Displaying publications 101 - 120 of 942 in total

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  1. "Complement fractionation" in natural diploid orchid species
    Teoh SB
    Theor Appl Genet, 1982 Mar;61(1):91-5.
    PMID: 24271380 DOI: 10.1007/BF00261517
    Four out of 10 diploid orchid species showed "complement fractionation" a complex cytological phenomenon, hitherto reported only in polyploid plants. The manifestation of this phenomenon during meiosis is the formation of chromosome subgroups resulting eventually in cells with more than the usual four sporads; five or six being the optimum number in the investigated orchid species. No implications whatsoever can be deduced as to the genetic or genomic constitution of the end products. The presence of the phenomenon in these orchid species could perhaps indicate a polyploid ancestry or concealed hybridity. The operation of "complement fractionation", however, could be interpreted as an alternative evolutionary pathway opposed to polyploidy.
    Matched MeSH terms: Plants
  2. Structural and functional characterization of Solanum lycopersicum phosphatidylinositol 3-kinase C2 domain
    Pak Dek MS, Padmanabhan P, Tiwari K, Todd JF, Paliyath G
    Plant Physiol Biochem, 2020 Mar;148:180-192.
    PMID: 31972387 DOI: 10.1016/j.plaphy.2020.01.014
    Phosphatidylinositol 3-kinases (PI3Ks) are characterized by the presence of a C2 domain at the N-terminal end (class I, III); or at both the N-terminal and C-terminal ends (class II), sometimes including a Plextrin homology domain and/or a Ras domain. Plant PI3Ks are analogous to the class III mammalian PI3K. An N-terminal fragment (~170 aa) of the tomato PI3K regulatory domain including the C2 domain, was cloned and expressed in a bacterial system. This protein was purified to homogeneity and its physicochemical properties analyzed. The purified protein showed strong binding with monophosphorylated phosphatidylinositols, and the binding was dependent on calcium ion concentration and pH. In the overall tertiary structure of PI3K, C2 domain showed unique characteristics, having three antiparallel beta-sheets, hydrophobic regions, acidic as well as alkaline motifs, that can enable its membrane binding upon activation. To elucidate the functional significance of C2 domain, transgenic tobacco plants expressing the C2 domain of PI3K were generated. Transgenic plants showed defective pollen development and disrupted seed set. Flowers from the PI3K-C2 transgenic plants showed delayed wilting, and a decrease in ethylene production. It is likely that introduction of the PI3K-C2 segment may have interfered with the normal binding of PI3K to the membrane, delaying the onset of membrane lipid catabolism that lead to senescence.
    Matched MeSH terms: Plants, Genetically Modified
  3. Fulltext Evaluation on Soil Hardness in Riparian Forest Restoration along Kayan Ulu River, Sarawak, Malaysia
    AINA NADIA NAJWA MOHAMD JAFFAR, MOHD EFFENDI WASLI, MUGUNTHAN PERUMAL
    Trends in Undergraduate Research, 2018;1(1):0-0.
    MyJurnal
    Soil hardness plays a vital role in evaluating the physical properties of soil structure. With regards to the impact of compaction on practical forest management issues, most report and review forms were available. Thus, the aim of this study was to evaluate the soil condition in riparian forest restoration planted with indigenous species along Kayan Ulu River with special reference to soil hardness. Soil hardness was measured by using Hasegawa-type cone penetrometer from the surface soils to 100 cm depth, with a total of 48 random points for both study sites surveyed; restoration sites planted with Shorea macrophylla in year 1996 and 1998 (SPD96 and SPD98, respectively) for both on and between planting lines. Our findings indicated that, soil hardness in SPD98 was harder as compared to SPD96 at shallow depth presented in one drop penetrability. Likewise, soil penetration resistance on planting line in SPD98 was significantly higher than SPD96 at surface soils (0-20 cm) and subsurface soils (20-40 cm). A high number of strikes and soil penetration resistance indicate that the soils were highly compacted. However, there was no significant difference in term of soil penetration resistance between planting line. In order to avoid effects on tree productivity, it is recommended that in future, the evaluation of soil hardness should be determined during the early establishment for future restoration of riparian ecosystem. 
