Reed plants

Table 6.6 Selenium toxicity (or critical concentration of Se in used media, mg Se kg DW) in some Se-nonaccumulator plants in different media (hydroponics, soil and in vitro solid media) sulphate concentration (mM) in the rhizosphere comparing with gaint reed plant...

D. J. Reed, E. N. Dost, and C. H. Want, "Inorganic Eluoride Propellant Oxidizers, Vol. 1 Their Effects Upon Seed Germination and Plant... 

Reed, J.B., Hendrix, C M. Jr., Hendrix, D.L. 1986. In Quality Control Manual for Citrus Processing Plants. Volume I. INTERCIT, Inc. Safety Harbor, FL. 

Reed, H. S., Short History of Plant Sciences, Waltham, Mass., Chronica Botanica Co., 1942. 

Other aquatic weeds such as reed mat, mangrove (leaves), and water lily (Nymphaceae family plants) have been found to be promising biosorbents for chromium removal. The highest Cr(III) adsorption capacity was exhibited by reed mat (7.18 mg/g), whereas for Cr(VI), mangrove leaves showed maximum removal capacity (8.87 mg/g) followed by water lily (8.44 mg/g). It is interesting to mention that Cr(VI) was reduced to Cr(III), with the help of tannin, phenolic compounds, and other functional groups on the biosorbent, and subsequently adsorbed. Unlike the results discussed previously for the use of acidic treatments, in this case, such treatments significantly increased the Cr(VI) removal capacity of the biosorbents, whereas the alkali treatment reduced it.118... 

In the wetlands of Idaho, the formation of an Fe(III) precipitate (plaque) on the surface of aquatic plant roots (Typha latifolia, cat tail and Phalaris arundinacea, reed canary grass) may provide a means of attenuation and external exclusion of metals and trace elements (Hansel et al, 2002). Iron oxides were predominantly ferrihydrite with lesser amounts of goethite and minor levels of siderite and lepidocrocite. Both spatial and temporal correlations between As and Fe on the root surfaces were observed and arsenic existed as arsenate-iron hydroxide complexes (82%). 

Copper is not accumulated from soils by most crop plants, suggesting a soil-plant barrier for copper (Levine et al. 1989). Thus, com (Zea mays) did not accumulate copper from soils treated with 365 kg of copper per surface hectare (as copper-rich pig manure or copper sulfate) over a 13-year period. Com yield is not affected under these conditions (Reed et al. 1993). 

Reed, S.T., M.G. Allen, D.C. Martens, and J.R. McKenna. 1993. Copper fractions extracted by Mehlich-3 from soils amended with either CuS04 or copper rich pig manure. Comm. Soil Sci. Plant Anal. 24 827-839. 

Atrazine enters plants primarily by way of the roots and secondarily by way of the foliage, passively translocated in the xylem with the transpiration stream, and accumulates in the apical meristems and leaves (Hull 1967 Forney 1980 Reed 1982 Wolf and Jackson 1982). The main phytotoxic effect is the inhibition of photosynthesis by blocking the electron transport during Hill reaction of photosystem II. This blockage leads to inhibitory effects on the synthesis of carbohydrate, a reduction in the carbon pool, and a buildup of carbon dioxide within the leaf, which subsequently causes closure of the stomates, thus inhibiting transpiration (Stevenson et al. 1982 Jachetta et al. 1986 Shabana 1987). 

Fenvalerate is not significantly absorbed or translocated in plants. Cotton, apples, and lettuce treated with fenvalerate contained surface residues of parent fenvalerate 8 weeks after treatment (Reed 1981). In addition to the parent compound, which accounted for 80% of all residues, identified metabolites included 3-phenoxybenzaldehyde, 3-phenoxybenzyl methylbutyric acid, and conjugates of these compounds. Half-time persistence of fenvalerate on plant surfaces is between 2 and 4 weeks, and degradation is primarily a result of weathering (Reed 1981). 

Sediments and biota collected from the Hersey River, Michigan, in 1978, were heavily contaminated with phenanthrene, benz[a]anthracene, and benzo[a]pyrene when compared to a control site. Elevated PAH concentrations were recorded in sediments, whole insect larvae, crayfish muscle, and flesh of lampreys (family Petromyzontidae), brown trout (Salmo trutta), and white suckers (Catostomus commersoni), in that general order (Black et al. 1981). The polluted collection locale was the former site of a creosote wood preservation facility between 1902 and 1949, and, at the time of the study, received Reed City wastewater treatment plant effluent, described as an oily material with a naphthalene-like odor (Black et al. 1981). In San Francisco Bay, elevated PAH concentrations in fish livers reflected elevated sediment PAH concentrations (Stehr et al. 1997). In Chesapeake Bay, spot (Leiostomus xanthurus) collected from a PAH-contaminated tributary (up to 96 mg PAHs/kg DW sediment) had elevated cytochrome P-450 and EROD activity in liver and intestine microsomes (Van Veld et al. 1990). Intestinal P-450 activity was 80 to 100 times higher in fish from highly contaminated sites than in conspecifics from reference sites intestinal EROD activity had a similar trend. Liver P-450 and EROD activity was about 8 times higher in spot from the contaminated sites when compared to the reference sites. Liver P-450 activity correlated positively with sediment PAH, but intestinal P-450 activity seemed to reflect dietary exposure (Van Veld et al. 1990). The poor correlation between hepatic concentrations of PAHs and P-4501A is attributed to the rapid metabolism of these compounds (van der Weiden et al. 1994). 

We have studied the uptake, translocation and distribution of Cs, Sr and by sunflower, poplar and reed. Attention has been focused not only on the time eourse of uptake from a radioactive hydroponic solution, but also on the distribution of radioactivity across plant tissues. Sunflower has also been used to identify the influence of K", Ca " and NHq" on Cs and Sr uptake and aeeumulation, with the aim of evaluating the effect of these ions whieh are normally present in the soil. 

Figure 6. Distribution of radioactivity in reed. A photograph of plant (a) and its autoradiogram (b). Plants were treated by [ " C]TNT (1.02 MBq/L) for 14 days. A plant was washed, dried and exposed to film for 3 weeks. (Nepovim et al., 2005).

Emergent plants (helophytes) showed a potential for removal of TNT from contaminated water under in vitro conditions with small differences in the formation of the major degradation products - monoaminodinitrotoluenes. Most of TNT degradation products (using " C-radiolabelled TNT) were localized in the roots of reed (53% of total radioactivity) as insoluble compounds (33% of total radioactivity) (Nepovim et al. 2005). 

Graham D, Reed ML, Patterson BD, Hockley DG. 1984. Chemical properties, distribution, and physiology of plant and algal carbonic anhydrase. Annals of the New York Academy of Science 429 222-237. 

Aquatic plants Algae, water weed, water hyacinth, reed and rushes... 

An effective and environmentally friendly acoustic barrier consists of a framework of woven, freshly cut willow, filled with soil, into which the willow stems root. Variations include a soil-filled framework of dried willow, in which ground-cover plants are established. Dense, compressed reed walls designed to reduce noise are also available. 

Voles M.pennsylvanicus) suffer renal lesions (interstitial nephritis) when fed extracts of white clover, T. repens. Milder lesions were observed after feeding on reed phalaris Phalaris arundinacea) and timothy Phleum pratense). Many varieties of reed phalaris contain the toxic compoimds gramine and tryptamine (Fig.11.15). In summer and autumn, protein levels in the leaves decrease, fiber content goes up, and secondary compoimds increase in concentration. Therefore, second growth plants have more toxic effects on voles than the spring plants that grow fast and have lower levels of secondary compounds (Bergeron etal, 1987). 

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