The adaptive role and molecular mechanism of thermoregulated corolla opening and closure in the alpine species Gentiana rigescens.

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. Previous studies have shown that its corolla can open and close in a temperature-regulated manner. Distinct calcium signaling pathways and dynamic cell wall modifications underpin the repetitive flowering process under varying temperatures (Yang et al., BMC Biology 24:38, 2026). However, the mechanism of this movement and its role in alpine reproduction has only been partially explored in studies of G. algida (Bynum and Smith, Am J Bot 88:1088–95, 2001) and G. scabra (Nemoto et al., Plant Cell 34:2652–70, 2022). 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. Our findings show that floral opening and closure aid alpine acclimatization, advancing understanding of this species' adaptation. These data may also provide a valuable reference point for the elucidation of the molecular mechanism of corolla opening and closure.