Pea cultivation has been developed as a rich source of protein in many countries. The spring cultivation of chickpeas has low performance and efficiency due to the short length of the growth period and the confrontation of the reproductive period with drought and high temperature stress. Autumn cultivation of chickpeas is introduced as an important solution in reducing the yield caused by high temperature and drought stress during the flowering time of spring cultivation. However, in autumn cultivation, sensitivity to cold is the main limitation. So, the present study was performed to investigate the effect of nitric oxide on stress memory due to seed priming with sodium nitroprusside for cold tolerance of chickpea seedlings under simulated autumn temperatures. This experiment was conducted as a factorial in a completely randomized design with nine replicates at the Research Center for Plant Sciences of Ferdowsi University, Mashhad Iran, in 2020. Experimental factors included seed priming at two levels (control and sodium nitroprusside) and chickpea cultivars, including a susceptible genotype (MCC505) and a cold-tolerant cultivar (Saral). This experiment evaluated the gene expression of antioxidant enzymes (superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase) in the seedling stage. The results revealed that superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase genes were expressed in sodium nitroprusside and control treatments. In the Saral cultivar, sodium nitroprusside increased the gene expression of superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase enzymes by 29, 88, 54, and 63%, respectively. On the other hand, the gene expression of these enzymes in the control treatment may be due to the effect of temperature on them. There was a significant increase in the expression of superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase genes in the Saral cultivar compared to the MCC505 genotype. In general, sodium nitroprusside increased the activity of antioxidant enzymes in the Saral cultivar through the expression of antioxidant enzyme genes.

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