    Matched MeSH terms: Plants
  4. Therapeutic propensities, phytochemical composition, and toxicological evaluation of Anagallis arvensis (L.): A wild edible medicinal food plant
    Saleem H, Zengin G, Ahmad I, Htar TT, Naidu R, Mahomoodally MF, et al.
    Food Res Int, 2020 11;137:109651.
    PMID: 33233230 DOI: 10.1016/j.foodres.2020.109651
    Anagallis arvensis (L.) is a wild edible food plant that has been used in folklore as a natural remedy for treating common ailments. This study aimed to explore the biochemical properties and toxicity of methanol (MeOH) and dichloromethane (DCM) extracts of A. arvensis (aerial and root parts). Bioactive contents were assessed spectrophotometrically, and the secondary metabolites were identified by UHPLC-MS analysis. DPPH, ABTS, FRAP, CUPRAC, phosphomolybdenum, and metal chelating assays were employed to assess antioxidant activity. Inhibitory potential against key enzymes (α-glucosidase, urease, lipoxygenase (LOX), acetylcholinesterase (AChE), and butyrylcholinesterase (BChE)) were also assessed. MTT assay was employed to test toxicity against SW-480, MDA-MB-231, CaSki, MCF-7, and DU-145 cancer cell lines. Methanolic extracts showed highest phenolic (aerial-MeOH: 27.5 mg GAE/g extract; root-MeOH: 21.17 mg GAE/g extract) and flavonoid (aerial-MeOH: 26.15 mg QE/g extract; root-MeOH: 19.07 mg QE/g extract) contents, and potent antioxidant activities. The aerial-MeOH extract was most potent for DPPH (IC50: 231 ug/mL), ABTS (131.12 mg TE/g extract), FRAP (82.97 mg TE/g extract), and CUPRAC (137.15 mg TE/g extract) antioxidant assays. All extracts were cytotoxic towards tested cancer cells with IC50 values ranging from 12.57 to 294.5 µg/mL and conferred a comparatively strong inhibition against α-glucosidase (aerial-DCM extract showed the highest inhibition against α-glucosidase with IC50 value of 20.97 µg /mL), while aerial extracts were also considerably active against BChE (aerial-MeOH IC50: 224.63 µg /mL), LOX (aerial-DCM IC50: 385.7 µg /mL). Likewise, aerial-MeOH extract was most active against urease enzyme (IC50: 129.72 µg /mL). UHPLC-MS investigation of methanolic extracts showed the existence of important phenolics, flavonoids, and saponins, including methyl gallte, quercetin, lanceoletin, and balanitesin, amongst others. Moreover, principal component analysis (PCA) highlighted the correlation amongst bioactive contents and observed biological activities. A. arvensis extracts could be regarded as a natural source of bioactive antioxidants, enzyme inhibitors and anticancer agents and can be further investigated as a lead source for food and pharmaceutical products. However, further studies to isolate, purify, and to characterize its bioactive phytochemicals are needed.
    Matched MeSH terms: Plants, Edible
  5. Fulltext Bacterial endophytes: a reservoir of bioactive anti-microbial compounds
    Mohamed Ikhtifar Rafi, Cheah, Yoke Kqueen
    Life Sciences, Medicine and Biomedicine, 2018;2(1):22-28.
    MyJurnal
    Bacterial endophytes are found on all types of plants and is a potential source of bioactive compounds which can be utilized to fight against multi-resistant pathogens and could be further develop into new leads for antibiotic development. However, the research done on the bacterial endophytes is relatively new and has potential to grow as it is theorized that each plant has one or more bacterial endophytes inhabiting them. This review aims to review the studies that have been done previously and give new insights on the latest trends in this field of research.
