[luxAB genes as marker for detecting Rhizobium fredii HN01 nodulation functions]

A suicide plasmid pHNC3 which contains Tn5-luxAB was transferred into Rhizobium fredii HN01 by the help of pRK2013. Then Tn5-luxAB inserted on the genome of HN01 and gave luminescence activity. The luminescence colonies were picked up and the Eckhardt gel was performed for plasmids profile detection. The location of Tn5-luxAB on the genome was determined using the luxAB as probe. The colonies which were marked by Tn5-luxAB on the chromosome and different plasmids of HN01 were chosen for pot experiment, and a chromosome labelled strain HN01LC02 was detected by soil pot experiment. The detections included the nodulation occupancy and the luminescent nodules distribution on the root system formed by the luxAB-marked rhizobia.