Quantification of Glc exudation from the tip and base of maize primary roots. Quantification of Glc exudation from the tip and base of maize primary roots. A, Two-day-old maize seedlings were placed on filter paper strips for 30 min to collect Glc exuded from the root tip and base. Glc from triplicate samples (with exudates pooled from nine seedlings each) was extracted and quantified by HPAE chromatography. The efficiency of Glc extraction was assessed by including filter paper strips with 450 ng of d-Glc (FP+G). Filter paper (FP) strips without added Glc or exudates were used as controls. Data are means ± se; n = 3 (from triplicate samples). Letters denote significant differences between samples as determined by one-way ANOVA and the Student-Newman-Keuls test (P ≤ 0.05). B, Average Glc exudation rate (ng min−1 during the first 30 min of incubation on the gel) from the tip and base of the well-watered maize primary root. Data are means ± se; n = 3 (from triplicate samples). The asterisk denotes a significant difference at P < 0.01 using Student’s t test. The experiment was performed twice with similar results. Priyamvada Voothuluru et al. Plant Physiol. 2018;178:1002-1010 ©2018 by American Society of Plant Biologists