Prophylactic phage biocontrol prevents Burkholderia gladioli infection in a quantitative ex planta model of bacterial virulence.

Agricultural crop yield losses and food destruction due to infections by phytopathogenic bacteria such as Burkholderia gladioli, which causes devastating diseases in onion, mushroom, corn, and rice crops, pose major threats to worldwide food security and cause enormous damage to the global economy. Biocontrol using bacteriophages has emerged as a promising strategy against a number of phytopathogenic species but has never been attempted against B. gladioli due to a lack of quantitative infection models and a scarcity of phages targeting this specific pathogen. In this study, we present a novel, procedurally straightforward, and highly generalizable fully quantitative ex planta maceration model and an accompanying quantitative metric, the ex planta maceration index (xPMI). In utilizing this model to test the ex planta virulence of a panel of 12 strains of B. gladioli in Allium cepa and Agaricus bisporus, we uncover substantial temperature-, host-, and strain-dependent diversity in the virulence of this fascinating pathogenic species. Crucially, we demonstrate that Burkholderia phages KS12 and AH2, respectively, prevent and reduce infection-associated onion tissue destruction, measured through significant (P < 0.0001) reductions in xPMI, by phytopathogenic strains of B. gladioli, thereby demonstrating the potential of agricultural phage biocontrol targeting this problematic microorganism.IMPORTANCEAgricultural crop destruction is increasing due to infections caused by bacteria such as Burkholderia gladioli, which causes plant tissue diseases in onion, mushroom, corn, and rice crops. These bacteria pose a major threat to worldwide food production, which, in turn, damages the global economy. One potential solution being investigated to prevent bacterial infections of plants is "biocontrol" using bacteriophages (or phages), which are bacterial viruses that readily infect and destroy bacterial cells. In this article, we demonstrate that Burkholderia phages KS12 and AH2 prevent or reduce infection-associated plant tissue destruction caused by strains of B. gladioli, thereby demonstrating the inherent potential of agricultural phage biocontrol.

Imaging plant cell walls using fluorescent stains: The beauty is in the details.

Plants continuously face various environmental stressors throughout their lifetime. To be able to grow and adapt in different environments, they developed specialized tissues that allowed them to maintain a protected yet interconnected body. These tissues undergo specific primary and secondary cell wall modifications that are essential to ensure normal plant growth, adaptation and successful land colonization. The composition of cell walls can vary among different plant species, organs and tissues. The ability to remodel their cell walls is fundamental for plants to be able to cope with multiple biotic and abiotic stressors. A better understanding of the changes taking place in plant cell walls may help identify and develop new strategies as well as tools to enhance plants' survival under environmental stresses or prevent pathogen attack. Since the invention of microscopy, numerous imaging techniques have been developed to determine the composition and dynamics of plant cell walls during normal growth and in response to environmental stimuli. In this review, we discuss the main advances in imaging plant cell walls, with a particular focus on fluorescent stains for different cell wall components and their compatibility with tissue clearing techniques. Lay Description: Plants are continuously subjected to various environmental stresses during their lifespan. They evolved specialized tissues that thrive in different environments, enabling them to maintain a protected yet interconnected body. Such tissues undergo distinct primary and secondary cell wall alterations essential to normal plant growth, their adaptability and successful land colonization. Cell wall composition may differ among various plant species, organs and even tissues. To deal with various biotic and abiotic stresses, plants must have the capacity to remodel their cell walls. Gaining insight into changes that take place in plant cell walls will help identify and create novel tools and strategies to improve plants' ability to withstand environmental challenges. Multiple imaging techniques have been developed since the introduction of microscopy to analyse the composition and dynamics of plant cell walls during growth and in response to environmental changes. Advancements in plant tissue cleaning procedures and their compatibility with cell wall stains have significantly enhanced our ability to perform high-resolution cell wall imaging. At the same time, several factors influence the effectiveness of cleaning and staining plant specimens, as well as the time necessary for the process, including the specimen's size, thickness, tissue complexity and the presence of autofluorescence. In this review, we will discuss the major advances in imaging plant cell walls, with a particular emphasis on fluorescent stains for diverse cell wall components and their compatibility with tissue clearing techniques. We hope that this review will assist readers in selecting the most appropriate stain or combination of stains to highlight specific cell wall components of interest.

