Effects of Fe and Mn cations on Cd uptake by rice plant in hydroponic culture experiment

PLoS One. 2020 Dec 10;15(12):e0243174. doi: 10.1371/journal.pone.0243174. eCollection 2020.

Abstract

Iron (Fe) and manganese (Mn) are nutritional components of rice, plays an important role in its physiological processes and can minimize absorption of cadmium (Cd) in rice. Fe, Mn, and Cd transporters such as CAL1, OsNRAMP5, OsNRAMP1, OsIRT1, OsHMA3, and OsNAAT1 regulate uptake of Cd in rice. However, the effect of exogenous application of Fe, and Mn on the accumulation of Cd and relative expression (RE) of these transporters in rice has not been investigated. Therefore, a hydroponic culture experiment was conducted to investigate the impact of Fe and Mn on Cd uptake and RE of these transporters in rice. The results showed that the Fe and Mn application significantly decreased Cd in the roots and shoots of rice. Whereas, Cd concentration in the rice significantly increased with increasing Cd concentration in the solution. The addition of manganese in the culture medium can reduce the cadmium content of rice roots by 11.9-82.3% and shoots by 11.6-85.0%, while the addition of iron in the culture medium can reduce the cadmium content of rice roots and shoots by 26-65% and 9-683% respectively. Meanwhile, application of sufficient doses of Fe and Cd in solution culture increased RE of CAL1, OsNRAMP5, OsNRAMP1, OsIRT1, and OsNAAT1 in roots, whereas expression level of OsHMA3 was decreased. Similarly, expression level of CAL1, OsNRAMP5, and OsNRAMP1 significantly increased in roots in high Cd and Mn deficient treatments. This may be concluded that the Cd increases expression of CAL1, OsNRAMP5, OsNRAMP1, OsIRT1, and OsNAAT1 but decreases OsHMA3 expression in rice roots, which resulted in increased Cd uptake in hydroponically grown rice.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cadmium / metabolism*
  • Gene Expression Regulation, Plant / drug effects
  • Hydroponics
  • Iron / pharmacology*
  • Manganese / pharmacology*
  • Oryza / drug effects*
  • Oryza / metabolism
  • Plant Leaves / metabolism
  • Plant Roots / metabolism
  • Plant Shoots / metabolism
  • Polymerase Chain Reaction

Substances

  • Cadmium
  • Manganese
  • Iron

Grants and funding

We are thankful to Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences and National Key Research and Development Program of China for funding and resources. The research was funded by the National Key Research and Development Program of China, under grant no (2016YFD0800406) and project “Research on Migration/Transformation and Safety Threshold of Heavy Metals in Farmland Systems. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.