Microbial nanotechnology for producing stress smart crops

Microbial nanotechnology includes the synthesis and/or functionalization of various types of nanoparticles using microorganisms such as bacteria, fungi, algae, and viruses. Microbial nanotechnology provides an easy, reliable and eco-friendly method for nanoparticle synthesis which has tremendous applications in different fields such as agriculture, biomedicines, the food industry, the environment, and electronics. While considering the agricultural aspects, the environmental changes have dramatically impacted crop production globally. Abiotic (drought, heat, salinity, heavy metals, cold, UV-radiations) and biotic stress factors (bacteria, fungi, parasites, weeds, insects) are negatively affecting crop growth and development. Nanotechnologies are looked upon as a potent tool for crop improvements targeted at yield enhancements and stress-tolerance. Microbially synthesized nanoparticles have been reported to alleviate the stress impacts and promote plant growth under stress conditions. Different types of nanoparticles including carbon-based, metal and metal oxide nanoparticles synthesized with the help of microbial resources are being successfully explored for conferring stress tolerance in crop plants, or in developing stress-smart crops that can withstand stressful conditions without much yield penalties. The current review focuses on the current understandings and updates on biosynthesis of nanoparticles using microorganisms and their resources. Success stories on exploring the microbial nanotechnological approaches and associated advantages for increasing biotic and abiotic stress tolerance and thus producing stress-smart crops are presented.