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Fulltext Plant carbonic anhydrase-like enzymes in neuroactive alkaloid biosynthesis

Nett RS, Dho Y, Tsai C, Passow D, Martinez Grundman J, Low YY, et al.

Nature, 2023 Dec;624(7990):182-191.
PMID: 37938780 DOI: 10.1038/s41586-023-06716-y

Plants synthesize numerous alkaloids that mimic animal neurotransmitters1. The diversity of alkaloid structures is achieved through the generation and tailoring of unique carbon scaffolds2,3, yet many neuroactive alkaloids belong to a scaffold class for which no biosynthetic route or enzyme catalyst is known. By studying highly coordinated, tissue-specific gene expression in plants that produce neuroactive Lycopodium alkaloids4, we identified an unexpected enzyme class for alkaloid biosynthesis: neofunctionalized α-carbonic anhydrases (CAHs). We show that three CAH-like (CAL) proteins are required in the biosynthetic route to a key precursor of the Lycopodium alkaloids by catalysing a stereospecific Mannich-like condensation and subsequent bicyclic scaffold generation. Also, we describe a series of scaffold tailoring steps that generate the optimized acetylcholinesterase inhibition activity of huperzine A5. Our findings suggest a broader involvement of CAH-like enzymes in specialized metabolism and demonstrate how successive scaffold tailoring can drive potency against a neurological protein target.

Matched MeSH terms: Plants/metabolism
Phytometabolites Targeting the Warburg Effect in Cancer Cells: A Mechanistic Review

Hasanpourghadi M, Looi CY, Pandurangan AK, Sethi G, Wong WF, Mustafa MR

Curr Drug Targets, 2017;18(9):1086-1094.
PMID: 27033190 DOI: 10.2174/1389450117666160401124842

Phytometabolites are functional elements derived from plants and most of them exhibit therapeutic characteristics such as anti-cancer, anti-inflammatory and anti-oxidant effects. Phytometabolites exert their anti-cancer effect by targeting multiple signaling pathways. One of the remarkable phenomena targeted by phytometabolites is the Warburg effect. The Warburg effect describes the observation that cancer cells exhibit an increased rate of glycolysis and aberrant redox activity compared to normal cells. This phenomenon promotes further cancer development and progression. Recent observations revealed that some phytometabolites could target metabolic-related enzymes (e.g. Hexokinase, Pyruvate kinase M2, HIF-1) in cancer cells, with little or no harm to normal cells. Since hyper-proliferation of cancer cells is fueled by higher cellular metabolism, phytometabolites targeting these metabolic pathways can create synergistic crosstalk with induced apoptotic pathways and sensitize cancer cells to chemotherapeutic agents. In this review, we discuss phytometabolites that target the Warburg effect and the underlying molecular mechanism that leads to tumor growth suppression.

Matched MeSH terms: Plants/metabolism*
Growth and anthraquinone production of Morinda elliptica cell suspension cultures in a stirred-tank bioreactor

Abdullah MA, Ariff AB, Marziah M, Ali AM, Lajis NH

J Agric Food Chem, 2000 Sep;48(9):4432-8.
PMID: 10995375

The effects of medium strategy, number of impellers, aeration mode, and mode of operation on Morinda elliptica cell suspension cultures in a stirred-tank bioreactor are described. A lower number of impellers and continuous aeration contributed toward high cell growth rate, whereas a higher number of impellers reduced cell growth rate, although not anthraquinone yield. The semicontinuous mode could indirectly imitate the larger scale version of production medium strategy and improved anthraquinone production even with 0. 012% (v/v) antifoam addition. Production medium promoted both growth (maximum dry cell weight of 24.6 g/L) and anthraquinone formation (maximum content of 19.5 mg/g of dry cell weight), without any necessity for antifoam addition. Cultures in production medium or with higher growth rate and anthraquinone production were less acidic than cultures in growth medium or with lower growth rate and anthraquinone production. Using the best operating variables, growth of M. elliptica cells (24.6 g/L) and anthraquinone yield (0.25 g/L) were 45% and 140%, respectively, lower than those using a shake flask culture after 12 days of cultivation.

