Identification of Stress-Responsive Metabolites in Plants Using an Untargeted Metabolomics Approach.

Stress can affect different groups of plant metabolites and multiple signaling pathways. Untargeted metabolomics enables the collection of whole-spectrum data for the entire metabolite content present in plant tissues at that point in time. We present a thorough approach for large-scale, untargeted metabolomics of plant tissues using reverse-phase liquid chromatography connected to high-resolution mass spectrometry (LC-MS) of dilute methanolic extract.

Towards realizing nano-enabled precision delivery in plants.

Nanocarriers (NCs) that can precisely deliver active agents, nutrients and genetic materials into plants will make crop agriculture more resilient to climate change and sustainable. As a research field, nano-agriculture is still developing, with significant scientific and societal barriers to overcome. In this Review, we argue that lessons can be learned from mammalian nanomedicine.

Advanced applications of sustainable and biological nano-polymers in agricultural production.

Though still in its infancy, the use of nanotechnology has shown promise for improving and enhancing agriculture: nanoparticles (NP) offer the potential solution to depleted and dry soils, a method for the controlled release of agrochemicals, and offer an easier means of gene editing in plants. Due to the continued growth of the global population, it is undeniable that our agricultural systems and practices will need to become more efficient in the very near future. However, this new technology comes with significant worry regarding environmental contamination.

Comprehensive Risk Assessment of Carbon Nanotubes Used for Agricultural Applications.

Carbon-based nanomaterials (CBNs) are often used for potential agricultural applications. Since CBNs applied to plants can easily enter plant organs and reach the human diet, the consequences of the introduction of CBNs into the food chain need to be investigated. We created a platform for a comprehensive investigation of the possible health risks of multiwalled carbon nanotubes (CNTs) accumulated in the organs of exposed tomato plants.

Whole-Transcriptome Responses to Environmental Stresses in Agricultural Crops Treated with Carbon-Based Nanomaterials.

Carbon-based nanomaterials (CBNs) such as carbon nanotubes (CNTs) and graphene can be beneficial to crops exposed to abiotic stresses such as drought and high salinity. Our findings suggest that the improvement observed in stressed crops treated with CBNs can be associated with CBN-induced restoration of gene expression. When subjected to salt stress, sorghum seedlings showed modified expression in 51 stress-related genes.

Improvement of Commercially Valuable Traits of Industrial Crops by Application of Carbon-based Nanomaterials.

Carbon-based nanomaterials (CBNs) have great potential as a powerful tool to improve plant productivity. Here, we investigated the biological effects of graphene and carbon nanotubes (CNTs) on fiber-producing species (cotton, Gossypium hirsutum) and ornamental species (vinca, Catharanthus roseus). The exposure of seeds to CNTs or graphene led to the activation of early seed germination in Catharanthus and overall higher germination in cotton and Catharanthus seeds.

Carbon-based nanomaterials as stimulators of production of pharmaceutically active alkaloids in cell culture of Catharanthus roseus.

Carbon-based nanomaterials (CBNs) were previously described as regulators of plant cell division. Here, we demonstrated the ability of multi-walled carbon nanotubes (MWCNT) and graphene to enhance biomass production in callus culture of the medicinal plant Catharanthus roseus cultivated in dark conditions. Furthermore, both tested CBNs were able to stimulate biosynthesis of total produced alkaloids in CBN-exposed callus culture of Catharanthus.

Multiwalled Carbon Nanotubes Dramatically Affect the Fruit Metabolome of Exposed Tomato Plants.

Here, we reported that multiwalled carbon nanotubes (MWCNT) added to hydroponics system can enhance fruit production of exposed tomato plants. We quantified the exact amount of MWCNT accumulated inside of fruits collected by MWCNT-exposed plants using an advanced microwave induced heating technique (MIH). We found that absorption of MWCNT by tomato fruits significantly affected total fruit metabolome as was confirmed by LC-MS.

Assessment of Effects of the Long-Term Exposure of Agricultural Crops to Carbon Nanotubes.

Carbon-based nanoparticles (CBNs) are nanomaterials that have been shown to be plant growth regulators. Here, we investigated the effects of long-term exposure to multi-walled carbon nanotubes (MWCNTs) on the growth of three important crops (barley, soybean, and corn). The tested species were cultivated in hydroponics supplemented with 50 μg/mL MWCNTs.

Graphene and carbon nanotubes activate different cell surface receptors on macrophages before and after deactivation of endotoxins.

Nanomaterial synthesis and handling in a non-sterile environment can result in the final product becoming contaminated with bacterial endotoxin or lipopolysaccharides (LPB). During toxicological testing, the effects caused by endotoxin-contaminated nanomaterials can be misinterpreted in the end-point analysis (such as cytotoxicity and immune responses) and could result in erroneous conclusions. The objective of this study was twofold: (i) to test different carbon-based nanomaterials (CBNs) [pristine graphene and multi-wall carbon nanotubes (MWCNTs)] for the presence of endotoxin and develop strategies for depyrogenation, and (ii) to compare the immune response exhibited by macrophages after exposure to native CBNs versus depyrogenated CBNs.

Carbon nanotubes as carriers of Panax ginseng metabolites and enhancers of ginsenosides Rb1 and Rg1 anti-cancer activity.

A major benefit to nanomaterial based-medicine is the ability to provide nanosized vehicles for sporadic metabolites. Here, we describe how the conjugation of valuable ginseng secondary metabolites (ginsenoside Rb1 or Rg1) with carbon nanotubes (CNT) can enhance their anti-proliferative and anti-cancer effects. Ginsenoside-CNT conjugate (Rb-CNT or Rg-CNT) permitted the ginsenosides to be used at a low dose, yet achieve a higher incidence of cancer killing.

