Journal of Pure and Applied MicrobiologyVol. 9 No. 2

Analysis of Stable Expression of Chimeric cry2AX1 Gene in Insect Resistant Cotton Progeny over Successive Generations

Karunamurthy Dhivya, Natarajan Balakrishnan, Varatharajalu Udayasuriyan and Duraialagaraja Sudhakar*

Department of Plant Biotechnology, Centre for Plant Molecular Biology and Biotechnology, Tamil Nadu Agricultural University, Coimbatore - 641 003, India.

Received on 06 April 2015 and accepted on 09 May 2015

 

ABSTRACT

The lepidopteran pests are a major threat to cotton production worldwide and are considered as a major constraint in cotton productivity. Stable inheritance and expression of transgenes in transgenic plants is of paramount importance in successful application of genetic engineering in crop improvement. The aim of producing transgenic crop is to obtain a durable protection which requires, in particular, the stability of gene expression during generation advancement and introgression of transgenes into other genetic backgrounds. Insect resistant cotton lines of a Coker310 event, CH12 expressing cry2AX1 gene were evaluated in T1 and T2 generations for stable integration, expression and resistance against cotton bollworm, Helicoverpa armigera. The expression of Cry2AX1 protein ranged from 0.466 to 0.899 and 0.094 to 1.374 ?g/g of fresh leaf tissue in the T1 and T2 progeny respectively. The detached leaf disc bioassay recorded mortality of 46.66 to 86.66 and 73.33 to 90.00 per cent in T1 and T2 progeny respectively against H. armigera. These results indicate that the expression of chimeric cry2AX1 is stable and possesses insecticidal activity against H. armigera in transgenic cotton progeny.

Keywords : cry2AX1; Helicoverpa armigera; Bacillus thuringiensis; Insect bioassay.