ALBERT

Description: 〈h3〉Abstract〈/h3〉 〈span〉 〈h3〉Background and aims〈/h3〉 〈p〉Increasing cadmium (Cd) contamination of agricultural soils is a serious problem. Identification of the mechanisms that control Cd uptake by roots is essential if we wish to improve the efficiency of plants in removing Cd from contaminated soils.〈/p〉 〈/span〉 〈span〉 〈h3〉Methods〈/h3〉 〈p〉We dissected the role and the mechanism of 〈em〉S〈/em〉-nitrosoglutathione reductase (GSNOR) in regulating root Cd uptake in 〈em〉Arabidopsis〈/em〉 plants using GSNOR-related mutants and pharmacological methods.〈/p〉 〈/span〉 〈span〉 〈h3〉Results〈/h3〉 〈p〉Exposure to Cd stimulated the activity of GSNOR in roots. Both treatment with 〈em〉S〈/em〉-nitrosoglutathione (substrate of GSNOR) in wild-type plants and loss of GSNOR function in 〈em〉gsnor〈/em〉 mutants improved expression of 〈em〉IRON-REGULATED TRANSPORTER 1〈/em〉 (〈em〉IRT1〈/em〉) and increased root Cd uptake, thereby elevating the Cd levels in plants. The opposite patterns were observed in the 〈em〉GSNOR〈/em〉 over-expression transgenic plant 〈em〉GSNOR〈/em〉〈sup〉〈em〉OE〈/em〉〈/sup〉, suggesting a negative regulation of 〈em〉IRT1〈/em〉 expression and Cd uptake by GSNOR. However, both the improvement of Cd uptake owing to 〈em〉S〈/em〉-nitrosoglutathione treatment or 〈em〉GSNOR〈/em〉 mutation and the inhibition of Cd uptake due to 〈em〉GSNOR〈/em〉 over-expression, could be blocked by loss of function of IRT1 in plants.〈/p〉 〈/span〉 〈span〉 〈h3〉Conclusions〈/h3〉 〈p〉We concluded that induction of GSNOR reduced Cd uptake because of its negative regulation of IRT1 in roots, which lowered Cd accumulation in plants.〈/p〉 〈/span〉