[Compartmentation of salicylate-induced proteins].

A key factor of immunity, salicylic acid (exogenous or accumulating under the action of biotrophic or semibiotrophic pathogens on plants), causes the formation of not only protective antipathogenic proteins but also many proteins, which enhance the resistance of host plant cells. Salicylate-induced proteins, which are encoded by nuclear genes and formed with cytoplasmic ribosomes, function in the cytosol or are transported into nuclei, vacuoles, plastids, mitochondria, and outside the plasmalemma. This review is focused on salicylate-induced proteins, which are not only delivered into different compartments but are also involved in their transmembrane transport.

[Salicylate-induced modification of plant proteomes (review)].

Here we present a brief review of the reports concerning proteome modifications under the influence of salicylic acid, which is one of the major mediators of both local and systemic immunity. We describe also the results of our own studies of the salicylate-induced changes in proteomes of pea leaves and roots. Fifteen salicylate-inducible proteins, which were previously unknown, have been identified. Unlike the roots, leaves accumulated some chloroplast proteins and enzymes capable of degrading the pathogen cell walls. In the roots, salicylic acid increased the content of enzymes, improving the resistance of plant cells themselves, and promoted the disappearance of reductase of oxophytodienic acid. The latter could lead to inhibition of jasmonic acid synthesis and stimulation of local immunity. High (apoptotic) concentration of salicylic acid intensified synthesis of root proteins involved in the formation of heteroprotein complexes, which play an important role in the functioning of the signaling system, DNA synthesis and repair, and protein synthesis, refolding, and proteolysis.

[Immunomodulating activity of chitosan derivatives with salicylic acid and its fragments].

A study of biological activity of the derivatives of the chitin-chitosan oligomer with salicylic acid and its fragments showed that chitosan salicylate actively protected potato tubers against Phytophthora infestans but sharply inhibited reparation of potato tissues. N-(2-Hydroxybenzyl)chitosan exhibited good protective properties but did not influence wound reparation. N-(2-Hydroxy-3-methoxybenzyl)-N-pyridox-chitosan, which contained the pyridoxal and 2-hydroxy-3-methoxy fragments, was the most efficient, stimulating both defense against late blight and wound reparation in potato tissues.

[Pathogen-induced plant proteins]. / Patogen-indutsiruemye belki rasteni

Pathogen-induced plant proteins are classified by their functional characteristics: (a) involvement in plant cell signaling; (b) inhibition of enzymes excreted by the pathogens; (c) stabilization of plant cell walls or ability to trigger apoptosis; (d) enzymatic activity producing lysis of cell walls of pathogenic fungi and bacteria; (e) enzymatic activity in metabolic pathways of phenylpropane and terpene phytoalexins; and (f) ability to affect the pathogens directly, by disturbing the function of their cell membranes or by inactivating their ribosomes. Examples of transgenic plants with increased immunity against pathogens are also provided.

[Involvement of polar lipids in polyenoic fatty acid formation in greening wheat seedlings]. / Ob uchastii poliarnykh lipidov v obrazovanii polienovykh zhirnykh kislot v zeleneiushchikh propostkakh pshenitsy.

After the dark incorporation of [1-14C]acetate into etiolated wheat seedlings the bulk of the labelled fatty acids was found in the neutral lipids of mitochondria and microsomes; the incorporation into etioplast fatty acids was considerably smaller. The saturated fatty acids, namely palmitic and stearic ones, were predominantly synthesized in the dark; the incorporation of the label into the polyenoic fatty acids was not detected. Upon continuous illumination the radioactivity of fatty acids was increased, firstly in the phospholipids and then in the galactolipids. The illumination caused desaturation of oleic acid to linoleic and linolenic acids. The formation of linoleate was associated with microsomal phosphatidylcholine, and that of linolenate--with plastidal galactosyldiacylglycerol. The kinetics of the label incorporation into the unsaturated fatty acids is consistent with the concept that microsomal phosphatidylcholine can act as a linoleate donor for its further desaturation within the composition of chloroplast galactolipids. Galabiosyldiacylglycerol differs from galactosyldiacylglycerol by a lower content of [14C]linolenic acid and unsaturated 14C--fatty acids of the hexadecanoate type. The specific localization of [14C] linolenate in galactosyldiacylglycerol suggests that either lynoleoyl-CoA (with the further acyl transfer on galactosylmonoacylglycerol) or linoleate-containing molecular species of galactosyldiacylglycerol can be true substrates fo linoleate delta 15-desaturase. A scheme for the proposed subcellular localization of dark- and light-induced paths of free and complex lipid-bound fatty acids synthesis is presented.

[Glycerolipid biosynthesis in vivo in subcellular fractions of greening wheat sprouts]. / Biosintez glitserolipidov in vivo v subkletochnykh fraktsiiakh zeleneiushchikh propostkiv pshenitsy.

The kinetics of [I-14C]acetate incorporation into the glycerolipids of subcellular fractions during the greening of dark-grown wheat sprouts were studied. Up to 80% of the label were incorporated into neutral lipids in the darkness. The main labelled polar lipids were phosphatidic acid, phosphatidyl choline and phosphatidyl glycerol. The synthesis of the latter two compounds was predominantly coupled with the microsomal fraction. Illumination increased the galactolipid formation in the plastids, particularly that of galactosyldiacylglycerol. The role of phosphatidic acid and phosphatidyl choline as possible precursors of the galactolipid biosynthesis in developing plastids is discussed.