Effects of Lat-B and Jas on mitochondrial membrane potential. Mitochondrial membrane potential was assessed using the fluorescent potentiometric dye JC-1. Red particles represented mitochondria with high membrane potential, and green particles represented those with low membrane potential. (A1) Green fluorescence image of mitochondria with low membrane potential labeled with JC-1 in control root hair. (A2) Red fluorescence image of mitochondria with high membrane potential labeled with JC-1 in the same control root hair. (B1) and (B2) Green and red fluorescence images of mitochondria in the same root hair, 5 min after the addition of 500 nM Lat-B. (C) and (D) The actin-acting drugs reduced the red/green fluorescence ratio, i.e. mitochondrial membrane potential. This effect was inhibited by a 30-min pretreatment with 2 μM Cs A. The diamond curve showed the 500 nM actin drugs treatment over a 20 min period; the dotted curve showed the change in [Ca2+]m with Cs A pretreatment before actin drugs application; and the square curve represented the buffer control in drug-free medium. F represented the ratio of red/green fluorescence, and F0 represented the ratio of red/green fluorescence before treatments. All scale bars = 10 μm.