title: Production and function of jasmonates in nodulated roots of soybean plants inoculated with Bradyrhizobium japonicum.
abstract: Little is known regarding production and function of endogenous jasmonates (JAs) in root nodules of soybean plants inoculated with Bradyrhizobium japonicum. We investigated (1) production of jasmonic acid (JA) and 12-oxophytodienoic acid (OPDA) in roots of control and inoculated plants and in isolated nodules; (2) correlations between JAs levels, nodule number, and plant growth during the symbiotic process; and (3) effects of exogenous JA and OPDA on nodule cell number and size. In roots of control plants, JA and OPDA levels reached a maximum at day 18 after inoculation; OPDA level was 1.24 times that of JA. In roots of inoculated plants, OPDA peaked at day 15, whereas JA level did not change appreciably. Shoot dry matter of inoculated plants was higher than that of control at day 21. Chlorophyll a decreased more abruptly in control plants than in inoculated plants, whereas b decreased gradually in both cases. Exogenous JA or OPDA changed number and size of nodule central cells and peripheral cells. Findings from this and previous studies suggest that increased levels of JA and OPDA in control plants are related to senescence induced by nutritional stress. OPDA accumulation in nodulated roots suggests its involvement in "autoregulation of nodulation."
authors.affiliation: Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, 5800 Río Cuarto, Córdoba, Argentina.
authors.forename: María Emilia
authors.initials: ME
authors.lastname: Costanzo
authors.forename: Andrea
authors.initials: A
authors.lastname: Andrade
authors.forename: María
authors.initials: M
authors.lastname: del Carmen Tordable
authors.forename: Fabricio
authors.initials: F
authors.lastname: Cassán
authors.forename: Guillermina
authors.initials: G
authors.lastname: Abdala
mesh_terms: D000328:Adult; D020369:Bradyrhizobium / Q000378:metabolism / Q000502:physiology*; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D003517:Cyclopentanes / Q000378:metabolism* / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D054883:Oxylipins / Q000378:metabolism* / Q000494:pharmacology; D010937:Plant Growth Regulators / Q000494:pharmacology; D018517:Plant Roots / Q000187:drug effects; D018520:Plant Shoots / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology; D053204:Root Nodules, Plant / Q000382:microbiology*; D013025:Glycine max / Q000187:drug effects / Q000254:growth & development / Q000382:microbiology*; D013559:Symbiosis / Q000187:drug effects / Q000502:physiology
chemical_list: D003517:Cyclopentanes; D005231:Fatty Acids, Unsaturated; D054883:Oxylipins; D010937:Plant Growth Regulators; D002734:Chlorophyll; C025999:12-oxophytodienoic acid; C011006:jasmonic acid; D000077194:Chlorophyll A