Displaying publications 1 - 20 of 42 in total

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  1. Fulltext Ascorbate peroxidase activity of Aranda Broga Blue orchid protocorm-like bodies (plbs) in response to PVS2 cryopreservation method
    Khor, Soo Ping, Rahmad Zakaria, Subramaniam, Sreeramanan
    Trop Life Sci Res, 2016;27(11):139-143.
    MyJurnal
    Throughout the cryopreservation process, plants were exposed to a series of
    abiotic stresses such as desiccation and osmotic pressure due to highly concentrated
    vitrification solution. Abiotic stress stimulates the production of reactive oxygen species
    (ROS) which include hydrogen peroxide, superoxide radicals, and singlet oxygen. Higher
    production of ROS may lead to oxidative stress which contributes to the major injuries in
    cryopreserved explants. Antioxidant enzymes in plant such as ascorbate peroxidase
    (APX) can protect plants from cell damage by scavenging the free radicals. This study was
    determined based on APX enzyme activity of Aranda Broga Blue orchid’s protocorm-like
    bodies (PLBs) in response to PVS2 (Plant Vitrification Solution 2) cryopreservation
    treatments at different stages. PLBs that were precultured at 0.25 M sucrose for 3 days
    were subjected to vitrification cryopreservation method. Results obtained showed that the
    highest APX activity was achieved at PVS2 cryoprotectant treatment prior liquid nitrogen
    (LN) storage. This phenomenon indicating that accumulation of osmotic and dehydrating
    stress throughout the cryopreservation treatment resulted in oxidative burst which in turn
    leads to higher APX activity in order to control the excess production of ROS. To
    conclude, PVS2 treatment was revealed as the most detrimental step throughout
    cryopreservation treatment. Thus, this research also suggested that exogenous
    antioxidant such as ascorbic acid can be added throughout cryopreservation procedure
    especially at PVS2 treatment in the future experiments to aid in regrowth of cryopreserved
    explants by reducing oxidative stress.
  2. Fulltext Chemotaxis movement and attachment of Agrobacterium tumefaciens to Phalaenopsis violacea orchid tissues: an assessment of early factors influencing the efficiency of gene transfer
    Subramaniam, Sreeramanan, Balasubramaniam, Vinod, Poobathy, Ranjetta, Sreenivasan, Sasidharan, Rathinam, Xavier
    Trop Life Sci Res, 2009;20(1):-.
    MyJurnal
    An early step in the Agrobacterium-mediated transformation of Phalaenopsis violacea orchid was investigated to elucidate the plant-bacterium interaction. Directed movement in response to chemical attractants is of crucial importance to Agrobacterium tumefaciens strains. Chemotaxis of A. tumefaciens strains (EHA 101 and 105) towards wounded orchid tissues has been studied by using swarm agar plates. The results obtained indicate a minor role for chemotaxis in determining host specificity and suggest that it could not be responsible for the absence of tumourigenesis in P. violacea orchid under natural conditions. The spectrometric GUS and green fluorescent protein (GFP) assays provided information on the amount of inoculated A. tumefaciens that effectively bound to various orchid tissues. It can be concluded that, at least during the two early steps of interaction, A. tumefaciens appears to be compatible with P. violacea, indicating a potential basis for genetic transformation.
  3. Fulltext Early studies on protoplast isolation of Ludisia discolor, a wild orchid
    Poobathy, Ranjetta, Rahmad Zakaria, Syed Mohd. Edzham Syed Hamzah, Subramaniam, Sreeramanan
    Trop Life Sci Res, 2016;27(11):15-19.
    MyJurnal
    The terrestrial Ludisia discolor, also referred to as the jewel orchid is prized for
    the quality of its leaves. L. discolor is known as a medicinal herb and is touted for its heatand
    pathogen-resisting qualities. L. discolor is valuable in the production of both flavonoids
    and anthocyanins, antioxidants that are exalted in the health industry. Plant cell cultures
    have emerged as alternative sources of anthocyanin production. Plant protoplast cultures
    are used frequently in transient gene expression studies and in the establishment of callus
    and cell suspension cultures. Benefits of plant protoplast system include similarity to cells
    found in plant tissues, reproduction under controlled conditions, and prevention of masking
    of stress responses to previous handling techniques. A study was conducted to assess the
    amenability of the stem and leaves of L. discolor to protoplast isolation. The stem and leaf
    segments were weighed, sliced into thin layers, immersed in a digestion medium, washed
    and then cultured onto a recovery medium. Results indicated that the production of plant
    protoplasts from L. discolor may be viewed as an alternative in the generation of cell
    cultures and ultimately in the production of anthocyanins from the cell cultures.
