Displaying publications 1 - 20 of 21 in total

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  1. Taweesak V, Lee Abdullah T, Hassan SA, Kamarulzaman NH, Wan Yusoff WA
    ScientificWorldJournal, 2014;2014:254867.
    PMID: 25478586 DOI: 10.1155/2014/254867
    Influences of irrigation frequency on the growth and flowering of chrysanthemum grown under restricted root volume were tested. Chrysanthemum cuttings (Chrysanthemum morifolium "Reagan White") were grown in seedling tray which contained coconut peat in volumes of 73 and 140 cm(3). Plants were irrigated with drip irrigation at irrigation frequencies of 4 (266 mL), 6 (400 mL), and 8 (533 mL) times/day to observe their growth and flowering performances. There was interaction between irrigation frequency and substrate volume on plant height of chrysanthemum. Plants grown in 140 cm(3) substrates and irrigated 6 times/day produced the tallest plant of 109.25 cm. Plants irrigated 6 and 8 times/day had significantly higher level of phosphorus content in their leaves than those plants irrigated 4 times/day. The total leaf area, number of internodes, leaf length, and leaf width of chrysanthemums grown in 140 cm(3) substrate were significantly higher than those grown in 73 cm(3) substrate. The numbers of flowers were affected by both irrigation frequencies and substrate volumes. Chrysanthemums irrigated 8 times/day had an average of 19.56 flowers while those irrigated 4 times/day had an average of 16.63 flowers. Increasing irrigation frequency can improve the growth and flowering of chrysanthemums in small substrate volumes.
    Matched MeSH terms: Plant Leaves/growth & development*
  2. Noh A, Rafii MY, Mohd Din A, Kushairi A, Norziha A, Rajanaidu N, et al.
    Genet. Mol. Res., 2014;13(2):2426-37.
    PMID: 24781997 DOI: 10.4238/2014.April.3.15
    Twelve introgressed oil palm (Elaeis guineensis) progenies of Nigerian dura x Deli dura were evaluated for bunch yield, yield attributes, bunch quality components and vegetative characters at the Malaysian Palm Oil Board Research Station, in Keratong, Pahang, Malaysia. Analysis of variance revealed significant to highly significant genotypic differences, indicating sufficient genetic variability among the progenies for bunch yield and its attributes, vegetative characters and bunch quality components, except fruit to bunch ratio. Fresh fruit bunch yield ranged from 167 kg·palm(-1)·year(-1) in PK1330 to 212 kg·palm(-1)·year(-1) in PK1351, with a mean yield of 192 kg·palm(-1)·year(-1). Among the progeny, PK1313 had the highest oil to bunch ratio (19.36%), due to its high mesocarp to fruit ratio, fruit to bunch ratio and low shell to fruit ratio. Among the progenies, PK1313 produced the highest oil yield of 31.4 kg·palm(-1)·year(-1), due to a high mesocarp to fruit ratio (61.2%) and a low shell to fruit ratio (30.7%), coupled with high fruit to bunch ratio (65.6%). PK1330 was found promising for selection, as it had desirable vegetative characters, including smaller petiole cross section (27.15 cm2), short rachis length (4.83 m), short palm height (1.85 m), and the lowest leaf number (164.6), as these vegetative characters are prerequisites for selecting palms for high density planting and high yield per hectare. The genetic variability among the progenies was found to be high, indicating ample scope for further breeding, followed by selection.
