Abstract
Arabidopsis thaliana VAM3, a syntaxin homologous to yeast Vam3p, is classified as Qa-SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) and interacts with AtVTI11 (Qb-SNARE) and SYP5 (Qc-SNARE). Although yeast Vam3p is known to function in vacuolar fusion, the physiological function of VAM3 in plants remains unknown. To elucidate a role of VAM3 in protein trafficking and development of plant cells, we generate vam3 mutants of Arabidopsis thaliana. These mutants exhibited the phenotypes of wavy leaves, delayed growth and semi-dwarfism. We focused on myrosin cell development in leaves. Myrosin cells, which play an important role in plant defense, were distributed only along with the veins. Vam3 mutants developed a larger number of myrosin cells than wild type. The network of myrosin cells was found throughout the leaves of the vam3 mutants. Our findings suggest that VAM3 plays a role in the myrosin cell development.