Genetic reduction of inositol triphosphate (InsP₃) increases tolerance of tomato plants to oxidative stress.

We demonstrate here that the reduction of InsP 3 , the key component of the phosphoinositol pathway, results in changes in ROS-scavenging machinery and, subsequently, increases the tolerance of tomato plants to light stress. Different plant stress signaling pathways share similar elements and, therefore, 'cross-talk' between the various pathways can exist. Links between the phosphoinositol signaling pathway and light signaling were recently found.

Impact of carbon nanotube exposure to seeds of valuable crops.

Multiwalled carbon nanotubes (MWCNTs) affected seed germination, growth, and the development of three important crops (barley, soybean, corn). Early seed germination and activation of growth in exposed seedlings was observed when MWCNTs were added to sterile agar medium. Similarly, seed germination was activated for all tested crop species when MWCNTs were deposited on seed surfaces.

Modification of tomato growth by expression of truncated ERECTA protein from Arabidopsis thaliana.

ERECTA family genes encode leucine-rich repeat receptor-like kinases that control multiple aspects of plant development such as elongation of aboveground organs, leaf initiation, development of flowers, and epidermis differentiation. These receptors have also been implicated in responses to biotic and abiotic stress, probably as a consequence of their involvement in regulation of plant architecture. Here, ERECTA signalling in tomatoes (Solanum lycopersicum) was manipulated by expressing truncated ERECTA protein (AtΔKinase) from Arabidopsis using two different promoters.

Carbon nanotubes as plant growth regulators: effects on tomato growth, reproductive system, and soil microbial community.

Multi-walled carbon nanotubes (CNTs) can affect plant phenotype and the composition of soil microbiota. Tomato plants grown in soil supplemented with CNTs produce two times more flowers and fruit compared to plants grown in control soil. The effect of carbon nanotubes on microbial community of CNT-treated soil is determined by denaturing gradient gel electrophoresis and pyrosequencing analysis.

Surface chemistry of carbon nanotubes impacts the growth and expression of water channel protein in tomato plants.

Specific properties of carbon nanotubes, such as their level of agglomeration in the medium and their surface characteristics, can be critical for the physiological response of plants upon application of carbon nanotubes. The correlations among the level of aggregation, the type of functional group on the surface of the carbon nanotubes, and the growth performance of tomato plants are documented.

Carbon nanotubes induce growth enhancement of tobacco cells.

Carbon nanotubes have shown promise as regulators of seed germination and plant growth. Here, we demonstrate that multiwalled carbon nanotubes (MWCNTs) have the ability to enhance the growth of tobacco cell culture (55-64% increase over control) in a wide range of concentrations (5-500 μg/mL). Activated carbon (AC) stimulated cell growth (16% increase) only at low concentrations (5 μg/mL) while dramatically inhibited the cellular growth at higher concentrations (100-500 μg/mL).

Reduction of inositol (1,4,5)-trisphosphate affects the overall phosphoinositol pathway and leads to modifications in light signalling and secondary metabolism in tomato plants.

The phosphoinositol pathway is one of the major eukaryotic signalling pathways. The metabolite of the phosphoinositol pathway, inositol- (1,4,5) trisphosphate (InsP(3)), is a regulator of plant responses to a wide variety of stresses, including light, drought, cold, and salinity. It was found that the expression of InsP 5-ptase, the enzyme that hydrolyses InsP(3), also dramatically affects the levels of inositol phosphate metabolites and the secondary metabolites in transgenic tomato plants.

In vivo plant flow cytometry: a first proof-of-concept.

In vivo flow cytometry has facilitated advances in the ultrasensitive detection of tumor cells, bacteria, nanoparticles, dyes, and other normal and abnormal objects directly in blood and lymph circulatory systems. Here, we propose in vivo plant flow cytometry for the real-time noninvasive study of nanomaterial transport in xylem and phloem plant vascular systems. As a proof of this concept, we demonstrate in vivo real-time photoacoustic monitoring of quantum dot-carbon nanotube conjugates uptake by roots and spreading through stem to leaves in a tomato plant.

Physiological responses induced in tomato plants by a two-component nanostructural system composed of carbon nanotubes conjugated with quantum dots and its in vivo multimodal detection.

Plant seedlings were exposed to single-walled carbon nanotube-quantum dot conjugates (SWCNT-QD) mixed in the growth medium in order to understand the interactions between these multicomponent nanosystems and plants. A combination of fluorescent and Raman-scattering 2D mapping analysis was used to clearly monitor the presence of the SWCNT-QD conjugates in various parts of the tomato seedlings. We found that the addition of QDs to SWCNTs dramatically changed the biological viability of the tomato plants by significantly accelerating leaf senescence and inhibiting root formation.

Complex genetic, photothermal, and photoacoustic analysis of nanoparticle-plant interactions.

Understanding the nature of interactions between engineered nanomaterials and plants is crucial in comprehending the impact of nanotechnology on the environment and agriculture with a focus on toxicity concerns, plant disease treatment, and genetic engineering. To date, little progress has been made in studying nanoparticle-plant interactions at single nanoparticle and genetic levels. Here, we introduce an advanced platform integrating genetic, Raman, photothermal, and photoacoustic methods.

Nanostructural materials increase mineralization in bone cells and affect gene expression through miRNA regulation.

We report that several nanomaterials induced enhanced mineralization (increased numbers and larger areas of mineral nests) in MC3T3-E1 bone cells, with the highest response being induced by silver nanoparticles (AgNPs). We demonstrate that AgNPs altered microRNA expression resulting in specific gene expression associated with bone formation. We suggest that the identified essential transcriptional factors and bone morphogenetic proteins play an important role in activation of the process of mineralization in bone cells exposed to AgNPs.