    Matched MeSH terms: Plant Leaves/growth & development*
  3. Shahidullah SM, Hanafi MM, Ashrafuzzaman M, Razi Ismail M, Salam MA, Khair A
    C. R. Biol., 2010 Jan;333(1):61-7.
    PMID: 20176338 DOI: 10.1016/j.crvi.2009.10.002
    A field experiment was conducted to evaluate photosynthetic efficiency along with different growth parameters of aromatic rice genotypes. Forty genotypes including three non-aromatic checks exhibited enormous variations for leaf area index (LAI), crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR), grain yield, total dry matter, harvest index and photosynthetic efficiency or energy use efficiency (Emu) at panicle initiation and heading stages. Minimum LAI-value was 0.52 in Khazar at PI stage and maximum was 4.91 in Sakkor khora at heading stage. The CGR-value was in the range of 4.80-24.11 g m(-2) per day. The best yielder BR39 produced grain of 4.21 t ha(-1) and the worst yielder Khazar gave 1.42 t ha(-1). Total dry matter (TDM) yield varied from 4.04 to 12.26 t ha(-1) where genotypes proved their energy use efficiency a range between 0.58 to 1.65%. Emu showed a significant positive relation with TDM (r=0.80(**)), CGR (r=0.72(**)) and grain yield (r=0.66(**)). A negative correlation was established between TDM and harvest index and LAI and RGR. Path analysis result showed that NAR at heading stage exerted highest positive direct effect (0.70) on Emu.
    Matched MeSH terms: Plant Leaves/growth & development
  4. Nasim W, Belhouchette H, Tariq M, Fahad S, Hammad HM, Mubeen M, et al.
    Environ Sci Pollut Res Int, 2016 Feb;23(4):3658-70.
    PMID: 26498803 DOI: 10.1007/s11356-015-5613-1
    Nitrogen (N) fertilizer is an important yield limiting factor for sunflower production. The correlation between yield components and growth parameters of three sunflower hybrids (Hysun-33, Hysun-38, Pioneer-64A93) were studied with five N rates (0, 60, 120, 180, 240 kg ha(-1)) at three different experimental sites during the two consecutive growing seasons 2008 and 2009. The results revealed that total dry matter (TDM) production and grain yield were positively and linearly associated with leaf area index (LAI), leaf area duration (LAD), and crop growth rate (CGR) at all three sites of the experiments. The significant association of yield with growth components indicated that the humid climate was most suitable for sunflower production. Furthermore, the association of these components can be successfully used to predict the grain yield under diverse climatic conditions. The application of N at increased rate of 180 kg ha(-1) resulted in maximum yield as compared to standard rate (120 kg ha(-1)) at all the experimental sites. In this way, N application rate was significantly correlated with growth and development of sunflower under a variety of climatic conditions. Keeping in view such relationship, the N dose can be optimized for sunflower crop in a particular region to maximize the productivity. Multilocation trails help to predict the input rates precisely while taking climatic variations into account also. In the long run, results of this study provides basis for sustainable sunflower production under changing climate.
    Matched MeSH terms: Plant Leaves/growth & development
  5. Hakim MA, Juraimi AS, Hanafi MM, Ali E, Ismail MR, Selamat A, et al.
    J Environ Biol, 2014 Mar;35(2):317-26.
    PMID: 24665756
    Selection of salt tolerant rice varieties has a huge impact on global food supply chain. Five Malaysian rice (Oryza sativa L.) varieties, MR33, MR52, MR211, MR219 and MR232 were tested in pot experiment under different salinity levels for their response in term of vegetative growth, physiological activities, development of yield components and grain yield. Rice varieties, BRRI dhan29 and IR20 were used as a salt-sensitive control and Pokkali was used as a salt-tolerant control. Three different salinity levels viz. 4, 8, and 12 dS m(-1) were used in a randomized complete block design with four replications under glass house conditions. Two Malaysia varieties, MR211 and MR232 performed better in terms of vegetative growth (plant height, leaf area plant(-1), number of tillers plant(-1), dry matter accumulation plant(-1)), photosynthetic rate, transpiration rate, yield components, grain yield and injury symptoms. While, MR33, MR52 and MR219 verities were able to withstand salinity stress over salt-sensitive control, BRRI dhan29 and IR20.
    Matched MeSH terms: Plant Leaves/growth & development
  6. Zain NA, Ismail MR, Mahmood M, Puteh A, Ibrahim MH
    Molecules, 2014;19(2):1795-819.
