The harsh and changeable ecological environment in mountainous areas greatly inhibits the growth and reproduction of plant species. In order to survive such abiotic stress, plants often adapt to alpine environments through morphological and molecular specialization. Gentiana rigescens Franch. is an alpine medicinal plant species, the corolla of which can open and close in a temperature regulated manner. However, the mechanism of this movement and its role in alpine reproduction is unknown. In the current study, we verified the protective role of the temperature regulated opening and closure of the corolla of this species in relation to the reproductive biology of the plant by determining the stigma receptivity, pollen viability, fruiting rate and seed setting rate at different stages of flower development. Through transcriptome sequencing, we identified the differential gene expression that occurs during floral opening and closure, and mapped the regulatory mechanisms associated with this process. Furthermore, through the overexpression of the GrPME40 gene in Arabidopsis thaliana, we demonstrated that pectin methyl-esterification had an important role in cellular morphological alterations. The present study provides compelling and direct evidence for the alpine acclimatization of floral opening and closure and presents a novel insight into understanding the adaptive strategy of this alpine species. These data may also provide a valuable reference point for the elucidation of the molecular mechanism of corolla opening and closure.