Growth and Structural Responses of Maize Primary Roots to Aluminium Stress

Abstract

The higher Al content in soils has become an important growth limiting factor for many plants. Identifications of Al uptake sites in the roots were studied using hematoxylin (Polie et al. 1978) or morin staining (Vitorello and Haug 1996). The addition of Al induced drastic structural changes of the peripheral root cells including swelling of the root tip, sloughing off the rhizodermis and stimulation of callose deposition (de Lima and Copeland 1994, Delhaize and Ryan 1995). Structural responses of root cells were intensified with increased exposition to Al (Eleftheriou et al. 1993, de Lima and Copeland 1994). Within 12 h the majority of the rhizodermal cells collapsed (Danilova et al. 1992, Eleftheriou et al. 1993, de Lima and Copeland 1994). The surviving cells reveal ultrastructure alterations (Danilova et al. 1992, Ikeda and Tadano 1993). Generally, the degree of root cell damage depends on their distance from the root surface and developmental stage.