Linked Life Data

16663881

Source:http://linkedlifedata.com/resource/pubmed/id/16663881

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2010-6-29
pubmed:abstractText
Frankia sp., the actinomycetous endophyte in nitrogen-fixing actinorhizal nodules, may differentiate two forms from its hyphae: vesicles and sporangia. In root nodules of Comptonia peregrina (L.) Coult. and Myrica gale L., sporangia may be either absent or present. Nitrogenase activity and symbiotic efficiency were contrasted in spore(+) and spore(-) nodules of these two host genera. Seedlings of C. peregrina nodulated with the spore(+) inoculum showed only 60% of the nitrogenase activity and 50% of the net size of their spore(-) counterparts after 12 weeks of culture. Measurements of acetylene reduction (i.e., nitrogenase activity) were coordinated with samplings of nodules for structural studies. Significant differences in acetylene reduction rates were discernible between spore(+) and spore(-) nodules commencing 4 weeks after nodulation, concomitant with the maturation of sporangia in the nodule. Spore(+) nodules ultimately reached less than half of the rate of nitrogenase activity of spore(-) nodules. Both types of nodules evolved only small amounts of molecular hydrogen, suggesting that both were equally efficient in recycling electrons lost to the reduction of hydrogen ions by nitrogenase. Respiratory cost of nitrogen fixation, expressed as the quotient of micromole CO(2) to micromole ethylene evolved by excised nodules, was significantly greater in spore(+) than in spore(-) nodules. M. gale spore(-) nodules showed variable effectivity, though all had low CO(2) to ethylene evolution ratios. M. gale spore(+) nodules resembled C. peregrina spore(+), with low effectivity and high respiratory cost for nitrogen fixation.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Nov
pubmed:issn
0032-0889
pubmed:author
pubmed:issnType
Print
pubmed:volume
76
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
556-60
pubmed:dateRevised
2010-9-15
pubmed:year
1984
pubmed:articleTitle
Consequences of Sporangial Development for Nodule Function in Root Nodules of Comptonia peregrina and Myrica gale.
pubmed:affiliation
Department of Botany, University of Massachusetts, Amherst, Massachusetts 01003.
pubmed:publicationType
Journal Article