Aluminum Tolerance in Sorghum and Maize - Translational Genomics for Crop Breeding: Abiotic Stress, Yield and Quality - page 95

transport, their transport is highly sensitive to
extracellular Al (except for the barley homo-
logue), being highly inhibited at low micromo-
lar concentrations. This functional property is
quite different from the direct Al-enhancement
for members of the ALMT family and for
the Al-activation of root citrate efflux seen in
planta . Preliminary findings from our group indi-
cate there are other proteins that may interact
with SbMATE to facilitate the Al activation, as
well as other post translational modifications of
the SbMATE-type transporters that are involved
in the regulation of the transporter in planta.
These preliminary findings will set the stage for
basic research on the structure-function of these
transporters, quite likely expanding our toolbox
for molecular breeding of enhanced cereal Al
tolerance.

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Conclusions

A major point that we hope we have made in this
chapter is that agricultural research has advanced
to the point where findings from basic molecular,
genomic, and genetic investigations of crop plant
traits are now being translated for use in crop
improvement programs. In this example, basic
research has allowed us to identify physiolog-
ical mechanisms and the associated genes that
confer enhanced Al tolerance in sorghum and
maize. We also are beginning to understand the
role of genetic diversity and population structure
in Al tolerance. This information is now being
used to facilitate the effective molecular breeding
of improved Al tolerance in both sorghum and
maize, in order to improve sorghum and maize
yields on acid soils that are prevalent in many
countries in the tropics and subtropics.

Acknowledgements

The research described in this chapter was sup-
ported by Generation Challenge Programme

grants G3007.04, G3008.02, G7010.03.02,

G7010.03.05, and G7010.03.03.