Imaging tools for plant nanobiotechnology

Abstract

The successful application of nanobiotechnology in biomedicine has greatly changed the traditional way of diagnosis and treating of disease, and is promising for revolutionizing the traditional plant nanobiotechnology. Over the past few years, nanobiotechnology has increasingly expanded into plant research area. Nanomaterials can be designed as vectors for targeted delivery and controlled release of fertilizers, pesticides, herbicides, nucleotides, proteins, etc. Interestingly, nanomaterials with unique physical and chemical properties can directly affect plant growth and development; improve plant resistance to disease and stress; design as sensors in plant biology; and even be used for plant genetic engineering. Similarly, there have been concerns about the potential biological toxicity of nanomaterials. Selecting appropriate characterization methods will help understand how nanomaterials interact with plants and promote advances in plant nanobiotechnology. However, there are relatively few reviews of tools for characterizing nanomaterials in plant nanobiotechnology. In this review, we present relevant imaging tools that have been used in plant nanobiotechnology to monitor nanomaterial migration, interaction with and internalization into plants at three-dimensional lengths. Including: 1) Migration of nanomaterial into plant organs 2) Penetration of nanomaterial into plant tissues (iii)Internalization of nanomaterials by plant cells and interactions with plant subcellular structures. We compare the advantages and disadvantages of current characterization tools and propose future optimal characterization methods for plant nanobiotechnology.

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

“…Qualitative, microscopy-based translocation evidence is useful in demonstrating the presence of organic NDVs at the tissue, cellular or subcellular level. 49 As listed on Table 1, several studies have used either fluorescence or electron microscopy to track organic NDVs in plants, with confocal laser scanning microscopy (CLSM) being the most widely used. Confocal microscopy allows 3D imaging of NDVs within plant tissues at multiple depths, 50 meaning different layers of plant tissues can be targeted for elucidation of uptake or translocation mechanisms.…”

“…53 Both fluorescence and confocal techniques are direct methods for NDV tracking with relatively simple operation and low cost when compared to quantitative analyses. 49 Moreover, portable fluorescence readers are available for in planta imaging of organic NDVs, 20,54,18 and stereomicroscopy can be used for the visualization of an entire intact plant or root section (though this method has limited resolution). 53 Challenges related to fluorescence-based microscopy include photobleaching, in which the sample's fluorescence reduces over time due to excitation, quenching by, or interference with other nontarget fluorescent molecules; 55 fluorescent probe leaching or release from NDVs; 56 and, for confocal microscopy, axial chromatic aberration.…”

“…Qualitative, microscopy-based translocation evidence is useful in demonstrating the presence of organic NDVs at the tissue, cellular or subcellular level . As listed on Table , several studies have used either fluorescence or electron microscopy to track organic NDVs in plants, with confocal laser scanning microscopy (CLSM) being the most widely used.…”

“…However, fluorescence microscopy captures images faster, since it does not scan multiple points in the sample, resulting in improved live sample viability . Both fluorescence and confocal techniques are direct methods for NDV tracking with relatively simple operation and low cost when compared to quantitative analyses . Moreover, portable fluorescence readers are available for in planta imaging of organic NDVs, ,, and stereomicroscopy can be used for the visualization of an entire intact plant or root section (though this method has limited resolution) .…”

“…These techniques allow for the detection of organic NDVs within intracellular structures due spatial resolutions of typically 3–20 nm . Another advantage of electron microscopy is that, depending on the detector, NDV elemental analysis, morphology, and crystal structure (if any), can be obtained, , and high lateral resolution allows for dynamic tracking of an individual NDV . This method, however, requires a high vacuum environment and is insensitive to elements with low electron density relative to the substrate, such as carbon .…”