    PMID: 24504074 DOI: 10.3390/molecules19021795
    The use of periodical water stress and potassium fertilization may enhance rice tolerance to drought stress and improve the crop's instantaneous water use efficiency without much yield reduction. This study was conducted to assess the effects of different periodical water stress combined with potassium fertilization regimes on growth, yield, leaf gas exchanges and biochemical changes in rice grown in pots and compare them with standard local rice grower practices. Five treatments including (1) standard local grower's practice (control, 80CF = 80 kg K2O/ha + control flooding); (2) 120PW15 = 120 kg K2O/ha + periodical water stress for 15 days; (3) 120DS15V = 120 kg K2O/ha + drought stress for 15 days during the vegetative stage; (4) 120DS25V = 120 kg K2O/ha + drought stress for 25 days and (5) 120DS15R = 120 kg K2O/ha + drought stress for 15 days during the reproductive stage, were evaluated in this experiment. Control and 120PW15 treatments were stopped at 100 DAS, and continuously saturated conditions were applied until harvest. It was found that rice under 120PW15 treatment showed tolerance to drought stress evidenced by increased water use efficiency, peroxidase (POX), catalase (CAT) and proline levels, maximum efficiency of photosystem II (fv/fm) and lower minimal fluorescence (fo), compared to other treatments. Path coefficient analysis revealed that most of parameters contribute directly rather than indirectly to rice yield. In this experiment, there were four factors that are directly involved with rice yield: grain soluble sugar, photosynthesis, water use efficiency and total chlorophyll content. The residual factors affecting rice yield are observed to be quite low in the experiment (0.350), confirming that rice yield was mostly influenced by the parameters measured during the study.
    Matched MeSH terms: Plant Leaves/growth & development
  7. 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*
  8. Zohner CM, Mo L, Renner SS, Svenning JC, Vitasse Y, Benito BM, et al.
    Proc Natl Acad Sci U S A, 2020 06 02;117(22):12192-12200.
    PMID: 32393624 DOI: 10.1073/pnas.1920816117
    Late-spring frosts (LSFs) affect the performance of plants and animals across the world's temperate and boreal zones, but despite their ecological and economic impact on agriculture and forestry, the geographic distribution and evolutionary impact of these frost events are poorly understood. Here, we analyze LSFs between 1959 and 2017 and the resistance strategies of Northern Hemisphere woody species to infer trees' adaptations for minimizing frost damage to their leaves and to forecast forest vulnerability under the ongoing changes in frost frequencies. Trait values on leaf-out and leaf-freezing resistance come from up to 1,500 temperate and boreal woody species cultivated in common gardens. We find that areas in which LSFs are common, such as eastern North America, harbor tree species with cautious (late-leafing) leaf-out strategies. Areas in which LSFs used to be unlikely, such as broad-leaved forests and shrublands in Europe and Asia, instead harbor opportunistic tree species (quickly reacting to warming air temperatures). LSFs in the latter regions are currently increasing, and given species' innate resistance strategies, we estimate that ∼35% of the European and ∼26% of the Asian temperate forest area, but only ∼10% of the North American, will experience increasing late-frost damage in the future. Our findings reveal region-specific changes in the spring-frost risk that can inform decision-making in land management, forestry, agriculture, and insurance policy.
    Matched MeSH terms: Plant Leaves/growth & development*
  9. Ordway EM, Asner GP
    Proc Natl Acad Sci U S A, 2020 04 07;117(14):7863-7870.
