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  1. Fulltext Analysis of banana plant health using machine learning techniques
    Thiagarajan JD, Kulkarni SV, Jadhav SA, Waghe AA, Raja SP, Rajagopal S, et al.
    Sci Rep, 2024 Jul 01;14(1):15041.
    PMID: 38951552 DOI: 10.1038/s41598-024-63930-y
    The Indian economy is greatly influenced by the Banana Industry, necessitating advancements in agricultural farming. Recent research emphasizes the imperative nature of addressing diseases that impact Banana Plants, with a particular focus on early detection to safeguard production. The urgency of early identification is underscored by the fact that diseases predominantly affect banana plant leaves. Automated systems that integrate machine learning and deep learning algorithms have proven to be effective in predicting diseases. This manuscript examines the prediction and detection of diseases in banana leaves, exploring various diseases, machine learning algorithms, and methodologies. The study makes a contribution by proposing two approaches for improved performance and suggesting future research directions. In summary, the objective is to advance understanding and stimulate progress in the prediction and detection of diseases in banana leaves. The need for enhanced disease identification processes is highlighted by the results of the survey. Existing models face a challenge due to their lack of rotation and scale invariance. While algorithms such as random forest and decision trees are less affected, initially convolutional neural networks (CNNs) is considered for disease prediction. Though the Convolutional Neural Network models demonstrated impressive accuracy in many research but it lacks in invariance to scale and rotation. Moreover, it is observed that due its inherent design it cannot be combined with feature extraction methods to identify the banana leaf diseases. Due to this reason two alternative models that combine ANN with scale-invariant Feature transform (SIFT) model or histogram of oriented gradients (HOG) combined with local binary patterns (LBP) model are suggested. The first model ANN with SIFT identify the disease by using the activation functions to process the features extracted by the SIFT by distinguishing the complex patterns. The second integrate the combined features of HOG and LBP to identify the disease thus by representing the local pattern and gradients in an image. This paves a way for the ANN to learn and identify the banana leaf disease. Moving forward, exploring datasets in video formats for disease detection in banana leaves through tailored machine learning algorithms presents a promising avenue for research.
    Matched MeSH terms: Plant Leaves*
  2. Fulltext External aluminium supply regulates photosynthesis and carbon partitioning in the Al-accumulating tropical shrub Melastoma malabathricum
    Mahmud K, Weitz H, H Kritzler U, Burslem DFRP
    PLoS One, 2024;19(3):e0297686.
    PMID: 38507439 DOI: 10.1371/journal.pone.0297686
    Aluminium (Al) is toxic to most plants, but recent research has suggested that Al addition may stimulate growth and nutrient uptake in some species capable of accumulating high tissue Al concentrations. The physiological basis of this growth response is unknown, but it may be associated with processes linked to the regulation of carbon assimilation and partitioning by Al supply. To test alternative hypotheses for the physiological mechanism explaining this response, we examined the effects of increasing Al concentrations in the growth medium on tissue nutrient concentrations and carbon assimilation in two populations of the Al-accumulator Melastoma malabathricum. Compared to seedlings grown in a control nutrient solution containing no Al, mean rates of photosynthesis and respiration increased by 46% and 27%, respectively, total non-structural carbohydrate concentrations increased by 45%, and lignin concentration in roots decreased by 26% when seedlings were grown in a nutrient solution containing 2.0 mM Al. The concentrations of P, Ca and Mg in leaves and stems increased by 31%, 22%, and 26%, respectively, in response to an increase in nutrient solution Al concentration from 0 to 2.0 mM. Elemental concentrations in roots increased for P (114%), Mg (61%) and K (5%) in response to this increase in Al concentration in the nutrient solution. Plants derived from an inherently faster-growing population had a greater relative increase in final dry mass, net photosynthetic and respiration rates and total non-structural carbohydrate concentrations in response to higher external Al supply. We conclude that growth stimulation by Al supply is associated with increases in photosynthetic and respiration rates and enhanced production of non-structural carbohydrates that are differentially allocated to roots, as well as stimulation of nutrient uptake. These responses suggest that internal carbon assimilation is up-regulated to provide the necessary resources of non-structural carbohydrates for uptake, transport and storage of Al in Melastoma malabathricum. This physiological mechanism has only been recorded previously in one other plant species, Camellia sinensis, which last shared a common ancestor with M. malabathricum more than 120 million years ago.
