Tag Archives: salicylic acid

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.