Establishment of an Infection System for Gentian (Gentiana spp.) Sclerotial Flower Blight Disease.

Gentians (Gentiana spp.) as floriculture crops are constantly exposed to several fungal and viral pathogens in the field. Among the fungal diseases afflicting gentian production, gentian sclerotial flower blight caused by Ciborinia gentianae incurs economic losses, as it affects flowers before and after harvest. Currently, preventive measures for this disease are limited, and no resistant cultivars have been reported. This is partly because of the lack of a reliable infection system that could promote research on this plant-fungus interaction. In this study, Gentiana plant tissue culture material was inoculated with C. gentianae culture filtrate. We successfully demonstrated non-ascospore-mediated infection of C. gentianae. Inoculation of individual hyphal structures present in the culture filtrate suggested that sclerotial primordia are the main agents of this infection. Interestingly, our results indicated that primary infection of C. gentianae occurs in petals rather than leaves, which enables systemic infection and therefore mirrors the fungus's infection strategy observed in the field. Moreover, we showed that (i) non-ascospore hyphal structures can also cause disease in flowers grown in the field, and (ii) ascosporic infection can also be observed using the in vitro system, opening possibilities for both practical and basic research aimed to combat gentian sclerotial flower blight disease.

Transcriptome analysis reveals the effect of propyl gallate on kiwifruit callus formation.

KEY MESSAGE: Exploring the potential action mechanisms of reactive oxygen species during the callus inducing, they can activate specific metabolic pathways in explants to regulate callus development. Reactive oxygen species (ROS) play an important role in the regulation of plant growth and development, but the mechanism of their action on plant callus formation remains to be elucidated. To address this question, kiwifruit was selected as the explant for callus induction, and the influence of ROS on callus formation was investigated by introducing propyl gallate (PG) as an antioxidant into the medium used for inducing callus. The results have unveiled that the inclusion of PG in the medium has disturbed the equilibrium of ROS during the formation of the kiwifruit callus. We selected the callus that was induced by the addition of 0.05 mmol/L PG to the MS medium. The callus exhibited a significant difference in the amount compared to the control medium without PG. The callus induced by the MS medium without PG was used as the control for comparison. KEGG enrichment indicated that PG exposure resulted in significant differences in gene expression in related pathways, such as phytohormone signaling and glutathione in kiwifruit callus. Weighted gene co-expression analysis indicated that the pertinent regulatory networks of both ROS and phytohormone signaling were critical for the establishment of callus in kiwifruit leaves. In addition, during the process of callus establishment, the ROS level of the explants was also closely related to the genes for transmembrane transport of substances, cell wall formation, and plant organ establishment. This investigation expands the theory of ROS-regulated callus formation and presents a new concept for the expeditious propagation of callus in kiwifruit.

Enhanced azadirachtin production in neem (Azadirachta indica) callus through NaCl elicitation: Insights into differential protein regulation via shotgun proteomics.

