Table 3.

Parameters of osmotic and salt-induced series of action potentials in 3-week old Helianthus annuus.

Solution injected	Number of treated plants	% of excitable plants	n	Series of AP
				APs number	Series duration (min)
Distilled water 0 mOsm	9	70	6	6 ± 1a	11 ± 2a
D-sorbitol 500 mM 500 mOsm	8	100	8	8 ± 1a	13 ± 1a
KCl 250 mM 500 mOsm	7	100	7	17 ± 1b	27 ± 2b
NaCl 250 mM 500 mOsm	10	0	0	lack of series of APs

The duration of the series is the time between the first and the last AP in the series. n—number of excitable plants. AP number: data normally distributed, unequal variance (Levene's test p = 0.0025), Kruskal-Wallis ANOVA (Chi square = 13.48 df = 2 p = 0.0012). Series duration: data normally distributed, unequal variance (Levene's test p = 0.0017), Kruskal-Wallis ANOVA (Chi square = 17.29 df = 2 p = 0.0002). Mann-Whitney U-test was used to assess the statistical differences in one parameter between the groups; different letters denote statistical difference.