Journal of Pure and Applied MicrobiologyVol. 8 No. 6

Expression of a Novel Synthetic cry gene of Bacillus thuringiensis in Transgenic Tobacco Confers Resistance to Helicoverpa armigera and Spodoptera litura

S.P. Jayaprakash1?, P. Nandeesha1?@, A.E. Sozhavendan1, A. Naveenkumar1, A. Illakiya Priya1, N. Balakrishnan1, V. Balasubramani1, P.K. Singh2, D. Sudhakar1, P. Balasubramanian1 and V. Udayasuriyan1*

1Department of Plant Biotechnology, Centre for Plant Molecular Biology and Biotechnology, Tamil Nadu Agricultural University, Coimbatore -641003, India. 2National Botanical Research Institute, Lucknow -226 001, India.

Received on 06 August 2014 and accepted on 30 October 2014

 

ABSTRACT

The cry2AX1 is a chimeric gene consisting sequences of cry2Aa and cry2Ac of Bacillus thuringiensis. The Cry2AX1 is more potent than its parental proteins. A newly constructed, codon optimized synthetic cry2AX1 gene was validated for expression in transgenic tobacco as a model plant and analyzed for its insecticidal efficacy against larvae of Helicoverpa armigera and Spodoptera litura. The presence of gene and its transcripts was confirmed by PCR and RT-PCR analysis, respectively, in T0 transgenic tobacco leaves. Expression of Cry2AX1 protein in T1 generation plants of two events (PT4 and PT7) was 1.2 ?g/g of fresh leaf tissue. T2 generation plants exhibited sustained significant level of mortality, 100 per cent in H. armigera and 91 to 98 per cent in S. litura. Southern analysis of T2 progenies revealed single locus integration of cry2AX1 gene in the event PT7. The synthetic cry2AX1 gene could be effectively used for developing transgenic crop plants resistant to lepidopteran insect pests.

Keywords : Bacillus thuringiensis, cry2AX1, Helicoverpa armigera, Spodoptera litura, Transgenic tobacco.