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

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.

[Isolation and properties of lectins from cell walls of wheat seedlings infected by Fusarium graminearum and treated by salicylic acid].

Lectins from cell walls of wheat seedlings in normal conditions and infected by Fusarium sp. and treated by salicylic acid were isolated by the methods of gel-filtration, affinity chromatography and isoelectric focusing, their biochemical properties were studied. It is shown that isolated preparations of lectins suppressed the development of colonies of fungus Fusarium graminearum. A conclusion was made on the possibility of employment of isolated lectins in the molecular-breeding programs on raising wheat resistance towards fusariosis.

[Response of corn plants to the effect of salicylic acid and Fusarium moniliforme]. / Otvetnaia reaktsiia rastenii kukuruzy na deistvie salitsilovoi kisloty i Fusarium moniliforme.

Effect of salicylic acid and Fusarium moniliforme on trypsin inhibitor activity, lectine activity, lectine carbohydrate specificity, and salicylic acid content in sprouted maize was studied. Changes in trypsin inhibitor activity, lectine activity, and content of endogenous salicylic acid during action of exogenous salicylic acid or pathogen were shown to depend on resistance of maize lines to fusariosis pathogen. Salicylic acid was proposed to take part in induction of trypsin and lectine inhibitors. Trypsin and lectine inhibitors are important in formation of sprouted maize resistance to abiotic and biotic factors.

[Genetic stability of wheat to fusaria and its connection with trypsin inhibitor activity in seed]. / Geneticheskaia ustoichivost' pshenitsy k fuzariozu i ee sviaz' s aktivnost'iu ingibitora tripsina v zerne.

The results of a complex estimation of hybrid lines isolated in F10 from a crossing octoploid triticale and winter hard wheat after a spontaneous hybridization of partially sterile plants with synthetic amphiploid H74/90-245 are presented. It is shown that neither contents of trypsin inhibitor nor resistance to fusarial rots conjugate with resistance to other diseases or to frost. Activity of trypsin inhibitor in grain endosperm allow a decision to be made concerning the presence of alien genetic material in the wheat genome. The donors of group resistance to diseases with a high protein content in a flour are selected.

[Trypsin inhibitors of wheat seedlings infected and treated with salicylic acid]. / Ingibitory tripsina iz infitsirovannykh i obrabotannykh salitsilovoi kislotoi prorostkov pshenitsy.

Using the method of affinity chromatography for trypsin-sepharose, followed by PAGE electrophoresis the component composition of trypsin inhibitors was studied. The inhibitors were extracted from the winter wheat seedlings which were infected with Fusarium fungus and also from the seedlings treated with salicylic acid. Under the action of pathogen not only a quantitative increase in the protein components of trypsin inhibitor but also the appearance of a new component with a molecular weight of 29 kDa are observed. The influence of Fusarium graminearum and salicylic acid on the amino acid composition of trypsin inhibitors has been studied. After the inhibitors purification their antienzyme spectrum was studied along with their influence on the pathogen proteases. It was established that the inhibitors influence only the activity of trypsin and chymotrypsin and do not influence the activity of pepsin, elastases, papain, proteinases from the wheat seedlings. The existence of arginine and absence of lysine was demonstrated in the active centre of the inhibitors.