NANOBIOTECHNOLOGY IN NUTRITIONAL SUSTAINABILITY TO CROP PLANTS
The most vital issue in recent years regarding food production is to increase food production to address the pressing food demand globally under limited resources and changing climate scenarios. Increasing the efficiency and minimum use of agrochemicals like fertilizers, herbicides, and pesticides, and other agrochemicals without adversely affecting the environment are in great interest of agriculture sustainability.
Effective nutritional uptake by the crop is one of the vital factors that control plant growth and productivity. However, the excessive and indiscriminate application of chemical fertilizers in the agriculture field increased productivity but also raised the environmental issues, which included decreased soil fertility, accumulation of fertilizers in the soil leading to perturb soil harmony, etc. which adversely affects the crop productivity. However, in the recent years, nano-fertilizers extends new opportunity in the agriculture sector to enhance crop productivity by striking a nutritional balance to plants, which are an essential component for proper growth and better productivity without compromising environmental issues. Several nanomaterials were tested for their impact on seed germination, seedling growth, plant growth, pathogen attack, etc., which can improve crop productivity. The studies on the uptake of several metals or metal oxide NPs, i.e., ZnO, TiO,, FeO A1,03, etc. by the plants revealed a significant positive effect on plant growth. Apart from NPs, CNTs, QDs, nanorods also exhibit a unique set of properties that offers potential applications in the development of nanodevices and nanostructures that can be used in agriculture to enhance crop productivity and crop protection. For instance, carbons nanotubes (CNTs) can be used in targeted delivery of agrochemicals, thus offer efficient use of resources and prevent excess chemicals released into the environment [47]. QDs exhibit unique spectral features that enables it excellent fluorescent material that can be used to develop nanodevices for live bioimaging and biosensing in plants to monitor the physiological processes [48].
NANOBIOTECHNOLOGY IN CROP PROTECTION AND DISEASE MANAGEMENT IN PLANTS
Nanotechnology offers great potential in the agricultural sector for precise and effective agriculture management practices by augmenting the efficacy of the management system and conservation of resource inputs in crops [49]. Disease and pathogen attacks are major limiting factors for crop development and productivity. Agrochemicals like pesticides, insecticides are most widely applied in agriculture to improve crop yield. Conventional methods and approaches for the application of pesticides in the agricultural felids suffer several drawbacks such as uneven distribution and application of more than required quantity and accumulation in the soil. However, nanotechnology helps in preventing the excessive use of chemical pesticides by offering the controlled delivery system for pesticides/insecticides/fertilizers for effective agricultural management. Nano-encapsulation is the most potent tool that could offer the best control over the effective release of the agrochemical, thus provides better management in plant host defense against pests and insects. The encapsulation of important agrochemicals like pesticides, fungicides, or nematicides with suitable NPs provides an effective solution for sustained release of agrochemical offers an effective tool towards pest’s management and nutrient management as well. Moreover, controlled the release of agrochemicals into the soil also effectively absorbed by plants and do not accumulate in the soil to the toxic level, therefore make a more environmental-friendly approach. Nanotechnology is also helpful in releasing a very small quantity of agrochemicals including pesticides, herbicides, fungicides, etc. at the target site leading to effective uptake; therefore it offers better control and effective management of agrochemicals and reduces unused access accumulation of agrochemicals thus making it more environmental-friendly and cost-effective [49]. The focus on the development of nanoformulated agrochemicals intended to enhance the solubility of less soluble agrochemical to increase their wide impact and protection against biotic stress [50]. In the recent year’s development of nanoencapsulated formulation for effective and sustained release of pesticides, fungicides, and herbicides hold the key concern in crop protection management practices, which further broaden the crop protection scenario in the agriculture sector and minimizing crop loss and the adverse impact on the environment [51].
NANOBIOTECHNOLOGY IN ABIOTIC STRESS TOLERANCE TO PLANTS
Abiotic stress, which includes salinity, drought, heat, heavy metal toxicity, flood, etc. are the major limiting factors that affect plant growth and productivity to a significant extent leading to declining in crop yield. Realizing the frequent incidences of diverse stresses and changing climate scenarios globally in recent years, sincere efforts were made to apply nanotechnology in the agriculture sector to cope with the deleterious effect abiotic as well as biotic stress on crop yield to maintain food availability. Nanobiotechnology could be applied in the development of tolerant crops or by mitigating the adverse effect on stress on plants [21]. Several studies in the last decade suggested the potential role of NPs in crop protection against abiotic stress. The application of different concentrations of silicon nanoparticles (SNPs at 0,10,50, and 100 mg L_1) on hawthorns (Crataegus sp.) seedlings revealed that SNP played in a positive role in maintaining the important physiological and biochemical attributes under drought stress [52]. In the last decade, there are several metals or metal oxide-based NPs, i.e., AgNPs in wheat under salinity stress [53]. CuNPs, FeNPs, ZnNPs in wheat infected with eyespot causal agents [54]. ZnNPs and CuNPs (Zinc and Copper) NPs on wheat under drought stress [55], Ti02NPs on spinach seedling growth [56], ZnONPs on lupine (Lupinus tennis) plants under salinity stress, AgNPs nonpriming in rice seed revealed the enhanced seed germination and enhanced antioxidant system [57], were synthesized and tested for their efficacy in seed germination, seedling growth and under stress tolerance in various crops wheat, spinach, lupin. Rice etc when seed were pre-treated with these NPs. Although the mechanism of NP induces seed germination is not well understood yet. Some studies suggested that TiO, and SiO, NPs have shown the potential to improve seed germination and enhanced the antioxidant system in Glycine max and onion seeds [58, 59].