    Matched MeSH terms: Plants
  6. Fulltext Environment and host affects arbuscular mycorrhiza fungi (AMF) population
    Norahizah Abd Rahim, Hasnah Md Jais, Hasnuri Mat Hassan
    Trop Life Sci Res, 2016;27(11):9-13.
    MyJurnal
    The association of arbuscular mycorrhiza fungi (AMF) and roots undoubtedly
    gives positive advantages to the host plant. However, heavily fertilised soil such as in oil
    palm plantation, inhibit the growth of mycorrhiza. Thus, the aim of this research is to
    distinguish and quantify the availability of AMF population and propagules at different sites
    of an oil palm plantation by Most Probable Number (MPN) assay. In addition, root infection
    method was employed to observe host compatibility through the propagation of AMF using
    two different types of hosts, monocotyledon (Echinochloa cruss-galli) and dicotyledon
    (Vigna radiata). Three different locations at an oil palm plantation were chosen for
    sampling. Each location was represented by a distinctive soil series, and were further
    divided into two sites, that is canopy and midway area. Midway site had a greater
    population of AMF compared to canopy. The result showed that different environments
    affect the availability of AMF in the soil. Higher number of AMF infection observed in
    monocotyledon host suggests that the fibrous root system provide a better association
    with mycorrhiza.
    Matched MeSH terms: Plants
  7. Fulltext Radioactivity of 210Po in the environmental samples from Kapar, Malaysia
    Asnor Azrin Sabuti, Che Abd Rahim Mohamed, Zaharudin Ahmad
    Journal of Nuclear and Related Technologies, 2010;2010(1):29-39.
    MyJurnal
    Various environmental samples (seawater, TSS, sediment, rainwater and fly ash) from eight different stations near Kapar coastal area were analyzed. The 210 Po activity concentrations in liquid samples (seawater and rainwater) varied between 0.34 ± 0.03 mBq L-1 to 22.44 ± 0.53 mBq L-1 . Whereas the concentrations in particulate samples (TSS, sediment and fly ash) varied between 43.79 ± 2.31 Bqkg-1 to 364.48 ± 5.43 Bqkg-1 . Results also showed the radioactivity in Kapar coastal is higher than most of Malaysian coast, reaching a factor of seven. This condition is mainly due to the operation of a coal-fired power plant nearby. This study also clarify the variability of 210 Po in environment was strongly influenced from rainfall events especially during wet seasons.
    Matched MeSH terms: Power Plants
  8. Fulltext A quarter century of molecular population genetics research in Southeast Asia: a lifetime experience
    Tan, S.G.
    Buletin Persatuan Genetik Malaysia, 2006;12(1):18-0.
    MyJurnal
    The genetic relationship between any two populations is a function of the differences between them in allele frequencies, with this relationship commonly expressed in terms of a genetic distance. For example if the two populations are homozygous for different alleles at a particular locus, the distance is the maximum possible whereas if the allele frequencies in the two populations are identical, the distance is zero. The estimated genetic distances may vary among loci. Thus, the most accurate measures of relationships will be obtained by averaging many loci (Nei, 1978). In plant and animal breeding, it is expected that a cross between two individuals originating from two populations with a large genetic distance between them will result in maximum heterosis or hybrid vigour. Many estimates of genetic distances are available in the literature but Nei’s standard genetic distance, D, (Nei, 1972, 1978) had been extensively used in studies of human, animal and plant varieties, races, breeds, strains, populations, species and genera.
    Matched MeSH terms: Plants
  9. Fulltext Intelligent Monitoring interfaces for Coal fired Power Plant Boiler Trips: a review
    Nistah, N. N. M., Samyudia, Y., Alnaimi, F. B. I., Motalebi, F.
    Pertanika Journal of Science & Technology, 2014;22(2):593-601.