    Matched MeSH terms: Plant Leaves/chemistry
  3. Transcriptome dataset of Metroxylon sagu palms from multiple sago plantations in Sarawak
    Pendi FH, Hussain H
    BMC Res Notes, 2024 Sep 05;17(1):251.
    PMID: 39238033 DOI: 10.1186/s13104-024-06924-3
    OBJECTIVE: Sago palm (Metroxylon sagu Rottb.) is one of the most important economic crops abundantly found in Mukah, Sarawak, Malaysia. The robustness of the palm triggered the Sarawak government's selection as one of the state's commodity crops, with the opening of several sago palm plantations. However, stunted (non-trunking) palms were reported in several sago palm plantations despite attaining a maturity period of more than ten years after cultivation. Research targeting this problem has been conducted in various fields, yet information on molecular mechanisms is still scarce. This study aimed to determine the genes responsible for sago palm's normal phenotype (trunking) by attaining leaf transcriptomes from samples of all trunking sago palms from different sago palm plantations.

    DATA DESCRIPTION: The conventional CTAB method was employed in the present investigation to extract total RNA from leaf tissues. Transcriptome sequencing was conducted on the Illumina NovaSeq 6000 platform. Differential expression analysis was performed using the DESeq2 package. A total of 6,119 differentially expressed genes, comprising 4,384 downregulated and 1,735 upregulated genes, were expressed in all three sago palm datasets. The datasets provide insights into the commonly expressed genes among trunking sago palms.

    Matched MeSH terms: Plant Leaves/genetics
  4. Sugarcane disease recognition through visible and near-infrared spectroscopy using deep learning assisted continuous wavelet transform-based spectrogram
    Ong P, Jian J, Li X, Zou C, Yin J, Ma G
    Spectrochim Acta A Mol Biomol Spectrosc, 2025 Jan 05;324:125001.
    PMID: 39180971 DOI: 10.1016/j.saa.2024.125001
    Utilizing visible and near-infrared (Vis-NIR) spectroscopy in conjunction with chemometrics methods has been widespread for identifying plant diseases. However, a key obstacle involves the extraction of relevant spectral characteristics. This study aimed to enhance sugarcane disease recognition by combining convolutional neural network (CNN) with continuous wavelet transform (CWT) spectrograms for spectral features extraction within the Vis-NIR spectra (380-1400 nm) to improve the accuracy of sugarcane diseases recognition. Using 130 sugarcane leaf samples, the obtained one-dimensional CWT coefficients from Vis-NIR spectra were transformed into two-dimensional spectrograms. Employing CNN, spectrogram features were extracted and incorporated into decision tree, K-nearest neighbour, partial least squares discriminant analysis, and random forest (RF) calibration models. The RF model, integrating spectrogram-derived features, demonstrated the best performance with an average precision of 0.9111, sensitivity of 0.9733, specificity of 0.9791, and accuracy of 0.9487. This study may offer a non-destructive, rapid, and accurate means to detect sugarcane diseases, enabling farmers to receive timely and actionable insights on the crops' health, thus minimizing crop loss and optimizing yields.
    Matched MeSH terms: Plant Leaves/chemistry
  5. Fulltext Scoping Review: Evaluation of Moringa oleifera (Lam.) for Potential Wound Healing in In Vivo Studies
    Mohammad Shafie N, Raja Shahriman Shah RNI, Krishnan P, Abdul Haleem N, Tan TYC
    Molecules, 2022 Aug 28;27(17).