  4. Mapping of the Interaction Between Agrobacterium tumefaciens and Vanda Kasem's Delight Orchid Protocorm-Like Bodies
    Gnasekaran P, Subramaniam S
    Indian J Microbiol, 2015 Sep;55(3):285-91.
    PMID: 26063938 DOI: 10.1007/s12088-015-0519-7
    Physical contact between A. tumefaciens and the target plant cell walls is essential to transfer and integrate the transgene to introduce a novel trait. Chemotaxis response and attachment of Agrobacterium towards Vanda Kasem's Delight (VKD) protocorm-like bodies (PLBs) were studied to analyse the interaction between Agrobacterium and PLB during the transformation event. The study shows that initially A. tumefaciens reversibly attached to PLB surface via polar and lateral mode of adherence followed by the irreversible attachment which involved the production of cellulosic fibril by A. tumefaciens. Cellulosic fibril allows formation of biofilm at the tip of trichome. Contrarily, attachment mutant Escherichia coli strain DH5α was significantly deficient in the attachment process. Spectrophotometric GUS assay showed the mean value of attachment by A. tumefaciens was 8.72 % compared to the negative control E. coli strain DH5α that produced 0.16 %. A. tumefaciens swarmed with sharper and brighter edge when severe wounding was applied to the PLBs producing the highest swarming ratio of 1.46 demonstrating the positive effect of the plant exudates on bacterial movement. The study shows that VKD's PLBs are the suitable explants for Agrobacterium-mediated transformation since the bacteria expressed higher competency rate.
  5. Fulltext Comparative analysis of lycorine in wild plant and callus culture samples of Hymenocallis littoralis by HPLC-UV method
    Subramaniam S, Sundarasekar J, Sahgal G, Murugaiyah V
    ScientificWorldJournal, 2014;2014:408306.
    PMID: 24895650 DOI: 10.1155/2014/408306
    The Hymenocallis littoralis, an ornamental and medicinal plant, had been traditionally used for wound healing. In the present study, an analytical method using HPLC with ultraviolet detection was developed for the quantification of lycorine in the extracts of different parts of wild plant and tissue culture samples of H. littoralis. The separation was achieved using a reversed-phase column. The method was found to be accurate, repeatable, and sensitive for the quantification of minute amount of lycorine present in the samples. The highest lycorine content was found in the bulb extract (2.54 ± 0.02 μg/mg) whereas the least was in the root extract (0.71 ± 0.02 μg/mg) of the wild plants. Few callus culture samples had high content of lycorine, comparable to that of wild plants. The results showed that plant growth regulators, 2,4-dichlorophenoxyacetic acid (2,4-D) alone at 4.5 μM (2.58 ± 0.38 μg/mg) or a combination of 2,4-D at 9.00 μM with 4.5 μM of 6-benzylaminopurine (BAP), were the optimum concentrations for the production of high lycorine (2.45 ± 0.15 μg/mg) content in callus culture. The present analytical method could be of value for routine quantification of lycorine in the tissue culture production and standardization of the raw material or extracts of H. littoralis.
  6. Fulltext Variations in Hormones and Antioxidant Status in Relation to Flowering in Early, Mid, and Late Varieties of Date Palm (Phoenix dactylifera) of United Arab Emirates
    Cheruth AJ, Kurup SS, Subramaniam S
    ScientificWorldJournal, 2015;2015:846104.
