Kinetics of plasmid transfer among Bacillus cereus group strains within lepidopteran larvae.

摘要: The cry toxin encoding plasmid pHT73 was transferred from Bacillus thuringiensis subspecies kurstaki KT0 to six B. cereus group strains in three lepidopteran (Spodoptera exigua, Plutella xyllostella and Helicoverpa armigera) larvae by conjugation. conjugation kinetics of the precisely studied during larval infection using a new protocol. infections were performed with both vegetative sporulated strains. However, death only occurred when made spore preparations. Likewise, germinations donor recipient observed killed larvae, 44–56 h post-infection. Accordingly, showed that gene transfer between strain other took place dead among vegetatively growing bacteria. conjugational ratios varied different combinations larvae. highest ratio reached 5.83 × 10−6 CFU/donor AW05R armigera, all transconjugants gained ability produce insecticidal crystal. These results indicated horizontal might play key role for acquisition extra plasmids evolution these susceptible insect