plants
Zinc hyperaccumulation in Thlaspi caerulescensas a chemical defence against herbivory Thlaspi caerulescens is one of several plant species known to accumulate heavy metals in excess of 2% of their above ground plant biomass. The reasons for hyperaccumulation are unknown, but several studies conclude that it may be a plant chemical defence. This has been of interest to biologists because these metals are usually toxic. The accumulation of these metals may serve as a model for coevolution. We examined the effects of zinc hyperaccumulation in Thlaspi on Xanthomonas campestris and found that the plants containing zinc thrived when inoculated with this bacteria, while plants not containing zinc showed signs of There are several wild plant species that have the ability to accumulate high quantities of heavy metals in their above ground biomass, up to three percent or more. Many of these plants are found in the Brassicaceae family throughout Europe and the British Isles. These plants thrive on mineral outcrops with calamine and serpentine soils rich with high levels of zinc, cadmium, and nickel (Baker et al, 1994). Several theories have been advanced on the
herbivory. The insects fed non nickel bearing leaves survived or hyperaccumulating plant found in the British Isles. It has been These results demonstrate that zinc hyperaccumulation in Our results were consistent with other studies in this area. beaker containing 25ml of solution. The ten Rorison's plants After twenty days, each plant was transferred to an individual Several studies have supported the chemical defence against insect herbivores in two different feeding experiments. that it is reasonable to assume that the hyperaccumulated metals, showed weight gain while the insects fed nickel bearing leaves did investigation, the results were not biased. Boyd et at (1994) also demonstrated that nickel hyperaccumulating
Some common words found in the essay are:
Conviron E-15, Martens Boyd, Average Rank, Boyd Martens, Mann-Whitney Test, Pollard Baker, ABSTRACT Thlaspi, British Isles, Thlaspi Xanthomonas, RESULTS Scale, effective defence, thlaspi caerulescens, zinc hyperaccumulation thlaspi, zinc plants, xanthomonas campestris, defence herbivory, chemical defence, zinc hyperaccumulation, hyperaccumulation thlaspi, heavy metals, zinc 200, insects fed nickel, effects zinc hyperaccumulation, martens boyd 1993, fed nickel bearing,
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Approximate Pages = 5 (250 words per page double spaced)
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