Potential role of biosynthesized zinc oxide nanoparticles in counteracting lead toxicity in Solanum lycopersicum L.

Critical Review: Uptake and Translocation of Organic Nanodelivery Vehicles in Plants

“…Traditionally, research on NDVs in agriculture has relied on mostly inorganic materials, such as metal and metal oxide nanoparticles for antimicrobial activity and micronutrient supplementation; 2,19 carbon dots (CDs) for photosynthesis and nutritional assimilation enhancement and resistance to biotic and abiotic stress; 20 carbon nanotubes (CNTs) and quantum dots (QDs) for improved plant growth and biosensing; 21,22 mesoporous silica nanoparticles for delivery of pesticides and herbicides; 19 and many of the aforementioned as vectors for gene delivery into plants. 23 For these NDVs, size, shape, surface chemistry (which may include partial or complete organic coating), and dose have been shown to affect not only their uptake and translocation following root or foliar administration 24,4,8 but also plant growth, development, response, and toxicity. 2,7,25 Research on organic NDVs (e.g., polymeric nanocarriers, liposomes, solid lipid nanoparticles, and polymer dots) for agricultural applications is a growing area of research which has been slower to develop than research on inorganic NDVs due to the higher complexity of organic formulations and the difficulty in tracking organic NDVs within the organic matrix of plant tissue.…”

“…NDV size has also been reported as an important factor governing inorganic NDV uptake and loading into the vascular bundle. 8 In wheat plants, only titanium oxide (TiO 2 ) nanoparticles smaller than 36 nm penetrated through the root tissue and reached the stele, allowing for their subsequent translocation, while larger particles (36−140 nm) accumulated in the parenchyma cells on root cortex. 119 In poplar trees, gold nanoparticles (AuNPs) ranging from 15 to 50 nm were imaged on the surface of primary and secondary roots as well as on the root vascular bundle 6 days after exposure; however, the concentration of gold detected in leaves decreased with particle size, suggesting less penetration and loading of larger particles.…”

“…94 Improvements in root concentration of atrazine (ATZ) in mustard plants have also been observed when the active ingredient was encapsulated in ∼250 nm anionic surfactant-stabilized PCL carriers, with 4 times higher concentration than for free ATZ exposure over 24 h. 54 The dose of inorganic NDVs has not been directly linked to their root uptake, but it has been shown to be an important factor on plant growth and development. 8,121,122 5.2. Translocation of NDVs after Root Uptake.…”

“…126 This body of evidence suggests that, as with the foliar uptake pathways, cationic NDVs may electrostatically interact with anionic root outer surface, and if internalized, with anionic root cells, resulting in reduced mobility. 25,8…”

“…2 Instead of restricting ENMs by size, a more all-encompassing definition focuses on the characteristics and properties of ENMs that make them advantageous relative to their bulk counterparts, 5,11 such as high surface-to-volume ratio and high specific surface area (which enhance their reactivity) and, depending on the ENM, good colloidal stability. 8,5,3,6,7,1 ENMs are often classified based on their composition, most frequently categorized into the broad classes of inorganic and organic. 5,3,2 Several types of ENMs fall exclusively into just one category, but organic− inorganic hybrids are also possible.…”