Natural Plant Tissue Research Articles

Natural Plant Tissue with Bioinspired Nano Amyloid and Hydroxyapatite as Green Scaffolds for Bone Regeneration.

Bone defects have been increasingly prevalent around the globe and traditional bone substitutes are constantly limited by low abundance and biosafety due to their animal-based resources. Plant-based scaffolds are currently studied as a green candidate but the bioinertia of cellulose to mammalian cells leads to uncertain bone regeneration. Inspired by the cross-kingdom adhesion of plants and bacteria, this work proposes a concept of a novel plant bone substitute, involving coating decellularized plant with nano amyloids and nano hydroxyapatites, to bridge the plant scaffold and animal tissue regeneration. Natural microporosity of plants can guide alignment of mammalian cells into various organ-like structures. Taking advantage of the bioactive nano amyloids, the scaffolds drastically promote cell adhesion, viability, and proliferation. The enhanced bio-affinity is elucidated as positively charged nano amyloids and serum deposition on the nanostructure. Nano-hydroxyapatite crystals deposited on amyloid further prompt osteogenic differentiation of pre-osteoblasts. In vivo experiments prove successful trabeculae regeneration in the scaffold. Such a hierarchical design leverages the dedicated microstructure of natural plants and high bioactivity of nano amyloid/hydroxyapatite coatings, and addresses the abundant resource of bone substitutes. Not limited to their current application, plant materials functionalized with nano amyloid/hydroxyapatite coatings allow many cross-kingdom tissue engineering and biomedical applications.

Nanocellulose Hybrid Lignin Complex Reinforces Cellulose to Form a Strong, Water-Stable Lignin-Cellulose Composite Usable as a Plastic Replacement.

The significant challenges in the use of cellulose as a replacement for plastic are its mechanical properties’ degradation and uncontrolled deformation during the rewetting process. Herein, inspired by the reinforcement of cellulose by lignin in natural plant tissue, a strong and water-stable lignin–cellulose composite (LCC) was developed. A nanocellulose hybrid lignin complex (CHLC) created from bagasse residue after enzymatic hydrolysis was added into a pulp of bleached fibre extracted from pine to produce a lignin–cellulose sheet. The lignin as a water-stable reinforcing matrix, via the hydrogen bonding of the nanocellulose in the CHLC with the fibre was efficiently introduced onto the fibres and the fibre network voids. Compared with a typical lignin-free cellulose sheet, the dry strength and wet strength of the LCC were 218% and 2233% higher, respectively. The developed LCC is an eco-friendly and biodegradable alternative to plastic.

In vitro propagation, lactucin quantification, and antibacterial activity of Indian lettuce (Lactuca indica L.)

Lactuca indica L. (Asteraceae), a wild lettuce, is used as a vegetable and in traditional medicine. This study aims to establish in vitro propagation protocol and evaluate lactucin and antibacterial property from in vitro and natural plant tissues. Leaf blades and petioles were cultured in vitro on Murashige and Skoog (MS) medium supplemented with various concentrations of 6-benzylaminopurine (BAP) and 1.2 mg L–1 indoleacetic acid (IAA). Leaf petioles and a lower BAP concentration (0.5 mg L–1) were optimal for direct shoot induction, while the leaf blade and a higher BAP (4 mg L–1) concentration performed best for callus induction. When the callus was subcultured, 98.7% of samples regenerated plants on MS medium supplemented with 1.5 mg L–1 BAP and 0.5 mg L–1 IAA. MS medium containing 1 mg L–1 IAA was best for in vitro rooting. A high-performance liquid chromatography analysis of the in vitro samples revealed a higher amount of lactucin (sesquiterpene lactones) in the root than the callus and the leaf, whereas in naturally grown plants, higher lactucin amounts were obtained from the juvenile root followed by the root of the flowering plant and juvenile leaf as the lowest concentration. All tissue extracts showed antibacterial activity against Pseudomonas fuscovaginae (a rice pathogen) and Escherichia coli, which was directly proportional to amount of lactucin produced. This in vitro regeneration and phytochemical investigation will facilitate the further exploitation of this useful wild plant.

Bioinspired aligned magnetic features in aerogels for humidity sensing

Many natural plant tissues, such as pinecones, utilize structures to transduce changes in humidity into movement or strain. These often employ layered structures with aligned features in order to create differential stress across the material as different portions swell at different rates. By replicating these types of structures in synthetic materials we can create structures that respond to humidity in a similar manner. Taking these aligned features as inspiration, silica aerogels with tailored humidity reactive properties were created. This behavior was achieved by creating aligned features in these aerogels using a Helmholtz coil to produce a uniform magnetic field that aligned ferrofluid droplets into chains and needle like features. These magnetite-based structures were shown to retain their superparamagnetic properties, allowing them to easily be removed from the aerogels, leaving a large number of aligned channels. Aerogels with the removed needles experienced significantly different strains than both unmodified aerogels and aerogels with the aligned features still in place. Aerogels with these tunable aligned features could be used in humidity sensors that can transduce changes in humidity into strain and could be used in applications such as volatile organic compound capture.

