Seed Priming Improves Biochemical and Physiological Performance of Wheat Seedlings under Low-Temperature Conditions

Wheat is a widely cultivated cereal throughout the world and stress caused by low temperatures significantly affects all stages of wheat development. Seed priming is an effective method to produce stress-resistant plants. This work was carried out to determine whether different priming methods (hormo-, halo-, osmo-, and hydropriming) can increase the resistance of wheat to low-temperature conditions (10 °C). The effect of priming on growth, as well as the biochemical and physiological performance of wheat seedlings were monitored. In general, priming had a significant stimulatory effect on the monitored characteristics. Hormo- and halopriming had a positive effect on the growth, vigor index, and total soluble protein content of wheat seedlings. Additionally, hormopriming reduced the malondialdehyde (MDA) content in wheat seedlings compared to unprimed seeds. A dominant effect on antioxidant enzymes (superoxide-dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase, and pyrogallol peroxidase) was recorded after seed priming with KNO₃. The effectiveness of priming was also confirmed through the increased content of phenolic compounds (including flavonoids), and total antioxidant activity. The HPLC analysis showed increased content of chlorogenic acid, catechin, 4-hydroxy benzoic acid, sinapic acid, rutin, naringin, and quercetin in primed wheat seedlings compared to unprimed grown seedlings under low-temperature conditions with the best effects achieved by hormo- and hydropriming. It is concluded that seed priming can be regarded as a promising approach for increasing the resistance of wheat seedlings to low-temperature stress.