Matched MeSH terms: Plants/metabolism*
How plants respond to heavy metal contamination: a narrative review of proteomic studies and phytoremediation applications

Al-Obaidi JR, Jamaludin AA, Rahman NA, Ahmad-Kamil EI

Planta, 2024 Mar 29;259(5):103.
PMID: 38551683 DOI: 10.1007/s00425-024-04378-2

Heavy metal pollution caused by human activities is a serious threat to the environment and human health. Plants have evolved sophisticated defence systems to deal with heavy metal stress, with proteins and enzymes serving as critical intercepting agents for heavy metal toxicity reduction. Proteomics continues to be effective in identifying markers associated with stress response and metabolic processes. This review explores the complex interactions between heavy metal pollution and plant physiology, with an emphasis on proteomic and biotechnological perspectives. Over the last century, accelerated industrialization, agriculture activities, energy production, and urbanization have established a constant need for natural resources, resulting in environmental degradation. The widespread buildup of heavy metals in ecosystems as a result of human activity is especially concerning. Although some heavy metals are required by organisms in trace amounts, high concentrations pose serious risks to the ecosystem and human health. As immobile organisms, plants are directly exposed to heavy metal contamination, prompting the development of robust defence mechanisms. Proteomics has been used to understand how plants react to heavy metal stress. The development of proteomic techniques offers promising opportunities to improve plant tolerance to toxicity from heavy metals. Additionally, there is substantial scope for phytoremediation, a sustainable method that uses plants to extract, sequester, or eliminate contaminants in the context of changes in protein expression and total protein behaviour. Changes in proteins and enzymatic activities have been highlighted to illuminate the complex effects of heavy metal pollution on plant metabolism, and how proteomic research has revealed the plant's ability to mitigate heavy metal toxicity by intercepting vital nutrients, organic substances, and/or microorganisms.

Matched MeSH terms: Plants/metabolism
Comprehensive review on phytotechnology: Heavy metals removal by diverse aquatic plants species from wastewater

Rezania S, Taib SM, Md Din MF, Dahalan FA, Kamyab H

J Hazard Mater, 2016 Nov 15;318:587-599.
PMID: 27474848 DOI: 10.1016/j.jhazmat.2016.07.053

Environmental pollution specifically water pollution is alarming both in the developed and developing countries. Heavy metal contamination of water resources is a critical issue which adversely affects humans, plants and animals. Phytoremediation is a cost-effective remediation technology which able to treat heavy metal polluted sites. This environmental friendly method has been successfully implemented in constructed wetland (CWs) which is able to restore the aquatic biosystem naturally. Nowadays, many aquatic plant species are being investigated to determine their potential and effectiveness for phytoremediation application, especially high growth rate plants i.e. macrophytes. Based on the findings, phytofiltration (rhizofiltration) is the sole method which defined as heavy metals removal from water by aquatic plants. Due to specific morphology and higher growth rate, free-floating plants were more efficient to uptake heavy metals in comparison with submerged and emergent plants. In this review, the potential of wide range of aquatic plant species with main focus on four well known species (hyper-accumulators): Pistia stratiotes, Eicchornia spp., Lemna spp. and Salvinia spp. was investigated. Moreover, we discussed about the history, methods and future prospects in phytoremediation of heavy metals by aquatic plants comprehensively.

Matched MeSH terms: Plants/metabolism*
Progress in phytoremediation of chromium from the environment

Han L, Gu H, Lu W, Li H, Peng WX, Ling Ma N, et al.

