Transcriptome-wide analysis reveal dynamic expression changes during endoplasmic reticulum stress in tomato

Endoplasmic reticulum (ER) stress is a cellular condition induced by environmental stressors. Transcriptomic approaches reveal the response of plants to ER stress and provide a broadened view. Tomato plants were treated with tunicamycin, and total RNA isolated from the tomato leaves was sequenced on an RNA-sequencing platform to be analyzed for differential expressions. A total of 856 differentially expressed genes (DEGs) were discovered in tunicamycin-treated tomato leaves. Upregulation of ER stress marker gene expressions was detected after 2h, while a prolonged ER stress downregulated most of the protein-coding genes. Pathways such as: response to stress, jasmonic acid mediated signaling, signal transduction regulation, plant hormone signal transduction, and protein processing in ER were enriched. Prolonged stress mostly resulted in reduced transcript levels, possibly related to a mechanism functioning to lower the load of nascent transcripts in the ER. Our findings emphasize the key role of JA-regulated signaling in tomato ER stress responses due to the differential expressions of the pathway components, along with other plant hormones and signaling-related or regulatory genes. ER stress being a common response to many stressors in plants, transcriptome data obtained here will provide for further studies of understanding plant stress tolerance or generating stress-resistant tomato plants.