Ultrastructure of Gladiolus x hybridus root endodermis

Abstract

Gladiolus.x hybridus Van Houtte roots had primary, secondary and tertiary endodermis depending on the distance from the root apex. Free calcium ions were localized with the method of Slocum and Roux (1982). Electron microscopic observations revealed that electron dense calcium antimonite deposits were localized in some endodermis cells. Endodermis cells situated above xylem elements were rich in calcium antimonate deposits in contrary to those situated above the phloem elements and passage cells. The cells rich in calcium ions were present both in endodermis 11 and III stage of development. Localization of calcium deposits was on plasma membrane and tonoplast. There were also numerous calcium antimonate deposits in vacuoles. Dictiosome's cisterns and Golgi derived vesicles show presence of calcium ions. Calcium rich endodermis cells had plastids with antimonate deposits present in their tylacoids lumen. Plasmode-smata looked the same in all endodermis cells, but those from calcium rich endodermis cells had calcium antimonate deposits in the lumen of plasmodesmata.

Keywords

• root endodermis
• calcium uptake
• electron microscopy