恶臭假单胞菌HB3S-20在棉花中的定殖及诱导抗性研究OA北大核心CSTPCD

Endophytes are important biocontrol resources in controlling plant diseases.The Pseudomonas putida HB3S-20 was screened as a potential biocontrol agent which had significant control effect against cotton Verticillum wilt in our laboratory.The colonization dynamics and colonization sites of strain HB3S-20 in cotton tissues were detected using rifampicin resistance labeling technique and GFP labeling technique in this study.Moreover,the activities of the plant defense-related enzymes SOD,POD and CAT of cotton after inoculation of the strain HB3S-20 were detected.The rifampicin resistance labeling experiment showed that the strain HB3S-20 mainly colonized the roots of cotton,the amount of bacteria of the strain HB3S-20 detected in cotton roots ranged from 2.2× 104 to 6.7× 104 cfu/g on the 3rd to 30th day after inoculation of the strain HB3S-20.The amount of bacteria of the strain HB3S-20 detected in cotton stems ranged from 0.04 X 104 to 2.7 X 104 cfu/g,lower than the amount of bacteria in roots,but not found in leaves.The results of GFP labeling experiment showed that the strain HB3S-20 not only attached to the surface of cotton roots but also colonized the vascular system of cotton roots.Moreover,the strain HB3S-20 could increase the activities of the plant defense-related enzymes SOD and POD in cotton,and it indicated that the strain HB3S-20 could induce systemic resistance and enhance the resistance of cotton to the pathogens.In this research,the colonization regulation and induced resistance of Pseudomonas putida HB3S-20 in cotton were studied,which provides theoretical basis for the mechanism of the strain HB3S-20 controlling cotton Verticillium wilt.