Fermentative production of enantiopure (S)-linalool using a metabolically engineered Pantoea ananatis

BackgroundLinalool, an acyclic monoterpene alcohol, is extensively used in the flavor and fragrance industries and exists as two enantiomers, (S)- and (R)-linalool, which have different odors and biological properties. Linalool extraction from natural plant tissues suffers from low product yield. Although linalool can also be chemically synthesized, its enantioselective production is difficult. Microbial production of terpenes has recently emerged as a novel, environmental-friendly alternative. Stereoselective production can also be achieved using this approach via enzymatic reactions. We previously succeeded in producing enantiopure (S)-linalool using a metabolically engineered Pantoea ananatis, a member of the Enterobacteriaceae family of bacteria, via the heterologous mevalonate pathway with the highest linalool titer ever reported from engineered microbes.ResultsHere, we genetically modified a previously developed P. ananatis strain expressing the (S)-linalool synthase (AaLINS) from Actinidia arguta to further improve (S)-linalool production. AaLINS was mostly expressed as an insoluble form in P. ananatis; its soluble expression level was increased by N-terminal fusion of a halophilic β-lactamase from Chromohalobacter sp. 560 with hexahistidine. Furthermore, in combination with elevation of the precursor supply via the mevalonate pathway, the (S)-linalool titer was increased approximately 1.4-fold (4.7 ± 0.3 g/L) in comparison with the original strain (3.4 ± 0.2 g/L) in test-tube cultivation with an aqueous-organic biphasic fermentation system using isopropyl myristate as the organic solvent for in situ extraction of cytotoxic and semi-volatile (S)-linalool. The most productive strain, IP04S/pBLAAaLINS-ispA*, produced 10.9 g/L of (S)-linalool in “dual-phase” fed-batch fermentation, which was divided into a growth-phase and a subsequent production-phase. Thus far, this is the highest reported titer in the production of not only linalool but also all monoterpenes using microbes.ConclusionsThis study demonstrates the potential of our metabolically engineered P. ananatis strain as a platform for economically feasible (S)-linalool production and provides insights into the stereoselective production of terpenes with high efficiency. This system is an environmentally friendly and economically valuable (S)-linalool production alternative. Mass production of enantiopure (S)-linalool can also lead to accurate assessment of its biological properties by providing an enantiopure substrate for study.

Pyrrolizidine Alkaloids-Free Extract from the Cell Culture of Lithospermum officinale with High Antioxidant Capacity.

The benefits of Lithospermum officinale has encouraged people to continue using its extract (CAS 90063-58-4) in both medicinal and cosmetic industries despite the fact that chemical analysis confirms the presence of pyrrolizidine alkaloids (PAs) in the extract. While the cultivation of L. officinale takes, at least, 2years to produce usable crops, its callus culture proliferated 8.3 times with 4.9-fold biomass in less than 30days under the applied conditions in this study. Under the applied conditions, the cell extract contained no toxic PAs while phenylpropanoid pathway was active toward phenolic acids formation not toward naphthoquinone derivatives. Rosmarinic acid was produced as the main constituent. Total phenolic content and antioxidant capacity of the proliferated cell extracts were similar to those of the extracts of the natural plant tissues, in particular from the root. These results support the idea that the extract of L. officinale cells can be a reliable substitute for the extract of the natural plant tissues.

Discovery of nano-sized gold particles in natural plant tissues

Biological effects of nanoparticles have attracted widespread attention. However, the interaction between plants and nanoparticles remains unclear. The purpose of this study was to investigate characteristics of nano-sized metal particles in two representative plant species, Erigeron canadensis and Boehmeria nivea, in the Guangdong Province, China. The stems of the plants were sliced and placed on Ni–C grids for field-emission transmission electron microscopy (TEM). The metal-bearing nanoparticles were further analysed for their size, shape, composition, content and other characteristics using X-ray energy spectrum analysis, scanning TEM and selected-area electron diffraction pattern. The results revealed that the plants contain nano-sized Au-bearing particles with a diameter of 5–50 nm, ellipsoid, spherical and bone-rod shapes or irregular morphology with smooth edges. These nanoparticles primarily consisted of Au, Cu, O and Cl. The discovery of Au-bearing nanoparticles in natural plant tissues is of great significance for biological nanoscience. Here, we discuss the function and absorption mechanism of Au-bearing nanoparticles in plants and present the influence of the discovery of Au-bearing nanoparticles in natural plants.

