Table I.

pH modifiers alter the pHc of tier 2 and 3 root columella cells of Arabidopsis without affecting root growth

TreatmentpHcStatistical SignificanceRoot GrowthStatistical Significance
μm
Control medium7.20 ± 0.02582 ± 72
0.3 μm Bafilomycin A17.10 ± 0.04NS475 ± 97NS
1.3 μm Bafilomycin A16.75 ± 0.02S431 ± 39NS
100 μmBenzoic Acid5.52 ± 0.03S580 ± 57NS
50 μm Procaine7.63 ± 0.08S640 ± 66NS
100 μmProcaine7.65 ± 0.08S540 ± 131NS
500 μmMethylamine8.12 ± 0.04S466 ± 63NS

The average pHc from separate roots after a control treatment was 7.20 ± 0.02 (n = 5). Control or pH modifying solutions were applied solely to the root cap. Root growth was measured over 5 h and pHc of the same roots was measured in tier 2 and tier 3 columella cells. Data are means ± se (n = 5 for pHc data, n = 20 for growth data). A t test (95% confidence interval) was used to compare experimental and control values. NS, Not significant.