Polishchuk O. Glycans Basidiomycetes as inhibitors of TMV infection and inductors of plants resistance to viruses

Dissertation is dedicated to investigation of glycans Basidiomycetes as inhibitors of TMV infection and inductors of plants resistance to viruses. On the model of tobacco mosaic virus (TMV) the ability of glycans extracted from Basidiomycota mushrooms to inhibit biological activity of plant viruses and induce plant resistance to viral infection has been demonstrated first. It was investigated the character of polysaccharides action as a plant resistance inductor and viral infection inhibitor. The mechanisms of their influence on TMV infection in sensitive and hypersensitive plants have been differentiated. It was shown that Tremella mesenterica, Ganoderma lucidum, Ganoderma applanatum and Ganoderma adspersum produce substances that can inhibit a TMV infections and reproduction in tobacco and datura plants. The substances with antiviral activity which has been extracted by different methods from a cultural liquid and mycelium of Basidiomycetes mushrooms are presented as glucans. From a mycelium of G.adspersum a glucan was extracted with molecular weight in 48 kDa through acid boiling and in 70 kDa through alkali boiling. Glucan which was extracted through water boiling contains some components with a different molecular weight - 95, 48 and 20 kDa. Polysaccharide preparations, extracted from cultural liquid both Ganoderma lucidum and Ganoderma applanatum in tobacco plants, don't influence on the protective mechanisms which are determined by N-gene, whereas glucuronoxylomannan (GXM) of T.mesenterica and glucan of G. adspersum can activate them. It was shown that resistance induced by GXM of T.mesenterica and glucan of G. adspersum is formed with participation of cellular genome, in particular, through the RNA synthesis on the DNA matrix in a cell de novo. Also, it was found out that these glycopolymers can influence on initial stages of hypersensitive reactions based on conformational protein-carbohydrate interaction of molecules. It was proved through a partial reduction of antiviral activity of preparations at the presence of a-methyl-D-mannoside. GXM of T.mesenterica and glucan of G.adspersum inhibit early stages of TMV reproduction in sensitive tobacco plants.