    PMID: 26167536 DOI: 10.1155/2015/846104
    The present study was carried out to assess the status of various hormones responsible for the flower induction of Nagal, Lulu, and Khalas date palm varieties in UAE. The nonenzymatic antioxidant compounds and the antioxidant enzymatic activities at preflowering, flowering, and postflowering stages of the date palm varieties were quantified. The ABA and zeatin concentrations were found to be significantly higher during the preflowering stage but gradually decreased during the flowering period and then increased after the flowering stage. Gibberellic acid (GA) concentrations were significantly higher in the early flowering varieties and higher levels of ABA may contribute to the delayed flowering in mid and late varieties. The results on hormone profiling displayed a significant variation between seasons (preflowering, flowering, and postflowering) and also between the three date palms (early, mid, and late flowering varieties). Ascorbic acid (AA) concentration was low at the preflowering stage in the early flowering Nagal (0.694 mg/g dw), which is similar with the late flowering Lulu variety (0.862 mg/g dw). However, Khalas variety showed significantly higher amount of AA content (7.494 mg/g dw) at the preflowering stage when compared to other varieties. In flowering stage, Nagal (0.814 mg/g dw) and Lulu (0.963 mg/g dw) were similar with respect to the production of AA, while the mid flowering variety showed significantly higher amount of AA (9.358 mg/g dw). The Khalas variety produced the highest tocopherol at 4.78 mg/g dw compared to Nagal and Lulu, at 1.997 and 1.908 mg/g dw, respectively, during the preflowering stage. In Nagal variety, the content of reduced glutathione (GSH) at the preflowering stage was 0.507 mg/g dw, which was not significantly different from the flowering and postflowering stages at 0.4 and 0.45 mg/g dw, respectively. The GSH was significantly higher in Khalas compared to Nagal and Lulu varieties, at 1.321 mg/g w in the preflowering phase followed by 3.347 mg/g dw and 2.349 mg/g dw at the flowering and postflowering phases, respectively. Catalase activity increased with different stages of growth. The lowest catalase activity was observed at the preflowering stage in Khalas (0.116), with similar observations noted during flowering (0.110) and postflowering stage. This study provides an insight into the possible roles of endogenous hormones and antioxidants and in the activities of antioxidant enzymes in the regulation of flower development in date palm varieties.
  7. Effects of salt and heat pre-treatment factors on efficient regeneration in barley (Hordeum vulgare L.)
    Haque M, Islam SMS, Subramaniam S
    3 Biotech, 2017 May;7(1):63.
    PMID: 28452013 DOI: 10.1007/s13205-017-0675-z
    An efficient callus induction and plant regeneration system has been developed using salt and heat as pre-treatment factors for three barley genotypes viz. BB-3, BB-6 and BHL-18. Different concentrations of NaCl (1.5, 2.5, 3.5, 4.5, 5.5 and 6.5 g/L) were used and its effects were determined on the basis of the viability of callus (CV), plant regeneration (PR), relative growth rate (RGR) and tolerance index (TI). The BB-6 showed highest performance on tolerance based on CV (14.72%), PR (7.69%), RGR (0.91%) and TI (0.42%) at 6.5 g/L NaCl. Various NaCl concentrations displayed significantly differences at P 
  8. Fulltext Autofluorescence study and selected cyanidin quantification in the Jewel orchids Anoectochilus sp. and Ludisia discolor
    Poobathy R, Zakaria R, Murugaiyah V, Subramaniam S
    PLoS One, 2018;13(4):e0195642.
    PMID: 29649288 DOI: 10.1371/journal.pone.0195642
    Anoectochilus sp. and Ludisia discolor are known as Jewel orchids. Both species are terrestrial wild orchids that grow in shaded areas of forests. The Jewel orchids are renowned for the beauty of their leaves, which are dark-green laced with silvery or golden veins. The orchids are used as a cure in various parts of Asia. Overharvesting and anthropogenic disturbances threaten the existence of the Jewel orchids in the wild, necessitating human intervention in their survival. An understanding of the structure and adaptations of a plant may assist in its survival when propagated outside of its habitat. In this study, ex vitro leaves of Anoectochilus sp. and L. discolor were subjected to freehand sectioning, and then inspected through brightfield and fluorescence microscopy. The study indicated that all parts of both plants presented typical monocotyledonous characteristics except the leaves. The leaves displayed dorsiventrality with distinct palisade and spongy mesophyll layers. The spongy mesophyll layer contained cells which fluoresced a bright red when exposed to ultraviolet, blue, and green light wavelengths, hinting at the presence of anthocyanins for photoprotection. Cyanidin was detected in the leaves of L. discolor, as enumerated through high performance liquid chromatography (HPLC). The observations indicated that Anoectochilus sp. and L. discolor are well-adapted to live under shaded conditions with minimal exposure to light.