NANOBIOTECHNOLOGY IN GENETIC ENGINEERING AND CROP IMPROVEMENT
Genetic engineering towards crop improvement in plants is an important tool to address agricultural sustainability and climate change etc. The development of improved verities of the desired trait through genetic engineering is important to meet inflating food demand. Therefore, it is a prerequisite to have an effective genetic transformation tool and gene delivery system for plants. Although there are several methods of gene delivery system available for plants especially biolistic method and Agrobacterium-mediated gene delivery system, electroporation, etc. But these methods have their own limitations which restrict their wide spectrum application, for example, less efficiency, tissue damage, effective only in certain types or species of plants, etc. Gene delivery in the plants is more complex as compared to the animal system due to the presence of a multilayered cell wall, which additionally puts a hindrance in the gene delivery system [60]. In recent years’ development of nanobiotechnology also opens an opportunity for potential technology development in the gene delivery system with strong efficacy in the plant system. The role of NPs as an instrument for the gene delivery system in plants is gaining much attention in recent years. There are reports available on the role of NPs as drug and gene delivery vehicles in an animal system [61]. So far, several applications of NPs are studied in the plants for agrochemical and fertilizer delivery systems [62].
Recent studies indicated that most of the NPs adsorb on the surface of biomolecules and get access into the cell. Therefore, studies on DNA conjugated NPs have taken much concern with the development of suitable strategies for nanoparticle surface modification to improve the efficacy and stability of nanoparticle as the delivery system to transform plants [63]. Recently calcium phosphate nanoparticle (CaPN) based gene delivery system has shown better genetic transformation frequency in Cichorium intybus L. plants and offers a better choice over conventional methods of gene transformation to develop crop plants with desired agronomic traits [64]. Mou, Chang, et al. [65] studied better gene transformation in
Arabidopsis thaliana roots using the functionalized mesoporous silica nanoparticles (MSNs). The results indicated that MSNs act as an effective gene delivery vehicle without the need for any mechanical force [65].
NANOBIOSENSORS IN PRECISION AGRICULTURE
Nanotechnology has revolutionaries several sectors of industries, such as the food and agriculture sectors. Food and agriculture sectors are now more sensitive to technology development. These sectors which derive the economic growth are now well-adopting technology in developing crops, integrated pest management, precision agricultural practices, food processing, food packaging, livestock development, etc. In the last decade, nanosensors have emerged as a promising tool for the applications in agriculture and food production. Development of nanosensors and their corresponding biological version as nanobiosensors have opened the new heights in the food and agriculture sector by providing highly sensitive analytical tools alternative to conventional chemical and biological sensors. The nanobiosensors offers have several advantages over conventional sensors. Nanobiosensors exhibit high sensitivity due to strong signal amplification and selectivity. Nanosensors have revolutionized the agriculture sector by providing real-time sensing assets for effective and timely management practices in precision fanning. Nanosensors are advantageous because of their low cost and portability. Nanobiosensors offer several detection measures like food contamination, pathogens, heavy metals, pollutants [66], monitoring of physicochemical and biological attributes of soil like temperature, humidity, pH, etc. [67].
Recently, several micro nano-based systems developed as a project of the European Commission (2015) and applied for smart agri-food systems. Currently, nanobiosensors offers smart technology in the precision pharming like crop monitoring, sustained, and effective release of nutrients and other agrochemicals in small quantity, nutrient immobilization, monitoring soil pH, soil moisture environmental changes and monitoring of interaction between plant and pathogens, etc. This tiny network of wireless nanosensors can timely sense and provide early warning according to changing conditions leading to efficient agricultural management. The network of nanobiosensors in the field helps the effective and efficient utilization of resources, whether it is water, nutrients, fertilizers, pesticides, and herbicides insecticides. Most importantly, these nanobiosensors raise the automatic alert in real-time conditions, therefore help farmers in taking appropriate, timely measures which help not only better resource utilization and enhanced crop protection and production but also reduce agricultural cost, agrochemical wastage and their environment accumulation [68]. In the recent development, nanobarcodes and nanoprocessing potentially offer the best and early detection of biotic as well as abiotic stresses, which include pathogen attack, insect detection, the onset of disease, chemical, and toxic contaminants, etc., to adopt quick response management to prevent crop loss [69]. Aptasensors are biosensors that are made up of a combination of biocomponent (single-stranded DNA or peptides molecules) and nanomaterial, which can be of different types of metal NPs, carbon NPs, magnetic NPs, etc. These aptasensors are very sensitive and target specific, which can detect their target (microbes, viruses proteins precisely and send early warning signals in order to take appropriate preventive measures. Aptasensors can also detect pesticides, insecticides, antibiotics drugs, and their residues, which are the main concern in today’s scenario in the food industry [22, 70, 71]. Technological innovations and involvement of nanotechnology in agriculture sectors help farmers to be great extant by enabling them with better agriculture management practices and effective control over agricultural resources and different phases of crop cultivation [69].
