BACKGROUND: Garden pea (Pisum sativum L.) possesses the ability to form beneficial symbioses with various soil microorganisms. However, different pea cultivars, genotypes, and lines gain more or less benefit from these interactions, so the trait named efficiency of interaction with soil microorganisms (EIBSM) was suggested to describe this phenomenon. The molecular mechanisms underlying the manifestation of the EIBSM trait are not properly studied, and only few works focusing on plant responses to combined microbial preparations have been published to date. METHODS: Eight pea lines previously described as contrasting in manifestation of the EIBSM trait were grown in pots with soil under combined inoculation with nodule bacteria and arbuscular mycorrhizal fungi, and the transcriptome profiles of the whole root systems of the plants were investigated using 3'MACE RNA sequencing. RESULTS: The relatedness of the lines inferred from the analysis of transcripts SNVs (Single Nucleotide Variants) corresponded to the manifestation of the EIBSM trait: three high-EIBSM lines and three low-EIBSM lines formed two distinct clusters. Thus, the gene expression profiles were compared between these two clusters, which enabled identification of transcriptome signatures characteristic for each group. The lines previously described as high-EIBSM have lower symbiotic activity, and the expression levels of pathogen response genes were elevated compared to the lines with low EIBSM. CONCLUSION: This result suggests that the mechanism of high interaction efficiency may be connected to stricter host control of symbionts, allowing such plants to expend less on the symbioses.

Background. The active and careless applying of antibiotics in medicine and agriculture leads to the emergence of resistance to the existing antimicrobial drugs, which reduces the effectiveness of their use. One of the ways to solve this problem is the development of new antibiotics based on plant peptides with antimicrobial activity, for example plant defensins (which identified in all plants) and NCR peptides that are specifically synthesized in nodules of some leguminous plants. Materials and methods. In the present study, a meta-assembly of a transcriptome was constructed based on publicly available RNA-sequencing transcriptomes of pea nodules (Pisum sativum L.). This meta-assembly was used to search for sequences encoding antimicrobial peptides. Results. As a result, 55 and 908 unique sequences encoding defensins and NCR peptides, respectively, were identified. The recognition site for the signal peptidase was predicted and sequences were divided into the signal and mature part of the peptide. Among mature defensins, 22 peptides possess in silico predicted antimicrobial activity, and for the NCR peptides family their number was 422. Conclusion. Sequences encoding defensins and NCR peptides expressed in nitrogen-fixing pea nodules were identified. They are candidates for testing their antimicrobial activity in vitro.

Background. A major problem of the environmental pollution with heavy metals, including cadmium, requires an intensive study of the molecular and genetic mechanisms underlying the tolerance of plants to these toxic substances. In this study we present a comparative analysis of the expression of stress-related genes in two pea genotypes contrasting in tolerance to cadmium. Materials and methods. A unique mutant of pea SGECdt, characterized by the increased tolerance to cadmium, and initial line SGE were used. Gene expression was analyzed by Real Time PCR. Results. In the line SGE cadmium increase the expression of genes, encoding catalase, chitinase, chitinase-like protein PRP4A and dirigent protein PI206. In the mutant SGECdt cadmium increase the expression of genes, encoding chitinase, glutathione reductase and defensin DRR230. In control samples expression of genes encoding PRP4A and DRRR230 was enhanced in mutant SGECdt versus line SGE. Conclusion. It was shown that, the reaction of the mutant SGECdt at the molecular level differs from that of the line SGE. In the mutant SGECdt, a change in the expression of a number of genes is observed, which may indicate that cadmium entering the cell causes activation of defense reactions.