    MyJurnal
    A major source of contemporary power is a Coal-fired Power Plant. These power plants have the capacity to continuously supply electricity to almost 500,000 residential and business units. An essential component of a Coal-fired Power plant is automation. A feature of this automation is an Intelligent System developed for the Power Plant. These Intelligent Systems have different configurations and design. This research studies the various Intelligent Monitoring Interfaces developed for Coal-fired Power Plant Trips, their advantages, disadvantages and proposes a new Intelligent Monitoring Interface that would alleviate the disadvantages of the existing systems. Current systems that use Neural Network models are investigated. The improved Intelligent Monitoring Interface as proposed in this paper is a modification of the existing monitoring system for the Coal-fired Power Plant Boiler Trips. It is expected to improve the overall system by implementing remote accessibility and interactability between the plant operator and the control system interface. The interface will also assist the operator by providing guidelines to troubleshoot the identified trips and the remote server application will allow data collected to be viewed anytime, anywhere.
    Matched MeSH terms: Power Plants
  10. The effects of betel-nut chewing on the buccal mucosa of 296 Indians and Malays in West Malaysia. A clinical study
    Chin CT, Lee KW
    Br. J. Cancer, 1970 Sep;24(3):427-32.
    PMID: 5475750
    Changes in the buccal mucosa of 296 Indian and Malay betel-nut chewers in Perak, West Malaysia, were studied clinically. 167 out of 212 Indian subjects incorporated tobacco in their quids, while 45 out of 84 Malay subjects incorporated. "Gambir". The Indians appeared to show a higher proportion of mucosal changes, particularly when tobacco was used. "Gambir" did not appear to be potent in the production of mucosal changes. Comparison with studies in other parts of the world suggested comparable findings with respect to both tobacco and non-tobacco chewing samples, and there would appear to be some evidence that tobacco-containing quids are likely to produce a higher proportion of mucosal changes as compared to non-tobacco-containing quids. An attempt to demonstrate a dose-effect relationship by dividing the subjects into "slight" and "heavy" chewers did not yield significant differences between these two categories in each of the groups.
    Matched MeSH terms: Plants, Medicinal*; Plants, Toxic*
  11. What Has Come out from Phytomedicines and Herbal Edibles for the Treatment of Cancer?
    Bonam SR, Wu YS, Tunki L, Chellian R, Halmuthur MSK, Muller S, et al.
    ChemMedChem, 2018 09 19;13(18):1854-1872.
    PMID: 29927521 DOI: 10.1002/cmdc.201800343
    Several modern treatment strategies have been adopted to combat cancer with the aim of minimizing toxicity. Medicinal plant-based compounds with the potential to treat cancer have been widely studied in preclinical research and have elicited many innovations in cutting-edge clinical research. In parallel, researchers have eagerly tried to decrease the toxicity of current chemotherapeutic agents either by combining them with herbals or in using herbals alone. The aim of this article is to present an update of medicinal plants and their bioactive compounds, or mere changes in the bioactive compounds, along with herbal edibles, which display efficacy against diverse cancer cells and in anticancer therapy. It describes the basic mechanism(s) of action of phytochemicals used either alone or in combination therapy with other phytochemicals or herbal edibles. This review also highlights the remarkable synergistic effects that arise between certain herbals and chemotherapeutic agents used in oncology. The anticancer phytochemicals used in clinical research are also described; furthermore, we discuss our own experience related to semisynthetic derivatives, which are developed based on phytochemicals. Overall, this compilation is intended to facilitate research and development projects on phytopharmaceuticals for successful anticancer drug discovery.
    Matched MeSH terms: Plants, Medicinal
  12. Effects of fine-scale pattern of dwarf bamboo on understory species diversity in Abies faxoniana forest, Southwest, China
    Wang YJ, Shi XP, Peng Y, Tao JP, Zhong ZC
    Sains Malaysiana, 2012;41:649-657.
