The effects of excess and deficient boron and niacin on vascular tissues of carrot roots (Daucus carota L. cv. Nantes) were investigated in plants grown in medium both rich and poor in boron and also boron with niacin. | Turkish Journal of Botany Research Article Turk J Bot (2013) 37: 160-166 © TÜBİTAK doi: Effects of excess and deficient boron and niacin on the ultrastructure of root cells in Daucus carota cv. Nantes Hatice DEMİRAY*, Aylin EŞİZ DEREBOYLU Section of Biology, Department of Botany, Faculty of Science, Ege University, 35100 Bornova, İzmir, Turkey Received: Accepted: Published Online: Printed: Abstract: The effects of excess and deficient boron and niacin on vascular tissues of carrot roots (Daucus carota L. cv. Nantes) were investigated in plants grown in medium both rich and poor in boron and also boron with niacin. Five media were investigated: control (MS medium), boron-deficient MS medium, MS medium with excess boron, niacin-deficient MS medium, MS medium with niacin excess, and MS medium with excess boron and niacin. In anatomical cross sections, lignification was seen in middle lamellar pectins in the tracheary cells of boron deficit grown carrot roots, while in the other applications including excess boron lignification was in the secondary walls. Number of xylem arches and tracheary lengths of root cells were different, but not significantly so. Scanning electron microscopic (SEM) sections of vessels from roots grown in media with excess boron and deficient boron revealed paramural bodies in the tracheary walls. Paramural bodies were found in the tracheary cell walls of both boron deficient and boron excess grown carrot roots. In root cells grown in media with excess and deficient boron, tracheary cells had amyloplasts. While the boron deficient medium grown carrot roots had amyloplasts scarcely, in boron excess grown root cells these amyloplasts filled the vessels densely. Key words: Daucus carota, amyloplasts, excess boron 1. Introduction Boron (B) is an essential microelement for higher plants and has important physiological functions in .