  9. Assessment of genetic stability on in vitro and ex vitro plants of Ficus carica var. black jack using ISSR and DAMD markers
    Parab AR, Lynn CB, Subramaniam S
    Mol Biol Rep, 2021 Nov;48(11):7223-7231.
    PMID: 34586562 DOI: 10.1007/s11033-021-06714-1
    BACKGROUND: Clonal propagation is one of the attributes of plant tissue culture. Therefore, analysis of genetic stability among the in vitro cultured plants is a crucial step. It helps to signify the clonal propagation of the micropropagated plants. Regenerated Ficus carica var. Black Jack plantlets were established using woody plant medium supplemented with 20 μM 6-Benzylaminopurine and 8 μM Indole-3-acetic acid under different light treatments such as normal fluorescent white light (60 μmol m-2 s-1), and four different LED spectra, white (400-700 nm), blue (440 nm), red (660 nm) and blue + red (440 nm + 660 nm). Genetic stability analysis was performed on the in vitro and ex vitro plants of Ficus carica var. Black Jack.

    METHODS AND RESULTS: Ten primers of each, ISSR and DAMD molecular markers, were used to assess the genetic stability of the eight samples of Ficus carica var. Black Jack. ISSR markers showed 97.87% of monomorphism whereas DAMD markers showed 100% monomorphism. Polymorphism of 2.13% was observed for the UBC840 ISSR-DNA primer which was negated under the genetic similarity index analysis for the eight samples. The findings of this study revealed that ISSR and DAMD markers are efficient in determining the polymorphism and monomorphism percentage among the in vitro and ex vitro samples of Ficus carica var. Black Jack.

    CONCLUSION: Monomorphism of 100% obtained using DAMD markers and more than 95% of monomorphism obtained using ISSR markers indicate that the regenerated plants are significantly genetically stable. These molecular markers can be used to test the genetic stability of in vitro regenerated plants. It is recommended that genetic stability analysis should be performed for long-term maintenance of such micropropagated plants.

  10. Fulltext Agrobacterium-mediated transformation of the recalcitrant Vanda Kasem's Delight orchid with higher efficiency
    Gnasekaran P, Antony JJ, Uddain J, Subramaniam S
    ScientificWorldJournal, 2014;2014:583934.
    PMID: 24977213 DOI: 10.1155/2014/583934
    The presented study established Agrobacterium-mediated genetic transformation using protocorm-like bodies (PLBs) for the production of transgenic Vanda Kasem's Delight Tom Boykin (VKD) orchid. Several parameters such as PLB size, immersion period, level of wounding, Agrobacterium density, cocultivation period, and concentration of acetosyringone were tested and quantified using gusA gene expression to optimize the efficiency of Agrobacterium-mediated genetic transformation of VKD's PLBs. Based on the results, 3-4 mm PLBs wounded by scalpel and immersed for 30 minutes in Agrobacterium suspension of 0.8 unit at A 600 nm produced the highest GUS expression. Furthermore, cocultivating infected PLBs for 4 days in the dark on Vacin and Went cocultivation medium containing 200 μM acetosyringone enhanced the GUS expression. PCR analysis of the putative transformants selected in the presence of 250 mg/L cefotaxime and 30 mg/L geneticin proved the presence of wheatwin1, wheatwin2, and nptII genes.
  11. Improved cryopreservation of oil palm (Elaeis guineensis Jacq.) polyembryoids using droplet vitrification approach and assessment of genetic fidelity
    Gantait S, Sinniah UR, Suranthran P, Palanyandy SR, Subramaniam S
    Protoplasma, 2015 Jan;252(1):89-101.
