Abstract
Rice is the most Al resistant species among small-grain cereal crops, but the mechanism underlying its high Al resistance is still poorly understood. In the present study, a gene which is associated with Al tolerance in rice was cloned and characterized using an Al-sensitive rice mutant (als1). Rough mapping shows that Als1 was localized on chromosome 6. Fine mapping resulted in identification of Als1. By comparing the sequence of Als1 between the wild type and the mutant, a 15 bp deletion was found in the mutant. Als1 consists of four exons and three introns, encoding a 291 amino acid protein that is predicted to be a putative ABC transporter. The expression of this gene is relatively higher in the roots than in the shoots in the absence of Al and the expression was up-regulated by Al in the root tips but not basal roots.
