Transcriptome Analysis of the Development of Pedicel Abscission Zone in Tomato

Abstract

Plant organ abscission is a common phenomenon that occurs at a specific position called the abscission zone (AZ). The differentiation and development of the pedicel AZ play important roles in flower and fruit abscission, which are of great significance for abscission in tomatoes before harvest. Previous studies have reported some genes involved in AZ differentiation; however, the genes regulating pedicel AZ cell development in tomatoes after AZ differentiation remain poorly understood. In this study, transcriptome analyses of tomato pedicel AZ samples were performed at 0, 5, 15, and 30 days post-anthesis (DPA). Pedicel AZ growth was mainly observed before 15 DPA. A principal component analysis and a correlation analysis were carried out in order to compare the repeatability and reliability for different samples. We observed 38 up-regulated and 31 down-regulated genes that were significantly altered during 0 to 5 DPA, 5 to 15 DPA, and 0 to 15 DPA, which may play key roles in AZ cell enlargement. GO and KEGG enrichment analyses of the selected DEGs under all three different comparisons were conducted. Auxin-signaling-related genes were analyzed, as well as AUX/IAA, GH3, and small auxin up-regulated RNA (SAUR) gene expression patterns. The presented results provide information on pedicel AZ development, which might help in regulating flower or fruit pedicel abscission in tomato production facilities.