    PMID: 24893588 DOI: 10.1007/s00709-014-0660-x
    In the present study, polyembryoids of oil palm (Elaeis guineensis Jacq.) were cryopreserved with successful revival of 68 % for the first time using the droplet vitrification technique. Excised polyembryoids (3-5-mm diameter) from 3-month-old in vitro cultures were pre-cultured for 12 h in liquid Murashige and Skoog medium supplemented with 0.5 M sucrose. The polyembryoids were osmoprotected in loading solution [10% (w/v) dimethyl sulphoxide (DMSO) plus 0.7 M sucrose] for 30 min at room temperature and then placed on aluminium strips where they were individually drenched in chilled droplets of vitrification solution (PVS2) [30% (w/v) glycerol plus 15% (w/v) ethylene glycol (EG) plus 15% (w/v) DMSO plus 0.4 M sucrose] for 10 min. The aluminium strips were enclosed in cryovials which were then plunged quickly into liquid nitrogen and kept there for 1 h. The polyembryoids were then thawed and unloaded (using 1.2 M sucrose solution) with subsequent transfer to regeneration medium and stored in zero irradiance. Following for 10 days of storage, polyembryoids were cultured under 16 h photoperiod of 50 μmol m(-2) s(-1) photosynthetic photon flux density, at 23 ± 1 °C. Post-thaw growth recovery of 68% was recorded within 2 weeks of culture, and new shoot development was observed at 4 weeks of growth. Scanning electron microscopy revealed that successful regeneration of cryopreserved polyembryoids was related to maintenance of cellular integrity, presumably through PVS2 exposure for 10 min. The present study demonstrated that cryopreservation by droplet vitrification enhanced the regeneration percentages of oil palm in comparison with the conventional vitrification method previously reported.
  12. Effect of plasmolysis on protocorm-like bodies of Dendrobium Bobby Messina orchid following cryopreservation with encapsulation-dehydration method
    Antony JJ, Mubbarakh SA, Mahmood M, Subramaniam S
    Appl Biochem Biotechnol, 2014 Feb;172(3):1433-44.
    PMID: 24218184 DOI: 10.1007/s12010-013-0636-x
    Histological observation and scanning electron microscopy analyses in Dendrobium Bobby Messina indicates the cellular process of cryopreserved protocorm-like bodies (PLBs) was different comparative to non-cryopreserved PLBs. The cellular process was not only modified by the freezing and thawing effect but also due to the dehydration process itself during the cryopreservation procedure. Histological observation in Dendrobium Bobby Messina in encapsulation-dehydration method indicated that the degree of plasmolysis causes more cellular changes to the cryopreserved PLBs comparative to non-cryopreserved and stock culture PLBs. These results revealed higher amount of homogenous cell population and denser cytoplasm in cryopreserved PLBs. Histological analysis also revealed more voluminous nucleus in cryopreserved PLBs comparative to non-cryopreserved PLBs and PLBs stock culture. In contrast, scanning electron microscope analysis showed severe damages in cryopreserved PLBs and non-cryopreserved PLBs comparative to the PLBs stock culture which in return could be the possible reason of no regrowth in encapsulation-dehydration method. Damages incurred were on top part, side part, and at the stomata of the PLBs. Histological observation and scanning electron microscopy analyses in Dendrobium Bobby Messina indicates that the degree of plasmolysis causes changes in the cellular process of PLBs from cryopreserved PLBs was different comparative to non-cryopreserved PLBs.
  13. Effects of ascorbic acid on PVS2 cryopreservation of Dendrobium Bobby Messina's PLBs supported with SEM analysis
    Antony JJ, Keng CL, Mahmood M, Subramaniam S
    Appl Biochem Biotechnol, 2013 Sep;171(2):315-29.
    PMID: 23832189 DOI: 10.1007/s12010-013-0369-x
    Regrowth of the cryopreserved protocorm-like bodies (PLBs) of Dendrobium Bobby Messina was assessed based on the plant vitrification solution 2 (PVS2) optimisation conditions. The optimized protocol obtained based on TTC spectrophotometrical analysis and growth recovery were 3-4 mm of PLBs size precultured in 0.2 M sucrose for 1 day, treated with a mixture of 2 M glycerol and 0.4 M sucrose supplemented with half-strength liquid MS media at 25 °C for 20 min and subsequently dehydrated with PVS2 at 0 °C for 20 min prior to storage in liquid nitrogen. Following rapid warming in a water bath at 40 °C for 90 s, PLBs were treated with unloading solution containing half-strength liquid MS media supplemented with 1.2 M sucrose. Subsequently, the PLBs were cultured on half-strength semi-solid MS media supplemented with 2 % (w/v) sucrose without any growth regulators and resulted in 40 % growth recovery. In addition, ascorbic acid treatment was used to evaluate the regeneration process of cryopreserved PLBs. However, growth recovery rates of non-cryopreserved and cryopreserved PLBs were 30 and 10 % when 0.6 mM ascorbic acid was added. Scanning electron microscopy analysis indicates that there are not much damages observed on both cryopreserved and non-cryopreserved PLBs in comparison to PLBs stock culture.
