一株贝莱斯芽孢杆菌L21在薏苡植株体内的定殖研究OACSTPCD

Bacillus velezensis(L21)was labeled with green fluorescent protein granules containing antibiotics,which provided theoretical basis for further study on interaction between endophytic bacteria and Coix lacrima-jobi.Firstly,plasmid pHT01-P43GFPmut3a was transferred into endophyte L21(Bacillus velezensis)by natural transformation method to obtain engineered strain L21-GFP.The growth curves,genetic stability and functional stability of L21-GFP and L21 were measured.L21-GFP was introduced into Coix lacrima-jobi by watering method,and the colonization was detected by fluorescence microscopy.The results showed that there was no significant difference in colony morphology,growth rate and antagonistic activity between L21-GFP and L21,both of which changed from slow growth stage to logarithmic growth stage after 8 h culture.pHT01-P43GFPmut3a can be stably inherited in L21,and the stability of pHT01-P43GFPmut3a is 63%after 40 h.The engineered strain L21-GFP was able to colonize stably in Coix lacrima-jobi,with the highest density of 106 cfu/g in the root.In conclusion,L21-GFP has strong and stable colonization ability in Coix lacrima-jobi,and has good application prospect.