Identification and characterization of Arabidopsis mutants in genes useful for phytoremediation

MC ROMERO-PUERTAS; A SEVILLA-PEREA; M SANZ-FERNÁNDEZ; M RODRÍGUEZ-SERRANO; LB PENA; LM SANDALIO; MD MINGORANCE, M

Barcelona

Congreso; XV Spanish Portuguese Congress of Plant Physiology; 2017

Sociedad Española de Fisiología Vegetal

Emissions of heavy metals have risen largely over the past 200 years and significantly exceed those from natural sourcesfor practically all metals. Soil represents the most important sink for anthropogenic and natural heavy metal. Thus soil contaminated with metals pose a major environmental and human health problem that is still in need of an effective technological solution. Phytoremediation is a cost-effective ?green? technology based on the use of metal-accumulating plants to remove pollutants from the environment. Phytoremediation strategies may be able to recover soil productivity in self-sustaining ecosystems; however, there are few descriptions of the molecular mechanisms involved in plant heavy metal perception and signalling.The aim of this work is to assemble a ?molecular tool box? of genes useful for phytoremediation. To identify mutants with different heavy metal-tolerance, we first selected a medium from mixtures containing three metals based on their presence in two Spanish mining areas: Riotinto, highly contaminated and Alquife, moderately contaminated. We have screened about 7,000 lines of Arabidopsis T-DNA mutants and we found 74 lines more resistant and 56 more susceptible than wild type (WT). We have identified all these genes and classified depending on their metabolic function, showing that they were mainly linked to transport, protein modification and signalling, with RNA metabolism being the most representative category in the resistant phenotypes and protein metabolism in the sensitive ones. We have characterized some resistant mutants and one sensitive.These mutants showed differences in growth, oxidative metabolism and metal translocation. Additionally, we found that these mutants keep their phenotype inamended former soils, suggesting that these genes may be useful for phytoremediation and the recovery of contaminated soils.This study was supported by the Fundación Ramón Areces (http://www.fundacionareces.es) Spain, by ERDF co-financed grant BIO2015-67657-P from MICINN and the Junta de Andalucía (BIO-337).