    Dwarf bamboo is recognized as a significant determinant of the structure and dynamics in temperate forests. Quantitative relationships between the abundance (density and coverage) of dwarf bamboo, Fargesia nitida, and micro-environments, species diversity on the floor were estimated in an Abies faxoniana pure forest in southwest China. Understory microenvironmental conditions (daily differences temperature and moisture, RPPFD under bamboo layer and ground cover) changed dramatically with the bamboo density. Stepwise multiple regression analyses indicated that abundance of F. nitida was mainly correlated with canopy characteristics and disturbance factors in the A. faxoniana pure forest. All richness indices decreased significantly with the bamboo density and RPPFD under bamboo layer. Importance values (IV) of understory species in different bamboo densities and Detrended canonical correspondence analysis (DCCA) indicated three understory plant groups, resistant to high bamboo abundance (Group A), resistant to intermediate bamboo abundance (Group B) and sensitive to bamboo abundance (Group C). These groups mainly responded to abundance of bamboo and RPPFD under bamboo layer, resulted from the integration of characteristics of bamboo, canopy and topography factors. Different bamboo abundance had different influences on understory species diversity and groups. Dense F. nitida condition (> 10 culms/m2) had significant negative effect and 0-5 bamboo condition had not significant negative effect on understory species diversity in A. faxoniana forest. We suggest the fine-scale analysis on effects of bamboo abundance should be taken account into considering in heterogeneous patches in process of the succession and regeneration of natural forests.
    Matched MeSH terms: Plants
  13. Leaching and freeze-thaw events contribute to litter decomposition - a review
    Jiang L, Yue K, Yang Y, Wu Q
    Sains Malaysiana, 2016;45:1041-1047.
    Litter decomposition is vital for carbon and nutrient turnover in terrestrial ecosystems, and this process has now
    been thoroughly demonstrated to be regulated by various mechanisms. The total environment has been continuously
    changing in recent decades, especially in high-latitude regions; these alterations, however, profoundly contribute to the
    decomposition process, but a comprehensive recognition has not available. Here we reviewed the empirical observations
    and current knowledge regarding how hydrological leaching and freeze-thaw events modulate early decomposition of
    plant litter. Leaching contributes a considerable percentage of mass loss and carbon and nutrient release in early stage of
    decomposition, but the magnitudes are different between species levels depending on the chemical traits. Frequent freezing
    and thawing events could positively influence decomposition rate in cold biomes but also hamper soil decomposer and
    there is no general and predictable pattern has been emerged. Further experiments should be manipulated to estimate
    how the altered freezing and thawing effect on carbon and nutrient release from plant litter to better understanding the
    changing environment on litter decomposition.
    Matched MeSH terms: Plants
  14. Effects of gamma radiation treatment on three different medicinal plants: Microbial limit test, total phenolic content, in vitro cytotoxicity effect and antioxidant assay
    Khawory MH, Amat Sain A, Rosli MAA, Ishak MS, Noordin MI, Wahab HA
    Appl Radiat Isot, 2020 Mar;157:109013.
    PMID: 31889674 DOI: 10.1016/j.apradiso.2019.109013
    BACKGROUND AND AIM: The aim of this study is to evaluate the effects of gamma radiation treatment on three medicinal plants, namely Euodia malayana, Gnetum gnemon and Khaya senegalensis at two different forms; methanol leaf extracts and dried leaves respectively.

    EXPERIMENTAL PROCEDURE: The microbial limit test (MLT) studies indicated the suitable dosage of minimum and maximum gamma irradiation for leaf extracts as well as dried leaves of all the tested medicinal plants. Quantitative analysis of total phenolic content (TPC) analysis is based on calorimetric measurements determined using the Folin-Ciocalteu reagent with gallic acid (GA) used as the reference. In vitro cytotoxicity assay by using fibroblast (L929) cell lines was performed on each plant to determine the toxicity effect which sodium dodecyl sulfate (SDS) as the positive control. DPPH (2,2-diphenyl-1-picryl-hydrazyl) assay was conducted by using vitamin C and GA as the positive controls to determine the antioxidant property of each plant.

