[The participation of salicylic and jasmonic acids in genetic and induced resistance of tomato to Meloidogyne incognita (Kofoid and White, 1919)].

Salicylic (SA) and jasmonic (JA) acids are the best known mediators of signal systems in plants. In this investigation the participation and character of interactions between SA- and JA-signals under the induced and genetic resistance of plants to nematodes was investigated on the model system tomato (Lycopersicon esculentum) and the root-knot nematode Meloidogyne incognita. This study demonstrates that application of JA and SA to tomato foliage induces systemic effects that suppress root-knot nematode infestation, inhibition of nematode reproduction, and also increased activity of LOX and PAL, the enzymes of biosynthesis of JA and SA.

[Involvement of salicylic acid in induction of nematode resistance in plants].

The role of salicylic acid (SA) as a possible signaling component in the case of the infection of plants with nematodes has been studied using a model system consisting of the tomato (Lycopersicon esculentum (Mill.) and race 1 of the gall eelworm Meloidogyne incognita (Kofoid and White, 1919; Chitwood, 1949). The pre-planting SA treatment of tomato seeds results in an increased nematode resistance of susceptible tomato cultivars; the protective effect is higher in the case of SA combined with chitosan, a biogenic elicitor of plant resistance.

[Steroid furostanol glycosides: a new class of natural adaptogenes (review)].

The present review summarizes experimental data revealed while studying the mechanism of the adaptogenic effect of furostanol glycosides (FG) extracted from Dioscorea deltoidea Wall cell culture under the conditions of biotic stress in tomato plants Lycopersicon esculenium Mill. induced by the gall nematode Meloidogyne incognita Kofoid et White. Comparison of changes in isoprene content (phytosterines, tomatin, and carotenoids) and in the rate of oxidative processes in the leaves and roots of intact and treated plants evidence that FG cause nonspecific defense reactions resulting in the formation of systemic acquired resistance.

[Genetic variability and differentiation of three Russian populations of yellow potato cyst nematode Globodera rostochiensis as revealed by nuclear markers].

Genetic variability of yellow potato cyst nematode G. rostochiensis from three Russian populations (Karelia, Vladimir oblast, and Moscow oblast) was investigated using two types of nuclear markers. Using RAPD markers identified with the help of six random primers (P-29, OPA-10, OPT-14, OPA-11, OPB-11, and OPH-20), it was possible to distinguish Karelian population from the group consisting of the populations from two adjacent regions (Moscow oblast and Vladimir oblast).

[Adaptogenic effects of furostanol glycosides of Dioscorea deltoidea wall on oxidative processes in tomato plants in biotic stress].

The effect of furostanol glycosides of cell culture of Dioscorea deltoidea Wall on oxidative processes in tomato plants subjected to invasion with the gall nematode Meloidogyne incognita Kofoid et White was studied. We showed that furostanol glycosides induce a nonspecific defensive response in plants. Exposure of cell membranes to furostanol glycosides cause rearrangements in fatty acids resulting in the formation of conjugated dienes, which makes molecules thermodynamically more stable under stress conditions.

[Biochemical aspects of plant interactions with parasite nematodes. (A review)].

The review summarizes reports on molecular aspects of interactions of phytoparasitic nematodes with plant hosts. Data on the secrets of nematodes affecting plants (elicitors, toxins, products of parasitism genes, etc.) are analyzed and information flow pathways comprising all elements of the plant-parasite interaction (from elicitors to defense responses of plant cells), described.

[Interaction between structure of plant steroids and their effect on phytonematodes].

The effects of certain plant steroids of the groups of furostanol glycosides, glycoalkaloids, and alpha-ecdysone on growth and development of phytoparasitic nematodes were studied. It was shown using an experimental system including tomato, Lycopersicon esculentum Mill., and root-knot nematode, Meloidogyne incognita Kofoid et White, that steroid molecule had significant nematicidic activity if it contained a carbohydrate moiety and an additional heterocycle in the steroid core.

[Photosynthetic pigments of tomato under conditions of biotic stress and effects of furostanol glycosides].

Adaptogenic effect of furostanol glycosides (FG) on biosynthesis of photosynthetic pigments in tomato plants (Lycopersicon esculentum Mill.) were studied under conditions of biotic stress caused by root-knot nematode (Meloidogyne incognita Kofoid et White). Treatment of plants with 5 x 10(-4) M FG was accompanied by an increase in the rate of biosynthesis of pigments (particularly, chlorophyll b and carotenoids), which was observed against the background of a decrease in the relative contribution of beta-carotene and an increase in the relative contribution of pigments of violaxanthin cycle (VXC) to the overall pool of carotenoids.

[Role of isoprenoid compounds in plant adaptation to biogenic stress caused by parasitic nematodes].

Parasitic nematodes are considered as a biogenic stress factor in plants. The effects of various plant isoprenoids, including mono-, sesqui-, di-, and triterpenoids, sterols, and steroid glycosides, on parasitic nematodes are reviewed. Certain isoprenoids can be placed in the class of natural plant adaptogens.

[Modulation of plant resistance to diseases by water-soluble chitosan].

Low-molecular-weight water-soluble chitosan with a molecular weight of 5 kDa obtained after enzymatic hydrolysis of native crab chitosan was shown to display an elicitor activity by inducing the local and systemic resistance of Solanumi tuberosum potato and Lycopesicon esculentum tomato to Phytophthora infestans and nematodes, respectively. Chitosan induced the accumulation of phytoalexins in tissues of host plants, decreased the total content and changed the composition of free sterols producing adverse effects on infesters, activated chitinases, beta-glucanases, and lipoxygenases, and stimulated the generation of reactive oxygen species. The activation of protective mechanisms in plant tissues inhibited the growth of taxonomically different pathogens (parasitic fungus Phytophthora infestans and root knot nematode Meloidogyne incognita).