Chemosphere, 2023 Dec;344:140307.
PMID: 37769918 DOI: 10.1016/j.chemosphere.2023.140307

As chromium (Cr) in ecosystems affects human health through food chain exposure, phytoremediation is an environmentally friendly and efficient way to reduce chromium pollution in the environment. Here, we review the mechanism of absorption, translocation, storage, detoxification, and regulation of Cr in plants. The Cr(VI) form is more soluble, mobile, and toxic than Cr(III), reflecting how various valence states of Cr affect environmental risk characteristics, physicochemical properties, toxicity, and plant uptake. Plant root's response to Cr exposure leads to reactive oxygen species (ROS) generation and apoptosis. Cell wall immobilization, vacuole compartmentation, interaction of defense proteins and organic ligand with Cr, and removal of reactive oxygen species by antioxidants continue plant life. In addition, the combined application of microorganisms, genetic engineering, and the addition of organic acids, nanoparticles, fertilization, soil amendments, and other metals could accelerate the phytoremediation process. This review provides efficient methods to investigate and understand the complex changes of Cr metabolism in plants. Preferably, fast-growing, abundantly available biomass species should be modified to mitigate Cr pollution in the environment as these green and efficient remediation technologies are necessary for the protection of soil and water ecology.

Matched MeSH terms: Plants/metabolism
Fulltext A Review on Plants and Microorganisms Mediated Synthesis of Silver Nanoparticles, Role of Plants Metabolites and Applications

Mustapha T, Misni N, Ithnin NR, Daskum AM, Unyah NZ

Int J Environ Res Public Health, 2022 Jan 07;19(2).
PMID: 35055505 DOI: 10.3390/ijerph19020674

Silver nanoparticles are one of the most extensively studied nanomaterials due to their high stability and low chemical reactivity in comparison to other metals. They are commonly synthesized using toxic chemical reducing agents which reduce metal ions into uncharged nanoparticles. However, in the last few decades, several efforts were made to develop green synthesis methods to avoid the use of hazardous materials. The natural biomolecules found in plants such as proteins/enzymes, amino acids, polysaccharides, alkaloids, alcoholic compounds, and vitamins are responsible for the formation of silver nanoparticles. The green synthesis of silver nanoparticles is an eco-friendly approach, which should be further explored for the potential of different plants to synthesize nanoparticles. In the present review we describe the green synthesis of nanoparticles using plants, bacteria, and fungi and the role of plant metabolites in the synthesis process. Moreover, the present review also describes some applications of silver nanoparticles in different aspects such as antimicrobial, biomedicine, mosquito control, environment and wastewater treatment, agricultural, food safety, and food packaging.

Matched MeSH terms: Plants/metabolism
Recent progress on phytoremediation of urban air pollution

Duan X, Gu H, Lam SS, Sonne C, Lu W, Li H, et al.

Chemosphere, 2024 Feb;349:140821.
PMID: 38042424 DOI: 10.1016/j.chemosphere.2023.140821

The rapid growth of population and economy has led to an increase in urban air pollutants, greenhouse gases, energy shortages, environmental degradation, and species extinction, all of which affect ecosystems, biodiversity, and human health. Atmospheric pollution sources are divided into direct and indirect pollutants. Through analysis of the sources of pollutants, the self-functioning of different plants can be utilized to purify the air quality more effectively. Here, we explore the absorption of greenhouse gases and particulate matter in cities as well as the reduction of urban temperatures by plants based on international scientific literature on plant air pollution mitigation, according to the adsorption, dust retention, and transpiration functions of plants. At the same time, it can also reduce the occurrence of extreme weather. It is necessary to select suitable tree species for planting according to different plant functions and environmental needs. In the context of tight urban land use, the combination of vertical greening and urban architecture, through the rational use of plants, has comprehensively addressed urban air pollution. In the future, in urban construction, attention should be paid to the use of heavy plants and the protection and development of green spaces. Our review provides necessary references for future urban planning and research.

Matched MeSH terms: Plants/metabolism
Integrating phytoremediation and mycoremediation with biosurfactant-producing fungi for hydrocarbon removal and the potential production of secondary resources

Ahmad J, Marsidi N, Sheikh Abdullah SR, Hasan HA, Othman AR, Ismail N', et al.

