[Signal molecules involved in the regulation of the wheat defense response to Septoria nodorum infection].

The response of Triticum aestivum L. to infection by Septoria nodorum Berk, a pathogen causing speckled leaf blotch, was studied. The effect of salicylic acid (SA) and jasmonic acid (JA) signal molecules, as well as chitooligosaccharides (COSs) with different acetylation degrees (ADs), on the accumulation of hydrogen peroxide (Н2О2) in wheat leaves and the pathogenesis-related (PR) proteins of oxalate oxidase (AJ556991.1), peroxidase (TC 151917), and proteinase inhibitor (EU293132.1) was investigated. Treatment with the signal molecules inhibited S. nodorum growth and stimulated Н2О2 accumulation, as well as PR gene expression. SA and COS with 65% AD are found to be more efficient in Н2О2 induction and elevation of the transcriptional level of the oxalate oxidase and peroxidase genes. At the same time, JA and COS with 30% AD stimulated transcription of the proteinase inhibitor gene. The results suggest the existence of differential means of defense response induction by signal molecules with more prospects for the regulation of plant immunity.

[The effect of salicylic and jasmonic acids on the activity and range of protective proteins during the infection of wheat by the septoriosis pathogen].

The influence of salicylic (SA) and jasmonic (JA) acids as signaling systems mediators on the generation of H2O2 and expression of genes encoding protective proteins was studied in the leaves of wheat Triticum aestivum L. upon infection with the pathogen of septoriosis Septoria nodorum Berk. It was found that presowing treatment of seeds with SA and JA decreased the development of the fungus on the leaves of wheat and had a stimulating effect on the production of H2O2 in the area of infection. An increased expression of genes encoding oxalate oxidase AJ556991.1 and anionic peroxidase TC 151917 was shown in infected tissues with the method of polymerase chain reaction.

[Activity of protective proteins in wheat plants treated with chitooligosaccharides with different degrees of acetylation and infection with Bipolaris sorokiniana].

The influence of chitooligosaccharides (COS) with different degrees of acetylation (DA) on the production of hydrogen peroxide (H2O2) and changes in the level of gene expression of pathogenesis-related (PR) proteins (oxalate oxidase AJ556991.1, peroxidase TC 151917, chitinase AV029935L, proteinase inhibitor EU293132.1) in the roots of the wheat Triticum aestivum L. inoculated with root rot pathogen Bipolaris sorokiniana (Sacc.) Shoenaker was investigated. Differences were detected in plant responses to infection. These differences were due to the pretreatment of COS seeds with differing DA. Our results demonstrated that COS with a DA over 65% more effectively induced accumulation of H2O2 and increased the transcriptional activity of genes of PR-proteins as compared to COS with a DA of 30%. These data suggest an important role for DA in the manifestation of eliciting properties of COS, also in the presence of H2O2.

[Comparison of the transcriptional activity of protective protein genes in different wheat cultivars infected with Septoria nodorum Berk].

A comparison was performed with respect to the transcriptional activity of protective protein genes (peroxidase TC 151917, oxalate oxidase AJ556991.1, and proteinase inhibitor EU 293132.1) in five wheat cultivars (Omskaya 35 and 36, Simbirka, Bashkirskaya 26, and Kazakhstanskaya 10) infected with Septoria nodorum Berk, which causes septoria disease. The intensity of parasite development on leaves was assessed based on the areas of infectious sites in plant tissues. This value was minimal in cultivars Omskaya 35 and 36 and maximal in cultivars Simbirka and Kazakhstanskaya 10; cultivar Bashkirskaya 26 was at an intermediate position. Resistant cultivars had a higher degree of transcriptional activity of genes of anionic peroxidase, oxalate oxidase, and proteinase inhibitor during infection than sensitive cultivars. Our data demonstrate the prospects of using expression levels of the AJ556991. 1, TC 151917, and EU 293132.1 genes as markers for the selection of resistant wheat cultivars.