Endogenous jasmonates in salinized seedlings of Prosopis strombulifera

REGINATO , MARIANA ANDREA; ABDALA, GUILLERMINA IRENE; MIERSCH, OTTO; LUNA, MARÍA VIRGINIA

Huerta Grande, Córdoba

Congreso; First meeting of Argentine Biology Societies; 2007

Sociedad Latinoamericana de Microscopía Electrónica.; Centro Regional de Investigaciones Científicas y Tecnológicas (Mendoza, Argentina)

Alterations in Jasmonic acid (JA) and its metabolism have been reported in plant tissues under salt stress; however, the response in halophytic plants is unknown. Endogenous levels of jasmonates and metabolites in the halophyte Prosopis strombulifera were analyzed in this work. Seedling were grown hydroponically in Hoagland solutions with addition of 50 mmol/l NaCl for NaCl treatment, 38 mmol/l Na2SO4 for Na2SO4 treatment and the isoosmotic mixture of salts for bisaline treatment every 48 h until final Ψo = -1, -1,88, and -2,6 MPa were reached. Control plants were grown in Hoagland 25%. HPLC-GC-MS-SIM was used to separate and quantify the jasmonates. High content of the JA precursor, 12-oxophytodienoic acid (OPDA) and lower levels of JA were found in control roots. Under salinity, both compounds decreased with increasing salinity. In leaves, OPDA and JA levels were 4 fold lower than in roots, but the hidroxylated (11-OH-JA and 12-OH-JA) levels increased significantly in response to salinity, mainly 12-OH-JA. These results suggest that JA is not involved in salt tolerance, and the hydroxylation pathway would be an inactivation route of the JA signaling in this species, mainly in NaCl treated plants, confirming their increased tolerance to this salt in relation to Na2SO4.