333,286 research outputs found

    NRT2.5 a putative sodium dependent high affinity nitrate trasnporter of zostera marina l.

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    Seagrasses are the only group of vascular plants that recolonized the marine environment, possibly the most severe habitat shift ever accomplished by flowering plants. These plants have regained functions enabling them to thrive in liquid medium with an extremely high salinity (0.5 M Na+), high alkaline conditions (pH 8.2) and very low concentration of essential nutrients as NO3- or Pi. Despite this, seagrasses form one of the highest productive and widespread ecosystems of the planet (Larkum et al., 2006). Zostera marina was the first seagrass fully sequenced and its genome reveals important insights about this secondary adaption. Comparison with land plants indicates that less than 20 % of the genes families are specific in the genome of seagrasses. Thus, adaptation to marine environment seems to be due to molecular changes of the same family genes rather that the speciation of pre-existing genes. This appears to be the case of the high affinity nitrate transporter belonging to the NRT family. In contrast to terrestrial vascular plants, where NRT2 encode high affinity NO3- transporters that operate as H+ symporters, our electrophysiological analysis indicate that in Z. marina high affinity NO3- uptake is mediated by a Na+-dependent mechanism. A detailed analysis of the Z. marina genome indicates the presence of only one gene encoding for this type of transporter: Zosma70g00300.1. Phylogenetic analysis shows that this high affinity nitrate transporter is more related to NRT2.5 than to NTRT2.1, sharing a common ancestor with both, monocot and dicot plants. We have cloned Zosma70g00300.1 and the high-affinity nitrate transporter accessory protein NAR2 (Zosma63g00220.1) in order to characterize the specific transport mechanism mediated by these proteins in Z. marina. Thus, the putative Z. marina NRT2.5 transporter could have evolved to use Na+ as a driving ion, which might be an essential adaptation of seagrasses to colonize the marine environment.MICINN (BFU2017-85117-R; BIO2016-81957-REDT) Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Field Guide to Nonindigenous Marine Fishes of Florida

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    The purpose of this field guide is to provide information on nonindigenous (i.e., non-native) fishes that have been observed in Florida’s marine waters. Introductions of non-native marine fishes into Florida’s waters could be intentional or unintentional, and are likely from a variety of sources, including aquarium releases, escape from aquaculture, loss due to extreme weather events (e.g., flooding from hurricanes), and possibly transfer with ballast water or hull-fouling. Presently the lionfishes (Pterois volitans and P. miles) are the only non-native marine fish species known to be established along the coast of Florida. All other marine fishes in this guide (except the euryhaline species, see below) have infrequent occurrences, occur singly or in small groups, and have not yet become self-sustaining populations. Aquarium releases are one of the major pathways whereby nonindigenous fishes gain access to new environments (Ruiz et al. 1997; Fuller et al. 1999). Most of the nonindigenous marine fishes found in Florida’s waters are thought to be aquarium fishes that either were illegally released into the ocean or escaped captivity (e.g., during severe storm/flooding events). Indeed, south Florida is a hotspot for nonindigenous marine aquarium fishes (Semmens et al. 2004). Increased public awareness of the problems caused by released or escaped aquarium fishes may aid in stemming the frequency of releases. For example, HabitattitudeTM (www.habitattitude.net) is a national public awareness and partnership campaign that encourages aquarists and water gardeners to prevent the release of unwanted aquarium plants, fish and other animals. It prompts hobbyists to adopt alternative actions when dealing with these aquatic plants and animals. (PDF file contains 133 pages.

    Benthic algae and seagrasses of the Walpole and Nornalup Inlets Marine Park, Western Australia

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    A survey of the marine plants of the Walpole and Nornalup Inlets Marine Park has recorded 49 species of marine benthic algae and seagrasses, including 15 green algae, 11 brown algae, 18 red algae, 4 seagrasses, and one cyanobacterium, representing a substantial increase on the 14 previously recorded species. Most species are relatively common elements of the south-western Australian marine flora, but several are of taxonomic or biogeographic and ecological interest. Included in this group are: a new species of the green algal genus Codium, the first records of previously unknown reproductive phases in the red algae Mazoyerella australis and Spermothamnion cymosum, and a new distribution record for Ossiella pacifica, a species hitherto known only from warmer waters of the Pacific Ocean and not recorded for mainland Australia. The species diversity in the inlets decreases markedly with increasing distance from the ocean, reflecting a reducing marine and increasing estuarine influence

    Marine benthic plants of Western Australia's shelf-edge atolls

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    One hundred and twenty-one species of marine algae, seagrasses and cyanobacteria are reported from the offshore atolls of northwestern Western Australia (the Rowley Shoals, Scott Reef and Seringapatam Reef). Included are 65 species of Rhodophyta, 40 species of Chlorophyta, nine species of Phaeophyceae, three species of Cyanophyta and four species of seagrasses. This report presents the first detailed account of marine benthic algae from these atolls. Twenty-four species are newly recorded for Western Australia, with four species (Anadyomene wrightii, Rhipilia nigrescens, Ceramium krameri and Zellera tawallina) also newly recorded for Australia

    Perubahan PH Dan Salinitas Tanah Pasir Dan Tanah Liat Setelah Penambahan Pembenah Tanah Dari Bahan Dasar Tumbuhan Akuatik

