Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2005-6-30
pubmed:abstractText
The evolutionary origins of legume root nodules are largely unknown. We have identified a gene, LATD, of the model legume Medicago truncatula, that is required for both nodule and root development, suggesting that these two developmental processes may share a common evolutionary origin. The latd mutant plants initiate nodule formation but do not complete it, resulting in immature, non-nitrogen-fixing nodules. Similarly, lateral roots initiate, but remain short stumps. The primary root, which initially appears to be wild type, gradually ceases growth and forms an abnormal tip that resembles that of the mutant lateral roots. Infection by the rhizobial partner, Sinorhizobium meliloti, can occur, although infection is rarely completed. Once inside latd mutant nodules, S. meliloti fails to express rhizobial genes associated with the developmental transition from free-living bacterium to endosymbiont, such as bacA and nex38. The infecting rhizobia also fail to express nifH and fix nitrogen. Thus, both plant and bacterial development are blocked in latd mutant roots. Based on the latd mutant phenotype, we propose that the wild-type function of the LATD gene is to maintain root meristems. The strong requirement of both nodules and lateral roots for wild-type LATD gene function supports lateral roots as a possible evolutionary origin for legume nodules.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0894-0282
pubmed:author
pubmed:issnType
Print
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
521-32
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
The LATD gene of Medicago truncatula is required for both nodule and root development.
pubmed:affiliation
Department of Botany and Agricultural Biochemistry, University of Vermont, Burlington 05405-0086, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural