The investigation of some photorespiration genes relative expression in response to drought stress in canola (Brassica napus)

Drought is one of the most devastating environmental stresses that adversely affect plant metabolic processes. Many plant genes such as photorespiration ones are involve in response to drought stress. In the present study, the effects of drought stress on the expression level of two peroxisomal (Hydroxy pyruvate reductase (HPR1) and Glycolate oxidase (GO)) and two mitochondrial (Serine hydroxy methyl transferase (SHMT) and Glycine decarboxylase (GDC)) genes were studied in susceptible (Hayola308) and tolerant (SLM046) genotypes of canola (Brassica napus) under stress (irrigation cut at flowering stage) and non-stress conditions. The result of real time-PCR showed that in Hyola308 genotype the expression level of GO gene at 48, 72 and 96 hours after stress was higher than SLM046 genotype. In Hyola308 genotype, the highest expression level of GDC gene observed at 48 hours of stress and then decreased. The highest relative expression level of SHMT gene in both Hyola308 and SLM046 genotypes detected at 24 hours after stress and then in SLM046 genotype, its level decreased at 48 hours after stress, while in Hyola308 genotype, its expression declined over the time of exposure to stress. SLM046 genotype showed highest amount of HPR1 expression level at 48 hours after stress. It seems that the expression of photorespiration genes in SLM046 genotype increased at the initial times of exposure to stress and with continue the stress, it showed more adaptation to stress and control the photorespiration unlike Hyola308.