The Construction Of Overexpression Of Arabidopsis Thaliana Actin-binding Protein ADF1 And Its Role Under Salt Stress

It is one of the most important factors affecting crop yield to soil salinization.The high concentrations of salt can lead to the imbalance of ions and cause osmotic stress and other abiotic stresses in the plant.Therefore,the study on the mechanism of plant salt tolerance can not only enrich the theoretical knowledge of plant response to stress process but the results of this study can be used in agricultural production practice and it can provide an important theoretical basis for the cultivation of high salt tolerant crops.Our previous study found microfilament binding protein gene AtADF1 can be induced by salt stress,AtADF1 mutant caused the plant to be sensitive to salt and hindered the process of salt induced depolymerization of microfilaments.The results showed that the loss of actin binding protein AtADFl affected the response of Arabidopsis thaliana to salt stress.In this study,we first obtained the Arabidopsis thaliana overexpressing ADF1(AtADF1-OEs)plants by cloning,constructing and identification.And we use wild type Arabidopsis(WT),two strains overexpressing ADF1(AtADF1-OEs)plants as materials to observe the germination rate,growth and the dynamic changes of microfilaments in WT and AtADF1-OEs,the expression of salt response genes(SOS1,SOS2 and SOS3)in AtADF1-OEs under salt stress in Arabidopsis.And reveal the mechanism of Arabidopsis thaliana AtADF1-OE under salt stress.The main results were as follows:(1)The AtADF1 overexpression vector was constructed by cloning AtADF1 gene and obtained the overexpression of AtADF1.(2)The overexpression of AtADF1 was screened and identified,and obtained three lines AtADF1-OEs with different expression levels.In this study,the two strains were used as materials.(3)Under normal condition,the seed germination rate of WT and AtADF1-OEs has no significant difference.But under salt stress(NaCl treatment),the seed germination rate of AtADF1-OEs is obviously more than WT.(4)Under normal condition,the growth phenotype of WT and AtADF1-OEs plants has no significant difference.But under salt stress(NaCl treatment),the growth phenotype of AtADF1-OEs is obviously more than WT,for example,the lateral root numbers,leaf area and root lengths were all increased.(5)Under normal condition,both the WT and AtADF1-OE plants of Arabidopsis thaliana were in the polymerization state and there was no depolymerization.Under salt stress(NaCl treatment),the AtADF1-OE plants enhanced the depolymerization of microfilaments.(6)Under normal condition,the expression of SOS1,SOS2 and SOS3 of AtADF1-OEs and WT is almost same.However,under salt stress(NaCl treatment),the expression of SOS1,SOS2 and SOS3 is obviously increased in WT.But the expression level of SOS2 and SOS3 in AtADFl-OEs is higher than in WT.In summary,the actin-binding protein gene AtADF1 was induced by salt stress.The results showed that AtADF1 gene could enhance the tolerance to salt stress in Arabidopsis thaliana.The overexpression AtADFl gene enhanced the process of salt induced depolymerization of microfilaments,enhanced the expression of SOS2 and SOS3 genes induced by salt and the tolerance to salt stress in Arabidopsis thaliana.