Insect resistant rice generated by introduction of a modified delta-endotoxin gene of Bacillus thuringiensis.
As a first step towards development of insect resistant rice we have introduced a truncated delta-endotoxin gene, cryIA(b) of Bacillus thuringiensis (B.t.) which has specific biological activity against lepidopteran insects into a japonica rice. To highly express the cryIA(b) gene in rice the coding sequence was extensively modified based on the codon usage of rice genes. Transgenic plants efficiently expressed the modified cryIA(b) gene at both mRNA and protein levels. Bioassays using R2 generation plants with two major rice insect pests, striped stemborer (Chilo suppressalis) and leaffolder (Cnaphalocrosis medinalis), indicated that transgenic rice plants expressing the CryIA(b) protein are more resistant to these pests than untransformed control plants. Our results suggest that the B.t. endotoxin genes will be useful for the rational development of new rice varieties resistant to major insect pests.
Fujimoto
H
H
Plantech Research Institute, Yokohama, Japan.
Itoh
K
K
Yamamoto
M
M
Kyozuka
J
J
Shimamoto
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins; D001483:Base Sequence; D004731:Endotoxins / Q000235:genetics*; D015870:Gene Expression; D006460:Hemolysin Proteins; D007313:Insecta; D007306:Insecticides; D007915:Lepidoptera; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics*; D030821:Plants, Genetically Modified; D012333:RNA, Messenger / Q000378:metabolism
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; D012333:RNA, Messenger; C030956:insecticidal crystal protein, Bacillus Thuringiensis