Agriculture Reference
In-Depth Information
example, the transgenic lines (K24 and K34) containing the antifungal
genes, chitinase/glucanase, accumulated signi
cantly less toxin than
their parent genotype, Okrun (Banks et al. 1989; Chenault et al. 2004), or
those with nonheme chloroperoxidase (
cpo-p
) gene inhibited
A.
avus
hyphal growth (Niu et al. 2009). Because pod damage by insects provides
abundant opportunities to a
atoxin-producing fungi to invade and
colonize the damaged pods, lessening insect damage may be important
for reducing a
ed
Bt
cryIA(c) gene into peanut using microprojectile bombardment. The
transgenic plants containing
Bt
cryIA(c) protein showed varying levels of
resistance to lesser cornstalk borer,
Elasmopalpus lignosellus
, from
complete larval mortality to a 66% reduction in larval weight. Further-
more, the negative correlation between percent survival or larval weight
and the amount of Bt CryIA(c) protein indicated that
Bt
cryIA(c) gene has
potential to provide a barrier to fungal entry by reducing insect damage
to peanut tissue.
ICRISAT recently claimed of being able to generate transgenic events
that contain a
chitinase
gene from rice (
Rchit
) in three peanut cultivars
using
Agrobacterium
-mediated genetic transformation. The leaf assay
showed that chitinase activity in the leaves of the transgenic events was
3- to 14-fold greater than that of untransformed plants, with most of the
transgenic events showing 0
atoxin. Singsit et al. (1997) introduced a codon-modi
avus
infection during
in vitro
seed
inoculation bioassays. Furthermore, some of the offspring from trans-
genic events displayed signi
-
10%
A.
cantly higher disease resistance to late leaf
spot (
Phaeoisariopsis personata
(Berk. & Curt.) v. Arx), rust (
Puccinia
arachidis
Spreg.), and
A.
avus
infection, and are being advanced for
field evaluation (Prasad et al. 2013). This transgenic resistance against
fungal infection and a
atoxin production in combination with conven-
tional breeding efforts may lead to the development of agronomically
superior peanuts that are free from a
atoxin contamination (Nigam et al.
2009) if regulatory hurdles and societal aversion to transgenics can be
overcome.
C. Seed Protein Allergens
In plants, one of the most common methods for suppressing gene
expression and eliminating a protein is through RNA interference
(RNAi). This approach has been used to silence the major apple allergen
Mal d1 (Gilissen et al. 2005) and is already being applied in peanut (Dodo
et al. 2005, 2008; Gilissen et al. 2005; Ramos et al. 2006; Chu et al. 2008).
Cosuppression has also been used to remove an immunodominant
allergen from soybean. However,
these techniques
require the