    PMID: 32229568 DOI: 10.1073/pnas.1914420117
    Nearly 20% of tropical forests are within 100 m of a nonforest edge, a consequence of rapid deforestation for agriculture. Despite widespread conversion, roughly 1.2 billion ha of tropical forest remain, constituting the largest terrestrial component of the global carbon budget. Effects of deforestation on carbon dynamics in remnant forests, and spatial variation in underlying changes in structure and function at the plant scale, remain highly uncertain. Using airborne imaging spectroscopy and light detection and ranging (LiDAR) data, we mapped and quantified changes in forest structure and foliar characteristics along forest/oil palm boundaries in Malaysian Borneo to understand spatial and temporal variation in the influence of edges on aboveground carbon and associated changes in ecosystem structure and function. We uncovered declines in aboveground carbon averaging 22% along edges that extended over 100 m into the forest. Aboveground carbon losses were correlated with significant reductions in canopy height and leaf mass per area and increased foliar phosphorus, three plant traits related to light capture and growth. Carbon declines amplified with edge age. Our results indicate that carbon losses along forest edges can arise from multiple, distinct effects on canopy structure and function that vary with edge age and environmental conditions, pointing to a need for consideration of differences in ecosystem sensitivity when developing land-use and conservation strategies. Our findings reveal that, although edge effects on ecosystem structure and function vary, forests neighboring agricultural plantations are consistently vulnerable to long-lasting negative effects on fundamental ecosystem characteristics controlling primary productivity and carbon storage.
    Matched MeSH terms: Plant Leaves/growth & development
  10. Stephenson NL, Das AJ, Condit R, Russo SE, Baker PJ, Beckman NG, et al.
    Nature, 2014 Mar 6;507(7490):90-3.
    PMID: 24429523 DOI: 10.1038/nature12914
    Forests are major components of the global carbon cycle, providing substantial feedback to atmospheric greenhouse gas concentrations. Our ability to understand and predict changes in the forest carbon cycle--particularly net primary productivity and carbon storage--increasingly relies on models that represent biological processes across several scales of biological organization, from tree leaves to forest stands. Yet, despite advances in our understanding of productivity at the scales of leaves and stands, no consensus exists about the nature of productivity at the scale of the individual tree, in part because we lack a broad empirical assessment of whether rates of absolute tree mass growth (and thus carbon accumulation) decrease, remain constant, or increase as trees increase in size and age. Here we present a global analysis of 403 tropical and temperate tree species, showing that for most species mass growth rate increases continuously with tree size. Thus, large, old trees do not act simply as senescent carbon reservoirs but actively fix large amounts of carbon compared to smaller trees; at the extreme, a single big tree can add the same amount of carbon to the forest within a year as is contained in an entire mid-sized tree. The apparent paradoxes of individual tree growth increasing with tree size despite declining leaf-level and stand-level productivity can be explained, respectively, by increases in a tree's total leaf area that outpace declines in productivity per unit of leaf area and, among other factors, age-related reductions in population density. Our results resolve conflicting assumptions about the nature of tree growth, inform efforts to undertand and model forest carbon dynamics, and have additional implications for theories of resource allocation and plant senescence.
    Matched MeSH terms: Plant Leaves/growth & development
  11. Cristancho RJ, Hanafi MM, Omar SR, Rafii MY
    Plant Biol (Stuttg), 2011 Mar;13(2):333-42.
    PMID: 21309980 DOI: 10.1111/j.1438-8677.2010.00378.x
    Aluminium (Al) phytotoxicity is an important soil constraint that limits crop yield. The objectives of this study were to investigate how growth, physiology, nutrient content and organic acid concentration is affected by Al, and to assess the degree of Al tolerance in different oil palm progeny (OPP). Four OPPs ['A' (Angola dura × Angola dura), 'B' (Nigerian dura × Nigerian dura), 'C' (Deli dura × AVROS pisifera) and 'D' (Deli dura × Dumpy AVROS pisifera)] were grown in different Al concentrations (0, 100 and 200 μm) in aerated Hoagland solution, pH 4.4, for 80 days. We observed a severe reduction (57.5%) in shoot dry weight, and root tips were reduced by 46.5% in 200 μm Al. In 'B' and 'C', the majority of macro- and micronutrients in plants were reduced significantly by 200 μm Al, with Mg being lowered by more than 50% in roots and shoots. The 200 μm Al treatment resulted in a 56.50% reduction in total leaf area, a 20% reduction in net photosynthesis and a 17% reduction in SPAD chlorophyll value in the third leaf. Root tips (0-5 mm) showed a significant increase in oxalic acid content with increasing Al concentration (∼ 5.86-fold); progeny 'A' had the highest concentration of oxalic acid. There was a significant interaction between Al concentration × OPP on total leaf number, root volume, lateral root length, Mg and K in root and shoot tissues, and Ca and N in shoots. The OPPs could be ranked in their tolerance to Al as: 'A' > 'D' > 'B' > 'C'.
