of Highland Barely Endophytes Bacillus Sp.KLR2 On Arabidopsis Growth Under Salt Stress

Highland barley grown at an altitude of 2700-4500 meters in the cold area,barren resistance,low temperature resistance,cold tolerance,strong cold resistance,high yield and the characteristics of early maturity and wide adaptability,is one of the most widely qinghai-tibet plateau food crops(Shao et al.,1975;Dai et al.,2014).Endophytic bacteria is a kind of important microorganism resources and can promote the plant of growth.We choosed highland barley as the separation endogenous bacteria,and endophytes KLR2 under salt stress conditions how to promote the growth of arabidopsis thaliana made a primary exploration.The main research results are as follows:From different groups of highland barley,roots and leaves of the communist,separated to 3endophytes,root separation in two strains,respectively named Bacillus sp.KLR1 and Bacillus sp.KLR2.Leaf in the separation one endophyte named Bacillus sp.KLS1.Further experiments found that these 3 endophytes can promote the growth of the arabidopsis thaliana(including fresh weight,dry weight increase and the increase of leaf area).This paper choosed teh better effecting of the growth KLR2 in 75 mM on arabidopsis growth under salt stress conditions.Endophytic bacteria(Endophyte)refers to a certain stage or all stages in life to a healthy plant tissues or organs inside fungi or bacteria.Our study found that KLR2 not only under normal conditions promote the growth of arabidopsis,but under 75 mM NaCl conditions can also promote the growth of arabidopsis thaliana,including promoting the growth of aerial part(6.11 time)and underground(4.9 time)part,promote the increase of the number of lateral root,inhibit the growth of main root.The experimental results concluded that KLR2 can significantly increase the content of arabidopsis leaf of chlorophyll a increased 2.33 times,the content of chlorophyll b increased2.14 times of arabidopsis thaliana leaves.And our experimental results found that KLR2 can also promote the soluble sugar content and proline content of arabidopsis under salt stress conditions,reduce ion leakage in plant(IL)and malondialdehyde(MDA)content.And with 75 mM Na Cl with KLR2 handle arabidopsis at the same time,the levels of hydrogen peroxide in plant is reduced,compared with the control was reduced by 2.22 %.The reduced of ROS may be due to the increase of antioxidant enzyme activity,the results showed that under salt stress conditions compared to arabidopsis the activity of antioxidant enzymes is,indeed,increased.So we assumethat under salt stress conditions,KLR2 could promote the growth of arabidopsis may be by increasing the activity of antioxidant enzymes of arabidopsis.Further research,under 75 mM NaCl stress the content of GSH is higher,and the type of oxidized glutathione(GSSG)levels is reduced.This is indirect that under salt stress KLR2 improve the tolerance of arabidopsis to salt stress may be implemented by increasing the GSHcontent.