Tag Archives: Triticum aestivum L.

Influence of salicylic and succinic acids on formation of active oxygen forms in wheat coleoptiles

Yu. Ye. Kolupaev, T. O. Yastreb, M. V. Shvidenko, Yu. V. Karpets

V. V. Dokuchaev Kharkiv National Agrarian University, Ukraine;
e-mail: plant_biology@mail.ru

The comparative study of influence of exogenous salicylic (SaA) and succinic (SuA) acids on the production of reactive oxygen species by isolated wheat coleoptiles has been provided. Under the action of both acids the increase of generation of superoxide anion-radical (O2•–) was observed. This increase was partially suppressed by treatment of coleoptiles with inhibitors of peroxidase (salicylhydroxamic acid) and NADP·H-oxidase (imidazole and α-naphthol). The increase of hydrogen peroxide content, activity of peroxidase and superoxide dismutase (SOD) was registered under the influence of SaA and SuA; catalase activity did not change essentially. The treatment of coleoptiles with the indicated acids resulted in the increase of their resistance to abiotic stress (damaging heating, 43±0.1 °С, 10 min). The conclusion is made, that the increase of O2•– generation in wheat coleoptiles under the action of SaA and SuA is related, probably, to the increase of apoplast peroxidase and NADP·H-oxidase activity, and the rise of H2O2 content is related to the growth of SOD activity. These enzymatic systems are involved in the induction of plant cells protective reactions to the hyperthermia.

Purification and properties of lipoxygenase from wheat seedlings infected by Fusarium graminearum and treated by salicylic acid

О. О. Моlodchenkova1, V. G. Аdamovskaya1, L. Y. Ciselskaya1,
L. Ya. Bezkrovnaya1, T. V. Kаrtuzova1, V. B. Iablonska2

1Plant Breeding and Genetics Institute-National Center of Seed
and Cultivar Investigation, Ukraine;
e-mail: olgamolod@ukr.net;
2Оdessa National Medical University, Ukraine;
e-mail: 93vi_63@mail.ru

Lipoxygenase from wheat seedlings in normal conditions, infected by Fusarium graminearum and  treated by salicylic acid was isolated. The isolated enzyme was purified by the methods of salting-out (60% ammonium sulphate), dialysis, gel-filtration and ion-exchange chromatography. Specific activity of the purified enzyme was 8.0-12.5 ΔЕ234/mg of protein, degree of purification – 11.6-15.3 times. The enzyme yield was 18.3-27.9%. Molecular mass of lipoxygenase is 90 kDa, amino acid composition is distinguished by a high content of glutamic acid, proline, valine, isoleucine, leucine and low level of histidine, tyrosine, phenylalanine, threonine, tryptophan, cystein. Research of lipoxygenase substrate dependence indicated that the enzyme  catalysed with the maximum velocity of the reaction of arachidonic acid oxidation at a substrate concentration of 4.5 mM at pH 7.2, the reaction of linoleic acid oxidation at a substrate concentration of 4.5 mM at pH 7.2 and the reaction of linolenic acid oxidation at a substrate concentration of 9.0 mM at pH 8.0. The change of wheat lipoxygenase activity depending on genotype resistance to Fusarium graminearum and millieu of germination was shown. One of the manifestations of the protective effect of salicylic acid is its ability to induce changes of lipoxygenase activity.

Participation of the active oxygen forms in the induction of ascorbate peroxidase and guaiacol peroxidase under heat hardening of wheat seedlings

Yu. E. Kolupaev, O. I. Oboznyi

V. V. Dokuchayev Kharkiv National Agrarian University, Ukraine;
e-mail: plant_biology@mail.ru

The influence of one-minute hardening heating at 42 °C on the dynamics of hydrogen peroxide generation and activity of antioxidant enzymes in roots of winter wheat seedlings has been investigated. It was shown that the content of hydrogen peroxide increased within the first 30 minutes after heat influence, whereupon it approached the level of control variant. The activity of superoxide dismutase (SOD) increased significantly within 10 min after heating and was maintained at a high level during 24 hours of observation. The activi­ty of ascorbate peroxidase and guaiacol peroxidase increased after 3-6 hours after the hardening and reached its maximum after 24 hours, when there was the most significant increase in heat resistance of seedlings. The short-term increase in hydrogen peroxide content caused by hardening heating was suppressed by treatment of seedlings with H2O2 scavenger dimethylthiourea, inhibitors of NADPH-oxidase (imidazole) and SOD (sodium diethyldithiocarbamate). All these effectors levelled the increase of activity of ascorbate peroxidase and guaiacol peroxidase and significantly inhibited the development of heat resistance of seedlings. The conclusion was made about the role of hydrogen peroxide produced with the participation of NADPH­-oxidase and SOD in the induction of antioxidant system by heat harde­ning of wheat seedlings.