  14. Catalase and superoxide dismutase activities and the total protein content of protocorm-like bodies of Dendrobium sonia-28 subjected to vitrification
    Poobathy R, Sinniah UR, Xavier R, Subramaniam S
    Appl Biochem Biotechnol, 2013 Jul;170(5):1066-79.
    PMID: 23640259 DOI: 10.1007/s12010-013-0241-z
    Dendrobium sonia-28 is an important ornamental orchid in the Malaysian flower industry. However, the genus faces both low germination rates and the risk of producing heterozygous progenies. Cryopreservation is currently the favoured long-term storage method for orchids with propagation problems. Vitrification, a frequently used cryopreservation technique, involves the application of pretreatments and cryoprotectants to protect and recover explants during and after storage in liquid nitrogen. However, cryopreservation may cause osmotic injuries and toxicity to cryopreserved explants from the use of highly concentrated additives, and cellular injuries from thawing, devitrification and ice formation. Reactive oxygen species (ROS), occurring during dehydration and cryopreservation, may also cause membrane damage. Plants possess efficient antioxidant systems such as the superoxide dismutase (SOD) and catalase (CAT) enzymes to scavenge ROS during low temperature stress. In this study, protocorm-like bodies (PLBs) of Dendrobium sonia-28 were assayed for the total protein content, and both SOD and CAT activities, at each stage of a vitrification exercise to observe for deleterious stages in the protocol. The results indicated that cryopreserved PLBs of Dendrobium sonia-28 underwent excessive post-thawing oxidative stress due to decreased levels of the CAT enzyme at the post-thawing recovery stage, which contributed to the poor survival rates of the cryopreserved PLBs.
  15. Effects of fusaric acid treatment on the protocorm-like bodies of Dendrobium sonia-28
    Dehgahi R, Zakaria L, Mohamad A, Joniyas A, Subramaniam S
    Protoplasma, 2016 Sep;253(5):1373-83.
    PMID: 26471909 DOI: 10.1007/s00709-015-0895-1
    Dendrobium sonia-28 is a popular orchid hybrid due to its flowering recurrence and dense inflorescences. Unfortunately, it is being decimated by fungal diseases, especially those caused by Fusarium proliferatum. In this study, selection of F. proliferatum-tolerant protocorm-like bodies (PLBs) was carried out by assessing the effects of differing concentrations of fusaric acid (FA). PLBs were cultured on Murashige and Skoog (MS) medium supplemented with 0.05 to 0.2 millimolar (mM) concentrations of FA. Higher concentrations of FA increased mortality of PLBs and reduced their growth. The survival rate for 0.05 mM FA was 20 % but only 1 % at the highest dose of 0.2 mM. Additionally, two different size ranges of PLBs were investigated, and growth increased more at lower FA concentrations for larger PLBs, whilst the growth rate of smaller PLBs was inhibited at an FA concentration of 0.2 mM. Histological examination using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses disclosed severe cell wall and organelle damage, as well as stomatal closure in PLBs treated with the high FA concentrations. Reductions in plantlet growth were much greater at the highest concentrations of FA. Some randomly amplified polymorphic DNA (RAPD) markers clearly discriminated between selected and non-selected variants of Dendrobium sonia-28, showing different banding patterns for each FA concentration and specific bands for selected and control plants.
  16. Fulltext Effects of droplet-vitrification cryopreservation based on physiological and antioxidant enzyme activities of Brassidium shooting star orchid
    Rahmah S, Ahmad Mubbarakh S, Soo Ping K, Subramaniam S
    ScientificWorldJournal, 2015;2015:961793.