    RESULTS AND CONCLUSION: The MLT analysis indicated that the suitable dosage gamma irradiation for leaf extracts was 6-12 kGy and dried leaves were 9-13 kGy. The amount of GA concentration in each plant increased significantly from 30-51 mg GAE g-1 before treatment to 57-103 mg GAE g-1 after treatment with gamma radiation. This showed no significant effect of in vitro cytotoxicity activity before and after treatment with gamma irradiation in this study. Effective concentration (EC50) values of Khaya senegalensis plant reduced significantly (P ≤ 0.005) from 44.510 μg/ml before treatment to 24.691 μg/ml after treatment with gamma radiation, which indicate an increase of free radical scavenging activity.

    Matched MeSH terms: Plants, Medicinal/metabolism; Plants, Medicinal/microbiology; Plants, Medicinal/radiation effects*
  15. Biosustainable production of nanoparticles via mycogenesis for biotechnological applications: A critical review
    Sudheer S, Bai RG, Muthoosamy K, Tuvikene R, Gupta VK, Manickam S
    Environ Res, 2022 03;204(Pt A):111963.
    PMID: 34450157 DOI: 10.1016/j.envres.2021.111963
    The demand for the green synthesis of nanoparticles has gained prominence over the conventional chemical and physical syntheses, which often entails toxic chemicals, energy consumption and ultimately lead to negative environmental impact. In the green synthesis approach, naturally available bio-compounds found in plants and fungi can be effective and have been proven to be alternative reducing agents. Fungi or mushrooms are particularly interesting due to their high content of bioactive compounds, which can serve as excellent reducing agents in the synthesis of nanoparticles. Apart from the economic and environmental benefits, such as ease of availability, low synthesis/production cost, safe and no toxicity, the nanoparticles synthesized from this green method have unique physical and chemical properties. Stabilisation of the nanoparticles in an aqueous solution is exceedingly high, even after prolonged storage with unperturbed size uniformity. Biological properties were significantly improved with higher biocompatibility, anti-microbial, anti-oxidant and anti-cancer properties. These remarkable properties allow further exploration in their applications both in the medical and agricultural fields. This review aims to explore the mushroom-mediated biosynthesis of nanomaterials, specifically the mechanism and bio-compounds involved in the synthesis and their interactions for the stabilisation of nanoparticles. Various metal and non-metal nanoparticles have been discussed along with their synthesis techniques and parameters, making them ideal for specific industrial, agricultural, and medical applications. Only recent developments have been explored in this review.
    Matched MeSH terms: Plants
  16. Application progress of bioactive compounds in microalgae on pharmaceutical and cosmetics
    Zhuang D, He N, Khoo KS, Ng EP, Chew KW, Ling TC
    Chemosphere, 2022 Mar;291(Pt 2):132932.
    PMID: 34798100 DOI: 10.1016/j.chemosphere.2021.132932
    Microalgae is an autotrophic organism with fast growth, short reproduction cycle, and strong environmental adaptability. In recent years, microalgae and the bioactive ingredients extracted from microalgae are regarded as potential substitutes for raw materials in the pharmaceutical and the cosmetics industry. In this review, the characteristics and efficacy of the high-value components of microalgae are discussed in detail, along with the sources and extraction technologies of algae used to obtain high-value ingredients are reviewed. Moreover, the latest trends in biotherapy based on high-value algae extracts as materials are discussed. The excellent antioxidant properties of microalgae derivatives are regarded as an attractive replacement for safe and environmentally friendly cosmetics formulation and production. Through further studies, the mechanism of microalgae bioactive compounds can be understood better and reasonable clinical trials conducted can safely conclude the compliance of microalgae-derived drugs or cosmetics to be necessary standards to be marketed.
    Matched MeSH terms: Plants
  17. Labisia pumila prevented osteoarthritis cartilage degeneration by attenuating joint inflammation and collagen breakdown in postmenopausal rat model
    Madzuki IN, Lau SF, Che Ahmad Tantowi NA, Mohd Ishak NI, Mohamed S
    Inflammopharmacology, 2018 Oct;26(5):1207-1217.