Chemosphere, 2024 Feb;349:140881.
PMID: 38048826 DOI: 10.1016/j.chemosphere.2023.140881

Treatment of petroleum-contaminated soil to a less toxic medium via physical and chemical treatment is too costly and requires posttreatment. This review focuses on the employment of phytoremediation and mycoremediation technologies in cleaning hydrocarbon-contaminated soil which is currently rare. It is considered environmentally beneficial and possibly cost-effective as it implements the synergistic interaction between plants and biosurfactant producing mycorrhiza to degrade hydrocarbon contaminants. This review also covers possible sources of hydrocarbon pollution in water and soil, toxicity effects, and current technologies for hydrocarbon removal and degradation. In addition to these problems, this review also discusses the challenges and opportunities of transforming the resultant treated sludge and treating plants into potential by-products for a higher quality of life for future generations.

Matched MeSH terms: Plants/metabolism
Fulltext Nickel stocks and fluxes in a tropical agromining 'metal crop' farming system in Sabah (Malaysia)

Tisserand R, van der Ent A, Nkrumah PN, Didier S, Sumail S, Morel JL, et al.

Sci Total Environ, 2024 Apr 01;919:170691.
PMID: 38325468 DOI: 10.1016/j.scitotenv.2024.170691

Nickel hyperaccumulator plants play a major role in nickel recycling in ultramafic ecosystems, and under agromining the nickel dynamics in the farming system will be affected by removal of nickel-rich biomass. We investigated the biogeochemical cycling of nickel as well as key nutrients in an agromining operation that uses the metal crop Phyllanthus rufuschaneyi in the first tropical metal farm located in Borneo (Sabah, Malaysia). For two years, this study monitored nine 25-m2 plots and collected information on weather, biomass exportation, water, and litter fluxes to the soil. Without harvesting, nickel inputs and outputs had only minor contributions (<1 %) to the total nickel budget in this system. The nickel cycle was mainly driven by internal fluxes, particularly plant uptake, litterfall and throughfall. After two years of cropping, the nickel litter flux corresponded to 50 % of the total nickel stock in the aerial biomass (3.1 g m-2 year-1). Nickel was slowly released from the litter; after 15 months of degradation, 60 % of the initial biomass and the initial nickel quantities were still present in the organic layer. Calcium, phosphorus and potassium budgets in the system were negative without fertilisation. Unlike what is observed for nickel, sustained agromining would thus lead to a strong depletion of calcium stocks if mineral weathering cannot replenish it.

Matched MeSH terms: Plants/metabolism
Fulltext Cytotoxicity of Plant-Mediated Synthesis of Metallic Nanoparticles: A Systematic Review

Hanan NA, Chiu HI, Ramachandran MR, Tung WH, Mohamad Zain NN, Yahaya N, et al.

