Activities of Hydrogen Peroxide-Scavenging Enzymes during Low-Temperature Hardening of Potato Plants Transformed by the desA Gene of Δ12-Acyl-Lipid Desaturase

• Published in: Russian journal of plant physiology 2018-09, Vol.65 (5), p.667-673
• Main Authors: Naraikina, N. V., Sin’kevich, M. S., Deryabin, A. N., Trunova, T. I.
• Format: Article
• Language: English
• Subjects: Ascorbic acid; Biomedical and Life Sciences; CAT2 protein; Catalase; Cold treatment; Decomposition; Desaturase; Electrophoresis; Enzymes; Fatty acids; Guaiacol; Hardening; Hydrogen peroxide; Isoforms; L-Ascorbate peroxidase; Life Sciences; Lipids; Low temperature; Peroxidase; Plant Physiology; Plant Sciences; Polyunsaturated fatty acids; Potatoes; Research Papers; Scavenging; Solanum tuberosum; Synechocystis; Vegetables
• ISSN: 1021-4437; 1608-3407
• DOI: 10.1134/S1021443718040064

Activities of enzymes decomposing hydrogen peroxide (H 2 O 2 ) under long exposure to hardening low temperatures and the effect of Δ12-acyl-lipid desaturase on these processes were studied on potato ( Solanum tuberosum L., cv. Desnitsa), which typically represents cold-tolerant plants. We compared nontransformed plants (control) and the line transformed with the construction carrying the target desA gene of the mentioned desaturase from cyanobacterium Synechocystis sp. PCC ( desA-licBM3 plants). The plants were hardened at 5°C for six days under illumination of 50 μmol/(m 2 s). The hardening was found to favor plant tolerance to the subsequent frost, and the desA-licBM3 plants exceed the controls in this property. Of the studied H 2 O 2 -scavenging enzymes, soluble type III peroxidases (guaiacol peroxidases) displayed the most activity, and type I peroxidase (ascorbate peroxidase) was the least active in the two potato lines over the hardening period. The activity of catalase increased twofold in the control and fourfold in the transformed plants in the first day of the hardening. However, the doubled catalase activity did not appear to compensate the H 2 O 2 accumulation over this period. The recorded rise in catalase activity in the desA-licBM3 plants, together with the high activity of guaiacol peroxidases, favored lowering the hydrogen peroxide level in comparison with the initial values. For the first time, electrophoresis revealed two catalase isoforms, CAT1 and CAT2, in leaves of both potato lines. The significance of CAT1 was greater than that of CAT2 in the total catalase activity during the hardening period. It is concluded that, under the long-term cold hardening of potato plants, the content of hydrogen peroxide is determined by highly active guaiacol peroxidases and Class I catalase exerting energy-independent H 2 O 2 decomposing. In this case, in the transformants that are rich in membrane lipids, where polyunsaturated fatty acids predominate, the activity of H 2 O 2 -scavenging enzymes increased significantly more than in the control, which is why the hardening of the transformants is more effective.