Ca2+-dependent oxidation of exogenous NADH and NADPH by the mitochondria of spring wheat and its relation with AOX capacity and ROS content at high temperatures

• Published in: Journal of plant physiology Vol. 283; p. 153943
• Main Authors: Fedotova, Olga A., Polyakova, Elizaveta A., Grabelnych, Olga I.
• Format: Journal Article
• Language: English
• Published: Elsevier GmbH 01.04.2023
• Subjects: Alternative oxidase; High temperature; Mitochondria; ROS; Type II NAD(P)H dehydrogenases; Wheat; OPPP; TCA cycle; NAD(P)H DHs; Alternative oxidase; AOX; High temperature; BHAM; COX; NDB; AP; Mitochondria; ETC; ROS; Type II NAD(P)H dehydrogenases; Wheat
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1016/j.jplph.2023.153943

Mitochondria are sources of reactive oxygen species (ROS) in a plant cell under high temperature. Mitochondrial alternative NAD(P)H dehydrogenases (type II NAD(P)H DHs) and cyanide-resistant oxidase (AOX) can regulate ROS production, but their role at high temperatures is unknown. This study investigates the influence heat acclimation (37 °C) and heat shock (50 °C) temperatures on ROS content, activity and protein abundance of external Ca2+-dependent NAD(P)H DHs (NDB) and AOX in mitochondria of 4- and 8-day-old seedlings of spring wheat (Triticum aestivum L., var. Novosibirskya 29). The shoots of 4-day-old seedlings contained more carbohydrates, had a higher rate of total respiration and a high rate of oxidation of exogenous NADH, a greater AOX capacity and a lower of ROS content, as compared to leaves of 8-day-old seedlings, and were more resistant to heat shock. The activity of external NADH DH was higher than the one of NADPH DH in mitochondria of both shoots and leaves. At 37 °C, high NADH oxidation was associated with increased AOX capacity in mitochondria of both shoots and leaves, whereas NADPH oxidation with COX capacity. At 50 °C, the NADPH oxidation by shoots’ mitochondria increased and the NADH oxidation stayed high. The content of NDB and AOX proteins depends on heat treatments and differs between mitochondria of shoots and leaves. Our data indicate that Ca2+-dependent type II NAD(P)H DHs can regulate the ROS content and together with AOX are involved in heat tolerance, depending on the development phase of spring wheat and is, probably, tissue-specific. •At high temperatures, the rate of exogenous Ca2+-dependent NAD(P)H oxidation depends on the development stage of plant.•A rate of NADH oxidation is related to AOX capacity, but NADPH oxidation is related to COX capacity at heat acclimation.•The Ca2+-dependent type II NAD(P)H DHs and AOX are involved in wheat seedlings' adaptation to high temperatures.•The Ca2+-dependent type II NAD(P)H DHs can regulate ROS production in mitochondria at high temperatures.