Introduction
Human health is major global concern and interests have been risen for the implementation of green and cost effective nanoscience driven technologies to enhance the quality of edible crop plants. It was done for enhancing their essential nutrients to be used as nutraceuticals, antioxidants, antimicrobial ingredients in foods supplement and enhancing flavors.1, 2, 3 Nano-formulation of antimicrobial plant growth promoting thymol containing nanoemulsion was also prepared by using Quillaja saponin, a glycoside surfactant of Quillaja tree.4, 5, 6 Past plant studies have been proposed for developing bioagents to replace chemical bactericides to be used against plant diseases like tomato bacterial wilt, Kimchi cabbage soft rot, and red pepper bacterial leaf spot to boost plant immunity in respective edible crop plants which commonly caused by gram-negative and gram-positive bacteria named, Dickeya and Pectobacterium (soft-rot bacterial plant pathogens). These nano based approaches are also reported for improving edible crop plants to minimize the post-harvest losses and early fruit ripening which occurred due to known bacterial and fungal diseases like bacterial spot, caused by Xanthomonas campestris; bacterial speck, caused by Pseudomonas syringae; and bacterial canker, caused by Clavibacter michiganensis, tomato target leaf spot caused by Corynespora cassiicola, tomato early blight caused by Alternaria solani.7, 8, 9 These potent antimicrobial green nanoformulations were found to have excellent storage capacity and antimicrobial to be used as bioagents for reducing occurrence of wilt effectively with combination of fluorescent Pseudomonas and T. harzianum by 74% and 67% in pots and field, respectively. 10, 11, 12
Brief Potential Payoff Matrix of Nanotechnology
The incorporation of health nutrients into edible crop plants in nano concentration is called nano-biofortification including boron, copper, iron, iodine, calcium, selenium and zinc nanoparticles to supplement human diet with balanced diet to combat human malnutrition.13, 14, 15 Green preparations were used to prepare biofortified foods and feed by synthesizing selenium nanoparticles, iron nanoparticles using leaves of Ocimum basilicum and green tea; Copper-nanoparticles of Eucalyptus globulus, zinc oxide-nanoparticles from Nilgiriantusciliantus leaf, nickel oxide-nanoparticles of Nigella sativa seeds and magnesium oxide-nanoparticles. 16, 17 These bio-engineered nanoparticles could be considered as good health supplements like food additives or food industry like colorants, flavor enhancers, and artificial sweeteners. 17, 18, 19 The positive effects of these bio-nanoengineered plant based preparations were found to promote plant enzymes like nitrate reductase, phosphatase, amylase, and phytase and used to enhance biosynthesis of chlorophyll and photosynthetic activities in edible vegetable crop plants. Zinc oxide nanoparticles are found to have influence on the Cadmium uptake by plants which have strong impact on wheat. 20
Green Aspect
Green preparation of high quality and non-toxic nanoparticles especially in consideration of having chemical purity, phase selectivity, crystallinity, and homogeneity in particle size with controlled state of agglomeration must be first choice for material chemists and bioengineers. High quality magnesium oxide (MgO) nanoparticles have been explore to study fate of nanoparticles in various environmental remediation stakes linked to the human health.20, 21, 22 Use of copper oxide nanoparticles was also explored in improving crop plant quality and their conservation to observe beneficial effects in seedlings, enhancing plant growth and the involvement of nitric oxide signalling in the phytotoxic effects.23, 24 Agricultural soils have found to improve by the use of nanoparticles-based fertilizers to achieve nano-biofortification by promoting structural alterations, modifying gene expression, and improving antioxidant defence systems by enhancing the nutrient utilization efficiency and decrease environmental problems.25, 26 Many biophysiochemical parameters have been studied for regulating uptake, translocation and distribution of nanoparticles in crop plants by fortification process which defines mode of application like aerial/foliar, root and seed priming also includes interactions with other environmental components like microbiota, soil water, soil surface and soil structure. 27, 28
Conclusion
Nanotechnology is found to be considered advanced tool to prepare biofortified foods or dietary supplements and also improving the nutritional quality of vegetable crop plants by the use of nanofertilizers or nanobiostimulats. Characteristics of food nutrients based nanoparticles and overall non-toxic uptake of nano-based nutritional components in edible crop plants were found to be their green and cost effective outcome in respective payoff matrix of nanotechnology approaches. Hence, in this urban scientific era, the various nanotechnology based practices in food and agricultural industries have vast scope adin the environment especially soil-plant systems, human exposure becomes inevitable through direct touching or via edible plant tissues causing hazardous health impacts.