    PMID: 36080308 DOI: 10.3390/molecules27175541
    Wound healing is a natural process to restore damaged tissues due to loss of tissue integrity. Moringa oleifera (locally known as merunggai in Malaysia) has been traditionally used in various ailments, including for wound management. To evaluate the wound healing properties in M. oleifera, publications were searched and selected following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement with predetermined inclusion criteria. The databases searched for primary studies include PubMed, Google Scholar, Science Direct, LILACS, ClinicalTrials.gov, and CENTRAL. In total, 18 in vivo studies were included, which involved the leaves, while the remaining 5 studies involved other plant parts tested on excision, incision, dead space, abrasion, and burn-induced wound models. All studies reported significant wound healing abilities. Most studies used different topical formulations of aqueous leaves extract. The accumulation of collagen content and underlying wound healing mechanism through antimicrobial, antioxidant, and anti-inflammatory activities may be contributed by its bioactive phytochemical content, which has the potential to accelerate the wound contraction, increase the rate of epithelialization, and protect tissues against oxidative damage. In conclusion, M. oleifera showed wound healing potential but further studies are warranted to determine the main bioactive phytocompounds and safety.
    Matched MeSH terms: Plant Leaves/chemistry
  6. Fulltext Optimization of ultrasonic-assisted extraction of phenolic compounds from Clinacanthus nutans using ionic liquid (ILs) binary solvent: Application of Peleg's model and response surface methodology
    Suan TY, Zubairi SI, Manuel RN, Kasim ZM, Huda-Faujan N
    PLoS One, 2025;20(7):e0326141.
    PMID: 40608755 DOI: 10.1371/journal.pone.0326141
    Clinacanthus nutans (Sabah snake grass) is widely recognized for its pharmacological properties, particularly its high phenolic content and antioxidant activity. However, the optimization of its ultrasonic-assisted extraction (UAE) remains underexplored. This study aims to enhance the extraction efficiency of phenolic compounds from Clinacanthus nutans leaves using ionic liquid (IL) binary solvents, with optimization based on Peleg's model and Response Surface Methodology (RSM). Peleg's model was used to determine the optimal extraction time, while RSM with a Central Composite Rotatable Design (CCRD) was applied to evaluate the effects of ultrasonic frequency (40-60 kHz) and the ratio of ILs to water (2:8, 5:5 and 8:2) on total phenolic content (TPC), DPPH radical scavenging activity, and Ferric Reducing Antioxidant Power (FRAP). The experimental results were statistically analyzed using ANOVA, model fitting, and desirability functions. Peleg's model indicated that the predicted maximum total phenolic content (TPC) of 42.556 ± 0.0003 mg GAE/g was achieved at an ultrasonic frequency of 50 kHz within 3 hours, making this duration as the predictive model benchmark for further optimization. The optimal extraction conditions were identified as an ultrasonic frequency of 60 kHz and an IL-to-water ratio of 2:8, yielding a maximum TPC of 0.01 ± 7.97 x 10-5 mg GAE/g, DPPH antioxidant activity of 95.08 ± 0.57%, and FRAP antioxidant capacity of 6.31 ± 0.10 mg AEAC/g. Peleg's model inadequately predicted the best exhaustive extraction time prior to RSM leading to a low TPC value throughout the optimization process while maintaining high in antioxidant efficacy. However, the use of IL binary solvents significantly enhanced the release of phenolic compounds compared to conventional solvents, demonstrating their potential as a green extraction alternative. This study highlights the effectiveness of ultrasonic-assisted extraction combined with IL binary solvents for maximizing the recovery of bioactive compounds from Clinacanthus nutans leaves. The optimized extraction method can be beneficial for pharmaceutical, nutraceutical, and functional food industries. Future research should focus on identifying specific phenolic compounds using High-Performance Liquid Chromatography (HPLC), combined kinetic and diffusion equilibrium model and further refining process optimization parameters (e.g., longer concoction duration) to enhance yield efficiency.
