5.4 Biotic Stress Alleviation
Agrochemicals have changed the face of wheat cultivation, but it has also developed
new challenge in the form of resistance against agrochemicals in pathogens and
insect pests. Nanoparticles have a great promise for the management and control of
insect pest and diseases in wheat (Table 5.2). Mishra et al. (2014) studied the effect
of silver nanoparticles in controlling spot blotch disease of wheat caused by
Bipolaris sorokiniana. The results revealed that application of silver nanoparticles
strongly inhibited B. sorokiniana infection in wheat. Moreover, decrease in plant
growth after pathogen challenge was overcome when wheat plants were treated with
silver nanoparticles. Silver nanoparticle-mediated reduction in melanin production
might be one of the factors for diminishing the pathogenicity of B. sorokiniana on
wheat (Mishra and Singh 2015). Similarly, the efficacy of zinc nanoparticles in
controlling Fusarium head blight and deoxynivalenol formation in wheat was
reported by Savi et al. (2015). Savi et al. (2015) demonstrated that zinc oxide
nanoparticles efficiently reduced deoxynivalenol (a toxin produced by
F. graminearum) formation and F. graminearum infection in wheat grains even at
100 mM concentration. In another study, Panyuta et al. (2016) studied the effect of
pre-sowing seed treatment with metal nanoparticles (silver, iron, manganese, copper,
and zinc) on the induction of defense reaction of wheat seedlings infected with
Pseudocercosporella herpotrichoides. Further, antioxidant effect of nonionic colloidal solutions of biogenic metals via inhibition of the synthesis of lipid peroxidation products has been observed. Besides nanoparticles, antimicrobial activity of
nanoparticles loaded with chitosan has been reported to control Fusarium head
blight of wheat (Fusarium graminearum). Kheiri et al. (2016) revealed that chitosan
nanoparticles have strong inhibitory effect on the fungal growth, colony formation,
and conidial germination of F. graminearum. However, plant protection by chitosan
nanoparticles is dependent on time period and growth stage of plant.
Nanoproducts have been experimenting as insecticides against different kinds of
wheat pests. Nano-silica is one of the widely and universally accepted nanoproduct
used as a nanopesticide (Barik et al. 2008). The mechanism of action of nano-silica is
based on the fact that insect pests used a variety of cuticular lipids for protecting
water barrier and thereby preventing mortality from desiccation. But nano-silica gets
absorbed into the cuticular lipids by physio-sorption and thereby causes death of
insects by physical means when applied on plant surface. Surface charged modified
hydrophobic nano-silica of 3–5 nm size is another product which could be successfully used to control a range of agriculturally important insect pests (Ulrichs et al.
2005). Yang et al. (2009) demonstrated the insecticidal activity of polyethylene
glycol-coated nanoparticles loaded with garlic essential oil against adult Tribolium
castaneum insect found in stored products. It has been observed that the control
efficacy against adult T. castaneum was about 80%, presumably due to the slow and
persistent release of the active components from the nanoparticles. Teodoro et al.
(2010) for the first time reported insecticidal activity of nanostructured alumina
against major insect pests in stored food grains. The results of the study showed
5 Nanotechnology in Wheat Production and Protection
175
Agrochemicals have changed the face of wheat cultivation, but it has also developed
new challenge in the form of resistance against agrochemicals in pathogens and
insect pests. Nanoparticles have a great promise for the management and control of
insect pest and diseases in wheat (Table 5.2). Mishra et al. (2014) studied the effect
of silver nanoparticles in controlling spot blotch disease of wheat caused by
Bipolaris sorokiniana. The results revealed that application of silver nanoparticles
strongly inhibited B. sorokiniana infection in wheat. Moreover, decrease in plant
growth after pathogen challenge was overcome when wheat plants were treated with
silver nanoparticles. Silver nanoparticle-mediated reduction in melanin production
might be one of the factors for diminishing the pathogenicity of B. sorokiniana on
wheat (Mishra and Singh 2015). Similarly, the efficacy of zinc nanoparticles in
controlling Fusarium head blight and deoxynivalenol formation in wheat was
reported by Savi et al. (2015). Savi et al. (2015) demonstrated that zinc oxide
nanoparticles efficiently reduced deoxynivalenol (a toxin produced by
F. graminearum) formation and F. graminearum infection in wheat grains even at
100 mM concentration. In another study, Panyuta et al. (2016) studied the effect of
pre-sowing seed treatment with metal nanoparticles (silver, iron, manganese, copper,
and zinc) on the induction of defense reaction of wheat seedlings infected with
Pseudocercosporella herpotrichoides. Further, antioxidant effect of nonionic colloidal solutions of biogenic metals via inhibition of the synthesis of lipid peroxidation products has been observed. Besides nanoparticles, antimicrobial activity of
nanoparticles loaded with chitosan has been reported to control Fusarium head
blight of wheat (Fusarium graminearum). Kheiri et al. (2016) revealed that chitosan
nanoparticles have strong inhibitory effect on the fungal growth, colony formation,
and conidial germination of F. graminearum. However, plant protection by chitosan
nanoparticles is dependent on time period and growth stage of plant.
Nanoproducts have been experimenting as insecticides against different kinds of
wheat pests. Nano-silica is one of the widely and universally accepted nanoproduct
used as a nanopesticide (Barik et al. 2008). The mechanism of action of nano-silica is
based on the fact that insect pests used a variety of cuticular lipids for protecting
water barrier and thereby preventing mortality from desiccation. But nano-silica gets
absorbed into the cuticular lipids by physio-sorption and thereby causes death of
insects by physical means when applied on plant surface. Surface charged modified
hydrophobic nano-silica of 3–5 nm size is another product which could be successfully used to control a range of agriculturally important insect pests (Ulrichs et al.
2005). Yang et al. (2009) demonstrated the insecticidal activity of polyethylene
glycol-coated nanoparticles loaded with garlic essential oil against adult Tribolium
castaneum insect found in stored products. It has been observed that the control
efficacy against adult T. castaneum was about 80%, presumably due to the slow and
persistent release of the active components from the nanoparticles. Teodoro et al.
(2010) for the first time reported insecticidal activity of nanostructured alumina
against major insect pests in stored food grains. The results of the study showed
5 Nanotechnology in Wheat Production and Protection
175