Jasmonates production by soybean roots inoculated with Bradyrhizobium japonicum

COSTANZO, MARÍA EMILIA; ANDRADE, ANDREA; TORDABLE, MARÍA; CASSÁN, FABRICIO Y ABDALA GUILLERMINA

ARCHIVES OF MICROBIOLOGY

SPRINGER

Lugar: Berlin; Año: 2012 p. 1 - 9

0302-8933

Little is known regarding production and function of endogenous jasmonates (JAs) in root nodules of soybean plants inoculated with Bradyrhizobium japonicum. We investigated (i) production of jasmonic acid (JA) and 12-oxophytodienoic acid (OPDA) in roots of control and inoculated plants, and in isolated nodules; (ii) correlations between JAs levels, nodule number, and plant growth during the symbiotic process; (iii) 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 (DM) 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".