Just like animals, plants accumulate metals and similar toxins throughout depending on the metal. Many things are accumulated in the roots, but also elsewhere. For example, in an unpublished study we were doing on an oxbow lake adjacent to the Red River we found Chromium and several other metals in the leaves and stems of water plants. This ability of plants to remove certain compounds from the environment stimulated the idea of phytoremediation to remove these things from soils and water.
Water soluble contaminants have a more complex fate in plants because they can enter and leave with water. However, they also have the capacity to more evenly distribute throughout the plant depending on their molecular size. Further, plants due to their use of photosynthesis have an extremely well developed antioxidant enzyme system which provides them with a powerful ability to detoxify compounds and deal with free radical damage generated by contaminants. Consequently, plants in some cases can break down these compounds very effectively break down these compounds. Many herbicides in particular attack either the cell membranes (paraquate like herbicides), the photosynthetic pathways, or growth and lipid production of the meristems. There are others. I don't know a whole lot about plant toxicology, however, if you want to learn more I would investigate the phytoremediation literature and the literature on herbicide action in plants. The agronomy literature will tell you a lot obout this too. Malcolm McCallum On Wed, Apr 13, 2011 at 11:20 PM, Ben Bowman <[email protected]> wrote: > I am looking for information about where different types of plants absorb and > retain heavy metals and other toxins. > > I would like to compile a list of edible plants that are safe to propagate and > consume despite soil contamination. This could include plants that absorb > toxins but deposit them in isolated areas. I have been told, for example, that > tree fruits can be planted in lead contaminated soil, because lead never rises > high enough in trees to wind up in their fruits. Or, if you know of such a > list already out there, I would love to see it! > > I think that lead is the most common toxin in many urban areas, so I am > particularly interested in where plants deposit lead, but I would appreciate > information on how/where they hold onto other toxins as well. > > Thanks for your help, > Ben > -- Malcolm L. McCallum Managing Editor, Herpetological Conservation and Biology "Peer pressure is designed to contain anyone with a sense of drive" - Allan Nation 1880's: "There's lots of good fish in the sea" W.S. Gilbert 1990's: Many fish stocks depleted due to overfishing, habitat loss, and pollution. 2000: Marine reserves, ecosystem restoration, and pollution reduction MAY help restore populations. 2022: Soylent Green is People! Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message.
