AN EVALUATION OF ALUMINUM TOLERANCE IN MEDICAGO TRUNCATULA

Authors: CHANDRAN, DIVYA - UNIVERSITY OF MINNESOTA; Garvin, David; Samac, Deborah - Debby

Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 2/27/2004
Publication Date: 7/24/2004
Citation: Chandran, D., Garvin, D.F., Samac, D.A. 2004. An evaluation of aluminum tolerance in Medicago truncatula [abstract]. American Society of Plant Biologists Annual Meeting, July 24-28, 2004, Orlando, FL. Abstract No. 692.

Interpretive Summary:

Technical Abstract: Aluminum (Al) toxicity is a severe impediment to crop production in acid soils (pH<5), which comprise up to 50% of the world's potentially arable land. Decades of research in the area of Al tolerance has focused on monocots such as wheat, maize, and barley, but very limited research has been conducted in dicots and legumes in particular. With the goal of identifying natural variation in Al tolerance in the model legume Medicago truncatula, root growth inhibition assays were conducted in a hydroponics system. An Al dose response curve was generated by exposing plant roots of cultivar Jemalong to a range of Al3+ concentrations (0-100 µM). Treatments of 25 µM resulted in 50% inhibition of root growth. A screen of 90 accessions identified 38 with greater tolerance than the cultivar Jemalong and 50 more sensitive to Al3+. Detailed characterization of selected accessions using Al dose response curves and haematoxylin staining will allow a greater understanding of the mechanisms involved in Al tolerance. In addition, a molecular approach to understanding responses to Al exposure is also underway using long oligonucleotide micro arrays to compare mRNA expression patterns from root tips with or without Al exposure. A cluster-based analysis will be performed to identify suites of genes relevant to Al stress.