MOLECULAR CHARACTERIZATION OF cry1A(a) IN NATIVE Bacillus thuringiensis
Loading...
Date
2003
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Agricultural Science, Dharwad
Abstract
"The focus of the present study was to characterize native Bacillus
thuringiensis isolates for cry!A (a) through bioassay, specific PCR for crylA(a) ,
plasmid profile analysis and to clone the c rylA (a) specific amplicon (1.2 kb) into
the pTZ57R/T vector having T overhangs. Among the ten isolates (PI, 513, D1,
D21, PP9, PP7, PP6, HD1, HD73, Bt42) which were used in the study, isolates
D1 (LC^o 1124.27 ppm), PP9 (LC^^ 1283.76 ppm) and PI (LC^^ 1541.22 ppm)
were found to have least LCg^ value for Spodoptera litura and hence can be used
for direct field applications. Among the isolates which are characterised for
presence or absence of cry1A (a) through specific PCR, only HD1, D1, PP9, SI3
and PI were found positive for c r y lA (a). Isolates HD1, D1, HD73, PP9, PPG,
SI3, PI and PP10 showed plasmid bands varying in number (1-10) and size (1.5
kb - > 29 kb).
The c ry lA (a) specific amplicon (1.2 kg) from B. thuringiensis PP9
plasmid DNA was cloned into linear pTZ57R/T with T overhangs. The recombinant
clone pSP500 was positive for specific amplification of c ry lA (a), which was
further confirmed by the restriction of recombinant pSP500 w ith EcoRI and Psti
that released insert of size 1.2 kb. However, SDS-PAGE studies and bioassay
studies showed that there was no expression of recombinant fusion protein. The
sequence data of pSP500 does not match with already established c r y lA (a)
sequence, but it is found to have 93 per cent homology with B. thuringiensis
serovar israelensis pGILOl and 90 per cent homology with B. cereus ATCC
14579 plasmid pBC lin 15. The functions of pGILOl and pBC Iin15 is not
known."
Description
Keywords
null
Citation
No. of references 136