TY - JOUR
T1 - Variant cry1Ab entomocidal Bacillus thuringiensis toxin gene facilitates the recovery of an increased number of lepidopteran insect resistant independent rice transformants against yellow stem borer (Scirpophaga incertulus) inflicted damage
AU - Dandapat, Abhijit
AU - Bhattacharyya, Jagannath
AU - Gayen, Srimonta
AU - Chakraborty, Anirban
AU - Banga, Anannya
AU - Mukherjee, Rajeswari
AU - Mandal, Chandi Charan
AU - Hossain, Munshi Azad
AU - Roy, Samarjit
AU - Basu, Asitava
AU - Sen, Soumitra Kumar
PY - 2014/1
Y1 - 2014/1
N2 - The primary technical constraint plant scientists face in generating insect resistant transgenic crops with insecticidal Bacillus thuringiensis (Bt) crystal protein (Cry) genes remains failing to generate sufficiently large numbers of effective resistant transgenic plant lines. One possible means to overcome this challenge is through deployment of a Cry toxin gene that contains high levels of insecticidal specific activity for target insect pests. In the present study, we tested this hypothesis using a natural variant of the Cry1Ab toxin under laboratory conditions that possessed increased insecticidal potency against the yellow stem borer (YSB, Scirpophaga incertulus), one of the most damaging rice insect pests. Following adoption of a stringent selection strategy for YSB resistant transgenic rice lines under field conditions, results showed recovery of a significantly higher number of YSB resistant independent transgenic plant lines with the variant cry1Ab gene relative to transgenic plant lines harbouring cry1Ab berliner gene. Structural homology modelling of the variant toxin peptide with the Cry1Aa toxin molecule, circular dichroism spectral analysis, and hydropathy plot analysis indicated that serine substitution by phenylalanine at amino acid position 223 of the Cry1Ab toxin molecule resulted in a changed role for α-helix 7 in domain I of Cry1Ab for enhanced toxicity.
AB - The primary technical constraint plant scientists face in generating insect resistant transgenic crops with insecticidal Bacillus thuringiensis (Bt) crystal protein (Cry) genes remains failing to generate sufficiently large numbers of effective resistant transgenic plant lines. One possible means to overcome this challenge is through deployment of a Cry toxin gene that contains high levels of insecticidal specific activity for target insect pests. In the present study, we tested this hypothesis using a natural variant of the Cry1Ab toxin under laboratory conditions that possessed increased insecticidal potency against the yellow stem borer (YSB, Scirpophaga incertulus), one of the most damaging rice insect pests. Following adoption of a stringent selection strategy for YSB resistant transgenic rice lines under field conditions, results showed recovery of a significantly higher number of YSB resistant independent transgenic plant lines with the variant cry1Ab gene relative to transgenic plant lines harbouring cry1Ab berliner gene. Structural homology modelling of the variant toxin peptide with the Cry1Aa toxin molecule, circular dichroism spectral analysis, and hydropathy plot analysis indicated that serine substitution by phenylalanine at amino acid position 223 of the Cry1Ab toxin molecule resulted in a changed role for α-helix 7 in domain I of Cry1Ab for enhanced toxicity.
KW - Bacillus thuringiensis δ-endotoxin
KW - Cry1Ab toxin
KW - Insect resistant plant
KW - Insecticidal activity enhancement
KW - Rice transgenic
KW - Stem borer
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U2 - 10.1007/s13562-013-0190-1
DO - 10.1007/s13562-013-0190-1
M3 - Article
AN - SCOPUS:84891892905
SN - 0971-7811
VL - 23
SP - 81
EP - 92
JO - Journal of Plant Biochemistry and Biotechnology
JF - Journal of Plant Biochemistry and Biotechnology
IS - 1
ER -