Figure 3.

Expression of PIP5K7 and PIP5K9 in Arabidopsis seedlings.

Histological GUS analyses of 5‐day‐old transgenic lines expressing (a–d) ProPIP5K7::GUS or (e–h) ProPIP5K9::GUS. Pictures show (a, e) cotyledons, (b, f) a general overview of the root and cross‐sections of (c, g) the root differentiation zone and (d, h) the division zone (root meristem). In (c, d, g, h), black arrowheads mark the protophloem cells. Results were confirmed in three independent transgenic lines. Bars represent 25 µm. (i, j) Effects of Spm on the expression of PIP5K7 and PIP5K9 genes using (i) a GUS reporter system and (j) RT‐PCR. (k) ³²P‐PIP₂ response in different sections of Arabidopsis seedlings. Type of section/length: (I) root tip, 2 mm, (II) root tip, 3 mm, (III) root tip, 5 mm, (IV) root tip, 5–7 mm, (V) hypocotyl and (VI) cotyledons. Results are expressed as the fold increase of PIP₂ with respect to control treatment of each section. In all cases, data are presented as the mean ± SD (n = 3).