Fig. 4.

Reconstructed ion images of carbohydrates found in the barley cv. Hindmarsh root, recorded with a scanning step size of 30 × 30 μm. Optical image of a longitudinal barley root section grown in control and saline conditions. The ion images are of a, a′ C₁₂H₂₂O₁₁ [M + Na]⁺ (m/z 365.106); b, b′ C₁₂H₂₂O₁₁ [M + K]⁺ (m/z 381.0802); c, c′ C₁₈H₃₂O₁₆ [M + Na]⁺ (m/z 527.1576); d, d′ C₁₈H₃₂O₁₆ [M + K]⁺ (m/z 543.1306); e, e′ C₂₄H₄₂O₂₁ [M + Na]⁺ (m/z 689.2068); f, f C₂₄H₄₂O₂₁ [M + K]⁺ (m/z 705.182) Ion image are displayed using the same intensity scale (rainbow: 0–100% signal intensity). The mass accuracy was at < 5 ppm. Scale bars: 500 μm. Control and salt treated images have been set to the same intensity scale and obtained from the same MALDI–MSI experiment