With their remarkable bioactivity and evolving commercial importance, plant secondary metabolites (PSMs) have gained significant research interest in recent years. Plant tissue culture serves as a credible tool to examine how abiotic stresses modulate the production of PSMs, enabling clear insights into plant stress responses and the prospects for controlled synthesis of bioactive compounds. Azadirachta indica, or neem has been recognized as a repository of secondary metabolites for centuries, particularly for the compound named azadirachtin, due to its bio-pesticidal and high antioxidant properties. Introducing salt stress as an elicitor makes it possible to enhance the synthesis of secondary metabolites, specifically azadirachtin. Thus, in this research, in vitro callus cultures of neem were micro-propagated and induced with salinity stress to explore their effects on the production of azadirachtin and identify potential proteins associated with salinity stress through comparative shotgun proteomics (LCMS/MS). To induce salinity stress, 2-month-old calli were subjected to various concentrations of NaCl (0.05-1.5%) for 4 weeks. The results showed that the callus cultures were able to adapt and survive in the salinity treatments, but displayed a reduction in fresh weight as the NaCl concentration increased. Notably, azadirachtin production was significantly enhanced in the salinity treatment compared to control, where 1.5% NaCl-treated calli produced the highest azadirachtin amount (10.847 ± 0.037 mg/g DW). The proteomics analysis showed that key proteins related to primary metabolism, such as defence, energy, cell structure, redox, transcriptional and photosynthesis, were predominantly differentially regulated (36 upregulated and 93 downregulated). While a few proteins were identified as being regulated in secondary metabolism, they were not directly involved in the synthesis of azadirachtin. In conjunction with azadirachtin elicitation, salinity stress treatment could therefore be successfully applied in commercial settings for the controlled synthesis of azadirachtin and other plant-based compounds. Further complementary omics approaches can be employed to enhance molecular-level modifications, to facilitate large-scale production of bioactive compounds in the future.

A rapid and robust colorimetric method for measuring relative abundance of auxins in plant tissues.

INTRODUCTION: Auxin estimation in plant tissues is a crucial component of auxin signaling studies. Despite the availability of various high-throughput auxin quantification methods like LC-MS, GC-MS, HPLC, biosensors, and DR5-gus/gfp-based assays, auxin quantification remains troublesome because these techniques are very expensive and technology intensive and they mostly involve elaborate sample preparation or require the development of transgenic plants. OBJECTIVES: To find a solution to these problems, we made use of an old auxin detection system to quantify microbe derived auxins and modified it to effectively measure auxin levels in rice plants. MATERIALS AND METHODS: Auxins from different tissues of rice plants, including root samples of seedlings exposed to IAA/TIBA or subjected to different abiotic stresses, were extracted in ethanol. The total auxin level was measured by the presently described colorimetric assay and counterchecked by other auxin estimation methods like LC-MS or gus staining of DR5-gus overexpressing lines. RESULTS: The presented colorimetric method could measure (1) the auxin levels in different tissues of rice plants, thus identifying the regions of higher auxin abundance, (2) the differential accumulation of auxins in rice roots when auxin or its transport inhibitor was supplied exogenously, and (3) the levels of auxin in roots of rice seedlings subjected to various abiotic stresses. The thus obtained auxin levels correlated well with the auxin levels determined by other methods like LC-MS or gus staining and the expression pattern of auxin biosynthesis pathway genes. CONCLUSIONS: The auxin estimation method described here is simple, rapid, cost-effective, and sensitive and allows for the efficient detection of relative auxin abundances in plant tissues.

Fast and low-cost method for direct and simultaneous determination of nitrogen and carbon in soybean leaves using benchtop and portable near-infrared devices.

BACKGROUND: The current techniques for determining carbon and nitrogen content to provide information about the nutritional status of plants are time-consuming and expensive. For this reason, the objective of this study was to develop an analytical method for the direct and simultaneous determination of nitrogen and carbon elemental content in soybean leaves using near-infrared spectroscopy and compare the performance of conventional (1100-2500 nm spectral range) and portable equipment (1100-1700 nm spectral range). Partial least-squares regression models were developed using 27 soybean leaf samples collected during the 2021 harvest and applied for the simultaneous determination of carbon and nitrogen in 13 samples collected during the 2022 harvest. RESULTS: The root-mean-square error of prediction values for nitrogen and carbon were low (2.42 g kg-1 and 4.37 g kg-1 respectively) for the benchtop method yielded low but higher for the portable method (3.82 g kg-1 and 10.7 g kg-1 respectively). The benchtop method did not show significant differences when compared with the reference method for determining nitrogen and carbon. In contrast, the portable methodology showed potential as a screening method for determining nitrogen levels, particularly in fieldwork. CONCLUSION: The methodologies evaluated in this study were implemented and evaluated under real crop monitoring conditions, using independent sets of calibration and prediction samples. Their utilization enables the acquisition of cost-effective, safe analytical data aligning with the principles of green analytical chemistry. © 2023 Society of Chemical Industry.

