Роль фитогормонов в регуляции экспрессии генов эффекторов и специфических факторов транскрипции патогена Stagonospora nodorum в культуре

Abstract

The causative agent of wheat blotch the pathogenic fungus Stagonospora nodorum Berk. is one of the most harmful wheat pathogens. Necrotrophic effectors (NE) have been identified in the pathogen, which ensure the virulence of S. nodorum strains to the host plant, in the genome of which the dominant susceptibility gene corresponding to the effector is present. Currently, the study of the regulation of the genes expression responsible for virulence is becoming an increasingly important objective. Recently, the role of various transcription factors (TFs) in the regulation of effector genes expression in the fungal pathogens has been established. However, new data are emerging on the effect of hormones on the growth, development, and virulence of pathogenic fungi. Therefore, the aim of our research was to study the effect of cytokinins (CK) and abscisic acid (ABA) on the expression of the NE SnToxA, SnTox1, SnTox3, and TF SnStuA, SnPf2, and SnCon7 genes in various isolates of the pathogen S. nodorum SnB, Sn4VD, Sn9MN-3A, and Sn1SP, which differ in virulence. Our results showed that the intensity of NE and TF gene expression was associated with the aggressiveness of the pathogen isolate, and TF gene expression correlated with NE gene expression. The highest expression of NE genes was found in SnB and Sn1SP isolates. When the hormones ABA or CK were added to the cultivation medium, they mainly had a positive effect on the expression of the NE and TF genes. ABA treatment increased the expression of all three NE genes SnToxA, SnTox3, and SnTox1. Treatment with CK had a positive effect only on the expression of the SnTox3 gene. Based on the results, an assumption was made about the indirect effect of hormones on virulence factors through the regulation of growth and metabolism of fungi.