MCT DGI BIO2000-1082, 2000-2003

Principal Investigator: José Luis Micol.
Investigators: María Rosa Ponce, Pedro Robles Ramos, Pedro Piqueras Peral and José Maria Barrero Sánchez.
Instituto de Bioingeniería. Universidad Miguel Hernández.

Characterization of genes involved in salt tolerance in Arabidopsis thaliana

Stress caused by the increased salinity of irrigated fields impairs plant growth and is one of the major constraints which limits crop productivity in many important agricultural areas. Due to the advantages it has for genetic and molecular analysis, we have chosen the model system Arabidopsis thaliana, aiming to contribute to solve such agronomic problem by means of the isolation of mutants capable of germinating in the presence of high salt concentrations. We have carried out a large scale screening for mutants induced on different genetic backgrounds by different mutagens. From the 675,500 seeds we screened, 17 mutant lines were isolated that displayed salt-tolerant germination and fell into five complementation groups, which were named SALOBREÑO1 to 5 (SAÑ1 to 5). The map positions of four of them suggest that they are novel Arabidopsis thaliana genes.

In our collection of mutants, the SAÑ1 gene is represented by four alleles, and SAÑ3 and SAÑ4 by two, most of which were induced by fast neutrons and probably carry deletions. We propose in this project the positional cloning and molecular analysis of these genes identified in our laboratory, with the aim to contribute to a better understanding and the eventual manipulation of salt perception and salt tolerance mechanisms in plants.