Review: structure and modifications of arabinogalactan proteins (AGPs).

The aim of this report is to provide general information on the molecular structure and synthesis of arabinogalactan proteins (AGPs) in association to their physiological significance. Assessment of genetic modifications of the activity of enzymes involved in the AGP biosynthesis is an efficient tool to study AGP functions. Thus, P4H (prolyl 4 hydroxylase) mutants, GLCAT (ß-glucuronosyltransferase) mutants, and GH43 (glycoside hydrolase family 43) mutants have been described. We focused on the overview of AGPs modifications observed at the molecular, cellular, and organ levels. Inhibition of the hydroxylation process results in an increase in the intensity of cell divisions and thus, has an impact on root system length and leaf area. In turn, overexpression of P4H genes stimulates the density of root hairs. A mutation in GLCAT genes responsible for the transfer of glucuronic acid to the AGP molecule revealed that the reduction of GlcA in AGP disrupts the substantial assembly of the primary cell wall. Furthermore, silencing of genes encoding GH43, which has the ability to hydrolyze the AGP glycan by removing incorrectly synthesized ß-1,3-galactans, induces changes in the abundance of other cell wall constituents, which finally leads to root growth defects. This information provides insight into AGPs as a crucial players in the structural interactions present in the plant extracellular matrix.

In vitro propagation of Codonopsis pilosula (Franch.) Nannf. using apical shoot segments and phytochemical assessments of the maternal and regenerated plants.

BACKGROUND: Codonopsis pilosula (Franch.) Nannf. is a medicinal plant traditionally used in China, Korea, and Japan to treat many diseases including poor gastrointestinal function, low immunity, gastric ulcers, and chronic gastritis. The increasing therapeutic and preventive use of C. pilosula has subsequently led to depletion of the natural populations of this species thus necessitating propagation of this important medicinal plant. Here, we developed an efficient and effective in vitro propagation protocol for C. pilosula using apical shoot segments. We tested various plant tissue culture media for the growth of C. pilosula and evaluated the effects of plant growth regulators on the shoot proliferation and rooting of regenerated C. pilosula plants. Furthermore, the tissues (roots and shoots) of maternal and in vitro-regenerated C. pilosula plants were subjected to Fourier-transform near-infrared (FT-NIR) spectrometry, Gas chromatography-mass spectrometry (GC-MS), and their total flavonoids, phenolics, and antioxidant capacity were determined and compared. RESULTS: Full-strength Murashige and Skoog (MS) medium augmented with vitamins and benzylaminopurine (1.5 mg·L-1) regenerated the highest shoot number (12 ± 0.46) per explant. MS medium augmented with indole-3-acetic acid (1.0 mg·L-1) produced the highest root number (9 ± 0.89) and maximum root length (20.88 ± 1.48 mm) from regenerated C. pilosula shoots. The survival rate of in vitro-regenerated C. pilosula plants was 94.00% after acclimatization. The maternal and in vitro-regenerated C. pilosula plant tissues showed similar FT-NIR spectra, total phenolics, total flavonoids, phytochemical composition, and antioxidant activity. Randomly amplified polymorphic DNA (RAPD) test confirmed the genetic fidelity of regenerated C. pilosula plants. CONCLUSIONS: The proposed in vitro propagation protocol may be useful for the rapid mass multiplication and production of high quality C. pilosula as well as for germplasm preservation to ensure sustainable supply amidst the ever-increasing demand.

Metabolic engineering of the anthocyanin biosynthetic pathway in Artemisia annua and relation to the expression of the artemisinin biosynthetic pathway.