    Matched MeSH terms: Plant Leaves/growth & development
  12. Sukiran NL, Ma JC, Ma H, Su Z
    Plant Mol Biol, 2019 Jan;99(1-2):161-174.
    PMID: 30604322 DOI: 10.1007/s11103-018-0810-1
    KEY MESSAGE: Morphological and transcriptomic evidences provide us strong support for the function of ANAC019 in reproductive development under drought stress. Plants are sensitive to drought conditions, particularly at the reproductive stage. Several studies have reported drought effects on crop reproductive development, but the molecular mechanism underlying drought response during reproduction is still unclear. A recent study showed that drought induces in Arabidopsis inflorescence increased expression of many genes, including ANAC019. However, the function of ANAC019 in drought response during reproductive development has not been characterized. Here, we report an investigation of the ANAC019 function in the response to drought during reproduction. ANAC019 is preferentially expressed in the inflorescence compared with the leaf, suggesting possible roles in regulating both stress response and flower development. The anac019 mutant was more sensitive to drought than WT plant, and exhibited a delay in recovery of floral organ development under prolonged drought stress. Moreover, many fewer genes were differentially expressed in the anac019 inflorescence under drought than that of WT, suggesting that the mutant was impaired in drought-induced gene expression. The genes affected by ANAC019 were associated with stress and hormone responses as well as floral development. In particular, the expression levels of several key drought-induced genes, DREB2A, DREB2B, ARF2, MYB21 and MYB24, were dramatically reduced in the absence of ANAC019, suggesting that ANAC019 is an upstream regulator these genes for drought response and flower development. These results provide strong support for the potential function of ANAC019 in reproductive development under drought stress.
    Matched MeSH terms: Plant Leaves/growth & development
  13. Ling Q, Sadali NM, Soufi Z, Zhou Y, Huang B, Zeng Y, et al.
    Nat Plants, 2021 05;7(5):655-666.
    PMID: 34007040 DOI: 10.1038/s41477-021-00916-y
    The maturation of green fleshy fruit to become colourful and flavoursome is an important strategy for plant reproduction and dispersal. In tomato (Solanum lycopersicum) and many other species, fruit ripening is intimately linked to the biogenesis of chromoplasts, the plastids that are abundant in ripe fruit and specialized for the accumulation of carotenoid pigments. Chromoplasts develop from pre-existing chloroplasts in the fruit, but the mechanisms underlying this transition are poorly understood. Here, we reveal a role for the chloroplast-associated protein degradation (CHLORAD) proteolytic pathway in chromoplast differentiation. Knockdown of the plastid ubiquitin E3 ligase SP1, or its homologue SPL2, delays tomato fruit ripening, whereas overexpression of SP1 accelerates ripening, as judged by colour changes. We demonstrate that SP1 triggers broader effects on fruit ripening, including fruit softening, and gene expression and metabolism changes, by promoting the chloroplast-to-chromoplast transition. Moreover, we show that tomato SP1 and SPL2 regulate leaf senescence, revealing conserved functions of CHLORAD in plants. We conclude that SP1 homologues control plastid transitions during fruit ripening and leaf senescence by enabling reconfiguration of the plastid protein import machinery to effect proteome reorganization. The work highlights the critical role of chromoplasts in fruit ripening, and provides a theoretical basis for engineering crop improvements.
    Matched MeSH terms: Plant Leaves/growth & development
  14. Cheah BH, Jadhao S, Vasudevan M, Wickneswari R, Nadarajah K
    PLoS One, 2017;12(10):e0186382.
