<i>Bacillus thuringiensis</i> δ‐endotoxin binding to brush border membrane vesicles of rice stem borers

Alcantara, Edwin P.; Aguda, R. M.; Curtiss, April; Dean, Donald H.; Cohen, Michael B.

doi:10.1002/arch.10128

Cited by 69 publications

(57 citation statements)

References 35 publications

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“…Based on the toxin regions included in the Cry1Ab-Cry1Ac hybrid produced by HH1 rice (37), the binding specificity of this hybrid toxin is dictated by domain II of Cry1Ab and domain III of Cry1Ac. In agreement with previous reports (18,19), we detected high-affinity binding of both Cry1Ab and Cry1Ac toxins to BBMV proteins from C. suppressalis. While similar high-affinity Cry1Ab and Cry1Ac binding was detected for S. inferens BBMV proteins, we detected a drastic reduction in the concentration of binding sites for the two toxins in S. inferens BBMV compared to that in C. suppressalis BBMV.…”

Section: Discussionsupporting

confidence: 93%

“…These high levels of resistance are expected in cases of field-evolved practical resistance to Bt crops (16). In the case of C. suppressalis, binding competition studies in larval brush border membrane vesicles (BBMV) revealed that Cry1A toxins share binding sites with Cry1Ba toxin (17) but they are not recognized by Cry2A, Cry9C, or Cry1C toxins (18,19). Diverse studies have suggested aminopeptidase-N and cadherin-like proteins as Cry1A binding sites in C. suppressalis BBMV (20,21).…”

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confidence: 99%

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Binding Site Concentration Explains the Differential Susceptibility of Chilo suppressalis and Sesamia inferens to Cry1A-Producing Rice

Han

Liu

et al. 2014

Appl Environ Microbiol

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Chilo suppressalis and Sesamia inferens are two important lepidopteran rice pests that occur concurrently during outbreaks in paddy fields in the main rice-growing areas of China. Previous and current field tests demonstrate that the transgenic rice line Huahui 1 (HH1) producing a Cry1Ab-Cry1Ac hybrid toxin from the bacterium Bacillus thuringiensis reduces egg and larval densities of C. suppressalis but not of S. inferens. This differential susceptibility to HH1 rice correlates with the reduced susceptibility to Cry1Ab and Cry1Ac toxins in S. inferens larvae compared to C. suppressalis larvae. The goal of this study was to identify the mechanism responsible for this differential susceptibility. In saturation binding assays, both Cry1Ab and Cry1Ac toxins bound with high affinity and in a saturable manner to midgut brush border membrane vesicles (BBMV) from C. suppressalis and S. inferens larvae. While binding affinities were similar, a dramatically lower concentration of Cry1A toxin binding sites was detected for S. inferens BBMV than for C. suppressalis BBMV. In contrast, no significant differences between species were detected for Cry1Ca toxin binding to BBMV. Ligand blotting detected BBMV proteins binding Cry1Ac or Cry1Ca toxins, some of them unique to C. suppressalis or S. inferens. These data support that reduced Cry1A binding site concentration is associated with a lower susceptibility to Cry1A toxins and HH1 rice in S. inferens larvae than in C. suppressalis larvae. Moreover, our data support Cry1Ca as a candidate for pyramiding efforts with Cry1A-producing rice to extend the activity range and durability of this technology against rice stem borers.

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Section: Discussionsupporting

confidence: 93%

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confidence: 99%

Binding Site Concentration Explains the Differential Susceptibility of Chilo suppressalis and Sesamia inferens to Cry1A-Producing Rice

Han

Liu

et al. 2014

Appl Environ Microbiol

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“…Therefore, combinations of Cry1A genes with other groups of Bt genes should be explored to prevent or delay the emergence of pest resistance. Based on the assay of ␦-endotoxin binding to brush border membrane vesicles of rice stemborers, it was proposed that Cry1A genes could be combined with Cry1C, Cry2A, or Cry9C for more durable resistance in transgenic plants (32).…”

Section: Progresses In Gene Identification and Development Of Gsrmentioning

confidence: 99%

Strategies for developing Green Super Rice

Zhang

2007

Proc. Natl. Acad. Sci. U.S.A.

717

438

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This contribution is part of the special series of Inaugural Articles by members of the National Academy of Sciences elected on May 1, 2007.From a global viewpoint, a number of challenges need to be met for sustainable rice production: (i) increasingly severe occurrence of insects and diseases and indiscriminate pesticide applications; (ii) high pressure for yield increase and overuse of fertilizers; (iii) water shortage and increasingly frequent occurrence of drought; and (iv) extensive cultivation in marginal lands. A combination of approaches based on the recent advances in genomic research has been formulated to address these challenges, with the long-term goal to develop rice cultivars referred to as Green Super Rice. On the premise of continued yield increase and quality improvement, Green Super Rice should possess resistances to multiple insects and diseases, high nutrient efficiency, and drought resistance, promising to greatly reduce the consumption of pesticides, chemical fertilizers, and water. Large efforts have been focused on identifying germplasms and discovering genes for resistance to diseases and insects, N-and P-use efficiency, drought resistance, grain quality, and yield. The approaches adopted include screening of germplasm collections and mutant libraries, gene discovery and identification, microarray analysis of differentially regulated genes under stressed conditions, and functional test of candidate genes by transgenic analysis. Genes for almost all of the traits have now been isolated in a global perspective and are gradually incorporated into genetic backgrounds of elite cultivars by molecular marker-assisted selection or transformation. It is anticipated that such strategies and efforts would eventually lead to the development of Green Super Rice.genomics ͉ rice genetic improvement ͉ sustainable agriculture

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“…The success of combining multiple Bt genes for resistance management is contingent on the individual toxins having different targets to prevent cross resistance developing [163][164][165]. Binding studies with various Cry toxins have been used to identify toxins with different binding sites in the lepidopteran midguts [105,166,167]. This information can be used to design combinations of Cry toxins that complement each other to delay the development of resistance to Bt crops.…”

Section: Management Of Resistance To Bt Cropsmentioning

confidence: 99%