MAIN CONCLUSION: Four types of cells were engineered from Artemisia annua to produce approximately 17 anthocyanins, four of which were elucidated structurally. All of them expressed the artemisinin pathway. Artemisia annua is the only medicinal crop to produce artemisinin for the treatment of malignant malaria. Unfortunately, hundreds of thousands of people still lose their life every year due to the lack of sufficient artemisinin. Artemisinin is considered to result from the spontaneous autoxidation of dihydroartemisinic acid in the presence of reactive oxygen species (ROS) in an oxidative condition of glandular trichomes (GTs); however, whether increasing antioxidative compounds can inhibit artemisinin biosynthesis in plant cells is unknown. Anthocyanins are potent antioxidants that can remove ROS in plant cells. To date, no anthocyanins have been structurally elucidated from A. annua. In this study, we had two goals: (1) to engineer anthocyanins in A. annua cells and (2) to understand the artemisinin biosynthesis in anthocyanin-producing cells. Arabidopsis Production of Anthocyanin Pigment 1 was used to engineer four types of transgenic anthocyanin-producing A. annua (TAPA1-4) cells. Three wild-type cell types were developed as controls. TAPA1 cells produced the highest contents of total anthocyanins. LC-MS analysis detected 17 anthocyanin or anthocyanidin compounds. Crystallization, LC/MS/MS, and NMR analyses identified cyanidin, pelargonidin, one cyanin, and one pelargonin. An integrative analysis characterized that four types of TAPA cells expressed the artemisinin pathway and TAPA1 cells produced the highest artemisinin and artemisinic acid. The contents of arteannuin B were similar in seven cell types. These data showed that the engineering of anthocyanins does not eliminate the biosynthesis of artemisinin in cells. These data allow us to propose a new hypothesis that enzymes catalyze the formation of artemisinin from dihydroartemisinic acid in non-GT cells. These findings show a new platform to increase artemisinin production via non-GT cells of A. annua.

High-throughput MALDI-MSI metabolite analysis of plant tissue microarrays.

A novel metabolomics analysis technique, termed matrix-assisted laser desorption/ionization mass spectrometry imaging-based plant tissue microarray (MALDI-MSI-PTMA), was successfully developed for high-throughput metabolite detection and imaging from plant tissues. This technique completely overcomes the disadvantage that metabolites cannot be accessible on an intact plant tissue due to the limitations of the special structures of plant cells (e.g. epicuticular wax, cuticle and cell wall) through homogenization of plant tissues, preparation of PTMA moulds and matrix spraying of PTMA sections. Our study shows several properties of MALDI-MSI-PTMA, including no need of sample separation and enrichment, high-throughput metabolite detection and imaging (>1000 samples per day), high-stability mass spectrometry data acquisition and imaging reconstruction and high reproducibility of data. This novel technique was successfully used to quickly evaluate the effects of two plant growth regulator treatments (i.e. 6-benzylaminopurine and N-phenyl-N'-1,2,3-thiadiazol-5-ylurea) on endogenous metabolite expression in plant tissue culture specimens of Dracocephalum rupestre Hance (D. rupestre). Intra-day and inter-day evaluations indicated that the metabolite data detected on PTMA sections had good reproducibility and stability. A total of 312 metabolite ion signals in leaves tissues of D. rupestre were detected, of which 228 metabolite ion signals were identified, they were composed of 122 primary metabolites, 90 secondary metabolites and 16 identified metabolites of unknown classification. The results demonstrated the advantages of MALDI-MSI-PTMA technique for enhancing the overall detection ability of metabolites in plant tissues, indicating that MALDI-MSI-PTMA has the potential to become a powerful routine practice for high-throughput metabolite study in plant science.

The priming effects of plant leachates on dissolved organic matter degradation in water depend on leachate type and water stability.

