The synergistic activity between Cry1Aa and Cry1c from Bacillus thuringiensis against Spodoptera exigua and Helicoverpa armigera.
OBJECTIVE
To investigate the interaction between two crystal proteins, Cry1Aa and Cry1C, for future development of biopesticides based on Bacillus thuringiensis, toxicities of the two individual proteins and in combinations have been determined against Spodoptera exigua and Helicoverpa armigera larvae, and synergism between the proteins has been evaluated using synergistic factor.


RESULTS
SDS-PAGE showed that Cry1Aa and Cry1C proteins could be expressed in acrystalliferous B. thuringiensis 4Q7 strain, with molecular weights of 135 and 130 kDa respectively. The bioassay results indicated a synergistic activity between Cry1Aa and Cry1C against S. exigua and H. armigera, and the highest toxicities could be observed in the combination of Cry1Aa and Cry1C at a ratio of 1 : 1.


CONCLUSIONS
The two toxins, Cry1Aa and Cry1C, interact synergistically to exhibit higher toxicity against S. exigua and H. armigera.


CONCLUSIONS
This is the investigation on the synergistic activity between two B. thuringiensis Cry1 toxins. It can be applied to the rational design of new generations of B. thuringiensis biopesticides and to strategies for management of resistant insects.
Xue
J-L
JL
Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China.
Cai
Q-X
QX
Zheng
D-S
DS
Yuan
Z-M
ZM
D000818:Animals; D001413:Bacillus thuringiensis / Q000201:enzymology*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000633:toxicity*; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000737:chemistry / Q000633:toxicity*; D004591:Electrophoresis, Polyacrylamide Gel; D004731:Endotoxins / Q000096:biosynthesis / Q000737:chemistry / Q000633:toxicity*; D006460:Hemolysin Proteins; D007814:Larva; D008970:Molecular Weight; D009036:Moths; D010574:Pesticide Synergists; D018411:Spodoptera
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D010574:Pesticide Synergists; C030956:insecticidal crystal protein, Bacillus Thuringiensis