EFFECT OF ALUMINUM ON ROOT AND LEAF CYTOPLASMIC PROTEINS IN MAIZE

Aluminium toxicity is believed to be one of tile major factors limitin g crop productivity in acid soils. Despite the complex nature of Al to xicosis. considerable evidence indicates that it is primarily associat ed with disruption of root physiology and function. Iii our study SDS- PAGE was used to monitor changes in gene expression following Al treat ment (100 mu mol.l(-1) AlCl3). Cytoplasmic proteins isolated from root apex, root base and first leaf of maize seedlings were fractionated u sing: anion exchange column Bio-Scale Q2. Two (root base) or three (ro ot apex and first leaf) fractions of proteins were eluted from tile co lumn with linear 0-1.0 mol.l(-1) NaCl gradient. SDS-PAGE of cytoplasmi c proteins isolated from maize seedlings treated with Al revealed mark ed differences in polypeptide compositions of cytoplasmic proteins iso lated from root and leaf. Al stress enhanced accumulation of 8 polypep tides in leaf cytoplasmic proteins fraction and 2 or 5 polypeptides in root cytoplasmic proteins, respectively. At the same time reduction o f 9 polypeptide bands was observed in cytoplasmic proteins isolated fr om two different parts of maize root. Reduction of polypeptide bands i n response to Al stress nas not found in leaf proteins. The difference s found in polypeptide compositions between root and leaf cytoplasmic proteins are the subject of ongoing studies.