Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/15/2007
Publication Date: 1/15/2008
Citation: Collins, N., Saeed, M., Shirley, N.J., Pallotta, M., Gustafson, J.P. 2008. Molecular Characterization of Aluminium (aluminum) Tolerance in Rye [abstract]. Plant and Animal Genome Conference, January 2008, San Diego, California. Paper No. W5. Interpretive Summary:
Technical Abstract: Aluminium (Al) toxicity, affecting around half of the world’s arable land, severely hinders the ability of crop plants to utilize moisture and nutrients by restricting root growth and function. Among the cultivated cereals, rye is the most Al-tolerant and represents an important potential source of genes for the improvement of Al-tolerance in wheat. At the Alt4 Al-tolerance locus on rye 7RS, there is a cluster of homologues of the ALMT1 malate transporter gene which confers Al-tolerance in wheat. This contrasts with wheat, in which only one ALMT1 gene copy at the tolerance locus has been reported. High-resolution genetic mapping excluded all other types of genes flanking the cluster as possibly providing the Alt4 tolerance, including a nearby homologue of a MATE transporter gene shown to control Al-tolerance and citrate secretion in barley. Two of the recombination events occurred within the cluster, one of which gave rise to a new hybrid gene (and novel-sequence protein) that is functional in providing tolerance. Although one ALMT1 gene is highly transcribed in root tips of the intolerant parent, a MITE transposable element present in one of its introns appears to cause inefficient mRNA splicing, which may contribute to the inability of this gene to provide Al-tolerance. We will report work to characterize the functionality of the rye ALMT1 genes using genetic recombinants, organic acid analysis of root exudates, and electrophysiology of ALMT1-expressing frog oocytes.