Project Number: 1907-21000-012-04
Project Type: Trust

Start Date: Sep 15, 2001
End Date: Sep 14, 2005

Objective:
Clone Al-activated organic acid transporters in the root apex of Al tolerant wheat that are involved in Al tolerance. Clone wheat root tip organic acid transporters via functional complementation of a yeast mutant defective in organic acid release. Identify wheat Al tolerance genes via comparison of expressed genes in a pair of chromosome 4DL segmental deletion lines that either carry or lack the major Al tolerance gene. Clone sorghum Al tolerance genes via map-based cloning approaches.

Approach:
A genomics approach based on sequences of known anion channel genes in Arabidopsis will be used to isolate and characterize homologous transporters from the root tip of Al tolerant wheat that are candidates for the organic acid transporter involved in Al tolerance. A second genomics-based approach to identify wheat Al tolerance genes will use RNA profiling of a pair of chromosome 4DL segmental deletion lines that either carry or lack the major Al tolerance gene against high density arrays of a root tip cDNA library from Al tolerant wheat. Functional complementation of the DPdf12 yeast mutant defective in organic acid efflux (which therefore is unable to grow in low pH/high organic acid containing media) with a root tip yeast expression library from Al tolerant wheat will also be used to screen for organic acid transporter and Al tolerance genes. Finally, we have mapped a major Al tolerance gene in sorghum, and will now proceed to fine-scale mapping to clone and then characterize this gene.

Project Team

Kochian, Leon

Project Annual Reports

FY 2003   FY 2002

Related National Programs

Soil Resource Management (202)   Plant Biological and Molecular Processes (302)