    PMID: 29045473 DOI: 10.1371/journal.pone.0186382
    A cross between IR64 (high-yielding but drought-susceptible) and Aday Sel (drought-tolerant) rice cultivars yielded a stable line with enhanced grain yield under drought screening field trials at International Rice Research Institute. The major effect qDTY4.1 drought tolerance and yield QTL was detected in the IR77298-14-1-2-10 Backcrossed Inbred Line (BIL) and its IR87705-7-15-B Near Isogenic Line (NIL) with 93.9% genetic similarity to IR64. Although rice yield is extremely susceptible to water stress at reproductive stage, currently, there is only one report on the detection of drought-responsive microRNAs in inflorescence tissue of a Japonica rice line. In this study, more drought-responsive microRNAs were identified in the inflorescence tissues of IR64, IR77298-14-1-2-10 and IR87705-7-15-B via next-generation sequencing. Among the 32 families of inflorescence-specific non-conserved microRNAs that were identified, 22 families were up-regulated in IR87705-7-15-B. Overall 9 conserved and 34 non-conserved microRNA families were found as drought-responsive in rice inflorescence with 5 conserved and 30 non-conserved families induced in the IR87705-7-15-B. The observation of more drought-responsive non-conserved microRNAs may imply their prominence over conserved microRNAs in drought response mechanisms of rice inflorescence. Gene Ontology annotation analysis on the target genes of drought-responsive microRNAs identified in IR87705-7-15-B revealed over-representation of biological processes including development, signalling and response to stimulus. Particularly, four inflorescence-specific microRNAs viz. osa-miR5485, osa-miR5487, osa-miR5492 and osa-miR5517, and two non-inflorescence specific microRNAs viz. osa-miR169d and osa-miR169f.2 target genes that are involved in flower or embryonic development. Among them, osa-miR169d, osa-miR5492 and osa-miR5517 are related to flowering time control. It is also worth mentioning that osa-miR2118 and osa-miR2275, which are implicated in the biosynthesis of rice inflorescence-specific small interfering RNAs, were induced in IR87705-7-15-B but repressed in IR77298-14-1-2-10. Further, gene search within qDTY4.1 QTL region had identified multiple copies of NBS-LRR resistance genes (potential target of osa-miR2118), subtilisins and genes implicated in stomatal movement, ABA metabolism and cuticular wax biosynthesis.
    Matched MeSH terms: Plant Leaves/growth & development
  15. Ghasemzadeh A, Jaafar HZ, Karimi E, Ibrahim MH
    BMC Complement Altern Med, 2012 Nov 23;12:229.
    PMID: 23176249 DOI: 10.1186/1472-6882-12-229
    BACKGROUND: The increase in atmospheric CO(2) concentration caused by climate change and agricultural practices is likely to affect biota by producing changes in plant growth, allocation and chemical composition. This study was conducted to evaluate the combined effect of the application of salicylic acid (SA, at two levels: 0 and 10-3 M) and CO(2) enrichment (at two levels: 400 and 800 μmol·mol-1) on the production and antioxidant activities of anthocyanin, flavonoids and isoflavonoids from two Malaysian ginger varieties, namely Halia Bentong and Halia Bara.

    METHODS: High-performance liquid chromatography (HPLC) with photodiode array detection and mass spectrometry was employed to identify and quantify the flavonoids and anthocyanins in the ginger extracts. The antioxidant activity of the leaf extracts was determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and thiobarbituric acid (TBA) assays. The substrate specificity of chalcone synthase, the key enzyme for flavonoid biosynthesis, was investigated using the chalcone synthase (CHS) assay.

    RESULTS: CO(2) levels of 800 μmol·mol-1 significantly increased anthocyanin, rutin, naringenin, myricetin, apigenin, fisetin and morin contents in ginger leaves. Meanwhile, the combined effect of SA and CO(2) enrichment enhanced anthocyanin and flavonoid production compared with single treatment effects. High anthocyanin content was observed in H Bara leaves treated with elevated CO(2) and SA. The highest chalcone synthase (CHS) activity was observed in plants treated with SA and CO(2) enrichment. Plants not treated with SA and kept under ambient CO(2) conditions showed the lowest CHS activity. The highest free radical scavenging activity corresponded to H Bara treated with SA under high CO(2) conditions, while the lowest activity corresponded to H Bentong without SA treatment and under atmospheric CO(2) levels. As the level of CO(2) increased, the DPPH activity increased. Higher TBA activity was also recorded in the extracts of H Bara treated with SA and grown under high CO(2) conditions.

