Fig 1. Expression cloning of rice CaS and Arabidopsis CaS using calcium imaging.

HEK293 cells were transiently transfected with empty vector, pcDNA₃-CAS, or pcDNA₃-OsCAS. The cytosolic Ca²⁺ status was analyzed using Fura-2-based Ca²⁺ imaging after treatment with 0.l mM and 2.5 mM extracellular Ca²⁺. Elevated relative calcium concentrations are indicated by an increased ratio of Fura-2 emission at 340 versus 380 nm wavelength excitation (see color bar). Arrows show cells with CICI (Ca²⁺ _o-induced [Ca²⁺]_i increases).