ABSTRACT
With the increasing demand for food due to the growing population, good crop yields have become essential. However, climate changes and anthropogenic activities have led to soil pollution and a decline in crop nutritional value. In addition to this, biotic and abiotic stress on plants results in decreased plant productivity. This is a concerning issue as food is necessary for survival. Along with being precautious of irrigation and fertilizer usage, emerging technologies have also been implemented to increase crop yield. One such application is the use of nanotechnology in agriculture specifically known as nanobiotechnology. The use of nanoparticles in the agroindustry has provided novel solutions to the ongoing food crisis. Nanoparticles due to their small size and high surface area to volume ratio enhance their activity and bioavailability in plants. Nanoparticles are now used as nanofertilizers and in managing abiotic stress in plants. Abiotic stress includes natural factors like drought, flooding and salinity. Plants respond to these stress conditions by altering the biochemical pathways and producing a molecular response. The use of nanoparticles in such cases has shown a positive impact on overall plant health and yield. This is attributed to the increase in photosynthetic rates and seed germination rates. Nanoparticles are also involved in upregulating different antioxidant enzymes like superoxide dismutase, peroxidases etc. which are essential to scavenging reactive oxygen species produced in response to abiotic stress. Nanoparticles due to their biochemical activity and bioavailability to plants are also involved in biofortification. Nanoparticles enhance the ability of plants to uptake nutrients and hence increase their nutritional value and biomass. Nano TiO2 particles are known to increase gluten and starch content in wheat. Similarly, silicon nanoparticles exhibited an enhancement of vegetative features and proline content of the basil plant. Even so, while nanoparticles are a great way to manage abiotic stress and biofortification in plants, they are toxic when used in high concentrations. They can modulate metabolic pathways and gene regulation. This can result in a reduction in growth, photosynthetic rate and oxidative stress. So it is important to study the positive as well as negative effects of nanoparticles on plants. Although we know that nanoparticles help in managing stress through different responses, the proper mechanism is not known. Understanding these mechanisms can help us to develop better methods to increase crop yield sustainably.
