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United States Department of Agriculture

Agricultural Research Service

Title: Molecular Cloning and Characterization of AltSB, A Major Aluminum Tolerance Gene in Sorghum)

Author
item Liu, Jiping
item Magalhaes, Jurandir
item Guimaraes, Claudia
item Lana, Uribacy
item Alves, Vera
item Hoekenga, Owen
item Shaff, Jon
item Pineros, Miguel
item Wang, Yihong
item Klein, Patricia
item Schaffert, Robert
item Kochian, Leon

Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract only
Publication Acceptance Date: 12/11/2006
Publication Date: 1/13/2007
Citation: Liu, J., Magalhaes, J., Guimaraes, C., Lana, U., Alves, V., Hoekenga, O., Shaff, J., Pineros, M., Wang, Y., Klein, P., Schaffert, R., Kochian, L.V. 2007. Molecular Cloning and Characterization of AltSB, A Major Aluminum Tolerance Gene in Sorghum [abstract]. Plant and Animal Genome VX Conference Abstracts. p. 59.

Interpretive Summary:

Technical Abstract: Aluminum (Al) toxicity on acid soils represents a major constraint for crop production as ~ 50% of the potentially arable soils worldwide are acidic. Therefore, understanding the genetic and molecular mechanisms underlying plant Al tolerance has been a major focus for a number of laboratories around the world. Here, we report on the isolation and characterization of AltSB, a major Al tolerance gene in sorghum. Through high-resolution mapping, we identified AltSB as a single, partially dominant Al tolerance gene on sorghum chromosome 3. We subsequently verified that AltSB is responsible for Al tolerance in sorghum based on: 1) a strong correlation between Al-inducible AltSB expression and Al-inducible tolerance and root citrate exudation; 2) sequence predictions indicating it is a member of a gene family involved in the efflux of organic solutes; 3) protein localization to the plasma membrane; and 4) AltSB expression in transgenic Arabidopsis resulting in significant increases in Al tolerance and Al-activated root citrate efflux. Sequence analysis of the parental AltSB alleles and the promoter region from selected members of a sorghum diversity panel, combined with determination of AltSB expression, Al tolerance and root citrate exudation in members of the diversity panel indicates that differences in gene expression are a major determinant of differential tolerance in sorghum. Furthermore, a MITE-type transposable element in the AltSB promoter appears to be a highly polymorphic motif in the promoter region and may play a role in the differential Al-inducible expression.

Last Modified: 8/24/2016
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