The Influence Of Tetracycline On Growth And Nutrient Absorption In Arabidopsis Thaliana And Oryza Sativa

Antibiotics are widely used in the diseases treatment of human and animals and in the livestock industry,antibiotics used as feed additives can promote the growth of animals and prevent diseases,but these antibiotics will contaminate soil,water and other environment when the animal wastes enter into the agricultural soil,and may do harm to plants,animals and microorganisms.This study investigated the most common veterinary antibiotics tetracycline(TC)to Arabidopsis thaliana and Oryza saliva on growth and physiological characteristics,the results as follows:With the increasing concentrations of tetracycline in MS medium,the growth of Arabidopsis seedlings was inhibited,when the stress concentration was 1 mg/L,TC significantly affected the growth of Arabidopsis,when the stress concentration reached to 5 mg/L seedlings’ fresh weight significantly declined,the biomass was only 40%as control.The changes of growth and physiology of Arabidopsis stressed in Hoagland solution for 12 days showed:TC seriously affected the biomass and root length of Arabidopsis,compared with the control,the fresh weight of Arabidopsis significantly decreased at 1 mg/L,the root length significantly decreased at 5 mg/L,the critical concentration of TC to Arabidopsis was 5 mg/L.TC inhibited the chlorophyll content of leaves in Arabidopsis,the content of chlorophyll a decreased with the increasing concentration of TC.With the increasing concentration of TC,the pod formation of was inhibited gradually,pods were severely damaged at 10 mg/L,the number of pods was only 1/4 as control,and the weight was less than 1/10.In addition,under the TC stress,the superoxide dismutase(SOD)and peroxidase(POD)activity of Arabidopsis also changed,SOD and POD activity first decreased and then increased with the increasing concentrations of TC,when the stress concentration was 10 mg/L,SOD,POD activity significantly increased compared with the control,SOD activity increased by 22.6%in roots and 32.8%in shoots;POD activity increased by 18.6%and 30.5%,which showed a positive response to TC stress in Arabidopsis,the activity of protective enzymes increased significantly to remove the excess free radicals in plants.The stress experiment of Oiyza saliva showed:TC stress had a great influence on the growth of Oryza sativa,the fresh weight of Oryza sativa decreased gradually with the TC concentration increasing,the fresh biomass significantly decreased at 10 mg/L compared with the control,and seriously injured at 20 mg/L,root was more sensitive to TC.Therefore,10 mg/L was the critical concentration to Oryza sativa.Oyrza sativa could absorb TC and transit migration in vivo,the absorption amount of TC rapidly increased in roots with the TC concentration increasing,the absorption amount at 20 mg/L was 22 times than 5 mg/L.In addition,the TC stress could affect the absorption of nutrients in Ortza the contents of potassium(K),sulfur(S),phosphorus(P),magnesium(Mg),zinc(Zn)and iron(Fe)in Oryza sativa gradually decreased with the increasing concentration of TC stress.