TABLE 4.

Elongation rate, final cell length, and cell production rate of control and KI-treated primary roots in line FR697 at 36 h after transplanting to well-watered or water-stressed (−1.6 MPa) conditions.

	FR697, well-watered			FR697, water-stressed
	Control	30 mM KI	Change compared to control (%)	Control	45 mM KI	Change compared to control (%)
Root elongation rate (mm h–1)	2.57 ± 0.02	2.07 ± 0.05**	−20	1.00 ± 0.00	1.38 ± 0.00**	38
Final cell length (μm)	190 ± 3	182 ± 8	−4	142 ± 4	164 ± 6**	15
Cell production rate (cells h–1)	13.6 ± 0.3	11.5 ± 0.5**	−16	7.1 ± 0.2	8.5 ± 0.4*	20

Elongation rates were calculated for the preceding 14 h (well-watered) or 8 h (water-stressed) periods. Values are means ± SE of five to six roots. Asterisks denote significant differences between the control and KI-treated roots (t-test; * P < 0.05; ** P < 0.01). Roots were pretreated with 30 mM and 45 mM KI for well-watered and water-stressed roots, respectively, since these pretreatments resulted in almost steady root elongation during the preceding 20 h (Figure 7B).