    PMID: 29460078 DOI: 10.1007/s10787-018-0452-6
    The tropical herb Labisia pumila is traditionally used in facilitating childbirth and post-partum care. The effects of L. pumila leaf extract (LP) in explant cartilage culture and on postmenopausal osteoarthritis (OA) rat model were assessed. The LP (10, 25 and 50 µg/ml) or diclofenac (10 µg/ml) was added to the cartilage explants containing bovine IL-1β (20 ng/ml), to evaluate their direct effects on cartilage degradation. In the preclinical study, rats were grouped (n = 8) into: non-treated OA; OA + diclofenac (5 mg/kg); OA + LP extract (150 and 300 mg/kg); and healthy control. To induce OA, monosodium iodoacetate was injected into the ovariectomised female rats' intra-articular knee joints and evaluated for OA severity after 8 weeks via physical (radiological, macroscopic and histological observations), biochemical, ELISA and mRNA expression analysis (for inflammation and cartilage degradation biomarkers). The LP reduced the nitric oxide and proteoglycan release from the cartilage explants under IL-1β induction. The radiological, macroscopic, microscopic and histological images showed the OA rats treated with LP and diclofenac had significantly reduced osteophytes and cartilage erosions compared to non-treated OA rats. The extract significantly up-regulated the anti-inflammatory interleukin-10, collagen type II and down-regulated pro-inflammatory PTGS2 (prostaglandin-endoperoxide synthase 2) mRNA expressions compared to non-treated control. The LP treatment significantly reduced serum collagenases (MMP-1 and MMP-3) and collagen type II degradation biomarker (CTX-II) levels in OA rats. The LP containing myricetin and gallic acid suppressed inflammation, collagenases and cartilage degradation, and helped cartilage matrix synthesis, to prevent OA at the dose equivalent to 30-60 mg/kg daily for humans.
    Matched MeSH terms: Plants, Medicinal
  18. Solutions to fire and shade: resprouting, growing tall and the origin of Eurasian temperate broadleaved forest
    Adie H, Lawes MJ
    Biol Rev Camb Philos Soc, 2023 Apr;98(2):643-661.
    PMID: 36444419 DOI: 10.1111/brv.12923
    Tree species of Eurasian broadleaved forest possess two divergent trait syndromes with contrasting patterns of resource allocation adapted to different selection environments: short-stature basal resprouters that divert resources to a bud bank adapted to frequent and severe disturbances such as fire and herbivory, and tall trees that delay reproduction by investing in rapid height growth to escape shading. Drawing on theory developed in savanna ecosystems, we propose a conceptual framework showing that the possession of contrasting trait syndromes is essential for the persistence of broadleaved trees in an open ecosystem that burns. Consistent with this hypothesis, trees of modern Eurasian broadleaved forest bear a suite of traits that are adaptive to surface and crown-fire regimes. We contend that limited opportunities in grassland restricts recruitment to disturbance-free refugia, and en masse establishment creates a wooded environment where shade limits the growth of light-demanding savanna plants. Rapid height growth, which involves investment in structural support and the switch from a multi-stemmed to a monopodial growth form, is adaptive in this shaded environment. Although clustering reduces surface fuel loads, these establishment nuclei are vulnerable to high-intensity crown fires. The lethal effects of canopy fire are avoided by seasonal leaf shedding, and aerial resprouting enhances rapid post-fire recovery of photosynthetic capacity. While these woody formations satisfy the structural definition of forest, their constituents are clearly derived from savanna. Contrasting trait syndromes thus represent the shift from consumer to resource regulation in savanna ecosystems. Consistent with global trends, the diversification of most contemporary broadleaved taxa coincided with the spread of grasslands, a surge in fire activity and a decline in wooded ecosystems in the late Miocene-Pliocene. Recognition that Eurasian broadleaved forest has savanna origins and persists as an alternative state with adjacent grassy ecosystems has far-reaching management implications in accordance with functional rather than structural criteria. Shade is a severe constraint to the regeneration and growth of both woody and herbaceous growth forms in consumer-regulated ecosystems. However, these ecosystems are highly resilient to disturbance, an essential process that maintains diversity especially among the species-rich herbaceous component that is vulnerable to shading when consumer behaviour is altered.
