Effects of Aluminum Toxicity on Growth and the Complement of Polypeptides in the Root Tips of Wheat

Abstract

Aluminum toxicity is the primary limiting growth factor in acid soils. Wheat <Triticum aestivum L.) expresses differential tolerance to aluminum <Al>. The wheat cultivar "Victory" is Al sensitive at 1 ug/ml Al, while the wheat cultivar "TAM W-101" is tolerant at 2 ug/ml Al. Aniol (4) proposed that a group of proteins present only in Al tolerance plants bind with Al to render it harmless to plant cells. This hypothesis was tested by determining if induction of specific proteins was associated with 2 ug/ml Al treatment in Victory and TAM W-101 root tips. The proteins extracted from each cultivar were quantified and analyzed by SOS-PAGE. The effect of Al on the proteins of wheat root tips was not dramatic. SDS-PAGE did not reveal the presence of any new, major proteins which might be Al-binding proteins. Two-dimensional PAGE analysis of the proteins of Victory cytoplasmic and microsomal fractions was conducted. This highly sensitive protein analytic tool revealed eight m~jor proteins in Al-treated Victory root tips that were not present in the controls, and three proteins that were present in the control and not in the Al-treated root tips.