Silicon Deposition in the Roots, Culm and Leaf of Phalaris canariensis L

Abstract

Silicon deposition in the roots, culm and leaf of canary grass (Phalaris canariensis L.) was investigated using light microscopy, scanning electron microscopy and electron probe microanalysis. In adventitious roots grown in solution silicon was concentrated in four endodermal walls. Silicon was not detected in the endodermis of aerial adventitious roots, but was present in the epidermis and outer cortical cell layers. Silicon deposition in the culm mainly took place in the epidermis, and particularly in epidermal papillae. The silica deposition pattern in the leaf was typical of the sub-group Festucoideae. The leaf blade showed deposits in costal prickle hairs and wavy rods, but few intercostal deposits. In the ligule deposition was confined to isolated groups of prickle hairs on the abaxial surface. The major sites of silica deposition in the leaf sheath were the stomatal subsidiary cells, papillae and intercostal idioblasts. Prickle hairs were much less common in the sheath than the blade, and costal wavy rods appeared to be absent in the sheath.