root nodule

root nodule

root nodule A swelling on the roots of certain plants, especially those of the family Fabaceae (Leguminosae), that contains bacteria (notably Rhizobium) capable of fixing atmospheric nitrogen into ammonia, which is subsequently converted to nitrates and amino acids (see bacteroid; nitrogen fixation). Plants that possess root nodules increase soil fertility by increasing the nitrate content of the soil. The practice of crop rotation will normally include the cultivation of a leguminous species. Certain nonleguminous plants, such as alder (Alnus) and bayberry (Myrica), also form root nodules, although the bacteria are filamentous actinomycetes (Frankia), not rhizobia.

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"root nodule." A Dictionary of Biology. 2004. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>.

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root nodule

root nodule (actinorrhiza) A small, gall-like growth on the roots of certain types of plant, especially leguminous plants. The nodules develop as a result of infection of the roots by bacteria (Rhizobium or Bradyrhizobium species in the case of legumes); the bacteria then inhabit the root nodules and benefit the plant by fixing atmospheric nitrogen, much of which becomes available to the plant.

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MICHAEL ALLABY. "root nodule." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>.

MICHAEL ALLABY. "root nodule." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O7-rootnodule.html

MICHAEL ALLABY. "root nodule." A Dictionary of Plant Sciences. 1998. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O7-rootnodule.html

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root nodule

root nodule(actinorrhiza) A small, gall-like growth on the roots of certain types of plant, especially leguminous plants. The nodules develop as a result of infection of the roots by bacteria (Rhizobium or Bradyrhizobium species in the case of legumes); the bacteria then inhabit the root nodules and benefit the plant by fixing atmospheric nitrogen, much of which becomes available to the plant.

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MICHAEL ALLABY. "root nodule." A Dictionary of Ecology. 2004. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>.

MICHAEL ALLABY. "root nodule." A Dictionary of Ecology. 2004. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O14-rootnodule.html

MICHAEL ALLABY. "root nodule." A Dictionary of Ecology. 2004. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O14-rootnodule.html

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root nodule

root nodule Small swelling in the roots of various plants, such as legumes, that contain nitrogen-fixing bacteria. See also nitrogen cycle; nitrogen fixation

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"root nodule." World Encyclopedia. 2005. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>.

"root nodule." World Encyclopedia. 2005. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O142-rootnodule.html

"root nodule." World Encyclopedia. 2005. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-rootnodule.html

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Free newspaper and magazine articles

Genetic diversity of Frankia strains in root nodules from Hippophae...
Magazine article from: Canadian Journal of Botany; 3/1/2008
Getting to the root of nodule formation.(nitrogen-fixing nodules can be grown...
Magazine article from: Science News; 8/12/1995
Differential effects of nitrate and ammonium supply on nodule initiation,...
Magazine article from: Canadian Journal of Botany; 6/1/2006

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