Poster: Salinity

Abs # 168: Overexpression of SOS1, a plasma membrane Na⁺/H⁺ antiporter, improves salt tolerance in Arabidopsis

Presenter:	Zhu, Jian-Kang , jkzhu@ag.arizona.edu
Authors	Zhu, Jian-Kang  (A)   Shi, Huazhong  (A)   Lee, Byeong-ha  (A)   Stevenson, Rebecca  (A)
Affiliations:	(A): University of Arizona
Web Site:	http://ag.arizona.edu/pls/zhulab

High concentrations of toxic Na⁺ in saline soils inhibit plant growth and reduce agricultural productivity. We report here that overexpression of the Arabidopsis SOS1 gene encoding a plasma membrane Na⁺/H⁺ antiporter driven by the CaMV 35S promoter improves plant salt tolerance. The transgenic plants showed a dramatic up-regulation of SOS1 transcript level upon NaCl treatments, suggesting a post-transcriptional control of SOS1 transcript accumulation. In response to NaCl treatment, transgenic plants overexpressing SOS1 accumulated less Na⁺ in the xylem transpirational stream and in the shoot. Undifferentiated callus cultures regenerated from the transgenic plants were also more tolerant to salt stress, which was correlated with reduced Na⁺ content in the trangenic cells. These results show that improved salt tolerance could be achieved by limiting Na⁺ accumulation in plant cells.