Figure 3From: Humic matter elicits proton and calcium fluxes and signaling dependent on Ca2+-dependent protein kinase (CDPK) at early stages of lateral plant root development Proton fluxes and surface pH measured along the apical and elongation zones of rice roots. Proton (H+) fluxes (A) and surface pH (B) measured along the apical (0 to 100 μm) and elongation (200 to 500 μm) zones of rice roots before (○) and after (●) incubation with 3.5 mM C L−1humic acid (HA).Back to article page