Abstract
Tracheary elements deposit secondary cell walls in appropriate patterns during plant development. To analyze regulatory mechanism of the secondary wall patterns, we have developed in vitro metaxylem vessel differentiation system using Arabidopsis suspension cells harboring inducible VND6, a master regulator of metaxylem vessel differentiation. In this study, we focused on dynamics of microtubules during secondary cell wall development. During the differentiation, the cortical microtubules were mainly distributed beneath the developing secondary wall thickenings and were gradually depleted in the secondary wall pits. Detailed observation revealed that the microtubules exhibit highly unstable dynamics in the secondary wall-free pits. We will discuss how microtubules are regulated during metaxylem vessel differentiation.
