The expression of GmP5CS, GmPAP3, and GmBZIP50 genes under saline condition in soybean using real-time PCR

Salinity in higher plants is the cause of toxicity and osmotic stress. To identify the expression pattern of salinity tolerance genes in soybean, it was investigated the relative expression of three genes, GmPAP3, GmBZIP50 and GmP5CS at two tissues leaf and root in Williams (as tolerant) and L17 (as susceptible) soybean genotypes under two levels zero (control) and 300 Mm NaCl. For adaptation of plantlets to salinity, salinity was started with 150 mM NaCl for first time and followed by 300 mM NaCl in two times. The housekeeping gene 18SrRNA was used to normalize data. Data analysis showed that all three genes expression increased under salinity stress. The expression of GmP5CS and GmBZIP50 was two-fold greater in Williams than in L17 genotype, while GmPAP3 expression was 2.5-fold greater in L17 than in Williams. The expression of GmP5CS and GmBZIP50 was higher in roots than in leaves, while GmPAP3 expression was higher in leaves than in roots. In conclusion, GmBZIP50 over-expressed more than two other genes by 375 and 273% in leaves and roots under stressed compared to non-stressed plants. Thus GmBZIP50 could be more effective candidate gene for producing soybeans with resistance to salinity that may be resulted from transferring and increasing copy number