Possible involvement of phosphorylation and Lys modifications in polar localization of OsLsi1. A to C) Scheme presentation of substitution sites of Flag-OsNIP1;1^dC-OsLsi1C A), Flag-OsLsi1^d2–40B), and Flag-OsLsi1^d265–287C). Orange letters show amino acids substituted. TMD indicates the transmembrane domain. D to H) Localization of Flag-OsNIP1;1^dC-OsLsi1C^{S281, 284A}D), and Flag-OsNIP1;1^dC-OsLsi1C^{K270, 275R}E), Flag-OsLsi1^{d2–40, S281,284Q}F), Flag-OsLsi1^{d2–40, S281,284E}G), and Flag-OsLsi1^{14–15A, d265–287}H) in roots of transgenic lines. Cross-sections of the mature region (15 to 20 mm from the root tip) of the crown roots sampled from transgenic seedlings carrying different variants of OsNIP1;1^dC-OsLsi1C, and Flag-OsLsi1 were subjected to immunostaining using anti-Flag antibody. Exodermis (Ex) and endodermis (En) in D) to H) were enlarged in the left or right of the lower half panel, respectively. Scale bars indicate 50 μm in the whole root picture or 10 μm in the enlarged picture. I) Polarity index of various Flag-OsNIP1;1^dC-OsLsi1C and Flag-OsLsi1 variants at the exodermis and endodermis. Thirty independent cells from more than 5 independent root slices were used for the quantification of the polarity index. Vertical bars indicate Sd. Different letters indicate significant differences at P < 0.05 by Tukey–Kramer's test.