Induced Genes Expression Pattern in Response to Drought Stress in Repeseed (Brassica napus)

To study the effects of drought stress treatments on rapessed, an experiment was carried out in greenhouse using a randomized complete block design with five replications. Seeds of Falcon cultivar were sown on light filler and transferred into the greenhouse after vernalization. Drought stress treatments were -0.5, -1, -2, -4 and -6 bar which applied by using equivalent water. To measure the amount of chlorophyll and TABARM (oxidative index at cellular level), leaf samples were collected monthly. Leaf sample were also collected at maximum vegetative growth for molecular studies and gene expression interpretation. Traits such as leaf number, leaf area, days to 50% flowering and phenotypic appearance were recorded in each treatment. Based on the results, amount of most traits decreased significantly by increasing drought intensity. Chlorophyll amount reflected also the same pattern. There was no visible difference between the effects of control treatment and -0.5 bar on gronomic traits and level of gene expression, whereas deterioration of traits and increase of TABARM were severe in -2 bar drought treatment which coincided with gene expression alteration. The activity of most drought stress related resistance genes started in -1 bar and increased by increase of drought stress intensity. A synchronization between alteration of traits, biochemical indices and gene expression in response to drought stress was detected in this investigation.