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Abiotic stresses such as heat, drought or salinity have been widely studied individually. Nevertheless, in the nature and in the field, plants and crops are commonly exposed to a different combination of stresses, which often result in a synergistic response mediated by the activation of several molecular pathways that cannot be inferred from the response to each individual stress. By screening microarray data obtained from different plant species and under different stresses, we identified several conserved stress-responsive genes whose expression was differentially regulated in tomato (Solanum lycopersicum L.) roots in response to one or several stresses. We validated 10 of these genes as reliable biomarkers whose expression levels are related to different signalling pathways involved in adaptive stress responses. In addition, the genes identified in this work could be used as general salt-stress biomarkers to rapidly evaluate the response of salt-tolerant cultivars and wild species for which sufficient genetic information is not yet available. [ABSTRACT FROM AUTHOR]

The effect of short-term treatments (10 days) by a high salt level (150mmNaCl) on vegetative and reproductive development was investigated in tomato plants (Solanum lycopersicumL. cv. Ailsa Craig) at two developmental stages. Salinity applied during flowering transition reduced shoot biomass and delayed the appearance of the first inflorescence. Both shoot and root biomasses were reduced when salt was applied during the development of the first inflorescence. At both stages, areas of young leaves decreased and time to first anthesis increased, while total number of flowers in the first inflorescence was not affected. Flower abortion, reduction of pollen number and viability were higher when salinity was applied during inflorescence development. Na+accumulated in all organs while K+decreased. Laser ablation inductively coupled plasma mass spectrometry microanalysis revealed that Na+accumulated in style, ovaries and anther intermediate layers but not in the tapetum nor in the pollen grains when salinity was applied during inflorescence development. K+was not significantly affected in these structures. Soluble carbohydrates dramatically increased in leaves and decreased in the inflorescence under salt stress conditions. The failure of inflorescence to develop normally under salt stress can be better explained in terms of altered source–sink relationships rather than accumulation of toxic ions. [ABSTRACT FROM AUTHOR]