The Experts below are selected from a list of 10002 Experts worldwide ranked by ideXlab platform
L. Kryger - One of the best experts on this subject based on the ideXlab platform.
-
Effects of mangrove soil ageing on the accumulation of hydrogen sulphide in roots ofAvicennia spp
Biogeochemistry, 1996Co-Authors: L. KrygerAbstract:The possibility for accumulation of hydrogen sulphide gas in roots of mangroves ( Avicennia spp) which had colonized reclaimed coastal areas in Singapore was investigated using a simple potentiometric technique preceded by an extraction step. The study showed that detectable amounts of hydrogen sulphide gas were present in the underground cable roots of the mangroves and that the concentrations increased with the age of the plant. Furthermore concentrations of hydrogen sulphide in the roots were 30–40 times higher than the concentrations of the gas which were simultaneously generated by anaerobic processes in the surrounding, ageing mangrove sediment. The reasons for these patterns and their possible impact on the succession of Avicennia spp by a different type of mangrove, Rhizophora spp, are discussed.
Jisheng Ruan - One of the best experts on this subject based on the ideXlab platform.
-
streptomyces Avicenniae sp nov a novel actinomycete isolated from the rhizosphere of the mangrove plant Avicennia mariana
International Journal of Systematic and Evolutionary Microbiology, 2009Co-Authors: Jing Xiao, Yin Wang, Yingxue Luo, Shujie Xie, Jisheng RuanAbstract:A novel isolate, designated strain MCCC 1A01535T, belonging to the genus Streptomyces was isolated from the rhizosphere of the mangrove plant Avicennia mariana from Fujian Province, south China. Characterization of the isolate was based on a polyphasic approach. Pairwise comparison of 16S rRNA gene sequences revealed that strain MCCC 1A01535T shared 97.7 and 97.5 % sequence similarities to Streptomyces specialis GW41-1564T and Streptomyces hainanensis YIM47672T, respectively, its most closely related neighbours, whereas the DNA–DNA relatedness value between strains MCCC 1A01535T and GW41-1564T was 50.2 %. The major fatty acids of strain MCCC 1A01535T were iso-C16 : 0, C16 : 0 and anteiso-C15 : 0. These differed from the fatty acid compositions of related strains. Strain MCCC 1A01535T exhibited an unusual menaquinone system that comprised MK-10(H6) as the predominant component and moderate amounts of MK-9(H6), MK-9(H8) and MK-10(H8); minor amounts of MK-9(H4), MK-10(H4), MK-9(H10) and MK-10(H10) were also present. Based on its chemotaxonomic, phenotypic and genotypic characteristics, strain MCCC 1A01535T is considered to represent a novel species of the genus Streptomyces, for which the name Streptomyces Avicenniae sp. nov. is proposed. The type strain is MCCC 1A01535T (=DSM 41943T=CGMCC 4.5510T).
Suhua Shi - One of the best experts on this subject based on the ideXlab platform.
-
re evaluation of phylogenetic relationships among species of the mangrove genus Avicennia from indo west pacific based on multilocus analyses
PLOS ONE, 2016Co-Authors: Norman C Duke, Lishi Huang, Yelin Huang, Renchao Zhou, Yuchen Yang, Yuxiang Zhu, Zhang Zhang, Cairong Zhong, Suhua ShiAbstract:Avicennia L. (Avicenniaceae), one of the most diverse mangrove genera, is distributed widely in tropical and subtropical intertidal zones worldwide. Five species of Avicennia in the Indo-West Pacific region have been previously described. However, their phylogenetic relationships were determined based on morphological and allozyme data. To enhance our understanding of evolutionary patterns in the clade, we carried out a molecular phylogenetic study using wide sampling and multiple loci. Our results support two monophyletic clades across all species worldwide in Avicennia: an Atlantic-East Pacific (AEP) lineage and an Indo-West Pacific (IWP) lineage. This split is in line with biogeographic distribution of the clade. Focusing on the IWP branch, we reconstructed a detailed phylogenetic tree based on sequences from 25 nuclear genes. The results identified three distinct subclades, (1) A. rumphiana and A. alba, (2) A. officinalis and A. integra, and (3) the A. marina complex, with high bootstrap support. The results strongly corresponded to two morphological traits in floral structure: stigma position in relation to the anthers and style length. Using Bayesian dating methods we estimated diversification of the IWP lineage was dated to late Miocene (c. 6.0 million years ago) and may have been driven largely by the fluctuating sea levels since that time.
-
MOLECULAR EVIDENCE FOR NATURAL HYBRIDIZATION IN THE MANGROVE GENUS Avicennia
2014Co-Authors: Lishi Huang, Yelin Huang, Suhua Shi, Renchao ZhouAbstract:Hybridization has been observed in several multi-species genera of mangroves; however, there has been no report on hybridization in Avicennia in the Indo-West Pacific region. In this study, we sequenced 5 low-copy nuclear genes of Avicennia marina, A. rumphiana and 2 individuals of their putative hybrid in the Southeast Asia region to test the hypothesis of natural hybridization between these 2 species. We demonstrated that both putative hybrid individuals possessed two types of sequences at each of the 5 genes, perfectly corresponding to those of A. marina and A. rumphiana, confirming the hybridization between these 2 Avicennia species, and the 2 hybrid individuals are most likely F1 hybrids. Sequencing of the chloroplast trnH-psbA regions indicated that A. marina was the maternal parent of the two hybrid individuals.
Mark W Hester - One of the best experts on this subject based on the ideXlab platform.
