Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 8/3/2002
Publication Date: 8/3/2002
Citation: MARON, L., WHITE, R.A., GIOVANNONI, J.J., SARAVANAN, R., ROSE, J., GARVIN, D.F., KOCHIAN, L.V. APPROACHES TO CLONE THE ALUMINUM TOLERANCE GENE IN WHEAT USING SEGMENTAL DELETION LINES OF THE CHROMOSOME ARM 4DL. AMERICAN SOCIETY OF PLANT BIOLOGISTS ANNUAL MEETING. 2002. Interpretive Summary:
Technical Abstract: Aluminum (Al) toxicity is the major factor limiting crop productivity on acid soils, which comprise up to 40% of the world's arable lands. Natural genetic variation for Al tolerance exists in many crops, and breeders have explored this for many years to develop varieties with increased Al tolerance. In bread wheat, tolerance is associated with Al-inducible release of an Al-detoxifying organic acid, malic acid, from the root tip. Also, Al tolerance often segregates as a single gene that maps to the long arm of chromosome 4D. Assessment of Al tolerance in chromosome deletion lines derived from Chinese Spring lacking different segments of chromosome arm 4DL mapped the Al tolerance gene to the segment between the break points of lines 4DL-14 (Al tolerant) and 4DL-2 (Al sensitive). These sister deletion lines differing for the presence vs. absence of the Al tolerance gene are a potentially useful tool identifying candidate Al tolerance genes. We are currently trying two approaches to accomplish this goal. First, a subtractive root tip cDNA library was constructed enriched for cDNAs present in deletion line 4DL-14 but absent in 4DL-2. This library was arrayed on high-density nylon filters and these filters are being used in a differential screening for cDNAs that map to the chromosomal segment that contains the Al tolerance gene. Second, differences in the protein populations of the root tips of both lines are being assessed using two-dimensional gel electrophoresis (2-DE) and subsequent protein identification by mass spectrometry (MALDI-TOF MS). In this presentation, progress on the identification, validation and characterization of candidate genes will be presented. Supported by USDA-NRI Competitive Grant #01-35301-10647 to LVK and CAPES (Brazil) fellowship to LGM.