    CONCLUSIONS: The biological activities of both ginger varieties were enhanced when the plants were treated with SA and grown under elevated CO(2) concentration. The increase in the production of anthocyanin and flavonoids in plants treated with SA could be attributed to the increase in CHS activity under high CO(2) levels.

    Matched MeSH terms: Plant Leaves/growth & development
  16. Monowar T, Rahman MS, Bhore SJ, Raju G, Sathasivam KV
    Biomed Res Int, 2019;2019:6951927.
    PMID: 30868071 DOI: 10.1155/2019/6951927
    Secondary bioactive compounds of endophytes are inevitable biomolecules of therapeutical importance. In the present study, secondary metabolites profiling of an endophytic bacterial strain, Acinetobacter baumannii, were explored using GC-MS study. Presence of antioxidant substances and antioxidant properties in chloroform (CHL), diethyl ether (DEE), and ethyl acetate (EA) crude extracts of the endophytic bacteria were studied. Total phenolic content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and ferrous ion chelating assay were evaluated. A total of 74 compounds were identified from the GC-MS analysis of the EA extract representing mostly alkane compounds followed by phenols, carboxylic acids, aromatic heterocyclic compounds, ketones, aromatic esters, aromatic benzenes, and alkenes. Among the two phenolic compounds, namely, phenol, 2,4-bis(1,1-dimethylethyl)- and phenol, 3,5-bis(1,1-dimethylethyl)-, the former was found in abundance (11.56%) while the latter was found in smaller quantity (0.14%). Moreover, the endophytic bacteria was found to possess a number of metal ions including Fe(II) and Cu(II) as 1307.13 ± 2.35 ppb and 42.38 ± 0.352 ppb, respectively. The extracts exhibited concentration dependent antioxidant and prooxidant properties at high and low concentrations, respectively. The presence of phenolic compounds and metal ions was believed to play an important role in the antioxidant and prooxidant potentials of the extracts. Further studies are suggested for exploring the untapped resource of endophytic bacteria for the development of novel therapeutic agents.
    Matched MeSH terms: Plant Leaves/growth & development
  17. Haddadi F, Aziz MA, Abdullah SN, Tan SG, Kamaladini H
    Molecules, 2015 Feb 23;20(3):3647-66.
    PMID: 25711423 DOI: 10.3390/molecules20033647
    An Agrobacterium-mediated transformation method was applied to introduce the luciferase reporter gene under the control of the CaMV35S promoter in the pGreen0049 binary vector into strawberry cv. Camarosa. The in vitro regeneration system of strawberry leaves to be used in the transformation was optimized using different TDZ concentrations in MS medium. TDZ at 16 µM showed the highest percentage (100%) of shoot formation and the highest mean number of shoots (24) produced per explant. Studies on the effects of different antibiotics, namely timentin, cefotaxime, carbenicillin and ampicillin, on shoot regeneration of strawberry leaf explants showed the best shoot regeneration in the presence of 300 mg/L timentin and 150 mg/L cefotaxime. Assessment of the different factors affecting Agrobacterium mediated-transformation of strawberry with the luciferase gene showed the highest efficiency of putative transformant production (86%) in the treatment with no preculture, bacterial OD600 of 0.6 and the addition of 150 mg/L cefotaxime in the pre-selection and selection media. The presence of the luciferase gene in the plant genome was verified by the luciferase reporter gene assay, nested PCR amplification and dot blot of genomic DNA isolated from the young leaves of each putatively transformed plantlet.
    Matched MeSH terms: Plant Leaves/growth & development*
  18. Butt M, Sattar A, Abbas T, Hussain R, Ijaz M, Sher A, et al.
    PLoS One, 2021;16(11):e0257893.