    PMID: 25861687 DOI: 10.1155/2015/961793
    Protocorm-like bodies (PLBs) of Brassidium Shooting Star orchid were successfully cryopreserved using droplet-vitrification method. Vitrification based cryopreservation protocol is comprised of preculture, osmoprotection, cryoprotection, cooling, rewarming, and growth recovery and each and every step contributes to the achievement of successful cryopreservation. In order to reveal the lethal and nonlethal damage produced by cryopreservation, histological observation, scanning electron microscopy (SEM), and biochemical analysis were carried out in both cryopreserved and noncryopreserved PLBs of Brassidium Shooting Star orchid comparing with the control PLBs stock culture. Histological and scanning electron microscopy analyses displayed structural changes in cryopreserved PLBs due to the impact of cryoinjury during exposure to liquid nitrogen. Total soluble protein significantly increased throughout the dehydration process and the highest value was achieved when PLBs were stored in liquid nitrogen. Ascorbate peroxidase (APX) and catalase (CAT) showed the highest enzyme activities in both dehydration and cryostorage treatments indicating that stress level of PLBs was high during these stages.
  17. Fulltext Larvicidal efficacy of different plant parts of railway creeper, Ipomoea cairica Extract Against Dengue Vector Mosquitoes, Aedes albopictus (Diptera: Culicidae) and Aedes aegypti (Diptera: Culicidae)
    AhbiRami R, Zuharah WF, Thiagaletchumi M, Subramaniam S, Sundarasekar J
    J Insect Sci, 2014;14:180.
    PMID: 25368088 DOI: 10.1093/jisesa/ieu042
    Natural insecticides from plant origin against mosquito vectors have been the main concern for research due to their high level of eco-safety. Control of mosquitoes in their larval stages are an ideal method since Aedes larvae are aquatic, thus it is easier to deal with them in this habitat. The present study was specifically conducted to explore the larvicidal efficacy of different plant parts of Ipomoea cairica (L.) or railway creeper crude extract obtained using two different solvents; methanol and acetone against late third-stage larvae of Aedes albopictus (Skuse) and Aedes aegypti (L.) (Diptera: Culicidae). Plant materials of I. cairica leaf, flower, and stem were segregated, airdried, powdered, and extracted using Soxhlet apparatus. Larvicidal bioassays were performed by using World Health Organization standard larval susceptibility test method for each species which were conducted separately for different concentration ranging from 10 to 450 ppm. Both acetone and methanol extracts showed 100% mortality at highest concentration tested (450 ppm) after 24 h of exposure. Results from factorial ANOVA indicated that there were significant differences in larvicidal effects between mosquito species, solvent used and plant parts (F=5.71, df=2, P<0.05). The acetone extract of I. cairica leaf showed the most effective larvicidal action in Ae. aegypti with LC50 of 101.94 ppm followed by Ae. albopictus with LC50 of 105.59 ppm compared with other fractions of I. cairica extract obtained from flower, stem, and when methanol are used as solvent. The larvae of Ae. aegypti appeared to be more susceptible to I. cairica extract with lower LC50 value compared with Ae. albopictus (F=8.83, df=1, P<0.05). Therefore, this study suggests that the acetone extract of I. cairica leaf can be considered as plant-derived insecticide for the control of Aedes mosquitoes. This study quantified the larvicidal property of I. cairica extract, providing information on lethal concentration that may have potential for a more eco-friendly Aedes mosquito control program.
  18. Fulltext Cryopreservation of oil palm (Elaeis guineensis Jacq.) polyembryoids via encapsulation-desiccation
    Palanyandy SR, Gantait S, Subramaniam S, Sinniah UR
    3 Biotech, 2020 Jan;10(1):9.
    PMID: 31850156 DOI: 10.1007/s13205-019-1997-9
    The current report assesses the efficiency of encapsulation-desiccation protocol to cryopreserve oil palm (Elaeis guineensis Jacq.) polyembryoids. Specifically identified polyembryoids, comprising of haustorium and torpedo-shaped structures, were encapsulated [comprising 3% (w/v) sodium alginate and 100 mM CaCl2]. Calcium alginate-encapsulated and sucrose-precultured polyembryoids were subjected to different spans of desiccation in a laminar air-flow cabinet, followed by freezing in liquid nitrogen. The effect of sucrose preculture (with gradual exposure to 0.3, 0.5, 0.75 and 1 M for 7 days) and dehydration periods (0-10 h) under sterile air-flow on post-freezing survival and regrowth of encapsulated polyembryoids were studied. Cryopreserved and thawed polyembryoids (initially precultured in sucrose, followed by 9 h air-desiccated to 23.3% moisture content) displayed the highest survival percentage (73.3%) and regeneration (of shoot, root and secondary somatic embryo) on Murashige and Skoog regrowth medium containing sucrose (0.3-1 M) and 0.2 mg/l 2,4-dichlorophenoxy acetic acid. In addition, ultrastructural study using scanning electron microscopy exhibited successful revival of cryopreserved polyembryoids, owing to retention of cellular membrane stability through optimized and protected (encapsulated) desiccation. The present study thus substantiates the potential of this encapsulation-desiccation procedure in cryopreservation of oil palm polyembryoids for long-term conservation programs.
