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Bt Research
2013, Vol.4, No.3, 14-20 http://bt.sophiapublisher.com
Research Report
Open Access
Distribution of
vip
Genes, Protein Profiling and Determination of
Entomopathogenic Potential of Local Isolates of
Bacillus thuringiensis
Prashant R. Shingote , Mangesh P. Moharil , Dipti R. Dhumale , Amit G. Deshmukh , Pravin V. Jadhav ,
Mahendra S. Dudhare , Niraj S. Satpute
Biotechnology Centre, Dr. Panjabrao Deshmukh Agricultural University, Akola (MS), 444 104, India
Corresponding Author email: mpmoharil@gmail.com;
Author
Bt Research, 2013, Vol.4, No.3 doi: 10.5376/bt.2013.04.0003
Copyright
© 2013 Mouharil et al. This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
The aim of this study was to screen the
Bacillus thuringiensis
(
Bt
) strains isolated from local ecological niche for the
presence of vegetative insecticidal protein (
vip
) genes and its characterization. PCR screening was carried out to determine different
vip
genes viz.,
vip1
/
vip2
and
vip3
genes, harboured by native
Bt
isolates using four gene specific primers. The PCR results depicted
the presence of all three vip-type genes in these isolates. Strains containing
vip3
-type genes were the most abundant (12.5%) in local
isolates, followed by
vip1
/
vip2
-type genes (10%). Insect bioassays for these proteins were conducted against
Helicoverpa armigera
(
H. armigera
). Four
Bt
isolates PDKV-08 (161.80), PDKV-21 (173.62), NCIM-5110 (170.57) and NCIM-5132 (178.61) depict lower
LC
50
values against
H. armigera
than the standard HD-1 (190.42). The present foundation work can be used for the production of
more effective
Bt
based biopesticide and the identified genes can be explored for the production of next generation insect resistant
transgenic plants.
Keywords
Bt
; Vegetative insecticidal proteins; Insect bioassay
Introduction
In nature, some microorganisms have the potential to
produce useful biological agents capable of infecting
other living organisms including insects. Many of
these infectious agents have a narrow host range and
are non toxic to beneficial insects or vertebrates
(Glazer and Nikaido, 1995). Therefore, the use of
these microorganisms has been developed as the
biological way of pest control. Viruses (baculoviruses),
some fungi, protozoa and bacteria have been used as
biological pest control agents for insects. Amongst all,
Bt
is the most important microorganism having
entomopathogenic activity against certain insect orders.
In addition to the crystal associated toxic polypeptides,
some insecticidal proteins produced during vegetative
growth of the bacteria have also been identified called
as vegetative insecticidal proteins (VIPs). These
proteins were reported from about 15 per cent of the
Bt
strains analyzed (Estruch et al., 1996). According to
the encoded amino acid sequence similarity the Bt
nomenclature committee classified these 103 kinds of
vegetative insecticidal protein genes into four groups
viz.
vip1
,
vip2
,
vip3
and
vip4
, eight subgroups, 29
classes and 103 subclasses (Crickmore, 2012). The
vip1
and
vip2
proteins are the components of the
binary toxin that exhibits toxicity to the coleopterans
(Warren, 1997).
Vip1Aa1
and
vip2Aa1
are very active
against corn rootworms, particularly Diabrotica virgife.
longicornis (Hann et al., 1999); whereas,
vip3
toxins
have Lepidoperan specificity (Estruch et al., 1996,
Warren, 1997). The transgenic cotton,
VipCot
,
developed by Syngenta in 1994 provides cotton
growers a way to control bollworms which offers the
added benefit of protecting cotton plants from
armyworm and loopers.
Bt Research
Preferred citation for this article:
Moharil et al., 2013, Distribution of
vip
Genes, Protein Profiling and Determination of Entomopathogenic Potential of Local Isolates of
Bacillus
thuringiensis
, Bt Research, Vol.4, No.3 14-20 (doi: 10.5376/bt.2013.04.0003)
Received: 27 Jun., 2013
|
Accepted: 10 Jul., 2013
|
Published: 29 Aug., 2013