Pan-Genome Analysis of TRM Gene Family and Their Expression Pattern under Abiotic and Biotic Stresses in Cucumber.

Cucumber (Cucumis sativus L.) is a vital economic vegetable crop, and the TONNEAU1 Recruiting Motif (TRM) gene plays a key role in cucumber organ growth. However, the pan-genomic characteristics of the TRM gene family and their expression patterns under different stresses have not been reported in cucumber. In this study, we identified 29 CsTRMs from the pan-genomes of 13 cucumber accessions, with CsTRM29 existing only in PI183967. Most CsTRM proteins exhibited differences in sequence length, except five CsTRMs having consistent protein sequence lengths among the 13 accessions. All CsTRM proteins showed amino acid variations. An analysis of CsTRM gene expression patterns revealed that six CsTRM genes strongly changed in short-fruited lines compared with long-fruited lines. And four CsTRM genes strongly responded to salt and heat stress, while CsTRM14 showed responses to salt stress, powdery mildew, gray mold, and downy mildew. Some CsTRM genes were induced or suppressed at different treatment timepoints, suggesting that cucumber TRM genes may play different roles in responses to different stresses, with expression patterns varying with stress changes. Remarkably, the expression of CsTRM21 showed considerable change between long and short fruits and in responses to abiotic stresses (salt stress and heat stress), as well as biotic stresses (powdery mildew and gray mold), suggesting a dual role of CsTRM21 in both fruit shape determination and stress resistance. Collectively, this study provided a base for the further functional identification of CsTRM genes in cucumber plant growth and stress resistance. [ABSTRACT FROM AUTHOR]