The modification of dissolved organic matter (DOM) degradation by plant carbon inputs represents a critical biogeochemical process that controls carbon dynamics. However, the priming effects (PEs) different plant tissues induce on the degradation of DOM pools with different stabilities remain unknown. In this study, PEs, induced by different tissue leachates of Phragmites australis, were evaluated via changes in DOM components and properties of both fresh and tidal water (with different stabilities). The results showed that DOM derived from different plant tissue leachates differed in composition and bioavailability. Inputs of tissue leachates induced PEs with different intensities and directions (negative or positive) on DOM degradation of fresh and tidal water. In fresh water, the PEs of leaf and root leachates were significantly higher than those of stem and rhizome leachates. The PE direction changed for DOM degradation between fresh and tidal water. The addition of leaf and root leachates tended to induce positive PEs on DOM degradation of fresh water, while resulting in negative PEs on DOM degradation of tidal water. Negative PEs for tidal water DOM may be due to preferential utilization of microbes, high salinity, and/or the promotion of exogenous DOM production from plant tissues. The results indicate that intensity and direction of PEs induced by plant leachates depend on both leachate type and water stability. The findings highlight the necessity to examine the nature of exogenous and native DOM when interpreting the interactive processes that regulate DOM degradation.

Identification of 'Candidatus Liberibacter asiaticus' the Huanglongbing Bacterium in citrus from Colombia.

Candidatus Liberibacter spp is the most prevalent microorganism in the citrus plant, associated with Citrus Huanglongbing (HLB), which is transmitted by the psyllid vector. In Colombia, the vector Diaphorina citri Kugayama has been reported in different regions, but "Ca. Liberibacter asiaticus" (CLas) has only been detected in insect vectors, not in citrus host plants. To identify the presence and quantify the pathogen in citrus tissues, we employed a combined strategy that involved three techniques based on polymerase chain reaction (PCR). First, we used endpoint PCR with specific primers for CLas (OI1-OI2c) to confirm the infection. Second, we used qPCR with specific primers CIT295a - CIT298 designed on 16S rDNA gene regions to quantify the pathogen load. Finally, we employed droplet digital PCR (ddPCR) to determine the copy number of the pathogen in citrus tissues using the ß-subunit of ribonucleotide reductase (RNR) gene (nrdB) that is specific to CLas. We identified the presence of CLas in citrus plants for the first time in Colombia and quantified its titer in the plant tissue. We employed ddPCR and qPCR to provide crucial information for the country's disease management, control strategies, and general crop health.

Ratiometric luminescent sensor based on BSA-coated gold/silver nanoclusters for the selective determination and spatiotemporal imaging of gallic acid in plants.

A new fluorescence sensing strategy has been developed. Four bimetallic nanoclusters, gold/silver, gold/copper, gold/molybdenum and gold/cobalt, were prepared using bovine serum albumin (BSA) as a reducing and stabilizing agent. The fluorescence properties of four nanoclusters were explored by solid-state UV and XPS. The gold/silver nanoclusters (BSA-Au/Ag NCs) with the best ratiometric fluorescence properties for gallic acid (GA) in plants were selected to realize the sensitive detection of GA. GA affected the conformation of BSA, thereby disrupting the luminescent environment of the nanoclusters, resulting in a pronounced fluorescence quenching at 566 nm. The ratiometric fluorescence signal (I566/I453) was used for trace detection of GA in plants. It has a wide response range of 1.25-40.0 µM and a low detection limit of 45.27 nM. GA was detected at 19.49 µM in the plant extract, and the spiked recoveries ranged from 96.09 to 104.6%. In addition, due to the non-toxic and biocompatible properties of BSA, BSA-Au/Ag NCs have also been validated for fluorescence imaging of plant tissues. It realized the comparison of GA content in different parts of plants and the difference of GA content in plants after abiotic stress. Therefore, the developed strategy offers potential application for the analytical study of active substances in plants.

Pharmacokinetic assessment and phytochemical triterpene control from Cecropia angustifolia using plant biotechnology.

