Metallothionein (MT) Expression and SEM-EDX Mapping on Cymodocea serrulata Seagrass (original) (raw)
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Biodiversitas Journal of Biological Diversity
Runoff of heavy metals as a result of urban and industrial development is a potential threat for seagrass populations in the coast. The objectives of this study were to study the anatomical changes in the tissues of roots, rhizomes, and leaves of seagrass Cymodocea serrulata in response to treatment with different concentrations of lead (Pb) for different time durations. This experiment used heavy metal Pb from a solution of Pb (NO3) 2with a concentration of 0 ppm, 5 ppm, 10 ppm, and 15 ppm and the treatment period extended up to 4 weeks with 3 replications. Analysis of changes in anatomical features showed that exodermis and endodermis cells in the roots thickened as lead concentration increased. The air spaces in the root cortex and rhizome also widened. Thickening of cell walls occurred in the epidermis and endodermis of rhizome. Likewise, in the leaves, thickening occurred in the upper and lower cuticle and also the upper and lower epidermis. In general, changes in anatomical features of root, rhizome, and leaves were observed in response to increasing lead concentrations. The results showed that C. serrulata developed some level of tolerance to heavy metals, especially lead.
Aquatic Science and Technology, 2014
Seagrass Thalassia hemprichii is used to study lead (Pb) metal accumulation and synthesis of phytochelatin (PC) and glutathione (GSH) as defense mechanisms against lead toxicity. The plants were exposed by lead (Pb (NO 3) 2) metal in some concentrations (0, 5, 15 and 25 ppm) for some periods of time (1, 2, 3 and 4 weeks). The contents of lead (Pb), phytochelatin (PC) and glutathione (GSH) are analyzed in leaf and root tissue. Lead accumulation in seagrass depends on the greatness of metal concentration and length of exposure time where the root accumulates lead higher than the leaf. Glutathione is produced higher in the root during lead exposure, while phytochelatin is produced in week 1 and 2. Then, production of phytochelatin turns to higher in the leaf in week 3, although it decreases in week 4.
2016
Thalassia hemprichii was used to study the accumulation and deposition of lead in tissues of roots, rhizomes and leaves, as well as their impact on changes in the anatomy of that tissue. This plant was exposed to lead from Pb(NO3)2 solution at the concentrations of 0, 5, 15 and 25 ppm for 4 weeks. Lead was absorbed and deposited in apoplast in the cell walls and in the spaces between cells in tissues of roots, rhizomes and leaves. Anatomical structure analysis shows that the cell wall of endodermis and exodermis root layer became thick along with the increase of lead concentration. Air spaces in the cortex of roots and rhizomes widened. Cell wall thickening occurs also in the epidermis and endodermis of rhizome also at cuticle and epidermis of leaves. In general, changes in the anatomy of the roots, rhizomes and leaves followed to the increasing of lead concentration. This is one strategy for minimizing the translocation of lead in other tissue of T. hemprichii.
Metals in Tropical Seagrass-Accumulation of Mercury and Lead
Accumulation of mercury and lead were analysed in seven tropical seagrass species: Enhalus acoroides, Halophila minor, Halophila spinulosa, Halophila ovalis, Thalassia hemprichii, Halodule uninervis and Cymodocea serrulata at Pulai Estuary, Johor Straits, Malaysia. Analyses of all seagrass samples were carried out using Perkin Elmer Atomic Absorption Spectrophotometer Model AAnalyst 400 and Pearson's correlation coefficients of metal concentrations were determined using SPSS version 16. The concentrations of Hg and Pb in different tissues of the seagrass are in the range of 0.1-69 µg/gDW and 81-249 µg/gDW respectively. There are significant correlations between the accumulation of Pb in roots-rhizomes, rhizomesleaves and leaves-roots for Enhalus acoroides, Halophila minor, Halophila ovalis, Thalassia hemprichii and Halodule uninervis. Meanwhile for Hg, there are significant correlations among plant parts for Halophila ovalis.
Trace metal content in the seagrass Cymodocea nodosa: Differential accumulation in plant organs
Aquatic Botany, 2011
Differences in the accumulation of seven metallic elements, including micronutrients (Cu, Fe, Mn, Ni and Zn) and non-essential elements (Cd and Pb) among plant organs (leaves, roots and rhizomes) were examined in the seagrass Cymodocea nodosa. Samples were taken from two coastal bays (Catalonia, Western Mediterranean), with a total of nine sampling sites encompassing different levels of metal availability. Metal content was generally higher in uptake organs (leaves and roots) than in rhizomes. However, accumulation in leaves and roots varied between elements. While Cd, Mn and Zn preferentially accumulate in leaves, Fe and Pb accumulate in roots and Cu and Ni in both. There were common spatial (between sites) trends in Cd, Mn, Cu and Zn accumulation in the three organs. However, these spatial trends varied according to the organ considered in the case of Fe, Pb, and Ni. Therefore, assessment of within-plant variability is strongly recommended prior to the use of C. nodosa for biomonitoring purposes, at least for Fe, Pb, and Ni.
