Tag Archives: lipoxygenase

Lipoxygenases and their metabolites in formation of plant stress tolerance

L. M. Babenko1, M. M. Shcherbatiuk1, T. D. Skaterna2, I. V. Kosakivska1

1M.G. Kholodny Institute of Botany, National Academy of Sciences of Ukraine, Kyiv;
2Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: lilia.babenko@gmail.com

The review focuses on the analysis of new information concerning molecular enzymology of lipoxygenases – proteins involved in lipid peroxidation and found in animals and plants. Modern concept of structural features, catalytic characteristics and functions of lipoxygenase family enzymes as well as products of their catalytic activity in plants have been discussed and summarized. Issues of enzyme localization in plant cells and tissues, evolution and distribution of lipoxygenases, involvement in production of signaling substances involved in formation of adaptation response to abiotic and biotic stress factors and in regulation of lipoxygenase signal system activity are highlighted. Participants of the elements signaling of LOX-pathway reception and transduction into genome are considered. Special attention is given to jasmonates, metabolites of the allene oxide synthase branch of the lipoxygenase cascade, because these metabolites have high biological activity, are ubiquitously present in all plant organisms, and are involved in regulation of vitally important processes. Data concerning lipoxygenase phylogeny, possible occurrence of a common predecessor for modern isoforms of the enzyme in pro- and eukaryote have been examined. Some results of our studies that open up possibilities of using the lipoxygenase catalytic activity characteristics as biological markers in plant stress tolerance researches are given.

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.

Lipoxygenases and plant cell metabolism regulation

I. V. Pokotylo, Y. S. Kolesnikov, M. V. Derevyanchuk, A. I. Kharitonenko, V. S. Kravets

Institute of Bioorganic Chemistry and Petrochemistry,
National Academy of Sciences of Ukraine, Kyiv;
e-mail: kravets@bpci.kiev.ua

Lipoxygenases are widespread plant enzymes that catalyze the peroxidation of polyunsaturated fatty acids. This reaction is pivotal in the enzymatic cascade that leads to production of numerous metabolism regulators named oxylipins. The activity of these biologically active substances is directly associated with defence reactions in conditions of biotic and abiotic stresses as well as with the regulation of plant growth, propagation and senescence. In this review the contemporary notions about lipoxygenases­ classification, structure and catalytic properties are summarized. The features of enzyme activity regulation by transcriptional and posttranslational mechanisms in addition to the role of lipoxygenase catalysis in plant cell signalling are discussed.