Expression Analysis of OsPMP3 Gene Family and the Improvement of Salt Tolerance by its Overexpression in Rice Plants

Abstract

For plant salt tolerance, it is important to understand mechanisms for Na⁺ transport and restriction of Na⁺ uptake in plants under saline conditions. In the previous reports, we have found that RCI2A can alleviate salinity-induced growth suppression and photooxidative damages via reducing Na⁺ uptake into the shoots in Arabidopsis plants. In this report, we identified seven expressed OsPMP3 genes of rice plants, which are homologous to RCI2A. The transcripts of three OsPMP3 genes were induced by high salinity. The mRNA of salt-inducible OsPMP3 genes was detected in mesophyll cells of leaf blades and lateral root cap cells of roots. The overexpression of OsPMP3-3 gene in rice plants alleviated the suppression of shoot growth under NaCl treatment via reducing Na⁺ uptake into the shoots. These results suggest that OsPMP3 gene family contributed to maintaining ion homeostasis and that the abundant expression of OsPMP3 can improve salt tolerance of rice plants.