Organization of microtubules in stabilized meristematic plant cells revealed by a rat monoclonal antibody reacting only with the tyrosinated form of α-tubulin

Abstract

A rat monoclonal antibody against yeast tubulin (clone YL 1 2 ; Kilmartin et al., 1982) that reacts specifically with mammalian α-tubulin carrying a carboxyterminal tyrosine residue (Wehland et al., 1983) was used to localize microtubules in plant cells derived from onion root apices ( Allium cepa L.). YL 1 2 reacted with all types of microtubular arrays known to occur in higher plant meristematic cells such as interphase cortical microtubules, pre-prophase bands, the mitotic spindle and phragmoplast microtubules. The specific labeling of microtubules in isolated cells from onion root tips by YL 1 2 indicates that plant cells like animal cells contain tubulin tyrosine ligase, the enzyme which posttranslationally modifies α-tubulin. This enzyme could be involved in the dynamic regulation of microtubular arrays in all eukaryotic cells.