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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Plant, Soil and Nutrition Research » Research » Publications at this Location » Publication #212393
Title: A member of the multidrug and toxic compound extrusion ‘MATE’ family is a major gene that confers aluminum tolerance in sorghum

Author
item MAGALHAES, J. - EMBRAPA, BRAZIL
item Liu, Jiping
item GUIMARAES, C. - EMBRAPA, BRAZIL
item LANA, U. - EMBRAPA, BRAZIL
item ALVES, V. - EMBRAPA, BRAZIL
item WANG, Y. - PENN STATE, ERIE
item SCHAFFERT, R. - EMBRAPA, BRAZIL
item Hoekenga, Owen
item SHAFF, JOHN - CORNELL UNIVERSITY
item KLEIN, P. - TEXAS A&M UNIV.
item CARNEIRO, N. - EMBRAPA, BRAZIL
item COELHO, C. - EMBRAPA, BRAZIL
item TRICK, H. - KANSAS STATE UNIV.
item Kochian, Leon

Submitted to: Nature Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/25/2007
Publication Date: 8/26/2007
Citation: Magalhaes, J., Liu, J., Guimaraes, C., Lana, U., Alves, V., Wang, Y., Schaffert, R., Hoekenga, O., Shaff, J., Klein, P., Carneiro, N., Coelho, C., Trick, H., Kochian, L.V. 2007. A member of the multidrug and toxic compound extrusion ‘MATE’ family is a major gene that confers aluminum tolerance in sorghum. Nature Genetics. 39(9):1107-1113.

Interpretive Summary: Large areas of land within the U.S. and over 40% of the world’s arable lands are acidic. In these acid soils, aluminum (Al) toxicity is the primary factor limiting crop production via Al-induced inhibition of root growth. The physiological and molecular basis for Al tolerance is still poorly understood. Thus, we need a more complete understanding of the mechanisms underlying Al tolerance and the identity of the tolerance genes if we are going to be able to develop more Al tolerant crop plants for improved cultivation on acid soils. In this paper, we report on the map-based cloning of a major sorghum Al tolerance gene that underlies the Al tolerance locus, Alt-SB, that we previously genetically characterized. We show that the tolerance gene is a member of the multidrug and toxic compound extrusion or MATE family of solute transporters. Alt-SB is shown to be a citrate efflux transporter localized to the root apex. Differential tolerance is shown to be caused by changes in Al-inducible gene expression, with much higher expression in response to Al observed in the tolerant sorghum lines. The significance of this work is that we have identified a new molecular tool for improving crop Al tolerance via molecular-based breeding and biotechnology strategies. This gene will open up new avenues whereby plant breeders and biotechnologists can use this gene and related versions of this gene in other species to improve the acid tolerance of many crop species.

Technical Abstract: Crop yields are significantly reduced by aluminum (Al) toxicity on highly acidic soils which comprise up to 50% of the world’s arable lands. Candidate Al tolerance proteins include organic acid efflux transporters, with the organic acids forming non-toxic complexes with rhizosphere Al. In this study, positional cloning was employed to identify a member of the MATE family encoding an Al-activated citrate transporter as responsible for the major sorghum Al tolerance locus, AltSB. Polymorphisms in regulatory regions of AltSB are likely to contribute to large allelic effects, acting to increase AltSB expression in the root apex of tolerant genotypes. Furthermore, Al-inducible AltSB expression is associated with induction of Al tolerance via enhanced root citrate exudation. These findings will allow us to identify superior AltSB haplotypes, which can be incorporated via molecular breeding and biotechnology into acid soil breeding programs, thus helping to increase crop yields in developing countries where acid soils predominate.