Number: 04 Date: 07/07/2006 Category: Agri-food Contact: Manuel Megías Guijo Telephone: 954 556 766 Email: megiasg@us.es

SEVILLE-BASED SCIENTISTS DESIGN LEGUMINOUS PLANTS RESISTANT TO SOIL ACIDITY OR SALINITY

Researchers from the University of Seville and ‘Las Torres-Tomejil’ CIFA (IFAPA, Andalusian Institute for Agrarian, Fishering and Food Research and Training ), a body attached to the Andalusian Ministry of Innovation, Science and Enterprise, are trying to increase the agrarian capacity of certain varieties of beans and soy under extreme conditions of salinity and acidity. They are using environmental-friendly techniques for that. The project, led by Dr. Manuel Megías Guijo and classified as a project of excellence by the Andalusian Ministry of Innovation, Science and Enterprise, is based on the study of the nodulation genes that are part of the symbiosis process between these leguminous plants and certain rhizobiaceae-type bacteria. In such process, bacteria help the plant to fix atmospheric nitrogen, although environmental factors such as acidity or salinity can limit this activity and slow down the growth. For the symbiosis to take place, the coordinated expression of both the bacteria and the plant’s genes is essential. The latter excretes a series of compounds (flavonoid compounds, among others) that make the bacteria synthesise and transport LCO molecules known as factor Nod or LCO. The presence of said molecule provokes a series of changes in the roots of leguminous plants that are essential for the symbiosis to be successfully completed. Hence the interest in studying the nodulation genes that intervene in such process. Leguminous plants are very important indeed thanks to their regular use in human and animal food. Moreover, they are pioneers in the recovery of soils, which is very relevant if we take into account that 25% of agrarian soil is degraded as a result of intensive farming. The research project methodology, funded with 180,000, includes regulation studies by means of classic genetics and new technologies (genomics, proteomics and transcriptomics) in order to assess the effects that abiotic stress causes in the regulation of bacterial genes involved in the symbiosis. If we understand this mechanism we will be able to correct the gaps of the symbiosis system by searching for strains that are highly tolerant under abiotic stress conditions which have a better regulation system to control the symbiosis, thus improving the leguminous plants production for human and animal food. Finally, the findings resulting from this research project could be expanded and applied to other scientific symbiosis pairs of rhizomes and leguminous plants that are useful for human and animal food (alfalfa, clovers, peas, lupines, chickpeas and peanuts) that allow the use of degraded soils as productive soils. In addition to this, the idea is to optimise the effectiveness of this symbiosis in acid or saline soils by choosing rhizomes and other plants adapted to these extreme conditions.