    Matched MeSH terms: Plant Leaves/chemistry
  7. A comprehensive review on adsorption of methylene blue dye using leaf waste as a bio-sorbent: isotherm adsorption, kinetics, and thermodynamics studies
    Mussa ZH, Al-Ameer LR, Al-Qaim FF, Deyab IF, Kamyab H, Chelliapan S
    Environ Monit Assess, 2023 Jul 12;195(8):940.
    PMID: 37436672 DOI: 10.1007/s10661-023-11432-1
    Water bodies with the dye methylene blue pose serious environmental and health risks to humans. Therefore, the creation and investigation of affordable, potential adsorbents to remove methylene blue dye from water resources as a long-term fix is one focus of the scientific community. Food plants and other carbon-source serve as a hotspot for a wider range of application on different pollutants that impact the environment and living organisms. Here, we reviewed the use of treated and untreated biosorbents made from plant waste leaves for removing the dye methylene blue from aqueous media. After being modified, activated carbon made from various plant leaves improves adsorption performance. The range of activating chemicals, activation methods, and bio-sorbent material characterisation using FTIR analysis, Barunauer-Emmett-Teller (BET) surface area, scanning electron microscope (SEM-EDX), and SEM-EDX have all been covered in this review. It has been thoroughly described how the pH solution of the methylene blue dye compares to the pHPZC of the adsorbent surface. The presentation also includes a thorough analysis of the application of the isotherm model, kinetic model, and thermodynamic parameters. The selectivity of the adsorbent is the main focus of the adsorption kinetics and isotherm models. It has been studied how adsorption occurs, how surface area and pH affect it, and how biomass waste compares to other adsorbents. The use of biomass waste as adsorbents is both environmentally and economically advantageous, and it has been discovered to have exceptional color removal capabilities.
    Matched MeSH terms: Plant Leaves/chemistry
  8. Fulltext Imaging of Subsurface Corrosion Using Gradient-Field Pulsed Eddy Current Probes with Uniform Field Excitation
    Li Y, Ren S, Yan B, Zainal Abidin IM, Wang Y
    Sensors (Basel), 2017 Jul 31;17(8).
    PMID: 28758985 DOI: 10.3390/s17081747
    A corrosive environment leaves in-service conductive structures prone to subsurface corrosion which poses a severe threat to the structural integrity. It is indispensable to detect and quantitatively evaluate subsurface corrosion via non-destructive evaluation techniques. Although the gradient-field pulsed eddy current technique (GPEC) has been found to be superior in the evaluation of corrosion in conductors, it suffers from a technical drawback resulting from the non-uniform field excited by the conventional pancake coil. In light of this, a new GPEC probe with uniform field excitation for the imaging of subsurface corrosion is proposed in this paper. The excited uniform field makes the GPEC signal correspond only to the field perturbation due to the presence of subsurface corrosion, which benefits the corrosion profiling and sizing. A 3D analytical model of GPEC is established to analyze the characteristics of the uniform field induced within a conductor. Following this, experiments regarding the imaging of subsurface corrosion via GPEC have been carried out. It has been found from the results that the proposed GPEC probe with uniform field excitation not only applies to the imaging of subsurface corrosion in conductive structures, but provides high-sensitivity imaging results regarding the corrosion profile and opening size.
    Matched MeSH terms: Plant Leaves
  9. Fulltext Ephemeroptera, Plecoptera and Trichoptera (Insecta) Abundance, Diversity and Role in Leaf Litter Breakdown in Tropical Headwater River
    Ab Hamid S, Md Rawi CS
    Trop Life Sci Res, 2017 Jul;28(2):89-105.
