nodule

[Jeff J. Doyle]

This is as much as I know about these nodules, too.  It has been 
pointed out to me by Ann Hirsch (UCLA) that calling them "stem" 
nodules is somewhat misleading since they still form on roots, albeit 
adventitious ones.  But the differences between these nodule types 
suggest that some distinction may be useful.

--Jeff

>It seems there is. I am not an expert, here is what I found about
>Sebastania:
>
>Sesbania rostrata is a native legume of West Africa. It forms a symbiotic
>relationship with Azorhizobium caulinodans and is renowned for it's stem
>nodulation. Both stem and root nodules fix nitrogen however root nodules
>form at the curled root hair while stem nodules occur at the sites of
>adventitious root primordia via "crack" entry. The stem nodules unlike the
>root nodules contain functioning chloroplasts in the nodule cortex and are
>therefore capable of carbon fixation.
>
>http://www.personal.dundee.ac.uk/~rparsons/sesbania.htm
>
>
>Katica
>
>
>On Fri, 11 Mar 2005, Sue Rhee wrote:
>
>>  Are there any anatomical, morphological, lineage differences between the
>>  nodules in the primary/lateral root and the 'stem' nodules in the
>>  adventitious root? It seems like the introduction of 'stem nodule' for the
>>  nodules that are not really part of stem could lead to some confusion.
>>
>>  Sue
>>
>>  On Fri, 11 Mar 2005, Katica Ilic wrote:
>>
>>  > Hi Jeff,
>>  >
>>  > Thanks for your comment.
>>  >
>>  > Would it be more appropriate to have 'root nodule' instead?
>>  > Actually to instantiate term 'nodule' to 'root nodule' and 'stem
>>  > nodule'?
>>  >
>>  > Katica
>>  >
>>  > On Fri, 11 Mar 2005, Jeff J. Doyle wrote:
>>  >
>>  > > >
>>  > > >PO:0003023
>>  > > >name: nodule
>>  > > >def: Enlargement or swelling on the roots of plants, 
>>particularly in the
>>  > > >Fabaceae, inhabited by nitrogen-fixing bacteria.
>>  > >
>>  > > There are also what are called "stem nodules" in some legumes (the
>>  > > papilionoid genus Sesbania is the prime example, but the caesalpiniod
>>  > > Neptunia also has nodules on floating stems).  Stem nodules are
>>  > > associated with adventitious roots, however, so the definition is not
>>  > > actually incorrect, even if the position of the roots in question is
>>  > > not typical.
>>  > >
>>  > > --Jeff
>>  > >
>>  > >
>>  > > --
>>  > > Jeff J. Doyle
>>  > > Professor, L. H. Bailey Hortorium, Department of Plant Biology,
>>  > > Cornell University
>>  > > office: 259 Plant Science Building
>>  > > tel: 607 255-7972 (lab: 607 255-1953); fax: 607-255-5407
>>  > > http://www.plantbio.cornell.edu/faculty.php?PB=jjd5
>>  > >
>>  > > mailing address:
>>  > >
>>  > > Department of Plant Biology
>>  > > 228 Plant Science Building
>>  > > Cornell University
>>  > > Ithaca, NY 14853-4301
>>  > >
>>  >
>>  > --------------------------------------------------------------------------
>>  > Katica Ilic            		katica at acoma.stanford.edu
>>  > The Arabidopsis Information Resource	Tel: (650) 325-1521 ext. 253
>>  > Carnegie Institution of Washington	FAX: (650) 325-6857
>>  > Department of Plant Biology		URL: http://arabidopsis.org/
>>  > 260 Panama St.
>>  > Stanford, CA 94305
>>  > U.S.A.
>>  > --------------------------------------------------------------------------
>>  >
>>  >
>>
>> 
>>-----------------------------------------------------------------------------
>>  Sue Rhee                        	rhee at acoma.stanford.edu
>>  The Arabidopsis Information Resource	URL: www.arabidopsis.org
>>  Carnegie Institution of Washington	FAX: +1-650-325-6857
>>  Department of Plant Biology		Tel: +1-650-325-1521 ext. 251
>>  260 Panama St.
>>  Stanford, CA 94305
>>  U.S.A.
>> 
>>-----------------------------------------------------------------------------
>>
>>
>
>--------------------------------------------------------------------------
>Katica Ilic            		katica at acoma.stanford.edu
>The Arabidopsis Information Resource	Tel: (650) 325-1521 ext. 253
>Carnegie Institution of Washington	FAX: (650) 325-6857
>Department of Plant Biology		URL: http://arabidopsis.org/
>260 Panama St.
>Stanford, CA 94305
>U.S.A.
>--------------------------------------------------------------------------


-- 
Jeff J. Doyle
Professor, L. H. Bailey Hortorium, Department of Plant Biology, 
Cornell University
office: 259 Plant Science Building
tel: 607 255-7972 (lab: 607 255-1953); fax: 607-255-5407
http://www.plantbio.cornell.edu/faculty.php?PB=jjd5

mailing address:

Department of Plant Biology
228 Plant Science Building
Cornell University
Ithaca, NY 14853-4301