Effect of Salt Stress on Polyamine Metabolism in Two Bean Cultivars

ELOÍSA HERNÁNDEZ-LUCERO, OSCAR A. RUIZ & JUAN FRANCISCO JIMÉNEZ-BREMONT

PLANT STRESS

Kagawa University, Japan

Año: 2008 vol. 2 p. 96 - 102

1749 0359

In agricultural areas, salinity affects plant growth, development and productivity, causing loss of economically important crops. Nitrogen-derived compounds such as polyamines are differentially accumulated in diverse plants species in response to salinity. Polyamine and chlorophyll contents, as well as water potential, were assessed in leaves of two common bean cultivars subjected to salt stress for one and seven days; these bean cultivars, ‘Pinto Villa’[SciRev1]  and ‘Canario 60’, differ in their drought tolerance phenotype. Salt stress induced a phenotypic behavior similar to that of drought in which the sensitive cultivar Canario 60 showed a pronounced decrease in water potential in comparison to the tolerant Pinto Villa. Regarding polyamines, after the first day of treatment, the levels of all of them (putrescine, spermidine and spermine) increased in tolerant cultivar (Pinto Villa) while in the sensitive one (Canario 60) the levels of spermidine and spermine only increased at 400 mM NaCl. At the seventh day, the tolerant cultivar showed an accumulation of spermine at the higher concentrations of NaCl used (150 and 400 mM), whereas a decrease in polyamine content occurred in the sensitive cultivar at all concentrations assayed. Furthermore, the effect of salt stress on the expression of the main genes involved in polyamines biosynthesis, including a new S-adenosyl-methionine decarboxylase gene identified in this work, was analysed. It is suggested that spermine accumulation in Pinto Villa cultivar might be part of the mechanism conferring salt tolerance.