Effects Of Bacillus Subtilis QM3 On Amylase In Germinatin And The Expression Of Key Genes In Wheat Seeds

Seed germination is the initial stage of plant growth and development and the basis of plant growth.Wheat is a very important food crop.The poor seed germination condition will affect the growth and even yield of wheat.Therefore,it is particularly important to study the germination process of wheat in order to increase the yield of wheat.Microorganisms have attracted the attention of many researchers because they are environmentally friendly,and some microbial fertilizers have been used in agricultural cultivation to increase their yield.Bacillus subtilis is a widely distributed biocontrol organism in the genus Bacillus.In this study,wheat was used as experimental material to study the effects of different concentrations of B.subtilis QM3 soaking seeds on wheat germination index,amylase activity,amylase isoenzyme and key genes of degraded starch,aiming to be Bacillus subtilis.Provide a scientific basis for promoting plant germination.The main findings are as follows:(1)Wheat seeds were soaked in different concentrations of B.subtilis QM3 for 3 h,cultured in a culture dish for 7 days,and the germination rate,germination potential and germination of wheat seeds were germinated by counting,weighing and root scanning system respectively.Index,bud length,seed vigor,wheat root body index,fresh weight,dry weight and root-shoot ratio analysis.The results showed that different concentrations of bacterial liquids did not promote the same germination index,and 10~7 CFU/mL B.subtilis QM3 soaked wheat seeds had the most significant effect on these indexes(p<0.05).In the control group,the germination potential and germination index increased by 9.20%and 8.59%,respectively.On the third day of wheat seed germination,the fresh weight of the underground part,the fresh weight of the aerial part and the root-shoot ratio increased by 24.55%,12.38 and 10.88%,respectively.On the fourth day of wheat seed germination,the shoot length and seed vigor index increased by 22.43%and 27.60%,respectively.On the fifth day of wheat seed germination,root length,surface area,projected area and volume increased by 61.47%.65.39%,63.07 and59.15%,the fresh weight and dry weight increased by 21.79%and 14.03%,respectively.Soaking wheat seeds with a certain concentration of B.subtilis QM3 can effectively promote wheat germination.(2)Wheat seeds were soaked in different concentrations of B.subtilis QM3 for 3 h,cultured in culture dishes for 7 days,different treated wheat seeds were taken every day,and wheat seeds were determined by 3,5-dinitrosalicylic acid method.Activity of?-amylase,?-amylase,and total amylase;activity of the limit dextrinase was measured by the pullulan method.The results showed that the activities of various enzymes in wheat seeds changed during germination.The activities of?-amylase,?-amylase,total amylase and limit dextrin enzymes increased first and then decreased,and the time to reach maximum activity was not completely the same.Basically,their activity reached 4-5 days after germination.maximum.After soaking seeds of various concentrations of B.subtilis QM3,the degree of influence on the activity of various enzymes was not completely the same as that of the control.10~6 CFU/mL of B.subtilis QM3 soaked wheat seeds can significantly increase the activity of various enzymes(p<0.05),and the treatment effect is the best.On the fourth day of wheat seed germination,10~6 CFU/mL of B.subtilis QM3 soaked wheat seeds treated with?-amylase,?-amylase,total amylase and limit dextrin activities,respectively,compared with the control group.Increased by 40.74%,30.85%,33.53%and 28.14%.Soaking wheat seeds at a certain concentration of B.subtilis QM3 can increase the activity of amylase and promote the germination of wheat seeds.(3)Wheat seeds were soaked in 106 CFU/mL B.subtilis QM3 solution for 3 h,cultured in a petri dish for 7 days,germinated wheat seed samples were taken every day,and wheat seed germination was determined by non-denaturing polyacrylamide gel electrophoresis.The?-amylase isoenzyme,?-amylase isozyme and total amylase isoenzyme in the seed during the process.The results showed that with the prolongation of germination time,the bands of?-amylase isoenzyme,?-amylase isoenzyme and total amylase isoenzyme of wheat seeds increased,the brightness became brighter and the band broadened,and the activity increased.After treatment with 10~6 CFU/mL of B.subtilis QM3,the activity of amylase isoenzyme was enhanced compared with the control,which showed an increase in brightness and a broadening of the band.And in the third angel of wheat seed germination,the brightness of the strip increased the most,and the brightness of the strip on the fifth day of germination reached the maximum value of the germination period.It indicated that a certain concentration of B.subtilis QM3 soaked wheat seeds could increase the activity of amylase isoenzyme in seeds and promote the germination of wheat seeds.(4)Wheat seeds were soaked in 10~6 CFU/mL B.subtilis QM3 solution for 3 h,incubated with culture dishes to germination,wheat seeds germinated for 3 days,and TaAmy1,TaAmy3and?-Amy in wheat seeds were determined by real-time fluorescent quantitative PCR.The amount of Amy gene expressed.The results showed that the expression of TaAmy1 gene was significantly increased compared with the control,and the expression of TaAmy3 gene was not significantly changed,and the expression of?-Amy gene was less.It is speculated that B.subtilis QM3 may promote seed germination by increasing the expression of TaAmy1 gene.