Genome-Wide Identification and Expression Analysis of the Thaumatin-like Protein Genes in Filipendula ulmaria under Bipolaris sorokiniana Infection

Pathogenesis-related (PR) proteins are crucial for plant defense against pathogen infection. However, the specific role of thaumatin-like proteins (TLPs), which comprise the PR-5 family, in plant immune responses has not been thoroughly investigated. Filipendula ulmaria is a medicinal plant with valuable pharmacological properties, including antimicrobial, anti-inflammatory, gastroprotective, immunomodulatory, and anticancer activities. The structure of the TLP family and its role in the immune system of meadowsweet have not been studied so far. The goal of this study was to analyze in detail the TLP gene family in meadowsweet and explore its response to fungal infection. In the meadowsweet genome, we identified 27 putative TLP genes, examined their structure and location on chromosomes, analyzed cis-regulatory elements in the promoter regions, predicted the structure and physicochemical characteristics of the encoded proteins, and performed a phylogenetic analysis. We also studied the differential expression of TLP genes under Bipolaris sorokiniana infection. Of six differentially expressed genes, three genes were up-regulated 48 h post-infection, suggesting their involvement in defense response to the fungus. The results obtained shed light on the role of the TLP gene family in the immune system of F. ulmaria and form the foundation for the creation of disease-resistant crops in agriculture and the development of bio-based antimicrobials in medicine.