Tissue-specific localization of OsHAK5 in the root and shoot of rice using the GUS reporter driven by the OsHAK5 promoter. Rice was transformed with OsHAK5 promoter:GUS. A, GUS activity was detected in root (a; root hair zone) and root-shoot junction (b; the outer layer is the leaf sheath) of rice grown in solution containing 1 mm
K or in root (c) and root-shoot junction (d) after 6 h of K deprivation. Bars = 1 mm. B, GUS staining of the cross sections of root and leaf blade observed by dissection microscopy. a to d, Root cross sections of rice after 6 h of K starvation: a, root cross section (approximately 3.5 cm from root tip); b and c, enlarged epidermis and stele, respectively, of a; and d, cross sections of stele and cortex at the lateral root branching zone. e and f, Cross sections of leaf blades of rice grown in 1 mm
K (+K) and in K-depleted solution (−K) for 10 d. g shows a leaf vascular tissue (enlarged part of f). Ph, Phloem; XP, xylem parenchyma. Bars = 100 μm. C, GUS activity was detected in embryonic tissue (a), tiller bud (b), flower (c), and pedicel (d). Bars = 1 mm.