INTRODUCTION: Cecropia angustifolia Trécul. is a native Andean plant containing high levels of pentacyclic triterpenes (PTs), including several isobaric molecules that serve as chemical markers. Preclinical studies suggest that PTs positively modulate metabolic and vascular diseases. However, their low oral absorption reduces their bioactive effects. OBJECTIVE: The objective of this study was (1) to improve the absorption of PTs from C. angustifolia and (2) to establish a platform to produce biomass or botanical reference material using a strategy for their accumulation. METHODS: MALDI-TOF and UPLC-MS were used to characterize and quantify PTs in different matrices. An in vitro platform for PT production was established. Chemical profiles of triterpenes were also evaluated from wild and in vitro herbal material using TLC coupled with mass spectrometry. RESULTS: To overcome the low absorption of PTs, a premier raw material was used, which increased their bioavailability to 9.2%. Active ingredients in herbal material can vary, and there is an urgent need for standardized extracts using pharmacokinetics as an effective tool to reveal the dynamics of active ingredients in vivo. A temporary immersion system was produced as a promising platform with a total PT accumulation exceeding 50% of the content in the dry fraction, indicating it is a feasible mechanism to produce biomass or botanical reference material. CONCLUSIONS: Plant tissue culture is a promising eco-friendly technology for phytochemical production and a modern strategy to protect biodiversity in natural assets. Alternative and modern, yet environmentally friendly production methods are needed to meet the large demand for herbal products.

Biotechnological Approaches to Producing Natural Antioxidants: Anti-Ageing and Skin Longevity Prospects.

Plants are the main source of bioactive compounds that can be used for the formulation of cosmetic products. Plant extracts have numerous proven health benefits, among which are anti-ageing and skin-care properties. However, with the increased demand for plant-derived cosmetic products, there is a crucial prerequisite for establishing alternative approaches to conventional methods to ensure sufficient biomass for sustainable production. Plant tissue culture techniques, such as in vitro root cultures, micropropagation, or callogenesis, offer the possibility to produce considerable amounts of bioactive compounds independent of external factors that may influence their production. This production can also be significantly increased with the implementation of other biotechnological approaches such as elicitation, metabolic engineering, precursor and/or nutrient feeding, immobilization, and permeabilization. This work aimed to evaluate the potential of biotechnological tools for producing bioactive compounds, with a focus on bioactive compounds with anti-ageing properties, which can be used for the development of green-label cosmeceutical products. In addition, some examples demonstrating the use of plant tissue culture techniques to produce high-value bioactive ingredients for cosmeceutical applications are also addressed, showing the importance of these tools and approaches for the sustainable production of plant-derived cosmetic products.

The Influence of Pulsed Electric Field and Air Temperature on the Course of Hot-Air Drying and the Bioactive Compounds of Apple Tissue.

Drying is one of the oldest methods of obtaining a product with a long shelf-life. Recently, this process has been modified and accelerated by the application of pulsed electric field (PEF); however, PEF pretreatment has an effect on different properties-physical as well as chemical. Thus, the aim of this study was to investigate the effect of pulsed electric field pretreatment and air temperature on the course of hot air drying and selected chemical properties of the apple tissue of Gloster variety apples. The dried apple tissue samples were obtained using a combination of PEF pretreatment with electric field intensity levels of 1, 3.5, and 6 kJ/kg and subsequent hot air drying at 60, 70, and 80 °C. It was found that a higher pulsed electric field intensity facilitated the removal of water from the apple tissue while reducing the drying time. The study results showed that PEF pretreatment influenced the degradation of bioactive compounds such as polyphenols, flavonoids, and ascorbic acid. The degradation of vitamin C was higher with an increase in PEF pretreatment intensity level. PEF pretreatment did not influence the total sugar and sorbitol contents of the dried apple tissue as well as the FTIR spectra. According to the optimization process and statistical profiles of approximated values, the optimal parameters to achieve high-quality dried apple tissue in a short drying time are PEF pretreatment application with an intensity of 3.5 kJ/kg and hot air drying at a temperature of 70 °C.

