Gene expression profile for SvGRP-transformant and WT Arabidopsis seedlings under salt stress

Sprobolus virginicus is a halophytic C4 grass found in worldwide from tropical to warm temperate regions. A Japanese genotype showed a salinity tolerance up to 1,500 mM NaCl, a three-fold higher concentration than seawater salinity. To identify key genes involved in the regulation of salt tolerance in S. virginicus, random cDNA libraries were constructed from salt-treated leaves, and were introduced into Arabidopsis for salt tolerant plant screening. Eight independent transgenic lines were found to be more salt tolerant than wild type from the screen of 3011 lines on the medium containing 175 mM NaCl. Among the selected lines, two contained cDNAs encoding glycine-rich RNA-binding proteins (GRPs). To identify transcriptomic change in the GRP-transgenic line, we performed microarray analysis of the transgenic line and WTunder salt stress. Gene expression in transgenic Arabidopsis expressing a gene for glycine-rich RNA-binding protein from S. virginics was analysed. Five-day old transgenic and WT (Col-0) seedlings were transplanted to medium supplemented with 0 or 150 mM NaCl, harvested at 24 h after transplanting, and used for RNA extraction. n=3