-
water use characteristics of black mangrove Avicennia germinans communities along an ecotone with marsh at a northern geographical limit
Ecohydrology, 2014Co-Authors: Ken W Krauss, Karen L Mckee, Mark W HesterAbstract:Mangroves are expanding into warm temperate-zone salt marsh communities in several locations globally. Although scientists have discovered that expansion might have modest effects on ecosystem functioning, water use characteristics have not been assessed relative to this transition. We measured early growing season sapflow (Js) and leaf transpiration (Tr )i nAvicennia germinans at a latitudinal limit along the northern Gulf of Mexico (Louisiana, United States) under both flooded and drained states and used these data to scale vegetation water use responses in comparison with Spartina alterniflora. We discovered strong convergence when using either Js or Tr for determining individual tree water use, indicating tight connection between transpiration and xylem water movement in small Avicennia trees. When Tr data were combined with leaf area indices for the region with the use of three separate approaches, we determined that Avicennia stands use approximately 10–13mmd –1 less water than Spartina marsh. Differences were only significant with the use of two of the three approaches, but are suggestive of net conservation of water as Avicennia expands into Spartina marshes at this location. Average Js for Avicennia trees was not influenced by flooding, but maximum Js was greater when sites were flooded. Avicennia and Spartina closest to open water (shoreline) used more water than interior locations of the same assemblages by an average of 13mmd 1 . Lower water use by Avicennia may indicate a greater overall resilience to drought relative to Spartina, such that aperiodic drought may interact with warmer winter temperatures to facilitate expansion of Avicennia in some years. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
Poppy Anjelisa Zaitun Hasibuan - One of the best experts on this subject based on the ideXlab platform.
-
Prominent Secondary Metabolites from Selected Genus of Avicennia Leaves.
Open Access Macedonian Journal of Medical Sciences, 2019Co-Authors: Mohammad Basyuni, Didi Nurhadi Illian, Meighina Atika Istiqomah, Dini Permata Sari, Arif Nuryawan, Poppy Anjelisa Zaitun Hasibuan, Sumaiyah Sumaiyah, Etti Sartina SiregarAbstract:BACKGROUND: Mangrove plants distributed in the intertidal of the tropical and subtropical region including in North Sumatra, Indonesia. The production of secondary metabolite compounds is well known to mangroves. Characterisation of prominent compounds from mangrove plants such as genus of Avicennia is required to explore for their biological and pharmacological properties of these compounds. AIM: The purpose of this research was to analyse the prominent secondary metabolites through the characterisation of phytochemical, physicochemical, and microscopic of the mangrove genus Avicennia leaves, particularly Avicennia alba, A. lanata, A. marina, and A. officinalis. METHODS: Phytochemical screening was carried out on Avicennia spp leaves to the established process. Physicochemical characters of mangrove leaves were investigated by simplicial powder consisting of moisture content, water-soluble, ethanol-soluble, ash content and ash soluble acid according to the WHO formula. Microscopic analysis on the simplicial powder was carried out based on the WHO procedure. RESULTS: The result showed that physicochemical feature displays diversity among the species and important findings on the water concentration was less than 10% as a prerequisite for the drug. The phytochemical search of simplified grain also depicted divergence among the species, only alkaloid, saponin, and triterpenoid or phytosterol were found entirely in Avicennia spp leaves. Microscopic search found a similar type of stoma in Avicennia spp leaves, namely diacytic. CONCLUSION: The prominent secondary metabolites in Avicennia spp leaves consisting of alkaloid and saponin in simplicial and triterpenoid/sterol was either in simplicial or hexane extract. The present study may provide significant pharmacological properties from mangrove Avicennia genus green foliages, which could accelerate another prospect for non-wood mangrove utilisation. nus green foliages, which could accelerate another prospect for non-wood mangrove utilization.
-
Polyisoprenoids from Avicennia marina and Avicennia lanata inhibit WiDr cells proliferation
Pharmacognosy Magazine, 2018Co-Authors: Didi Nurhadi Illian, Mohammad Basyuni, Ridha Wati, Poppy Anjelisa Zaitun HasibuanAbstract:Objectives: The current investigation was conducted to examine the anticancer effect of polyisoprenoids from Avicennia marina and Avicennia lanata leaves in WiDr cells. Selectivity index (SI), cell cycle inhibition, and apoptosis activity were evaluated. Materials and Methods: The anticancer activity of polyisoprenoids from A. marina and A. lanata leaves was determined by observing the activity of these compounds toward WiDr cells using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide assay. The SI was determined from the IC50 of the polyisoprenoid extract in normal cells (Vero) versus cancer cells (WiDr). Inhibited cell cycle and increased apoptosis were analyzed by flow cytometry. Results: Polyisoprenoid extract from A. marina and A. lanata leaves exhibited anticancer activity against WiDr cells with an IC50 of 154.987 μg/mL and 305.928 μg/mL, respectively. The polyisoprenoid extract from A. marina leaves had an SI value of 5.195 (>3) for categorization as exceptionally selective. Cell cycle analysis revealed that the inhibition occurred in the G0–G1 phase and apoptosis occurred in the early-apoptosis development. Conclusion: Polyisoprenoids from A. marina and A. lanata leaves can be used as anticancer agents against WiDr colon cancer cells. The mechanisms that underlie anticancer activity of the extract were due to by inhibiting of cell cycle and inducing of apoptosis. Abbreviations used: DMSO: Dimethylsulfoxide, MTT: 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide, PBS: Phosphate buffer saline, SDS: Sodium dodecyl sulfate.
