Field released transgenic papaya effect on soil microbial communities and enzyme activities

摘要

Soil properties, microbial communities and enzyme activities were stud ied in soil amended with replicase (RP)-transgenic or non-transgenic papaya unde r field conditions. Compared with non-transgenic papaya, significant differences (P<0.05) were observed in total nitrogen in soils grown with transgenic papaya. There were also significant differences (P<0.05) in the total number of colony forming units (CFUs) of bacteria, actinomycetes and fungi between soils amended with RP-transgenic plants and non-transgenic plants. Compared with non-transgen ic papaya, the total CFUs of bacteria, actinomycetes and fungi in soil with tran sgenic papaya increased by 0.43—1.1, 0.21—0.80 and 0.46—0.73 times respective ly. Significantly higher (P<0.05) CFUs of bacteria, actinomycetes and fungi res istant to kanamycin (Km) were obtained in soils with RP-transgenic papaya than t hose with non-transgenic papaya in all concentrations of Km. Higher resistance q uotients for Kmr (kanamycin resistant) bacteria, actinomycetes and fungi were fo und in soil planted with RP-transgenic papaya, and the resistance quotients for Kmr bacteria, actinomycetes and fungi in soils with transgenic papaya increased 1.6—4.46, 0.63—2.5 and 0.75—2.30 times. RP-transgenic papaya and non-transg enic papaya produced significantly different enzyme activities in arylsulfatase (5.4—5.9x), polyphenol oxidase (0.7—1.4x), invertase (0.5—0.79x), cellulase ( 0.23—0.35x) and phosphodiesterase (0.16—0.2x). The former three soil enzymes appeared to be more sensitive to the transgenic papaya than the others, and cou ld be useful parameters in assessing the effects of transgenic papaya. Transgen ic papaya could alter soil chemical properties, enzyme activities and microbial communities.