RESUMEN
Salinity significantly increased trisodium-8-hydroxy-1,3,6-pyrenetrisulphonic acid (PTS) uptake and decreased the K(+)/Na(+) ratio in salt-sensitive rice (Nipponbare) but did not markedly in salt-tolerant rice (Pokkali). Proline and glycinebetaine (betaine) suppressed the increase in PTS uptake and the decrease in the K(+)/Na(+) ratio in Nipponbare, but did not affect PTS uptake or the K(+)/Na(+) ratio in Pokkali.
Asunto(s)
Betaína/farmacología , Reguladores del Crecimiento de las Plantas/farmacología , Hojas de la Planta/efectos de los fármacos , Prolina/farmacología , Tolerancia a la Sal/efectos de los fármacos , Semillas/efectos de los fármacos , Cationes Monovalentes , Transporte Iónico/efectos de los fármacos , Oryza , Hojas de la Planta/fisiología , Potasio/metabolismo , Pirenos/metabolismo , Salinidad , Tolerancia a la Sal/fisiología , Semillas/fisiología , Sodio/metabolismo , Especificidad de la Especie , Ácidos Sulfónicos/metabolismoRESUMEN
We investigated the mechanism of selenium (Se) tolerance using an Arabidopsis thaliana knockout mutant of a sulfate transporter, sultr1;2. Se stress inhibited plant growth, decreased chlorophyll contents, and increased protein oxidation and lipid peroxidation in the wild type, whereas the sultr1;2 mutation mitigated damage of these forms, indicating that sultr1;2 is more tolerant of Se than the wild type is. The accumulation of symplastic Se was suppressed in sultr1;2 as compared to the wild type, and the chemical speciation of Se in the mutant was different from that in the wild type. Regardless of Se stress, the activities of ascorbate peroxidase, catalase, and peroxidase in the mutant were higher than in the wild type, while the activity of superoxide dismutase in the mutant was the same as in the wild type. These results suggest that the sultr1;2 mutation confers Se tolerance on Arabidopsis by decreasing symplastic Se and maintaining antioxidant enzyme activities.