Int J Mol Sci, 2018 Jun 11;19(6).
PMID: 29891772 DOI: 10.3390/ijms19061725

In the field of medicine, nanomaterials, especially those derived using the green method, offer promise as anti-cancer agents and drug carriers. However, the biosafety of metallic nanoparticles used as anti-cancer agents remains a concern. The goal of this systematic review was to compare the cytotoxicity of different plant-mediated syntheses of metallic nanoparticles based on their potency, therapeutic index, and cancer cell type susceptibility in the hopes of identifying the most promising anti-cancer agents. A literature search of electronic databases including Science Direct, PubMed, Springer Link, Google Scholar, and ResearchGate, was conducted to obtain research articles. Keywords such as biosynthesis, plant synthesis, plant-mediated, metallic nanoparticle, cytotoxicity, and anticancer were used in the literature search. All types of research materials that met the inclusion criteria were included in the study regardless of whether the results were positive, negative, or null. The therapeutic index was used as a safety measure for the studied compound of interest. Data from 76 selected articles were extracted and synthesised. Seventy-two studies reported that the cytotoxicity of plant-mediated synthesis of metallic nanoparticles was time and/or dose-dependent. Biosynthesised silver nanoparticles demonstrated higher cytotoxicity potency compared to gold nanoparticles synthesised by the same plants (Plumbago zeylanica, Commelina nudiflora, and Cassia auriculata) irrespective of the cancer cell type tested. This review also identified a correlation between the nanoparticle size and morphology with the potency of cytotoxicity. Cytotoxicity was found to be inversely proportional to nanoparticle size. The plant-mediated syntheses of metallic nanoparticles were predominantly spherical or quasi-spherical, with the median lethal dose of 1⁻20 µg/mL. Nanoparticles with other shapes (triangular, hexagonal, and rods) were less potent. Metallic nanoparticles synthesised by Abutilon inducum, Butea monosperma, Gossypium hirsutum, Indoneesiella echioides, and Melia azedarach were acceptably safe as anti-cancer agents, as they had a therapeutic index of >2.0 when tested on both cancer cells and normal human cells. Most plant-mediated syntheses of metallic nanoparticles were found to be cytotoxic, although some were non-cytotoxic. The results from this study suggest a focus on a selected list of potential anti-cancer agents for further investigations of their pharmacodynamic/toxicodynamic and pharmacokinetic/toxicokinetic actions with the goal of reducing the Global Burden of Diseases and the second leading cause of mortality.

Matched MeSH terms: Plants/metabolism*
The cadmium tolerance and bioaccumulation mechanism of Tetratostichococcus sp. P1: insight from transcriptomics analysis

Sahabudin E, Kubo S, Yuzir MAM, Othman N, Nadia Md Akhir F, Suzuki K, et al.

Bioengineered, 2024 Dec;15(1):2314888.
PMID: 38375815 DOI: 10.1080/21655979.2024.2314888

Cadmium (Cd) has become a severe issue in relatively low concentration and attracts expert attention due to its toxicity, accumulation, and biomagnification in living organisms. Cd does not have a biological role and causes serious health issues. Therefore, Cd pollutants should be reduced and removed from the environment. Microalgae have great potential for Cd absorption for waste treatment since they are more environmentally friendly than existing treatment methods and have strong metal sorption selectivity. This study evaluated the tolerance and ability of the microalga Tetratostichococcus sp. P1 to remove Cd ions under acidic conditions and reveal mechanisms based on transcriptomics analysis. The results showed that Tetratostichococcus sp. P1 had a high Cd tolerance that survived under the presence of Cd up to 100 µM, and IC50, the half-maximal inhibitory concentration value, was 57.0 μM, calculated from the change in growth rate based on the chlorophyll content. Long-term Cd exposure affected the algal morphology and photosynthetic pigments of the alga. Tetratostichococcus sp. P1 removed Cd with a maximum uptake of 1.55 mg g-1 dry weight. Transcriptomic analysis revealed the upregulation of the expression of genes related to metal binding, such as metallothionein. Group A, Group B transporters and glutathione, were also found upregulated. While the downregulation of the genes were related to photosynthesis, mitochondria electron transport, ABC-2 transporter, polysaccharide metabolic process, and cell division. This research is the first study on heavy metal bioremediation using Tetratostichococcus sp. P1 and provides a new potential microalga strain for heavy metal removal in wastewater.[Figure: see text]Abbreviations:BP: Biological process; bZIP: Basic Leucine Zipper; CC: Cellular component; ccc1: Ca (II)-sensitive cross complementary 1; Cd: Cadmium; CDF: Cation diffusion facilitator; Chl: Chlorophyll; CTR: Cu TRansporter families; DAGs: Directed acyclic graphs; DEGs: Differentially expressed genes; DVR: Divinyl chlorophyllide, an 8-vinyl-reductase; FPN: FerroportinN; FTIR: Fourier transform infrared; FTR: Fe TRansporter; GO: Gene Ontology; IC50: Growth half maximal inhibitory concentration; ICP: Inductively coupled plasma; MF: molecular function; NRAMPs: Natural resistance-associated aacrophage proteins; OD: Optical density; RPKM: Reads Per Kilobase of Exon Per Million Reads Mapped; VIT1: Vacuolar iron transporter 1 families; ZIPs: Zrt-, Irt-like proteins.