  19. Fulltext Morphogenetic and physiological effects of LED spectra on the apical buds of Ficus carica var. Black Jack
    Parab AR, Han KY, Chew BL, Subramaniam S
    Sci Rep, 2021 12 08;11(1):23628.
    PMID: 34880352 DOI: 10.1038/s41598-021-03056-7
    The use of artificial light sources such as light-emitting diodes (LEDs) has become a prerequisite in tissue culture studies to obtain morphogenetic enhancements on in vitro plants. This technology is essential for developmental enhancements in the growing plant cultures due to its light quality and intensity greatly influencing the in vitro growing explants at a cellular level. The current study investigates the effects of different light-emitting diode (LED) spectra on the growth of apical buds of Ficus carica var. Black Jack. Ficus carica, commonly known as figs is rich in vitamins, minerals, and phytochemicals capable of treating microbial infections and gastric, inflammatory, and cardiac disorders. Apical buds of Ficus carica var. Black Jack, presented morphogenetic changes when grown under six different LED spectra. The highest multiple shoots (1.80 per growing explant) and healthy growing cultures were observed under the blue + red LED spectrum. Wound-induced callus formation was observed on apical buds grown under green LED spectrum and discolouration of the growing shoots were observed on the cultures grown under far-red LED spectrum. Multiple shoots obtained from the blue + red LED treatment were rooted using 8 µM indole-3-acetic acid (IAA), and the rooted plantlets were successfully acclimatised. Compared with the other monochromatic LEDs, blue + red proved to be significantly better for producing excellent plant morphogeny. It is apparent that blue and red LED is the most suitable spectra for the healthy development of plants. The findings have confirmed that the combination of blue + red LED can potentially be used for enhancing growth yields of medicinally and commercially important plants.
  20. Fulltext OneHealth Approaches Contribute Towards Antimicrobial Resistance: Malaysian Perspective
    Mariappan V, Vellasamy KM, Mohamad NA, Subramaniam S, Vadivelu J
    Front Microbiol, 2021;12:718774.
    PMID: 34759896 DOI: 10.3389/fmicb.2021.718774
    On a global scale, antimicrobial resistance (AMR) is recognized as a One Health challenge due to the continual and increased development and distribution of resistant microbes and genes among humans, animals, and the environment. These sectors contribute to the increase in AMR, as antibiotics are widely used in healthcare to treat or prevent bacterial infection; as growth enhancers, therapeutics and metaphylactics in animal husbandry; and transmitted in the environment through irrigation using wastewater or inappropriate disposal and treatment of human and agricultural waste. However, there is a major drawback in terms of the lack of research assessing the coexistence of AMR in these sectors. Extensive research highlighted food-animal manufacture structures that are likely to harbor reservoirs or promote transmission of AMR, in addition to increasing human colonization with AMR commensal bacteria. Numerous antibiotic stewardship policies have been designed and implemented in medical practices and animal husbandry in high- and middle-income countries. However, research concentrating on high-income settings, attitudes, emotions, and beliefs on the utilization of antimicrobials remain underexplored in lower- and middle-income countries such as Malaysia. Microbiological, epidemiological, and social science exploration are required at community and farming across the One Health range to fill huge gaps in information and knowledge of AMR. Manipulating human activities and character associated with antibiotics is a multifaceted progression that includes elements like knowledge, social behavior, attitudes, approaches, social standards, socioeconomic settings, peer pressure, experiences, and biophysical environment. Therefore, understanding these aspects in the utilization of antimicrobial drugs among the different sectors is essential to develop and implement policies to curb AMR development and transmission that overarch all sectors within the One Health consortium in Malaysia.
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