Polyamines as short-term salt tolerance traits in tomato (original) (raw)

Effect of Salt Stress on Polyamine Metabolism in Two Bean Cultivars

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

Role of Polyamines in the Response to Salt Stress of Tomato

Plants

Plants irrigated with saline solutions undergo osmotic and oxidative stresses, which affect their growth, photosynthetic activity and yield. Therefore, the use of saline water for irrigation, in addition to the increasing soil salinity, is one of the major threats to crop productivity worldwide. Plant tolerance to stressful conditions can be improved using different strategies, i.e., seed priming and acclimation, which elicit morphological and biochemical responses to overcome stress. In this work, we evaluated the combined effect of priming and acclimation on salt stress response of a tomato cultivar (Solanum lycopersicum L.), very sensitive to salinity. Chemical priming of seeds was performed by treating seeds with polyamines (PAs): 2.5 mM putrescine (PUT), 2.5 mM spermine (SPM) and 2.5 mM spermidine (SPD). Germinated seeds of primed and non-primed (controls) were sown in non-saline soil. The acclimation consisted of irrigating the seedlings for 2 weeks with tap water, followed by...

Polyamines and salt stress response and tolerance in Arabidopsis thaliana flowers

Plant Physiology and Biochemistry, 2008

In the present study we analysed polyamine metabolism in Arabidopsis thaliana (ecotype Columbia) flowers and stalks collected from plants germinated and grown under increasing salt-stress conditions (0-75 mM NaCl). The expression level of the different isoforms of polyamine biosynthetic enzymes was analysed by reverse transcriptase-polymerase chain reaction (RT-PCR). Spermidine synthase enzyme activity determined both in supernatant and pellet fractions, together with RT-PCR results, led us to hypothesize a different intracellular compartmentation of the isoforms of these enzymes. Free and conjugated polyamines (perchloric acid-soluble and -insoluble) were measured. Free spermidine was the most abundant polyamine and its levels, such as those of free spermine, increased with salt concentration, supporting the hypothesis for a specific role of those polyamines in the response and tolerance to salt stress of Arabidopsis thaliana flowers.