Prospecting Application of Nanoparticles and Nearly Nanoscale Particles Within Plant Tissues

AbstractElement concentration analysis used in vegetation geochemical prospecting has acquired many achievements. Nevertheless, its limitations cannot be denied, which lead to the research subject of this paper. Plant samples were collected from Fankou lead–zinc deposit. Through high‐resolution analysis of transmission electron microscopy, here we show detailed information regarding nanoparticles and nearly nanoscale particles within natural plant tissues, whose compositions are mainly metallic elements (metal‐bearing particles). The particles exhibit a wide size range (from 30 nm to 1.5 µm in one dimension), diverse shapes and smooth edges. Natural Au particles could be observed. Pb‐, Zn‐, Ag‐, Cr‐bearing particles could be detected frequently as well, along with elemental S. Combined with the results of the background sample, a relationship between the particles contained in mine plant bodies and the known orebody buried underground was demonstrated. A continuous process whereby metallic elements are transferred from concealed orebody to the ground surface and then preserved within plant bodies has been taken into consideration. We verify the feasibility in theory and practice, and propose a model that particles contained in plant tissues can be applied to the exploration of deep concealed metal deposits, which may improve the accuracy and sensitivity of blind ore prospecting.

Probing Alignment and Phase Behavior in Intact Wood Cell Walls Using2H NMR Spectroscopy

This study presents the first application of (2)H NMR spectroscopy to quantify lignocellulose matrix orientation, and it demonstrates the ability to separately investigate oriented and unoriented amorphous domains in intact natural plant tissue. Matrix orientation is evaluated using NMR quadrupolar interactions in small deuterated probe molecules absorbed into bulk Liriodendron tulipifera sapwood. Ethylene glycol-d(4) deuterium spectra reveal two distinct amorphous domains, a highly oriented phase in the secondary wall S2 layer and an isotropic domain probably reflecting the compound middle lamella (CML). The oriented and isotropic signal areas exhibit thermally reversible changes, postulated to reflect probe redistribution between the S2 layer and the CML. Preliminary studies on a more powerful wood swelling agent, N,N-dimethylformamide-d(1), are also discussed. This (2)H NMR technique provides a new avenue for analysis and understanding of lignocellulose ultrastructure and promises to create new insights in correlating biomass processing with morphological change.

Mapping peroxidase in plant tissues by scanning electrochemical microscopy

Scanning electrochemical microscopy has been firstly used to map the enzymatic activity in natural plant tissues. The peroxidase (POD) was maintained in its original state in the celery ( Apium graveolens L.) tissues and electrochemically visualized under its native environment. Ferrocenemethanol (FMA) was selected as a mediator to probe the POD in celery tissues based on the fact that POD catalyzed the oxidation of FMA by H 2O 2 to increase FMA + concentration. Two-dimensional reduction current profiles for FMA + produced images indicating the distribution and activity of the POD at the surface of the celery tissues. These images showed that the POD was widely distributed in the celery tissues, and larger amounts were found in some special regions such as the center of celery stem and around some vascular bundles.

Controls on N Retention and Exports in a Forested Watershed

We conducted a 15N-tracer study in a fertilized, forested catchment at the Bear Brook Watersheds in Maine (BBWM), USA, in order to characterize N cycling processes, identify sinks for ammonium-N additions, and determine the contribution of the experimental ammonium additions to nitrate exports from the treated catchment. Distributions of 15N in plant tissues, soils, precipitation and streamwater collected before adding tracers showed that nitrate-N (the dominant form of inorganic N deposition at the site) inputs under ambient conditions were depleted in 15N relative to plants and that soil was enriched in 15N relative to plants. The 15N content of streamwater nitrate was within the range of 15N contents in natural plant tissues, suggesting that nitrate deposited from the atmosphere is reduced and assimilated into soil and plant N pools before being leached as nitrate from the catchment. Variations in 15N natural abundances also suggested that most N uptake by trees is from the forest floor and that nitrification occurs in soils at this catchment under ambient conditions. Changes in 15N contents of plant tissues, soils and streamwater after adding a 15N tracer to the ammonium sulfate fertilizer applied to the treated catchment showed that soils were the dominant sink for the labeled ammonium. Surface soils (Oca horizon plus any underlying mineral soil to 5cm depth) assimilated 19 to 31 percent of the 42 kg ha-1 of 15N-labelled ammonium-N during the tracer study. Aboveground biomass assimilated 8 to 17 percent of the labeled ammonium-N additions. Of the three forest types on the catchment, the soil:biomass assimilation ratio of labeled-N was highest in the spruce forest, intermediate in the beech-dominated hardwood forest and lowest in the mixed hardwood-spruce forest. Although ammonium sulfate additions led to increases in streamwater nitrate, only 2 of the 13 kg ha-1 of nitrate-N exported from the catchment during the 2 years of tracer additions was derived from the 42 kg ha-1 of labeled ammonium-N additions.