    PMID: 28890763 MyJurnal DOI: 10.21315/tlsr2017.28.2.7
    Leaf litter decomposition in a tropical stream was examined in two types of leaf packs; single species leaf packs of Pometia pinnata and two species leaf packs of equal combination of Pometia pinnata and Dolichandrone spathacea leaves. Both leaf packs were immersed in a river and weekly examined for remains of decomposed leaves and presence of EPT. In the control leaf packs, leaves in the two species leaf packs treatments decomposed within 35 days, faster than in single species leaf packs which decomposed after 42 days. In the presence of EPT, the leaf breakdown took 28 days in two species and 35 days for single species leaf packs. Higher abundance of EPT was observed in single species leaf packs but its diversity was higher in two species leaf packs. Litter breakdown in the stream was faster in the presence of EPT and softer leaves of D. spathacea with higher nitrogen content underwent faster decomposition and sustained higher numbers of EPT.
    Matched MeSH terms: Plant Leaves
  10. Fulltext Invariant feature descriptor based on harmonic image transform for plant leaf retrieval
    Sophia Jamila Zahra, Riza Sulaiman, Anton Satria Prabuwono, Seyed Mostafa Mousavi Kahaki
    Pertanika Journal of Science & Technology, 2017;25(106):107-114.
    MyJurnal
    Feature descriptor for image retrieval has emerged as an important part of computer vision and image analysis application. In the last decades, researchers have used algorithms to generate effective, efficient and steady methods in image processing, particularly shape representation, matching and leaf retrieval. Existing leaf retrieval methods are insufficient to achieve an adequate retrieval rate due to the inherent difficulties related to available shape descriptors of different leaf images. Shape analysis and comparison for plant leaf retrieval are investigated in this study. Different image features may result in different significance interpretation of images, even though they come from almost similarly shaped of images. A new image transform, known as harmonic mean projection transform (HMPT), is proposed in this study as a feature descriptor method to extract leaf features. By using harmonic mean function, the signal carries information of greater importance is considered in signal acquisition. The selected image is extracted from the whole region where all the pixels are considered to get a set of features. Results indicate better classification rates when compared with other classification methods.
    Matched MeSH terms: Plant Leaves
  11. Fulltext Optimisation of water soluble essential oil from Lemongrass leaves using steam distillation
    Lim, S.F., Pah, P.Y.L., David Chua, S.N., Nicholas Kuan, H.T.
    Pertanika Journal of Science & Technology, 2017;25(105):137-144.
    MyJurnal
    Lemongrass leaves are often under-utilised and unexploited. In this study, lemongrass leaves were used to produce water soluble essential oil using a steam distillation system. Water steam was passed through the lemongrass leaves which were placed and supported on a grid above the water in a distiller. The steam distillation system was fabricated and optimised using Response Surface Methodology (RSM). The maximum oil yield with optimal relative citral content is obtained at 6.69 of plant-to-water ratio, 26.68 minutes of distillation time using air-dried lemongrass leaves left under the shade for two days. At the optimum conditions, the predicted oil yield was 0.6719% of lemongrass (C. citratus) oil which contains 71.79% of citral content.
    Matched MeSH terms: Plant Leaves
  12. Senyumiagranitica (Gesneriaceae) from Johor, Malaysia, the second species of Senyumia
    Kiew R, Lau KH
    PhytoKeys, 2019.
    PMID: 30774505 DOI: 10.3897/phytokeys.117.31560
    The genus Senyumia was previously known from a single species, S.minutiflora (Ridl.) Kiew, A.Weber & B.L.Burtt, from a limestone karst, Gunung Senyum, in Pahang, Malaysia. Senyumiagranitica Kiew, here described and illustrated, is the second species of the genus. It differs from S.minutiflora, not only in its habitat, but also in its shorter leaves, larger, non-resupinate or only partially resupinate flowers and smaller seeds. It is known from a small, fragmented population from a low range of hills. Therefore, under the IUCN Red List Categories & Criteria, it is assessed as Critically Endangered.
    Matched MeSH terms: Plant Leaves
  13. Accumulation and distribution of lead and copper in Avicennia Marina and Rhizophora Apiculata from Balok mangrove forest, Pahang, Malaysia
    Rina Sharlinda M, Kamaruzzaman B, Akbar John B, Siti Waznah A
    Sains Malaysiana, 2011;40:1179-1186.
