Research On The Activity And Mechanism Of Bioactive Peptides Derived From Animals To Regulate The Growth Of Arabidopsis Thaliana

At present,most of the plant growth regulators have certain toxicity,which leads to a series of food safety problems.Therefore,the development of a new type,safe and non-toxic plant growth regulator is necessary.In this study,we used the active peptide HS6 as control to expore the effects of Y7 on the growth of Arabidopsis thaliana,and to explore the mechanism of Arabidopsis thaliana growth at the level of gene and protein.Firstly,purification of bioactive peptide Y7 by chemical synthesis.Secondly,we used Petri dish filter paper method to test the effect of active peptide on the growth of Arabidopsis thaliana.The results showed that Y7 and HS6 could significantly impove the seed germination,the seed vigor,germination uniformity and germination rate of Arabidopsis thaliana,etc..The optimum concentrations of Y7 and HS6 for promoting Arabidopsis seed germination and growth were 0.00001mg/L and 0.0001mg/L,the increase rate of the seed vigor were respectively up to 58.91%and 39.87%,the growth rate of seedling length reached 39.96%and 22.10%and the root length and germination rate also increased significantly.In all aspects,The effect of bioactive peptides is better than other plant growth substances.Thirdly,in this part,we analyzed the expression of the auxin regulator IAA1,ARF19 and SAUR-ACl in Arabidopsis thaliana seeds treated with bioactive peptides and other plant growth substances by semi-quantitative PCR and real-time fluorescence quantitative PCR,we preliminary explored the mechanism of bioactive peptides from animals in promoting the seed germination and growth of Arabidopsis thaliana at the genetic level.The results of semi-quantitative PCR showed that the expression of Arabidopsis' auxin regulator by Y7,HS6,IAA and GA3 treated was improved.In order to understand more accuratly the influence of the active peptide on the expression of the auxin regulators,we also carried out the real-time fluorescence quantitative PCR,the results showed that the expression of IAA1 and ARF19,SAUR-AC1 in Arabidopsis treated with Y7 were respectively as high as 3.26 times,6.32 times and 3.90 times compared with the control group(CK);The three auxin regulators of Arabidopsis by HS6 treated were respectively increased by 1.49 times,4.74 times and 1.97 times.Therefore,the bioactive peptides Y7 derived from animals can promote plant germination and growth by regulating the level of auxin.Fourthly,through the determining the protein content,superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)activity on seed germination of Arabidopsis by Y7 and HS6 treated,we had a preliminary analysis of its growth mechanism in the aspect of protein and antioxidant enzyme activity in this part.The results showed that the soluble protein content of Arabidopsis seed by Y7 treated was up to 0.494 gprot/L,the best effect of SOD,POD and CAT was 127.24 U/mgprot,31.47 U/mL and 17.20 U/mgprot respectively;the best effect of the soluble protein content,SOD,POD and CAT of HS6 treated were 0.458 gprot/L,117.76 U/mgprot,28.53 U/mL and 13.68 U/mgprot.Fifthly,the bioactive peptide Y7 from anmals has the similar effect as plant hormone.The physical and chemical properties,the two class structure were analyzed by bioinformatics.It is suggested that the receptor of Y7 in Arabidopsis may be the receptor-like kinases(RLKs)in the cell membrane,which can regulate the hormone signal transduction and growth of Arabidopsis thaliana.