title: Comparison of developmental and stress-induced nodule senescence in Medicago truncatula.
abstract: Mature indeterminate Medicago truncatula nodules are zonated with an apical meristem, an infection zone, a fixation zone with nitrogen-fixing bacteroids, and a "developmental" senescence zone that follows nodule growth with a conical front originating in the center of the fixation zone. In nitrogen-fixing cells, senescence is initiated coincidently with the expression of a family of conserved cysteine proteases that might be involved in the degradation of symbiotic structures. Environmental stress, such as prolonged dark treatment, interferes with nodule functioning and triggers a fast and global nodule senescence. Developmental and dark stress-induced senescence have several different structural and expression features, suggesting at least partly divergent underlying molecular mechanisms.
authors.affiliation: Department of Plant Systems Biology, Flanders Institute for Biotechnology, and Department of Plant Biotechnology and Genetics, Ghent University, B-9052 Ghent, Belgium.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Pérez Guerra
authors.forename: Griet
authors.initials: G
authors.lastname: Coussens
authors.forename: Annick
authors.initials: A
authors.lastname: De Keyser
authors.forename: Riet
authors.initials: R
authors.lastname: De Rycke
authors.forename: Stefanie
authors.initials: S
authors.lastname: De Bodt
authors.forename: Willem
authors.initials: W
authors.lastname: Van De Velde
authors.forename: Sofie
authors.initials: S
authors.lastname: Goormachtig
authors.forename: Marcelle
authors.initials: M
authors.lastname: Holsters
mesh_terms: D000375:Aging; D057056:Cysteine Proteases / Q000235:genetics*; D003624:Darkness; D046913:Medicago truncatula / Q000235:genetics / Q000254:growth & development*; D009586:Nitrogen Fixation; D010802:Phylogeny; D018749:RNA, Plant / Q000235:genetics; D053204:Root Nodules, Plant / Q000235:genetics / Q000254:growth & development*; D013312:Stress, Physiological
chemical_list: D018749:RNA, Plant; D057056:Cysteine Proteases