    Bioaccumulation of lead and Copper in Avicennia marina and Rhizophora apiculata was studied. Samples of leaves, barks and roots were collected from Balok mangrove forest, Pahang. Pb and Cu accumulation was higher in Avicennia marina root tissue compared to bark and leaf but lower than surrounding sediment level. The average concentration of Pb in A. marina leaf, bark, root and sediment was observed to be 5.39 ppm, 3.63 ppm, 18.21 ppm and 23.13 ppm, and average Cu concentration was 4.13 ppm, 4.27 ppm, 4.81 ppm and 12.33 ppm, respectively. R. apiculata also showed higher concentration of Pb and Cu in root tissue compared to bark and leaf tissues but lower than surrounding sediment. The average concentration of Pb in R. apiculata leaf, bark, root and sediment was observed to be 4.30 ppm, 2.97 ppm, 22.45 ppm and 31.23 ppm, respectively. The average Cu concentration was 2.93 ppm, 4.71 ppm, 4.81 ppm and 15.52 ppm, respectively. Results of concentration factors (CF) showed that the accumulation of Pb and Cu was higher in A. marina than in R. apiculata.
    Matched MeSH terms: Plant Leaves
  14. A view from a different angle: investigating the significance of rattan spines from a small mammals’ visual point of view using imageJ
    Nik Fadzly, Asyraf Mansor, Rahmad Zakaria, Syed Ahmad Edzham
    Sains Malaysiana, 2014;43:973-976.
    Rattans are one of the most unique and economically important plants for most tropical countries. There is however, a lack of interest in the specific study of the rattan spines. In this paper, we tested a new hypothesis concerning the functional role of rattan spines. We proposed that rattan spines also serve as a visual deterrent against herbivores or seed predators. In our proposed method we used an Imaging software, ImageJ, to measure the spine area of four species of rattan (Calamus insignis, Myrialepis schortechinii, Plectocomiopsis geminiflorus and Calamus caesius) from two different orientations (root to shoot and vice versa). Our results showed that rattan spines were very heterogeneous and highly variable between different species. One common trait that the rattan spines share is that spine area measurements of shoot to root (ShR) are larger than root to shoot (RH) orientation. We propose that the downwards spine angle might be specifically designed to discourage climbing leaf and seed predators.
    Matched MeSH terms: Plant Leaves
  15. Fulltext A Compact UWB Antenna with Independently Controllable Notch Bands
    Iqbal A, Smida A, Mallat NK, Islam MT, Kim S
    Sensors (Basel), 2019 Mar 22;19(6).
    PMID: 30909414 DOI: 10.3390/s19061411
    A minimally-sized, triple-notched band ultra-wideband (UWB) antenna, useful for many applications, is designed, analyzed, and experimentally validated in this paper. A modified maple leaf-shaped main radiating element with partial ground is used in the proposed design. An E-shaped resonator, meandered slot, and U-shaped slot are implemented in the proposed design to block the co-existing bands. The E-shaped resonator stops frequencies ranging from 1.8⁻2.3 GHz (Advanced Wireless System (AWS1⁻AWS2) band), while the meandered slot blocks frequencies from 3.2⁻3.8 GHz (WiMAX band). The co-existing band ranging from 5.6⁻6.1 GHz (IEEE 802.11/HIPERLANband) is blocked by utilizing the U-shaped section in the feeding network. The notched bands can be independently controlled over a wide range of frequencies using specific parameters. The proposed antenna is suitable for many applications because of its flat gain, good radiation characteristics at both principal planes, uniform group delay, and non-varying transfer function ( S 21 ) for the entire UWB frequency range.
    Matched MeSH terms: Plant Leaves
  16. Raw oil palm frond leaves as cost-effective substrate for cellulase and xylanase productions by Trichoderma asperellum UC1 under solid-state fermentation
    Ezeilo UR, Lee CT, Huyop F, Zakaria II, Wahab RA
    J Environ Manage, 2019 Aug 01;243:206-217.