Matched MeSH terms: Plants/metabolism
Carotenoid biosynthesis regulatory mechanisms in plants

Othman R, Mohd Zaifuddin FA, Hassan NM

J Oleo Sci, 2014;63(8):753-60.
PMID: 25017864

Carotenoids are bioactive compounds with remarkably special properties produced by plants in response to internal and external stresses. In this review paper, we focus on the subject of carotenoid biosynthesis and several factors that have been reported to significantly enhance or reduce carotenoid accumulation in studied plant species. These factors include varietal aspects, location, growing season, and type of stress experienced by a plant. In addition, we propose that there are three stress resistance mechanisms in plants: avoidance, tolerance, and acclimation. Better understanding of the environmental factors affecting carotenoid biosynthesis will help researchers to develop methods for enhancing the production of carotenoids and other pigments to desired concentrations in plant crops.

Matched MeSH terms: Plants/metabolism*
Fulltext Co-application of a biosolids product and biochar to two coarse-textured pasture soils influenced microbial N cycling genes and potential for N leaching

Shanmugam S, Jenkins SN, Mickan BS, Jaafar NM, Mathes F, Solaiman ZM, et al.

Sci Rep, 2021 01 13;11(1):955.
PMID: 33441591 DOI: 10.1038/s41598-020-78843-9

Co-application of biochar and biosolids to soil has potential to mitigate N leaching due to physical and chemical properties of biochar. Changes in N cycling pathways in soil induced by co-application of biological amendments could further mitigate N loss, but this is largely unexplored. The aim of this study was to determine whether co-application of a biochar and a modified biosolids product to three pasture soils differing in texture could alter the relative abundance of N cycling genes in soil sown with subterranean clover. The biosolids product contained lime and clay and increased subterranean clover shoot biomass in parallel with increases in soil pH and soil nitrate. Its co-application with biochar similarly increased plant growth and soil pH with a marked reduction in nitrate in two coarse textured soils but not in a clayey soil. While application of the biosolids product altered in silico predicted N cycling functional genes, there was no additional change when applied to soil in combination with biochar. This supports the conclusion that co-application of the biochar and biosolids product used here has potential to mitigate loss of N in coarse textured soils due to N adsoption by the biochar and independently of microbial N pathways.

Matched MeSH terms: Plants/metabolism
Connecting salt stress signalling pathways with salinity-induced changes in mitochondrial metabolic processes in C3 plants

Che-Othman MH, Millar AH, Taylor NL

Plant Cell Environ, 2017 Dec;40(12):2875-2905.
PMID: 28741669 DOI: 10.1111/pce.13034

Salinity exerts a severe detrimental effect on crop yields globally. Growth of plants in saline soils results in physiological stress, which disrupts the essential biochemical processes of respiration, photosynthesis, and transpiration. Understanding the molecular responses of plants exposed to salinity stress can inform future strategies to reduce agricultural losses due to salinity; however, it is imperative that signalling and functional response processes are connected to tailor these strategies. Previous research has revealed the important role that plant mitochondria play in the salinity response of plants. Review of this literature shows that 2 biochemical processes required for respiratory function are affected under salinity stress: the tricarboxylic acid cycle and the transport of metabolites across the inner mitochondrial membrane. However, the mechanisms by which components of these processes are affected or react to salinity stress are still far from understood. Here, we examine recent findings on the signal transduction pathways that lead to adaptive responses of plants to salinity and discuss how they can be involved in and be affected by modulation of the machinery of energy metabolism with attention to the role of the tricarboxylic acid cycle enzymes and mitochondrial membrane transporters in this process.