    Matched MeSH terms: Plants
  19. Plant-soil-microbe interactions in maintaining ecosystem stability and coordinated turnover under changing environmental conditions
    Aqeel M, Ran J, Hu W, Irshad MK, Dong L, Akram MA, et al.
    Chemosphere, 2023 Mar;318:137924.
    PMID: 36682633 DOI: 10.1016/j.chemosphere.2023.137924
    Ecosystem functions directly depend upon biophysical as well as biogeochemical reactions occurring at the soil-microbe-plant interface. Environment is considered as a major driver of any ecosystem and for the distributions of living organisms. Any changes in climate may potentially alter the composition of communities i.e., plants, soil microbes and the interactions between them. Since the impacts of global climate change are not short-term, it is indispensable to appraise its effects on different life forms including soil-microbe-plant interactions. This article highlights the crucial role that microbial communities play in interacting with plants under environmental disturbances, especially thermal and water stress. We reviewed that in response to the environmental changes, actions and reactions of plants and microbes vary markedly within an ecosystem. Changes in environment and climate like warming, CO2 elevation, and moisture deficiency impact plant and microbial performance, their diversity and ultimately community structure. Plant and soil feedbacks also affect interacting species and modify community composition. The interactive relationship between plants and soil microbes is critically important for structuring terrestrial ecosystems. The anticipated climate change is aggravating the living conditions for soil microbes and plants. The environmental insecurity and complications are not short-term and limited to any particular type of organism. We have appraised effects of climate change on the soil inhabiting microbes and plants in a broader prospect. This article highlights the unique qualities of tripartite interaction between plant-soil-microbe under climate change.
    Matched MeSH terms: Plants
  20. Tsunami run-up and inundation along the coast of Sabah and Sarawak, Malaysia due to a potential Brunei submarine mass failure
    Tan WK, Teh SY, Koh HL
    Environ Sci Pollut Res Int, 2017 Jul;24(19):15976-15994.
    PMID: 28343360 DOI: 10.1007/s11356-017-8698-x
    Submarine landslides, also known as submarine mass failures (SMFs), are major natural marine disasters that could critically damage coastal facilities such as nuclear power plants and oil and gas platforms. It is therefore essential to investigate submarine landslides for potential tsunami hazard assessment. Three-dimensional seismic data from offshore Brunei have revealed a giant seabed mass deposited by a previous SMF. The submarine mass extends over 120 km from the continental slope of the Baram Canyon at 200 m water depth to the deep basin floor of the Northwest Borneo Trough. A suite of in-house two-dimensional depth-averaged tsunami simulation model TUNA (Tsunami-tracking Utilities and Application) is developed to assess the vulnerability of coastal communities in Sabah and Sarawak subject to potential SMF tsunami. The submarine slide is modeled as a rigid body moving along a planar slope with the center of mass motion parallel to the planar slope and subject to external forces due to added mass, gravity, and dissipation. The nonlinear shallow water equations are utilized to simulate tsunami propagation from deepwater up to the shallow offshore areas. A wetting-drying algorithm is used when a tsunami wave reaches the shoreline to compute run up of tsunami along the shoreline. Run-up wave height and inundation maps are provided for seven densely populated locations in Sabah and Sarawak to highlight potential risks at each location, subject to two scenarios of slide slopes: 2° and 4°. The first wave may arrive at Kudat as early as 0.4 h after the SMF, giving local communities little time to evacuate. Over a small area, maximum inundated depths reaching 20.3 m at Kudat, 26.1 m at Kota Kinabalu, and 15.5 m at Miri are projected, while the maximum inundation distance of 4.86 km is expected at Miri due to its low-lying coast. In view of the vulnerability of some locations to the SMF tsunami, it is important to develop and implement community resilience program to reduce the potential damage that could be inflicted by SMF tsunamis.
    Matched MeSH terms: Power Plants
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