Influence of selenite on selenium uptake, differential antioxidant performance and gene expression of sulfate transporters in wheat genotypes

The effect of high selenite supply on Se uptake, antioxidant performance and gene expression of two sulfate transporters in three wheat genotypes was investigated. Puelche, Tinto and Kumpa wheat genotypes were grown hidroponically at 0, 30 or 60 mu M selenite. Shoots and roots were harvested during 7days to evaluate Se uptake, lipid peroxidation, SOD activity and radical scavenging activity. Measurements of ROS, chloroplasts morphological changes and sulfate transporters expression (Taesultr1.1a and Taesultr4.1) were also made. Tinto and Kumpa taken up lower Se amounts than Puelche and total biomass of all wheat genotypes decreased at 7days as a consequence of Se supply. Nevertheless, Puelche exhibited the lowest reduction of shoot yield without changes in root DW, which was concomitant with both the decrease of about 30 % of lipid peroxidation and the maintenance of SOD activity. Differential changes in ROS production, chloroplast morphology and gene expression of sulfate transporters were found among the three genotypes during the experiment. Puelche appear to be the most Se-tolerant wheat genotype because of its lowest oxidative damage due to preserved SOD activity and its greatest Se accumulation. This behaviour was associated with the strongest transcript level of Taesultr4.1 sulfate transporter in roots.