Phytochemical Diversity Comparison in Leaves and Roots of Wild and Micropropagated Latvian Sea Holly (Eryngium maritimum L.).

The goal of the current study was to compare the chemical composition of the roots, shoots, and leaves of wild-growing Eryngium maritimum L., and of in vitro and in field-cultivated plants in Latvia. The essential oil yield obtained by hydrodistillation ranged from 0.14% to 0.54%, while analysis of the chemical composition using GC-MS revealed a total of 44 different volatiles, with differences in the types and amounts of volatiles between the leaves and roots. Using 96-well plate techniques, the concentration of total phenolic compounds, saponins, and sugars in the aqueous ethanolic extracts of E. maritimum were assessed, along with their capacity to scavenge stable DPPH radicals. Extracts from roots had a lower concentration of total phenolic compounds compared to those from the leaves of wild grown and cultivated plants but did not differ from in vitro shoots. Root, leaf, and shoot samples of the same genotype from different growth conditions had approximately the same concentration of total saponins, while total sugar concentrations were higher in the roots. The growth conditions had a significant effect on the concentration of total phenolic compounds and antiradical activity, with differences that were significant observed between plant aboveground and belowground parts. Analysis using UHPLC-ESI-q-TOF-MS revealed 63 compounds, with amino acids and hydroxycinnamic acid derivatives (such as chlorogenic and rosmarinic acid) being the major compound groups that significantly differed between plant growth conditions. We also demonstrated that rapid screening of volatile compounds in in vitro plants using headspace gas chromatography mass spectrometry analyses can predict the formation of marker compounds in the same mericlones grown in field conditions. These findings provide valuable insights into the chemical composition of E. maritimum and its potential for use in various applications.

Phosphogypsum impacts on soil chemical properties and vegetation tissue following reclamation.

Phosphogypsum (PG) is a by-product of phosphorus fertilizer that is typically stacked near production sites. Phosphogypsum contains trace elements and naturally occurring radioactive materials which may be hazardous to the surrounding environment. Phosphogypsum stack reclamation typically involves placing a soil cap and seeding grass to create a barrier for reducing environmental impacts; using woody species is uncommon. This study used three soil treatments with grass and woody species to determine whether mixing PG with soil affects soil chemical properties, and metal and radionuclide concentrations in tissue. None of the elements in soil was above Canadian guidelines for industrial land use. Aluminum, beryllium, chromium, copper, iron, magnesium, manganese, nickel, and vanadium were significantly higher in both study and reference sites than in pure PG; cadmium, calcium, fluoride, and strontium were significantly higher in pure PG. There was a poor correlation between soil and plant concentrations for most elements indicating trace elements were not in a bioavailable form. Trace elemental concentrations in plant tissue generally differed significantly with vegetation type but not within similar species. Trace elements and isotopes in PG were not high enough to affect plant growth. Among the isotopes, 222Ra emissions differed significantly with vegetation covers; activity of 226Ra in pure PG was above Canadian guidelines, but lower in vegetation tissue. This study suggests 15 cm soil mixed with PG can be used for PG stack revegetation when fast-growing Salix and Populus species are used in reclamation.

[Application of tissue culture technology of medicinal plants in sustainable development of Chinese medicinal resources].

Chinese medicinal resources are the cornerstone of the sustainable development of traditional Chinese medicine industry. However, due to the fecundity of species, over-exploitation, and limitations of artificial cultivation, some medicinal plants are depleted and even endangered. Tissue culture, a breakthrough technology in the breeding of traditional Chinese medicinal materials, is not limited by time and space, and can allow the production on an annual basis, which plays an important role in the protection of Chinese medicinal resources. The present study reviewed the applications of tissue culture of medicinal plants in the field of Chinese medicinal resources, including rapid propagation of medicinal plant seedlings, breeding of novel high-yield and high-quality cultivars, construction of a genetic transformation system, and production of secondary metabolites. Meanwhile, the current challenges and suggestions for the future development of this field were also proposed.