Matched MeSH terms: Plants/metabolism*
Diverse and dynamic roles of F-box proteins in plant biology

Abd-Hamid NA, Ahmad-Fauzi MI, Zainal Z, Ismail I

Planta, 2020 Feb 18;251(3):68.
PMID: 32072251 DOI: 10.1007/s00425-020-03356-8

The SCF complex is a widely studied multi-subunit ring E3 ubiquitin ligase that tags targeted proteins with ubiquitin for protein degradation by the ubiquitin 26S-proteasome system (UPS). The UPS is an important system that generally keeps cellular events tightly regulated by purging misfolded or damaged proteins and selectively degrading important regulatory proteins. The specificity of this post-translational regulation is controlled by F-box proteins (FBPs) via selective recognition of a protein-protein interaction motif at the C-terminal domain. Hence, FBPs are pivotal proteins in determining the plant response in multiple scenarios. It is not surprising that the FBP family is one of the largest protein families in the plant kingdom. In this review, the roles of FBPs, specifically in plants, are compiled to provide insights into their involvement in secondary metabolites, plant stresses, phytohormone signalling, plant developmental processes and miRNA biogenesis.

Matched MeSH terms: Plants/metabolism*
Fulltext Riparian plant litter quality increases with latitude

Boyero L, Graça MAS, Tonin AM, Pérez J, J Swafford A, Ferreira V, et al.

Sci Rep, 2017 09 05;7(1):10562.
PMID: 28874830 DOI: 10.1038/s41598-017-10640-3

Plant litter represents a major basal resource in streams, where its decomposition is partly regulated by litter traits. Litter-trait variation may determine the latitudinal gradient in decomposition in streams, which is mainly microbial in the tropics and detritivore-mediated at high latitudes. However, this hypothesis remains untested, as we lack information on large-scale trait variation for riparian litter. Variation cannot easily be inferred from existing leaf-trait databases, since nutrient resorption can cause traits of litter and green leaves to diverge. Here we present the first global-scale assessment of riparian litter quality by determining latitudinal variation (spanning 107°) in litter traits (nutrient concentrations; physical and chemical defences) of 151 species from 24 regions and their relationships with environmental factors and phylogeny. We hypothesized that litter quality would increase with latitude (despite variation within regions) and traits would be correlated to produce 'syndromes' resulting from phylogeny and environmental variation. We found lower litter quality and higher nitrogen:phosphorus ratios in the tropics. Traits were linked but showed no phylogenetic signal, suggesting that syndromes were environmentally determined. Poorer litter quality and greater phosphorus limitation towards the equator may restrict detritivore-mediated decomposition, contributing to the predominance of microbial decomposers in tropical streams.

Matched MeSH terms: Plants/metabolism*
A rare non-canonical splice site in Trema orientalis SYMRK does not affect its dual symbiotic functioning in endomycorrhiza and rhizobium nodulation

Alhusayni S, Roswanjaya YP, Rutten L, Huisman R, Bertram S, Sharma T, et al.

BMC Plant Biol, 2023 Nov 24;23(1):587.
PMID: 37996841 DOI: 10.1186/s12870-023-04594-0

BACKGROUND: Nitrogen-fixing nodules occur in ten related taxonomic lineages interspersed with lineages of non-nodulating plant species. Nodules result from an endosymbiosis between plants and diazotrophic bacteria; rhizobia in the case of legumes and Parasponia and Frankia in the case of actinorhizal species. Nodulating plants share a conserved set of symbiosis genes, whereas related non-nodulating sister species show pseudogenization of several key nodulation-specific genes. Signalling and cellular mechanisms critical for nodulation have been co-opted from the more ancient plant-fungal arbuscular endomycorrhizal symbiosis. Studies in legumes and actinorhizal plants uncovered a key component in symbiotic signalling, the LRR-type SYMBIOSIS RECEPTOR KINASE (SYMRK). SYMRK is essential for nodulation and arbuscular endomycorrhizal symbiosis. To our surprise, however, despite its arbuscular endomycorrhizal symbiosis capacities, we observed a seemingly critical mutation in a donor splice site in the SYMRK gene of Trema orientalis, the non-nodulating sister species of Parasponia. This led us to investigate the symbiotic functioning of SYMRK in the Trema-Parasponia lineage and to address the question of to what extent a single nucleotide polymorphism in a donor splice site affects the symbiotic functioning of SYMRK.
RESULTS: We show that SYMRK is essential for nodulation and endomycorrhization in Parasponia andersonii. Subsequently, it is revealed that the 5'-intron donor splice site of SYMRK intron 12 is variable and, in most dicotyledon species, doesn't contain the canonical dinucleotide 'GT' signature but the much less common motif 'GC'. Strikingly, in T. orientalis, this motif is converted into a rare non-canonical 5'-intron donor splice site 'GA'. This SYMRK allele, however, is fully functional and spreads in the T. orientalis population of Malaysian Borneo. A further investigation into the occurrence of the non-canonical GA-AG splice sites confirmed that these are extremely rare.
CONCLUSION: SYMRK functioning is highly conserved in legumes, actinorhizal plants, and Parasponia. The gene possesses a non-common 5'-intron GC donor splice site in intron 12, which is converted into a GA in T. orientalis accessions of Malaysian Borneo. The discovery of this functional GA-AG splice site in SYMRK highlights a gap in our understanding of splice donor sites.

