Temporal and intra-plant variability of Cry1Ac expression in Bt-cotton and its influence on the survival of the cotton bollworm, Helicoverpa armigera (Hübner)(Noctuidae: Lepidoptera)

Journal or Publishing Institution: Current Science

Study: https://www.jstor.org/stable/pdf/24110575.pdf?casa_token=n7EZj02EayMAAAAA:JBixd84WFg1pMUZxfb5gZWx2ymMOS02__57kaCZe0C5RT1oey2UqTWWNijMEGVf7RuHXvAFfKBaAKV5NdARDtlWx3gu0jn5iWy-XFyXaI_Q9h2txpMUh

Author(s): Kranthi, K.R., Naidu, S., Dhawad, C.S., Tatwawadi, A., Mate, K., Patil, E., Bharose, A.A., Behere, G.T., Wadaskar, R.M. and Kranthi, S.

Article Type: Peer Reviewed Study

Record ID: 1283

Abstract: The quantitative levels of CrylAc and the seasonal de cline in expression differed significantly among the eight commercial Bollgard hybrids tested. The CrylAc ex pression was found to be variable among the hybrids and also between different plant parts. The leaves of ßt-cotton plants were found to have the highest levels of CrylAc expression followed by squares, bolls and flowers. The toxin expression in the boll-rind, square bud and ovary of flowers was clearly inadequate to confer full protection to the fruiting parts. Increasing levels of Helicoverpa armigera survival were correlated with the toxin levels decreasing below 1.8 pg/g in the plant parts. Genotype-independent seasonal decline of the CrylAc toxin levels was observed in all the hybrids. CrylAc expression decreased consistently as the plant aged. The decline in CrylAc was more rapid in some hybrids compared to others. The choice of parental background appeared to be crucial for sustainable ex pression of the crylAc transgene. The implications of variability in CrylAc expression and the seasonal decline on bollworm management are discussed.

Keywords: Helicoverpa armigera, Bt cotton, Bacillus thuringiensis, Cry1Ac, Cotton, Hybridity, Bollworms, Mortality, Gene expression, Bolls, Plant anatomy, Fruiting, Toxins, Transgenic plants

Citation: Kranthi, K.R., Naidu, S., Dhawad, C.S., Tatwawadi, A., Mate, K., Patil, E., Bharose, A.A., Behere, G.T., Wadaskar, R.M. and Kranthi, S., 2005. Temporal and intra-plant variability of Cry1Ac expression in Bt-cotton and its influence on the survival of the cotton bollworm, Helicoverpa armigera (Hübner)(Noctuidae: Lepidoptera). Current Science, pp.291-298.