Figure 1.

Windows in Echinochloa crus-galli var. praticola lack suberin lamellae and lignin deposits. Plants were grown in aerated nutrient solution for 10 days, and then transferred to deoxygenated stagnant 0.1% agar solution or left in aerated nutrient solution for another 14 days. Basal parts (15–25 mm below root-shoot junction) of 100- to 120-mm-long adventitious roots of length were stained as described in Supplemental methods. (a, b) Suberin lamellae at the exodermis and endodermis under aerated (a) and stagnant (b) conditions. Suberin lamellae are indicated by yellow-green fluorescence with Fluorol Yellow 088 (Yellow arrowhead). (c, d) Line plots of fluorescence intensity of Fluorol Yellow 088 along the exodermis under aerated (c) and stagnant (d) conditions. (e, f) Number of non-suberized exodermal cells at window sites under aerated (e) and stagnant (f) conditions. (g, h) Lignin at the sclerenchyma, exodermis, and endodermis under aerated (g) and stagnant (h) conditions. Basic Fuchsin fluorescence is shown by red color (Red arrowhead). (i, j) Line plots of fluorescence intensity of Basic Fuchsin along exodermis under aerated (i) and stagnat (j) conditions. (k, l) Number of non-lignified exodermal cells at window sites under aerated (k) and stagnant (l) conditions. Asterisks indicate areas of passage cells (windows) that lack both suberin lamellae and lignin deposits. White arrowheads indicate the apex of lateral root primordia. Abbreviations: CP, cortical parenchyma; end, endodermis; epi, epidermis; exo, exodermis; scl, sclerenchyma; ste, stele. Scale bars, 100 µm.