Fabiana Aparecida Cavalcante Silva^1,2, Carlos Eduardo Alves^1,2, Cássio David Alves da Paz³, Greecy M R Albuquerque², Carolina Elsztein², Maria Paloma S. de Barros², Tercilio Calsa Junior ³, Bianca Galucio Pereira Araujo², José Luiz Sandes de Carvalho Filho ¹

The tomato (Solanum lycopersicum L.), a solanaceous plant native to South America, is the second most widely used vegetable in the world. Northeast Brazil accounts for 13.3% of Brazilian tomato production, and the state of Pernambuco ranks 11th in national production. Diseases caused by plant pathogens are one of the main constraints on the expansion of tomato cultivation, particularly bacterial wilt, a disease caused by a complex of bacterial species of the genus Ralstonia. In the state of Pernambuco, R. solanacearum is prevalent in the sertão region, and R. pseudosolanacearum (Rp) is prevalent in the Agreste region and the metropolitan region of Recife. This study evaluated the proteomic response of three tomato cultivars, two of which are resistant and have low market accessibility: Hawaii 7996 (International Standard for Resistance to Rs) and Yoshimatsu (National Standard for Resistance to Rs). The cultivar Caline IPA-7, developed by the Agronomic Institute of Pernambuco (IPA), presents good agronomic performance and fruit characteristics, but is susceptible to bacterial wilt. The isolate CCRMRs202O of Rp, Biovar 3, Phylotype 1, Sequevar I-18, obtained in the city of Gravatá, Pernambuco (Rosa Mariano Culture Collection/UFRPE), was used. The experiment was conducted in a randomized block design in grow houses. Seedlings with 11 days of germination were used, and inoculation occurred by the root cut method using a bacterial cell concentration of approximately 1x108 CFU mL-1. Leaf tissue was collected 4 days after inoculation, and total soluble proteins were extracted using the phenolic method of Wang et al. (2006), with modifications, and quantified on the Qubit system. Proteins were then subjected to SDS-PAGE electrophoresis to verify sample integrity. Tryptic digestion was performed on aliquots of each triplicate, followed by LC-MS/MS mass spectrometry analysis. Bioinformatics analyses were performed using the Maxquant, Perseus, Uniprot, Blast2GO, ShynyGO, and String/Cytoscape platforms. A total of 1,385 proteins were obtained, of which those directly linked to the defense response of the Yoshimatsu and Caline IPA-7 cultivars were selected. The results revealed the occurrence of the uracil phosphoribosyltransferase (UPRT) protein exclusively in the resistant cultivar Hawaii, providing an integral role for pyrimidine metabolic genes in the tomato response to Rp. Several classes of pathogenesis-related proteins (PRs) were also identified, such as PR10, observed exclusively in the Yoshimatsu cultivar. The universal stress protein (PHOs/USP), known for promoting resistance to multiple stresses, regulating ROS homeostasis, and regulating plant growth/development, were identified. The results may aid in the development of breeding programs for the selection of resistant genotypes, contributing to the sustainability of tomato production in the face of phytopathogenic challenges.

Agradecimentos: FACEPE, CETENE, MCTI, UFRPE e UFPE