Advance in NRAMP gene functions in regulating plant heavy metal absorption and transport.

Abstract

Toxic heavy metals in soil may inhibit plant growth and seriously affect crop yield and quality. Natural resistance-associated macrophage transporter proteins (NRAMP) are widely distributed in the plasma and vacuolar membranes of roots, stems, and leaves. The amino acid sequences of NRAMP are highly conserved and have similar secondary structures among species. These proteins regulate the absorption of heavy metals in soil and their isolation, distribution, and transport to the stem from root. NRAMP gene plays an important role in regulating the absorption and tolerance of heavy metal in soil. Here, we reviewed the structural characteristics of NRAMP family members and their absorption, transport, accumulation, and detoxification effects on various heavy metals in different plant species. The mechanism and regulatory pathway of plant NRAMP gene affecting soil heavy metal absorption were discussed, which might provide a reference for further revealing the mechanism of plant NRAMP family and promoting the improvement of soil producing environment.