Enhanced salt tolerance of transgenic wheat ( Tritivum aestivum L.) expressing a vacuolar Na +/H + antiporter gene with improved grain yields in saline soils in the field and a reduced level of leaf Na +

Abstract

Wheat productivity is severely affected by soil salinity mainly due to Na + toxicity to plant cells. To improve the yield performance of wheat in saline soils, we have generated transgenic wheat expressing a vacuolar Na +/H + antiporter gene AtNHX1 from Arabidopsis thaliana, to enhance the plant capacity of reducing cytosolic Na + by sequestering Na + in the vacuole. The AtNHX1 transgenic wheat lines exhibited improved biomass production at the vegetative growth stage and germination rates in severe saline conditions. A field trial revealed that the transgenic wheat lines produced higher grain yields and heavier and larger grains in the field of saline soils with the electrical conductivity values of soil saturation extracts (EC e) of 10.6 and 13.7 dS m −1. The transgenic lines accumulated a lower level of Na + and a higher level of K + in the leaves than non-transgenic plants under saline conditions (100 and 150 mM NaCl). These results indicate that the salt tolerance of wheat and grain yield in saline soils can be improved by enhancing the level of the vacuolar Na +/H + antiporter.