Comparison of biochemical and molecular responses of two Brassica napus L. cultivars differing in drought tolerance to salt stress

Abstract

In this study, levels of MDA, total protein, soluble sugars, and enzymes activity including POX, APX, and CAT were measured in 12 dSm−1 NaCl treated seedlings belong to Licord (drought sensitive cultivar) and SLM046 (drought tolerant cultivar) of Brassica napus. The results showed that salinity increased the amount of MDA, soluble sugars and total protein in both cultivars. Two cultivars partially displayed different trend concerning enzymatic activities under salt stress experiment. Moreover, transcript abundance of four genes involved in signal transduction pathway including Auxin responsive protein, Protein kinase, MAPK3 and MAPK4 were explored at 0, 3, 6, 12 and 24 h under 12 dSm−1 NaCl treatment using RT-PCR approach. The molecular analyses of Licord cultivar revealed the lowest accumulation of all genes after 6 h exposure to NaCl except MAPK3 which was detected at the highest level at this time point. Molecular results of SLM046 cultivar showed that maximum expression of all genes occurred after 6 h treatment except MAPK3 which showed the lowest transcript at 6 h. Our studies indicate better response of SLM046 cultivar to salinity condition compared to Licord cultivar.