Matched MeSH terms: Plants/metabolism
Fulltext Importance of silicon and mechanisms of biosilica formation in plants

Sahebi M, Hanafi MM, Siti Nor Akmar A, Rafii MY, Azizi P, Tengoua FF, et al.

Biomed Res Int, 2015;2015:396010.
PMID: 25685787 DOI: 10.1155/2015/396010

Silicon (Si) is one of the most prevalent macroelements, performing an essential function in healing plants in response to environmental stresses. The purpose of using Si is to induce resistance to distinct stresses, diseases, and pathogens. Additionally, Si can improve the condition of soils, which contain toxic levels of heavy metals along with other chemical elements. Silicon minimizes toxicity of Fe, Al, and Mn, increases the availability of P, and enhances drought along with salt tolerance in plants through the formation of silicified tissues in plants. However, the concentration of Si depends on the plants genotype and organisms. Hence, the physiological mechanisms and metabolic activities of plants may be affected by Si application. Peptides as well as amino acids can effectively create polysilicic species through interactions with different species of silicate inside solution. The carboxylic acid and the alcohol groups of serine and asparagine tend not to engage in any significant role in polysilicates formation, but the hydroxyl group side chain can be involved in the formation of hydrogen bond with Si(OH)4. The mechanisms and trend of Si absorption are different between plant species. Furthermore, the transportation of Si requires an energy mechanism; thus, low temperatures and metabolic repressors inhibit Si transportation.

Matched MeSH terms: Plants/metabolism*
Fulltext Plants' metabolites as potential antiobesity agents

Gooda Sahib N, Saari N, Ismail A, Khatib A, Mahomoodally F, Abdul Hamid A

ScientificWorldJournal, 2012;2012:436039.
PMID: 22666121 DOI: 10.1100/2012/436039

Obesity and obesity-related complications are on the increase both in the developed and developing world. Since existing pharmaceuticals fail to come up with long-term solutions to address this issue, there is an ever-pressing need to find and develop new drugs and alternatives. Natural products, particularly medicinal plants, are believed to harbor potential antiobesity agents that can act through various mechanisms either by preventing weight gain or promoting weight loss amongst others. The inhibition of key lipid and carbohydrate hydrolyzing and metabolizing enzymes, disruption of adipogenesis, and modulation of its factors or appetite suppression are some of the plethora of targeted approaches to probe the antiobesity potential of medicinal plants. A new technology such as metabolomics, which deals with the study of the whole metabolome, has been identified to be a promising technique to probe the progression of diseases, elucidate their pathologies, and assess the effects of natural health products on certain pathological conditions. This has been applied to drug research, bone health, and to a limited extent to obesity research. This paper thus endeavors to give an overview of those plants, which have been reported to have antiobesity effects and highlight the potential and relevance of metabolomics in obesity research.

Matched MeSH terms: Plants/metabolism*

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