Tomato leaf mold disease caused by Cladosporium fulvum (C. fulvum) is one of the most common diseases affecting greenhouse tomato production. Cf proteins can recognize corresponding AVR proteins produced by C. fulvum, and Cf genes are associated with leaf mold resistance. Given that there are many physiological races of C. fulvum and that these races rapidly mutate, resistance to common Cf genes (such as Cf-2, Cf-4, Cf-5, and Cf-9) has decreased. In the field, Ont7813 plants (carrying the Cf-13 gene) show effective resistance to C. fulvum; thus, these plants could be used as new, disease-resistant materials. To explore the mechanism of the Cf-13-mediated resistance response, transcriptome sequencing was performed on three replicates each of Ont7813 (Cf-13) and Moneymaker (MM; carrying the Cf-0 gene) at 0, 9, and 15 days after inoculation (dai) for a total of 18 samples. In total, 943 genes were differentially expressed, specifically in the Ont7813 response process as compared to the Moneymaker response process. Gene ontology (GO) classification of these 943 differentially expressed genes (DEGs) showed that GO terms, including “hydrogen peroxide metabolic process (GO_Process)”, “secondary active transmembrane transporter activity (GO_Function)”, and “mismatch repair complex (GO_Component)”, which were the same as 11 other GO terms, were significantly enriched. An analysis of the Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that many key regulatory genes of the Cf-13-mediated resistance response processes were involved in the “plant hormone signal transduction” pathway, the “plant–pathogen interaction” pathway, and the “MAPK signaling pathway–plant” pathway. Moreover, during C. fulvum infection, jasmonic acid (JA) and salicylic acid (SA) contents significantly increased in Ont7813 at the early stage. These results lay a vital foundation for further understanding the molecular mechanism of the Cf-13 gene in response to C. fulvum infection.

PLATZ, a novel zinc finger DNA-binding protein, plays crucial regulatory roles in the growth and development of various plants and in the modulation of abiotic stress responses. However, knowledge of the functions of PLATZ genes in tomato (Solanum lycopersicum) is lacking. In our study, we established stable SlPLATZ17 gene overexpression and knockout lines to further analyze the regulatory functions of SlPLATZ17 under drought and salt stress. It was found that the overexpression lines presented increased drought and salt tolerance under stress. Transcriptome sequencing and screening for interacting proteins revealed that SlPLATZ17 may exert its effects by interacting with POR1, thereby influencing glutathione metabolism and arginine and proline metabolism. In conclusion, the findings lay the groundwork for a deeper understanding of the regulatory mechanisms underlying the role of SlPLATZ17 in stress resistance, as well as facilitating the application of SlPLATZ17 in the breeding of stress-resistant tomato varieties.