Table 1.

Successful use of nanoformulation used in crop plant as plant growth promoters

Nanoformulation	Mode of applications	Targeted crop	Properties (size/shape/Molecular weight/ pH)	Effect on Plant physiological processes			Key references
				Growth phases	Enzyme activities	Nutrient uptake and release
SiO2 NPs	Seed treatment	L. esculentum Mill	12 nm	Enhance seed germination	No visible effect on enzyme activity	–	[71, 72]
Nano-chitosan	Seed treatment	C. arietinum L	pH 4.8	Promote total biomass, germination, and vigor index up to (57%)	Increase activities of catalase and superoxide dismutase	–	[83, 170]
Chitosan-polymethacrylic acid-NPK NP	Foliar spray	P. vulgaris L	20 nm	Enhance plant growth and total biomass	Enhance the antioxidant enzyme activities	Promote nutrient uptake and accumulation	[73, 74]
Au NPs	Seed imbibition	Z. mays L	10–30 nm, spherical	Promote germination and seedling growth	Promote activity of Superoxide dismutase, peroxidase, and catalase	Increased nutrient uptake of maize excluding iron	[75, 76]
SiO2NPs	Seed imbibition	H. officinalis L	10–20 nm, spherical	Improve plant growth and seed germination	Enhance total soluble proteins	–	[77, 78]
SiO2 NPs	Seed Imbibition	Z. mays L	10–20 nm, spherical	Promotes seed germination	Enhanced the activities of antioxidant enzymes	Increase uptake of nitrogen, phosphorus, and potassium	[77, 79]
Chitosan-Cu NPs	Seed treatment	Z. mays L	Low molecular weight, 80%	Promote seedling growth	Enhance activity of α-amylase and protease	–	[2, 80]
Chitosan-Cu NPs	Foliar spray	Z. mays L	50–190 kDa, 80%	Promote seedling growth, overall plant height, and biomass	Enhance activities of defense enzymes	–	[2, 81]
Chitosan-Zn NPs	Foliar spray	T. durum L	60 kDa, 85%	Stomatal localization of nanoparticles	Promote defense enzyme activities	Enhance zinc content accumulation by 42%	[82, 83]
Nano-chitosan	Seed treatment	Z. mays L	pH 7.0–9.0	Enhance plant height, leaf area, and seed germination	Promote activities of glucose-6-phosphate dehydrogenase, succinate dehydrogenase, and superoxide dismutase	Enhance accumulate of potassium inside the plant	[102, 171]
Chitosan-γ-polyglutamic acid-gibberellic Acid-NPs	Seed treatment	P. vulgaris L	290 kDa, 75%–85%, pH 4.5	Promote seed germination, root development, and total leaf area	Enhance the hormonal efficiency, enhance extracellular enzymes, such as cutinase, lipase, and esterase	Increase efficiency of nutrients	[83, 84]
Chitosan-gibberellic acid NPs	Seed treatment	P. vulgaris L	27 kDa, 75%–85%, pH 4.5	Promote leaf area, carotenoid and chlorophyll content	Enhance the hormonal efficiency by 90%	Not significant effect on nutrient uptake	[172, 173]
Nano-chitosan	Seed treatment	P. vulgaris L	100–399 kDa	Increase seed germination and radical length	Enhance the activity of peroxidase and catalase	Increase Zinc uptake in plant	[174, 175]
Nano-chitosan	Seed treatment	Capsicum annuum L	110 kDa, 85–90%, pH 4.0	Enhance the root biomass (77%) and fresh leaf biomass (28%)	Increase the activity of catalase and peroxidase 33% and 23% respectively	Not much significant effect on nutrient uptake	[176, 177]
Chitosan-polymethacrylic acid-NPK NP	Seed treatment	Pisum sativum var. Master B	20 nm	Enhance mitotic cell division about 1.5 fold	Enhance total soluble proteins like legumin, convicilin and β, vicilin 1, 2 and 3	Enhances the efficiency of plants for the uptake of nutrients	[74, 85]
ZnO NPs	Seed soaked	Avena sativa L	20–50 nm, spherical shape	Promote percent germination	–	Modulate uptake of nitrogen and phosphorus in plants	[178, 179]
ZnO NPs	Seed imbibition	T. aestivum L	30–40 nm, sphere-crystal	Improve shoot length and total plant biomass	Enhance the activity of superoxide dismutase (22.8%) and catalase (60.7%)	Enhance nutrient acquisition in wheat	[86, 87]
Chitosan-thiamine NP	Seed treatment	C. arietinum L	27 kDa, 85%	Promote seed germination and plant growth	Enhance activities of peroxidase, polyphenol oxidase, chitinase, and protease enzyme	Enhance nutrient uptake	[83, 180]
CeO2 NPs	50 Mg-Ce per L hydroponic	Z. mays L	2–4 nm, crystal	Promote photosynthesis and gas exchange	Accumulation of hydrogen peroxidase enzyme	Increase nutrient uptake of maize	[91, 181]
CeO2 NPs	Foliar spray	S. oleracea L	4–7 nm	Enhance percent germination (4%) and vigor index	Catalase activity significantly increased	Enhance nutrient uptake	[89, 182]
Nano-chitosan	Foliar spray	Coffea canephora Piere var Robusta	600 kDa, 85%, pH 6.0	Increase (30–50%) chlorophyll content and photosynthetic rate (30%)	Enhance the enzymatic activities	Enhance nutrient uptake (Nitrogen 10–27%, Phosphorus 17–30% and Potassium 30–45%)	[83]
Chitosan-polymethacrylic acid-NPK NP	Foliar spray	T. aestivum L	20 nm	Increase crop yield (50%) and harvest index (24%)	Increase polysaccharides and total saccharides (11%), nitrate reductase enzyme	Accumulation of nitrogen, phosphorus, and potassium in plant	[83]
AuNPs	Spray on leaves	B. juncea L. Czern	10–20 nm, spherical	Enhance chlorophyll content and plant growth	Enhance antioxidative enzymes, proline and hydrogen peroxide	–	[92]
Carbon (CNTs)	Seeds in culture media	L. esculentum Mill	Nanotubes	Enhance seed germination and vigor index	Increase activities of peroxidase, catalase, and superoxide dismutase	Percentage concentration of nutrient elements present in germinated tomato increased	[182]
TiO2 NPs	Seeds soaked	S. oleracea L	30–60 nm, crystal shape	Enhance seedling growth, biomass, and chlorophyll content	Promote activities of antioxidant enzymes (0.25%)	Enhance nutrient uptake	[88]
TiO2 NPs	Spray on leaves	C.arietinum L	5–20 nm	Reduce membrane damage during cold stress	Increase activity of Rubisco enzyme	Increase the mineral uptake in plant	[183]