    PMID: 31096173 DOI: 10.1016/j.jenvman.2019.04.113
    Production of cellulases and xylanase by a novel Trichoderma asperellum UC1 (GenBank accession no. MF774876) under solid state fermentation (SSF) of raw oil palm frond leaves (OPFL) was optimized. Under optimum fermentation parameters (30 °C, 60-80% moisture content, 2.5 × 106 spores/g inoculum size) maximum CMCase, FPase, β-glucosidase and xylanase activity were recorded at 136.16 IU/g, 26.03 U/g, 130.09 IU/g and 255.01 U/g, respectively. Cellulases and xylanase were produced between a broad pH range of pH 6.0-12.0. The enzyme complex that comprised of four endo-β-1,4-xylanases and endoglucanases, alongside exoglucanase and β-glucosidase showed thermophilic and acidophilic characteristics at 50-60 °C and pH 3.0-4.0, respectively. Glucose (16.87 mg/g) and fructose (18.09 mg/g) were among the dominant sugar products from the in situ hydrolysis of OPFL, aside from cellobiose (105.92 mg/g) and xylose (1.08 mg/g). Thermal and pH stability tests revealed that enzymes CMCase, FPase, β-glucosidase and xylanase retained 50% residual activities for up to 15.18, 4.06, 17.47 and 15.16 h of incubation at 60 °C, as well as 64.59, 25.14, 68.59 and 19.20 h at pH 4.0, respectively. Based on the findings, it appeared that the unique polymeric structure of raw OPFL favored cellulases and xylanase productions.
    Matched MeSH terms: Plant Leaves
  17. Changes in photosynthesis and leaf characteristics with tree height in five dipterocarp species in a tropical rain forest
    Kenzo T, Ichie T, Watanabe Y, Yoneda R, Ninomiya I, Koike T
    Tree Physiol, 2006 Jul;26(7):865-73.
    PMID: 16585032
    Variations in leaf photosynthetic, morphological and biochemical properties with increasing plant height from seedlings to emergent trees were investigated in five dipterocarp species in a Malaysian tropical rain forest. Canopy openness increased significantly with tree height. Photosynthetic properties, such as photosynthetic capacity at light saturation, light compensation point, maximum rate of carboxylation and maximum rate of photosynthetic electron transport, all increased significantly with tree height. Leaf morphological and biochemical traits, such as leaf mass per area, palisade layer thickness, nitrogen concentration per unit area, chlorophyll concentration per unit dry mass and chlorophyll to nitrogen ratio, also changed significantly with tree height. Leaf properties had simple and significant relationships with tree height, with few intra- and interspecies differences. Our results therefore suggest that the photosynthetic capacity of dipterocarp trees depends on tree height, and that the trees adapt to the light environment by adjusting their leaf morphological and biochemical properties. These results should aid in developing models that can accurately estimate carbon dioxide flux and biomass production in tropical rain forests.
    Matched MeSH terms: Plant Leaves/anatomy & histology; Plant Leaves/metabolism; Plant Leaves/physiology
  18. The taxonomic significance of leaf micromorphology in the genus melastoma l. (melastomataceae)
    Noorma Wati Haron, Nordiyanah Anuar, Rubashiny Veeramohan
    Sains Malaysiana, 2015;44:643-650.
    A comparative leaf micromorphological study of Melastoma malabathricum, M. malabathricum var. alba and M.
    sanguineum (Melastomataceae) was carried out by scanning electron microscope. Characters such as epidermal cell
    shape, trichomes and stomatal type and distribution were observed. Non-glandular trichomes are present in all species
    examined. The stomata are all of paracytic type and dispersed randomly over the whole abaxial surface. The patterns of
    surface sculpturing and outer stomatal rim are unique in all the species examined. Leaf micromorphology has significant
    taxonomic value in the genus Melastoma and the present study has added some new taxonomic information for the genus
    Melastoma.
