State of antioxidant system in triticale seedlings at cold hardening of varieties of different frost resistance

Abstract

Effect of cold hardening on state of antioxidant system (AOS) of triticale (× Triticosecale Wittmack) seedlings of varieties, differed in frost resistance, namely Buket and Raritet (winter, high-frost-resistant), and Alexandra and Pidzymok Kharkovskiy (facultative, less resistant) was studied. In absence of cold hardening, a clear connection between studied indicators of the AOS state and frost resistance of the varieties was not observed. After hardening of seedlings at 2–4 °C for 6 days, the activity of superoxide dismutase (SOD) and catalase increased in the high-frost-resistant varieties Buket and Raritet. In less resistant ones—Alexandra and Pidzymok Kharkovskiy—the activity of these enzymes changed less significantly. At the same time, the activity of guaiacol peroxidase increased more noticeably after hardening in these varieties. Hardened seedlings of the Buket, Raritet and Alexandra varieties had significantly higher sugar content than the Pidzymok Kharkovskiy. The proline content in response to cold hardening increased in all varieties, while the absolute values in the varieties Buket, Raritet and Pidzymok Kharkovskiy were significantly higher than in the Alexandra. Cold hardening caused a significant increase in the content of anthocyanins and flavonoids, absorbing in UV-B, in the Buket, Raritet and Alexandra, but not in the Pidzymok Kharkovskiy. The content of lipid peroxidation product malondialdehyde after a 6-h damaging action of − 7 °C increased in the varieties Alexandra and Pidzymok Kharkovskiy and slightly changed in the Buket and Raritet. In general, a positive relationship was found between AOS activity and frost resistance of hardened triticale seedlings. This relationship was most clearly manifested for indicators of SOD activity and flavonoid content.