Fig. 4. Xylem vessel elements of the acl5 mutant are small and simple in structure. Two-month-old hypocotyls of acl5 and wild-type plants were macerated and their vessel element morphology was investigated using light microscopy. (A) Proportion of the different types of vessel elements. (B) Length of the vessel elements. (C) Width of the vessel elements. More than 200 cells were examined from three plants of each genotype. Data were compared (B,C) using a Welch corrected t-test (^***P<0.005; acl5 versus wild-type), and presented as average±s.e.m.