Table 3.

Successful application of nanocomposites for abiotic stress tolerance

Stress type	Nanoparticles	Plant species	Mode of application	Results	Key references
Drought	TiO2	L. usitatissimum L.	Foliar spray	Enhance chlorophyll and carotenoid content as well as lowers the activity of MDA and H2O2	[204]
	TiO2	T. aestivum L. c.v Pishtaz	Foliar spray	Enhance starch content, growth, and yield	[76]
	TiO2	T. aestivum L.	Amended soil	Increased seedling growth, antioxidant enzymes, total chlorophyll, and carotenoid content	[205]
	ZnO	G. max L.	Seed soaking	Enhance germination rate and percent germination	[119]
	Fe2O3	Mentha piperita L.	Hoagland solution	Increase activity of antioxidant enzymes	[206]
	Cu	Z. mays L.	Plant priming	Improve plant biomass, chlorophyll, anthocyanins, and grain yield	[207]
	CNTs, graphene	G. hirsutum L.	Seed priming	Increase seedling growth and biomass	[123]
	Chitosan NPs	Hordeum vulgare L.	Foliar spray	Increase proline content, CAT and SOD	[208]
Salinity	Ag	Trigonella foenum-graecum	Seed soaking	Improve percent germination, fresh and dry weight of seedlings	[209]
	ZnO	Abelmoschus esculentus L.	Foliar spray	Increase activity of superoxide dismutase, catalase, and photosynthetic pigments	[210]
	ZnO and Si	Mangifera indica L.	Foliar spray	Enhance nutrient uptake, carbon assimilation in plants	[211]
	SiO2	Solanum lycopersicum L.	Seed soaking	Upregulation of stress tolerance genes	[212]
	SiO2	Fragaria ananassa L.	Soil application	Enhance growth, proline, chlorophyll, epicuticular wax layer and leaf relative water content	[213]
	SiO2	Musa acuminate L.	Seed priming	Enhance chlorophyll content, shoot growth	[214]
	Ag	T. aestivum L.	Seed priming	Enhance total soluble sugars, proline content, and peroxidase activity	[185]
	Fe2O3	Helianthus annuus L.	Foliar spray	Enhance dry weight, leaf area, chlorophyll content	[215]
	Fe2O3	Dracocephalum moldavica L.	Foliar spray	Increase the enzymatic activity of guaiacol peroxidase, catalase, ascorbate peroxidase, and glutathione reductase	[215]
	Mn	C. annuum L.	Nanopriming	Improve plant growth	[216]
	CeO	G. hirsutum L.	Seed priming	Improve root growth and decrease ROS level	[121]
	CNTs, graphene	Catharanthus roseus L.	Murashige and Skoog medium	Enhance the number of leaves and flowers	[124]
	Chitosan-PVA and CuNPs	S. lycopersicum L.	Nutrient solution	Enhance chlorophyll, carotenoids, and lycopene content	[122]
Heat	Ag	T. aestivum L.	Soil application	Promote the root number, seedling length, and leaf area	[127]
	Se	S. bicolor L. Moench	Foliar spray	Improve thylakoid membrane stability and activity of antioxidant enzymes	[217]
Heavy metal	Fe	T. aestivum L.	Soil application	Increase rate of photosynthesis, chlorophyll content, and plant growth	[87]
UV-B	Si	T. aestivum L.	Nutrient solution	Improve antioxidant defense system	[218]
Cold	TiO2	C. arietinum L.	Amended soil	Decrease MDA levels and electrolyte leakage index	[219]
Flooding	Al2O3	G. max L.	Seed soaking	Increased hypocotyl length, mitochondrial membrane proteins	[220]