Physiological and differential protein expression analyses of the calcium stress response in the Drynaria roosii rhizome

High concentration Ca²⁺ in karst soil is harmful to agriculture. Some dominant plants can adapt well to karst soil, but how Ca²⁺ affect plant is unknown. <i>Drynaria roosii</i> is a Ca²⁺-tolerant fern and its dry rhizome is a common Chinese medicine of Miao nationality in Guizhou, China. This study analyzed the physiological and proteomic characteristics of the rhizome of <i>D</i>. <i>roosii</i> under calcium stress. Physiological results indicated that calcium stress may lead to osmotic stress. Proteomic results showed that 147 differentially expressed proteins (96 increased, 51decreased) were identified under calcium stress, and these proteins mainly involved in signal transduction, protein translation, material transport, antioxidant defense and secondary metabolism. This study will lay a foundation for studying the calcium adaptation mechanism of <i>D. roosii</i> at the molecular level.