Figure 1.

Mixed‐linked glucans (MLG) oligosaccharides trigger cytoplasmic Ca²⁺ elevations in Arabidopsis.

Ca²⁺ influxes were measured as relative luminescence units (RLU) over time in 8‐day‐old Arabidopsis Col‐0^AEQ seedlings after treatment with (a) β‐1,3/1,4‐glucans of barley (β‐glucan; B‐GLU), 4% KOH fraction of Equisetum arvense cell wall (E‐KOH) and lichenan from Cetraria islandica (C‐LICH) (0.25 mg ml⁻¹ final concentration) untreated or treated with lichenase enzyme (+L). Chitohexaose 50 μm was used as positive control. Undigested materials (0.25 mg ml⁻¹), lichenase suspension (L) and distilled water (mock) were used as negative controls.

(b) Ca²⁺ influx after treatment with commercial MLGs (50 μm) purified from barley (Megazyme). Data represent mean ± σ (n = 8) in all panels.

(c) Structural scheme of the different MLG oligosaccharides used in the experiments. A β‐d‐cellobiosyl‐(1,3)‐β‐d‐glucose (MLG43) structure is highlighted over the different structures. These data are from one representative experiment of at least three performed that gave similar results.