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    Soil acidity and salinity have important roles in determining soil fertility and plant productivity. Addition of soil conditioner to increase soil fertility and plant productivity should consider its acidity and salinity. In developing aquatic plants for soil conditioner, analyzes of their acidity and salinity property is necessary. The aim of this study is to analyze the acidity and salinity property from differnt sources of aquatic plants, i.e: fresh water, brackish water and marine plants. All collected aquatic plants were dried and mashed into powder. The resulted powder were then added by water to test their acidity and salinity using pH meter and refractometer. Results indicated that, fresh water aquatic plants have lower pH, whichi i 5.2, whereas from brackish and marine water have similar pH, i.e: 7. Soil conditioner from fresh water plant is suitable for base soil, while from brackish and marine plants are suitable for normal soil. However, Study from their salinity indicated that, their high salinity of brackish water plants (16 ppt) and marine water plants (43 ppt) need pretreatment by washing and diluting with fresh water

    Bulk Elastic Moduli and Solute Potentials in Leaves of Freshwater, Coastal, and Marine Hydrophytes. Are Marine Plants More Rigid?

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    Bulk modulus of elasticity (ɛ), depicting the flexibility of plant tissues, is recognized as an important component in maintaining internal water balance. Elevated ɛ and comparatively low osmotic potential (Ψπ) may work in concert to effectively maintain vital cellular water content. This concept, termed the ‘cell water conservation hypothesis’, may foster tolerance for lower soil-water potentials in plants while minimizing cell dehydration and shrinkage. Therefore, the accumulation of solutes in marine plants, causing decreases in Ψπ, play an important role in plant–water relations and likely works with higher ɛ to achieve favourable cell volumes. While it is generally held that plants residing in marine systems have higher leaf tissue ɛ, to our knowledge no study has specifically addressed this notion in aquatic and wetland plants residing in marine and freshwater systems. Therefore, we compared ɛ and Ψπ in leaf tissues of 38 freshwater, coastal and marine plant species using data collected in our laboratory, with additional values from the literature. Overall, 8 of the 10 highest ɛ values were observed in marine plants, and 20 of the lowest 25 ɛ values were recorded in freshwater plants. As expected, marine plants often had lower Ψπ, wherein the majority of marine plants were below −1.0 MPa and the majority of freshwater plants were above −1.0 MPa. While there were no differences among habitat type and symplastic water content (θsym), we did observe higher θsym in shrubs when compared with graminoids, and believe that the comparatively low θsym observed in aquatic grasses may be attributed to their tendency to develop aerenchyma that hold apoplastic water. These results, with few exceptions, support the premise that leaf tissues of plants acclimated to marine environments tend to have higher ɛ and lower Ψπ, and agree with the general tenets of the cell water conservation hypothesis

    Effects of the Santa Barbara, Calif., Oil Spill on the Apparent Abundance of Pelagic Fishery Resources

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    Many studies have been made of the effects of oil on marine invertebrates, plants (marine algae and phytoplankton), and vertebrates such as seabirds and marine mammals. An excellent review of these findings, which includes some references to fish and pathological effects of aromatic hydrocarbons, has been published by the Royal Society, London (Clark, 1982). That review dealt with the environmental effects of such major oil spills or releases such as those by the tankers Torry Canyon (119,000 t) on the south coast of England, Metula (50-56,000 t) in the Straits of Magellan, Argo Merchant (26,000 t) off Cape Cod, and the super tanker Amoco Cadiz (223,000 t) on the coast of northern Brittany. Those spills were studied to determine their effect on living resources. In contrast there are few references on the impact of oil spills on pelagic fishery resources

    Ocean acidification and the loss of phenolic substances in marine plants.

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    Rising atmospheric CO(2) often triggers the production of plant phenolics, including many that serve as herbivore deterrents, digestion reducers, antimicrobials, or ultraviolet sunscreens. Such responses are predicted by popular models of plant defense, especially resource availability models which link carbon availability to phenolic biosynthesis. CO(2) availability is also increasing in the oceans, where anthropogenic emissions cause ocean acidification, decreasing seawater pH and shifting the carbonate system towards further CO(2) enrichment. Such conditions tend to increase seagrass productivity but may also increase rates of grazing on these marine plants. Here we show that high CO(2) / low pH conditions of OA decrease, rather than increase, concentrations of phenolic protective substances in seagrasses and eurysaline marine plants. We observed a loss of simple and polymeric phenolics in the seagrass Cymodocea nodosa near a volcanic CO(2) vent on the Island of Vulcano, Italy, where pH values decreased from 8.1 to 7.3 and pCO(2) concentrations increased ten-fold. We observed similar responses in two estuarine species, Ruppia maritima and Potamogeton perfoliatus, in in situ Free-Ocean-Carbon-Enrichment experiments conducted in tributaries of the Chesapeake Bay, USA. These responses are strikingly different than those exhibited by terrestrial plants. The loss of phenolic substances may explain the higher-than-usual rates of grazing observed near undersea CO(2) vents and suggests that ocean acidification may alter coastal carbon fluxes by affecting rates of decomposition, grazing, and disease. Our observations temper recent predictions that seagrasses would necessarily be "winners" in a high CO(2) world

    Marine plants of Mandapam coast and their uses

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    In the sea 3 types of plants occur and they arePhytoplanktons, Seaweeds or Marine Algae and Seagrasses. Phytoplanktons are microscopic and free floating forms and they are the primary producers of the sea. Seaweeds or Marine Algae are macroscopic, attached or free floating plants
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