The aims of this study were: (i) to determine the content of copper and cadmium into seagrass Halodule pinifolia and Halophila minor from the Setiu Wetland and Setiu River estuary, Terengganu and (ii) to study the bioaccumulation response of the seagrass towards the metals. The contents of the two metals in leaves and root-rhizomes of the seagrasses collected from the field study samples were determined. in laboratory experiments, the two seagrass were exposed to sediments spiked with four different concentrations of copper (56.44 µg/g, 112.87 µg/g, 225.74 µg/g and 451.49 µg/g) or cadmium (36.00 µg/g, 72.00 µg/g, 144.00 µg/g and 288.00 µg/g). The exposure period was for 8 weeks during which plants were sampled weekly and the metal concentrations in leaves and root-rhizomes determined. The content of heavy metals was measured by aaS. Pearson Correlation were used to determine the relationship between the accumulation of heavy metals in root-rhizomes and leaves. in the exposure experiments, Cu and Cd were bioaccumulated, with tissue concentration generally increased with duration of exposure and increase in sediment metal concentrations. Metal concentrations in root-rhizomes were higher than in leaves for both species. in Halodule pinifolia, the mean copper in root-rhizomes and leaves were 120.86 ± 6.79 µg/g and 96.99 ± 8.58 µg/g respectively while the mean cadmium concentration in root-rhizomes was 38.40 ± 4.71 µg/g and in leaves was 36.08 ± 3.21 µg/g. In Halophila minor, the mean copper concentration in root-rhizomes and leaves were 49.53 ± 7.67 µg/g and 35.40 ± 6.52 µg/g respectively. The mean cadmium concentration in rootrhizomes was 30.34 ± 3.15 µg/g and in leaves was 29.71 ± 2.64 µg/g. Generally, the metals in rootrhizomes showed strong correlation with the metals in leaves. Halodule pinifolia and Halophila minor exposed to high concentrations of copper were dead in week 4 and 5 respectively, while exposure to high concentrations of cadmium resulted in death of plants in week 4. oxygen produced by both seagrass species also began showed negative values in week 4. For the field study, the highest concentrations of Cd and Cu in Halodule pinifolia and Halophila minor were found for the month of october 2004 and month of November respectively.
Tropical Seagrass as a Bioindicator of Metal Accumulation
Sains Malaysiana
Seven species of tropical seagrass found at seagrass bed located in Johor, Malaysia were analysed for As, Cu and Cd accumulation. The species were identified as Enhalus acoroides, Halophila minor, Halophila spinulosa, Halophila ovalis, Thalassia hemprichii, Halodule uninervis and Cymodocea serrulata. Seagrass plant is rapidly becoming one of the methods to determine the overall health condition of aquatic environment. Each seagrass samples were collected and divided into three parts i.e roots, rhizomes and leaves. Samples were grinded, digested and the correlation between each part was analysed using SPSS version 16. Each part of seagrass tissues have the ability to assimilate metals for example the concentration of As, Cu and Cd in tropical seagrass were in the range of 5-48, 6-60 and 10-69 µg/gDW, respectively. Halophila minor and Halophila ovalis indicates positive correlations to translocate metals (As, Cu and Cd) in plants parts (leaves-rhizomes, rhizomes-roots and roots-leaves). Seagrass can accumulate metals depending on pollution that occur, seasonal variation and internal capabilities to translocate metals. The seagrass species especially Halophila ovalis and Halophila minor can act as bioindicator for metal pollution.
Heavy metal impact on growth and leaf asymmetry of seagrass, Halophila ovalis
A major threat to the seagrass ecosystem worldwide, due to the growth of human population along the coastal environment, is pollution or contamination resulting from industrial and urban development. Although seagrass appears to be rather resistant to heavy metal contaminants, these substances may possibly harm some components of the seagrass and such responses have not been examined to a significant extent. Lead (Pb) and copper (Cu) was tested on seagrass, Halophila ovalis, to see whether the metals are environmental stressor on the seagrass. Reduced growth rate of the seagrass was observed both in Pb and Cu treatments. Leaf size of the plant also reduced as the metal concentrations increased and when the plants were exposed to the heavy metal for longer duration. An increased leaf asymmetry was more apparent at the 2 mg/L Cu treatment and no significant increases in fluctuating asymmetry were found in Pb treatment or in low levels of Cu treatment. Further discussion were made in v...
Marine Biotechnology, 2006
A metallothionein (MT) gene was isolated for the first time from Javanese medaka, Oryzias javanicus, which shows high adaptability from freshwater to seawater. The full-length cDNA of MT from O. javanicus (OjaMT) comprises 349 bp, excluding the poly(A) + stretch, and codes for a total of 60 amino acids. The positions of cysteine residues are highly conserved. The pattern of OjaMT expression induced by six heavy metals was analyzed via realtime quantitative polymerase chain reaction (PCR). The level of hepatic OjaMT mRNA was increased in a dose-dependent manner by Ag, Cd, Cu, and Zn after 24 h of exposure. However, after Cr and Ni exposure, a significant decrease in OjaMT levels was observed. Cadmium-induced OjaMT expression was detectable in fishes as young as 3 months. After Cd exposure, OjaMT induction was prominent in intestine and liver and moderate in muscle and gill.