Transcriptomic analysis on cucumber tendril reveals GLRs play important roles in thigmotropism and thigmomorphogenesis

Abstract

Thigmotropism and thigmomorphogenesis are two related and pervasive processes that play crucial roles in plant adaptation to the environment. However, there have been few investigations into the molecular regulatory mechanisms of these phenomena. Cucumber (Cucumis. Sativus L.) tendrils are ideal material for studying thigmotropism and thigmomorphogenesis because they display a combination of the two processes. Here, we generated the transcriptome profiles of cucumber tendrils at the young, stretch, and coiling stages. Genes related to receptor proteins, transmembrane transport, and ion transport were significantly enriched among those differentially expressed between stages. Pharmacological assays illustrated that three GLUTAMATE RECEPTOR (GLR) genes might play a vital function in perceiving or transducing touch stimulation signals. Comparing the transcriptomes of tendrils and roots after touch stimulation, we found that genes related to extracellular stimulus and xyloglucan metabolism might have conserved functions in the regulation of thigmomorphogenesis. The transcriptome atlas of thigmotropism and thigmomorphogenesis of cucumber tendrils constructed in this study will help further elucidate the molecular mechanisms behind these processes.