title: Responses of the cutworm Spodoptera litura (Lepidoptera: Noctuidae) to two Bt corn hybrids expressing Cry1Ab.
abstract: To examine the responses of the secondary lepidopteran pest Spodoptera litura to two Bacillus thuringiensis (Bt) corn hybrids [5422Bt1 (Event Bt11), 5422CBCL (MON810)] expressing Cry1Ab, larval bioassays with Cry1Ab toxin, corn leaves or kernels and bagging on corn plants were conducted. The results showed that larvae displayed a similar performance when fed kernels, but not leaves of 5422Bt1, 5422CBCL and their near-isogenic non-Bt corn (5422). Significantly higher Cry1Ab amounts were detected in larvae fed leaves than kernels of both Bt hybrids, with different molecular weights of protein band in plants (72 and 90 kDa for 5422Bt1 and 5422CBCL, respectively), gut contents (65 kDa), feces (50 kDa), which indicated that larvae had lower ingestion, higher degradation and excretion of Cry1Ab when fed kernels not leaves of both Bt hybrids. Significantly higher levels of cadherin-like receptors and alkaline phosphatase transcripts were detected in larvae fed leaves than kernels of two Bt hybrids. Catalase, superoxide dismutase and glutathione-S-transferase activities in larvae fed 5422Bt1 leaves were significantly higher than that of 5422 treatments. Therefore, S. litura had low susceptibility to 5422Bt1 and 5422CBCL when larvae fed kernels not leaves of Bt corn. Additionally, S. litura presented a much stronger tolerance to 5422CBCL than 5422Bt1.
authors.affiliation: Key Laboratory of Agro-Environment in the Tropics, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China.|Key Laboratory of Agroecology and Rural Environment of Guangdong Regular Higher Education Institutions, South China Agricultural University, Guangzhou 510642, China.|Department of Ecology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.|Department of Crop Science and Technology, College of Agriculture, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Yinghua
authors.affiliation: Key Laboratory of Agro-Environment in the Tropics, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China.|Key Laboratory of Agroecology and Rural Environment of Guangdong Regular Higher Education Institutions, South China Agricultural University, Guangzhou 510642, China.|Department of Ecology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Du
authors.initials: D
authors.lastname: Yan
authors.affiliation: Department of Crop Science and Technology, College of Agriculture, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Jin
authors.affiliation: Department of Crop Science and Technology, College of Agriculture, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Jiaxi
authors.affiliation: Key Laboratory of Agro-Environment in the Tropics, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China.|Key Laboratory of Agroecology and Rural Environment of Guangdong Regular Higher Education Institutions, South China Agricultural University, Guangzhou 510642, China.|Department of Ecology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Jianwu
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000201:enzymology / Q000235:genetics*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D004731:Endotoxins / Q000235:genetics* / Q000378:metabolism; D004789:Enzyme Activation; D015870:Gene Expression; D006460:Hemolysin Proteins / Q000235:genetics* / Q000378:metabolism; D006790:Host-Parasite Interactions; D054884:Host-Pathogen Interactions; D007814:Larva; D010572:Pest Control, Biological; D030821:Plants, Genetically Modified; D018411:Spodoptera / Q000382:microbiology*; D003313:Zea mays / Q000235:genetics* / Q000469:parasitology*
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis