Fig. 2.

Direct in vivo visualization of the spatial distribution of xylem embolisms induced by soil drying in intact maize leaves. (A) Schematic of scanned area on a maize leaf. (B) Typical X-ray images showing the patterns of xylem embolism in intact maize leaves according to soil water potential (Ψ_soil). The first row shows X-ray images for Ψ_soil of −0.04MPa. The second row corresponds to Ψ_soil of −1.5MPa in a and −1.8MPa in b and c, respectively. Columns a, b, and c were individually selected at different relative distances to the midrib (x): x=0, 0.5, and 1, respectively. Xylem vessels embolized entirely in the scanned FOV on maize leaves are called fully embolized vessels, and xylem vessels apparently cavitated or partially filled with gas in the FOV are called partially embolized vessels. The fully embolized vessels, partially embolized vessels, and water-filled vessels are represented by white, grey, and black arrows, respectively. Yellow arrows denote elongated gas bubbles in partially embolized vessels. Each X-ray image was captured from different leaves to show spatial embolism patterns from the midrib under different Ψ_soil conditions. This figure is available in colour at JXB online.