ANNUAL REPORT - Department of Biotechnology

attributed to the ribosome inactivating property of the
Bougainvillea antiviral protein. The recombinant
protein expressed in E.coli. was tested by SDS-
PAGE. Construction of suitable plant transformation
vector is in progress.
A study was supported at NBRI, Lucknow for
identification and characterization of fruit-specific
and ripening related gene promoters from banana. A
PCR select subtractive library was prepared using
mRNA from unripe and ripe banana fruit. Nucleotide
sequence analysis of these clones has identified
several ripening related genes that are involved in
ethylene biosynthesis, cell wall hydrolysis,
defence/stress and detoxification and
transcription/translation machinery. Most of the
genes show strong ethylene dependent expression
in ripening fruits, and are inhibited by treatment with
1-MCP an ethylene inhibitor. Different promoters
isolated in the above study were analysed in silico for
the presence of common cis acting regulatory
elements. Method for transient expression analysis
using reporter gene in banana fruit slices has been
standardized.
A study has also been supported at NBRI, Lucknow
to identify and characterize genes involved in petal
abscission in rose and senescence in gladioli. Partial
promoters of two rose xyloglucan transglucosylase/
hydrolase genes RbXTH1 and RbXTH2, which are
known to be differentially expressed during ethylene
induced petal abscission, were isolated and
AZ
Stigmatal hair
Stamen
A B C
D E F
GUS expression in transgenic Arabidopsis plants containing the RbXTH2
promoter (in translational fusion with GUS in pBI101)
A - D ethylene treated (0.5 ppm , 4h); E – ethylene untreated;
F – 1 - MCP treated (followed by ethylene treatment)
AZ - abscission zone
DBT Annual Report 2006-07
76
translational promoter-GUS fusions were introduced
into Arabidopsis. Expression of GUS was observed
consistently in most tissues after ethylene (2ppm, 4h)
treatment. Transformants of Arabidopsis expressing
RbXTH2 constitutively showed significant changes in
root length and plant height. These are being studied
in detail. In gladiolus, genes encoding SAM
synthetase, chalcone synthase, alpha mannosidase,
XTH and several unknown protein were shown to be
differentially regulated during the course of petal
senescence.
During the year, a major new initiative has been taken
on improvement of vegetable crops through
biotechnological approaches. Programmes have
been supported on development of transgenic brinjal
for insect resistant. In this programme, a novel
approach of pyramiding of genes cry 2A, cry1Ac,
vip3A and cry1f has been adopted. Transgenic onion
for resistant to purple blotch is also been studied. A
project on molecular approaches for repression of
cold induced sweetening in potato has also been
supported at CPRI, Shimla
Under the plantation crop area, one of the major
achievement during the year has been completion of
the field demonstration of tissue culture raised black
pepper in 100 ha of area in the states of Karnataka,
Kerala, Andaman & Nicobar Islands and North East.
The tissue culture raised plants have performed
better than the conventionally raised material and
more number of laterals thereby giving as higher
yield have been reported. Over 400 farmers have
been benefited.
Basic Research
The thrust of the programmes supported under basic
research is to study the signal transduction pathway
in identified plants to understand the mechanism
involved in responding to external stimuli and the
process of adaptation to these changed environment
conditions. A number of projects have been
supported broadly under three categories: signal
transduction, root differentiation and flowering.