[Not Available].

The influence of treatment with the donor of nitric oxide sodium nitroprusside (SNP – 0,5 mM) on the salt resistance of Arabidopsis plants of wild-type (Col-0) and transformant with the gene of bacterial salicylatehydroxylase (NahG) was compared. The basic resistance against the salt stress (200 mM of NaCl) in transformants NahG was higher. In the conditions of salt stress these plants differed in the higher activity of antioxidant enzymes and the raised content of carbohydrates and anthocyans.

[Content of Osmolytes and Flavonoids under Salt Stress in Arabidopsis thaliana Plants Defective in Jasmonate Signaling].

The effects of the salt stress (200 mM NaCl) and exogenous jasmonic acid (JA) on levels of osmolytes and flavonoids in leaves of four-week-old Arabidopsis thaliana L. plants of the wild-type (WT) Columbia-0 (Col-0) and the mutant jin1 (jasmonate insensitive 1) with impaired jasmonate signaling were studied. The increase in proline content caused by the salt stress was higher in the Col-0 plants than in the mutant jin1.

SIGNAL MEDIATORS AT INDUCTION OF HEAT RESISTANCE OF WHEAT PLANTLETS BY SHORT-TERM HEATING.

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 degrees C 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).

[SIGNAL MEDIATORS IN PLANTS RESPONSES AGAINST ABIOTIC STRESSORS: CALCIUM, REACTIVE OXYGEN AND NITROGEN SPECIES].

The perception of signals of abiotic stressors by plant cells is accompanied by the increase of cytosolic calcium concentration, content of reactive oxygen species (ROS) and nitrogen monoxide (NO) which execute the role of signal mediators at the activation of gene expression, supervising protective reactions. Calcium ions, ROS, and NO are in the multiple functional interactions which provides the intensifying and transduction of signals into genetic apparatus as well as their attenuation. The increase of content, at least, of one of these signal mediators in cells can cause activation of some signal cascades and formation of plant adaptive reactions.

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

The involvement of Ca2+ into the signal transduction of exogenous brassinosteroids (BS) (24-epi-brassinolide-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.