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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2010-6-29
pubmed:abstractText
Earlier studies indicated that bacteria responsible for nitrogenase activity of some grasses are located inside the roots. Those studies were conducted with excised roots in which a long, unexplained "lag phase" occurred before initiation of nitrogenase activity. When hydroponically maintained Spartina alterniflora Loisel. was incubated in a two-compartment system with acetylene, ethylene was produced following, at most, a 2-hour lag in both the upper (shoot) and lower (roots + water) phases. Ethylene production in the upper phase not attributable to leaf-associated acetylene-reducing activity or to diffusion of ethylene from around the roots is considered to represent "endorhizal acetylene-reducing activity," the internally produced ethylene diffusing into the upper phase via the lacunae. Ethylene produced in the lower phase is designated "exorhizal acetylene-reducing activity." The endorhizal acetylene-reducing activity, in comparison to exorhizal activity, was relatively insensitive to additions of HgCl(2), NH(4)Cl, or carbon sources to the lower phase. Post-lag acetylene-reducing activity of roots excised from plants growing in soil responded to additions in a manner similar to that of endorhizal acetylene-reducing activity, whereas post-lag acetylene-reducing activity of rhizosphere soil responded in a manner similar to that of exorhizal acetylene-reducing activity.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Aug
pubmed:issn
0032-0889
pubmed:author
pubmed:issnType
Print
pubmed:volume
66
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
276-80
pubmed:dateRevised
2010-9-15
pubmed:year
1980
pubmed:articleTitle
Endorhizal and Exorhizal Acetylene-reducing Activity in a Grass (Spartina alterniflora Loisel.)-Diazotroph Association.
pubmed:affiliation
Biology Department, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J1.
pubmed:publicationType
Journal Article