SUMMARY
The main goal of the present study is represented by the identification of proline level in several species of plants that are tolerant to stress. This study is part of the project entitled “Plant response to abiotic stress”. The correlation of the results obtained in the edafic conditions of the natural habitats, represents another goal of the project. This work is being funded by the Spanish Ministery of Science and Innovation) project CGL2008-00438/BOS), with contribution from the European Regional Development Fund. The first author was recipient of an Erasmus-Socrates fellowship during 2009 financed by Ministery and Science and Education, and took place within the Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia and EPSG, Gandia. This study also aims to compare the behavior of the same taxon in the conditions met in each of the experimental plots taken into study. In order to obtain an image of the evolution for the average value of proline, the value was compared to the results obtained in the field in winter and spring, and also by comparing it to the results obtained in condition of in vitro.