XVI International Botanical Congess
Trigonelline was identified as a cell cycle inhibitor that caused cells to preferantially arrest in G2 phase in cultured pea root.We tested whether the same phenomenon would occur in Lactuca sativa roots exposed to trigonel line.We measured replicon size and rates of nuclear DNA replication per single replication fork by DNA fibre autoradiography.In lettuce meristem 12h trigonelline treatment resulted in larger inter origins distances.The data are consistent with a mechanism which would switch off two origins in a normal cluster of four replicons. Trigonelline treatment also resulted in a 1.6-fold fork rate of DNA replication compared with the control, according to the positive relationship established between replicon size and fork rate for a number of unrelated grasses.