    Matched MeSH terms: Plant Leaves
  19. Systematic significance of stipe anatomy of selaginella (selaginellaceae) in peninsular Malaysia
    Haja Maideen, Nor Hazwani A, Nurfarahain Z, Damanhuri A, Noraini T, Qistina L, et al.
    Sains Malaysiana, 2013;42:693-696.
    An anatomical study was carried out on 14 taxa belonging to Selaginellaceae in an attempt to study their stipe anatomical characteristics and to provide anatomical data for the selected taxa in Selaginellaceae. Out of 29 taxa of Selaginellaceae recorded in Peninsular Malaysia, 14 taxa have been selected namely Selaginella alutacia, S. argentea, S. frondosa, S. intermedia var. intermedia, S. intermedia var. dolichocentrus, S. mayeri, S. morganii, S. ornata, S. plana, S. polita, S. roxburghii var. roxburghii, S. stipulata, S. wallichii and S. willdenowii. Method used in this study was sectioning using sliding microtome. Findings in this study have shown that Selaginellaceae species studied can be clustered into two groups based on the stipe stellar systems, which are monostelic and tristelic groups. There are some variations exist in the cross sections of the stipes of the same species due to the presence and absence of the leaf trace. Each species is proved to have distinct stipe anatomical characteristics that can be used to differentiate species in Selaginellaceae.
    Matched MeSH terms: Plant Leaves
  20. Fulltext Variation in the metabolites and α-glucosidase inhibitory activity of Cosmos caudatus at different growth stages
    Wan-Nadilah WA, Akhtar MT, Shaari K, Khatib A, Hamid AA, Hamid M
    BMC Complement Altern Med, 2019 Sep 05;19(1):245.
    PMID: 31488132 DOI: 10.1186/s12906-019-2655-9
    BACKGROUND: Cosmos caudatus is an annual plant known for its medicinal value in treating several health conditions, such as high blood pressure, arthritis, and diabetes mellitus. The α-glucosidase inhibitory activity and total phenolic content of the leaf aqueous ethanolic extracts of the plant at different growth stages (6, 8. 10, 12 and 14 weeks) were determined in an effort to ascertain the best time to harvest the plant for maximum medicinal quality with respect to its glucose-lowering effects.

    METHODS: The aqueous ethanolic leaf extracts of C. caudatus were characterized by NMR and LC-MS/MS. The total phenolic content and α-glucosidase inhibitory activity were evaluated by the Folin-Ciocalteu method and α-glucosidase inhibitory assay, respectively. The statistical significance of the results was evaluated using one-way ANOVA with Duncan's post hoc test, and correlation among the different activities was performed by Pearson's correlation test. NMR spectroscopy along with multivariate data analysis was used to identify the metabolites correlated with total phenolic content and α-glucosidase inhibitory activity of the C. caudatus leaf extracts.

    RESULTS: It was found that the α-glucosidase inhibitory activity and total phenolic content of the optimized ethanol:water (80:20) leaf extract of the plant increased significantly as the plant matured, reaching a maximum at the 10th week. The IC50 value for α-glucosidase inhibitory activity (39.18 μg mL- 1) at the 10th week showed greater potency than the positive standard, quercetin (110.50 μg mL- 1). Through an 1H NMR-based metabolomics approach, the 10-week-old samples were shown to be correlated with a high total phenolic content and α-glucosidase inhibitory activity. From the partial least squares biplot, rutin and flavonoid glycosides, consisting of quercetin 3-O-arabinofuranoside, quercetin 3-O-rhamnoside, quercetin 3-O-glucoside, and quercetin 3-O-xyloside, were identified as the major bioactive metabolites. The metabolites were identified by NMR spectroscopy (J-resolve, HSQC and HMBC experiments) and further supported by dereplication via LC-MS/MS.

    CONCLUSION: For high phytomedicinal quality, the 10th week is recommended as the best time to harvest C. caudatus leaves with respect to its glucose lowering potential.

    Matched MeSH terms: Plant Leaves/growth & development*; Plant Leaves/metabolism; Plant Leaves/chemistry
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