Abstract
ABSTRACT Salt stress is one of the very harsh abiotic stresses plants face which affects crops growth and productivity. Studying gene regulation in plants under salts attracts scientists worldwide. Using T-DNA strategy has become a crucial approach in studying gene function and regulation. In Arabidopsis, OSM1 (for osmotic stress-sensitive mutant 1) (At1g28490) gene; which is similar to SYP61 (syntaxin of plants 61) has not been investigated enough under abiotic stress. We tested this gene under salt stress using wild type and osm1 mutant line (Salk_107167) grown on soil for the first time. In this mutant, the T-DNA appeared in the promoter and in the correct site as reported by the database and genotyping investigation showed no deviation from Mendel’s bases. In the mutant, the transcript accumulation, based on cDNA detection, appeared lower comparing to wild type plants. Wilting and yellowish symptoms appeared earlier and clearer on homozygous plants compared to wild type. Salt tolerance measured as plant survival, was significantly reduced in homozygous comparing to wild type plants. This result shows that the T-DNA being inserted in the promoter has affected the level of gene transcription in the mutant under salt stress and the low survival with low transcript abundance may indicate a role of OSM1 gene in osmotic stress response but it was not enough to show clear differences in plant survival.