son1 affects circadian [Ca2+]cyt signals. A and B, Bioluminescence (photon counts per 1,500 s) from son1 and Ws-2 expressing 35S:AEQUORIN across two light/dark cycles and 5 d in constant 70 µmol m−2 s−1 white light grown on 20 mm mannitol (A) or 20 mm nicotinamide (NAM; B). Mean luminescence ± se is shown; n = 8. Data are representative of three independent experiments in the BC2F3 generation. C, ADPR cyclase activity measured using nicotinamide guanine dinucleotide assay at ZT4 in 70 µmol m−2 s−1 white light from 3- to 4-week-old Ws-2 (white) and son1 (red) seedlings, given as means of three biological replicates shown ± se. D, [Ca2+]cyt measured at ZT4 and ZT72 in constant 70 µmol m−2 s−1 white light from 11- and 14-d-old Ws-2 (white) and son1 (red) seedlings (n = 12). Data are representative of three independent experiments in the BC2F3 generation. WT, Wild type.