    PMID: 34735478 DOI: 10.1371/journal.pone.0257893
    Climate change is causing soil salinization, resulting in huge crop losses throughout the world. Multiple physiological and biochemical pathways determine the ability of plants to tolerate salt stress. Chili (Capsicum annum L.) is a salt-susceptible crop; therefore, its growth and yield is negatively impacted by salinity. Irreversible damage at cell level and photo inhibition due to high production of reactive oxygen species (ROS) and less CO2 availability caused by water stress is directly linked with salinity. A pot experiment was conducted to determine the impact of five NaCl salinity levels, i.e., 0,1.5, 3.0, 5.0 and 7.0 dS m-1 on growth, biochemical attributes and yield of two chili genotypes ('Plahi' and 'A-120'). Salinity stress significantly reduced fresh and dry weight, relative water contents, water use efficiency, leaf osmotic potential, glycine betaine (GB) contents, photosynthetic rate (A), transpiration rate (E), stomatal conductance (Ci), and chlorophyll contents of tested genotypes. Salinity stress significantly enhanced malondialdehyde (MDA) contents and activities of the enzymatic antioxidants such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). In addition, increasing salinity levels significantly reduced the tissue phosphorus and potassium concentrations, while enhanced the tissue sodium and chloride concentrations. Genotype 'Plahi' had better growth and biochemical attributes compared to 'A-120'. Therefore, 'Plahi' is recommended for saline areas to improve chili production.
    Matched MeSH terms: Plant Leaves/growth & development
  19. Panhwar QA, Naher UA, Radziah O, Shamshuddin J, Razi IM
    Molecules, 2015 Feb 20;20(3):3628-46.
    PMID: 25710843 DOI: 10.3390/molecules20033628
    Aluminum toxicity is widely considered as the most important limiting factor for plants growing in acid sulfate soils. A study was conducted in laboratory and in field to ameliorate Al toxicity using plant growth promoting bacteria (PGPB), ground magnesium limestone (GML) and ground basalt. Five-day-old rice seedlings were inoculated by Bacillus sp., Stenotrophomonas maltophila, Burkholderia thailandensis and Burkholderia seminalis and grown for 21 days in Hoagland solution (pH 4.0) at various Al concentrations (0, 50 and 100 μM). Toxicity symptoms in root and leaf were studied using scanning electron microscope. In the field, biofertilizer (PGPB), GML and basalt were applied (4 t·ha-1 each). Results showed that Al severely affected the growth of rice. At high concentrations, the root surface was ruptured, leading to cell collapse; however, no damages were observed in the PGPB inoculated seedlings. After 21 days of inoculation, solution pH increased to >6.0, while the control treatment remained same. Field study showed that the highest rice growth and yield were obtained in the bio-fertilizer and GML treatments. This study showed that Al toxicity was reduced by PGPB via production of organic acids that were able to chelate the Al and the production of polysaccharides that increased solution pH. The release of phytohormones further enhanced rice growth that resulted in yield increase.
    Matched MeSH terms: Plant Leaves/growth & development
  20. Taha RM, Wafa SN
    ScientificWorldJournal, 2012;2012:359413.
    PMID: 22593677 DOI: 10.1100/2012/359413
    Tissue culture studies of Celosia cristata were established from various explants and the effects of various hormones on morphogenesis of this species were examined. It was found that complete plant regeneration occurred at highest percentage on MS medium supplemented with 2.0 mg/L NAA and 1.5 mg/L BAP, with the best response showed by shoot explants. In vitro flowering was observed on MS basal medium after six weeks. The occurrence of somaclonal variation and changes in cellular behavior from in vivo and in vitro grown plants were investigated through cytological studies and image analysis. It was observed that Mitotic Index (MI), mean chromosome numbers, and mean nuclear to cell area ratio of in vitro root meristem cells were slightly higher compared to in vivo values. However, in vitro plants produced lower mean cell areas but higher nuclear areas when compared to in vivo plants. Thus, no occurrence of somaclonal variation was detected, and this was supported by morphological features of the in vitro plants.
    Matched MeSH terms: Plant Leaves/growth & development
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