Signal mediators at induction of heat resistance of wheat plantlets by short-term heating

Yu. V. Karpets, Yu. E. Kolupaev, T. O. Yastreb

V. V. Dokuchaev Kharkiv National Agrarian University, Ukraine;
e-mail: plant_biology@mail.ru

The effects of functional interplay of calcium ions, reactive oxygen species (ROS) and nitric oxide (NO) in the cells of wheat plantlets roots (Triticum aestivum L.) at the induction of their heat resistance by a short-term influence of hyperthermia (heating at the temperature of 42 °С during 1 minute) have been investigated. The transitional increase of NO and H2O2 content, invoked by heating, was suppressed by the treatment of plantlets with the antagonists of calcium EGTA (chelator of exocellular calcium), lanthanum chloride (blocker of calcium channels of various types) and neomycin (inhibitor of phosphatidylinositol-dependent phospholipase C). The rise of hydrogen peroxide content, caused by hardening, was partially suppressed by the action of inhibitors of nitrate reductase (sodium wolframate) and NO-synthase (NG-nitro-L-arginine methyl ester – L-NAME), and the increasing of nitric oxide content was suppressed by the treatment of plants with the antioxidant ionol and with the scavenger of hydrogen peroxide (dimethylthiourea). These compounds and antagonists of calcium also partially removed the effect of the rise of plantlets’ heat resistance, invoked by hardening heating. The conclusion on calcium’s role in the activation of enzymatic systems, generating reactive oxygen species and nitric oxide, and on the functional interplay of these signal mediators at the induction of heat resistance of plantlets by hardening heating is made.

Reactive oxygen forms and Ca ions as possible intermediaries under the induction of heat resistance of plant cells by jasmonic acid

Yu. V. Karpets, Yu. E. Kolupaev, T. O. Yastreb, O. I. Oboznyi,
M. V. Shvydenko, G. A. Lugova, A. O. Vayner

Dokuchayev Kharkiv National Agrarian University, Ukraine;
e-mail: plant_biology@mail.ru

The participation of reactive oxygen species (ROS) and calcium ions in realization of influen­ce of exogenous jasmonic acid (JA) on the heat resistance of wheat coleoptiles has been investigated­. Influence of 1 µM JA caused the transitional intensifying of generation of superoxide anion-radi­cal (O2•–) and hydrogen peroxide in coleoptiles with the maximum within 15-30 minutes after the treatment beginning. Within the first hour after the beginning of coleoptiles treatment with JA the increase of superoxide dismutase (SOD) activi­ty was noted. Later on (within 5-24 hours after the treatment beginning) there was the lowering of ROS generation by coleoptiles of experimental variant, and the SOD activity approached the control value. Intensifying of generation of superoxi­de radical induced by JA was suppressed by the antioxidant ionol and was partially levelled by imidazole (inhibitor of NADPH-oxidase), EGTA (chelator of extracellular calcium) and lanthanum chloride (calcium channels blocker). Pretreatment of coleoptiles with the ionol, imidazole, EGTA and LaCl3 also partially removed the effect of increase of their resistance to the damaging heating caused by exogenous JA. It is supposed that the ROS gene­rated with participation NADPH-oxidase, which activity depends on the receipt of calcium ions from extracellular space in the cytosol, are involved in realization of physio­logical effects of JA.

Role of Ca ions in the induction of heat-resistance of wheat coleoptiles by brassinosteroids

Yu. E. Kolupaev1, A. A. Vayner1, T. O. Yastreb1, A. I. Oboznyi1, V. A. Khripach2

1V. V. Dokuchaev Kharkiv National Agrarian University, Ukraine;
e-mail: plant_biology@mail.ru;
2Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus;
e-mail: khripach@iboch.bas-net.by

The involvement of Ca2+ into the signal transduction of exogenous brassinosteroids (BS) (24-epibrassinolide – 24-EBL and 24-epicastasterone – 24 ECS) causing the increase of heat resistance of the cells of wheat (Triticum aestivum L.) coleoptiles was investigated using calcium chelator EGTA and inhibitor of phosphatidylinositol-specific phospholipase C – neomycin. Twenty-four-hour treatment of coleoptile segments with 10 nM solutions of 24-EBL and 24-ECS led to a transient increase in the generation of superoxide anion radical by cell surface and the subsequent activation of superoxide dismutase and catalase. Pretreatment of coleoptiles with EGTA and neomycin depressed to a considerable extent these effects and leveled the increase in heat resistance of wheat coleoptiles that were caused by BS. Possible mechanisms of involvement of calcium signaling into the formation of reactive oxygen species in plant cells and induction of heat resistance of plant cells by the action of exogenous BS have been discussed.