Transgenic barley (Hordeum vulgare L.) expressing the wheat aluminium resistance gene (TaALMT1) shows enhanced phosphorus nutrition and grain production when grown on an acid soil
Article first published online: 12 MAR 2009
© 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd
Plant Biotechnology Journal
Volume 7, Issue 5, pages 391–400, June 2009
How to Cite
Delhaize, E., Taylor, P., Hocking, P. J., Simpson, R. J., Ryan, P. R. and Richardson, A. E. (2009), Transgenic barley (Hordeum vulgare L.) expressing the wheat aluminium resistance gene (TaALMT1) shows enhanced phosphorus nutrition and grain production when grown on an acid soil. Plant Biotechnology Journal, 7: 391–400. doi: 10.1111/j.1467-7652.2009.00403.x
- Issue published online: 8 MAY 2009
- Article first published online: 12 MAR 2009
- Received 20 November 2008; revised 22 December 2008; accepted 6 January 2009.
- acid soil;
- aluminium resistance;
- root growth
Barley (Hordeum vulgare L.), genetically modified with the Al3+ resistance gene of wheat (TaALMT1), was compared with a non-transformed sibling line when grown on an acidic and highly phosphate-fixing ferrosol supplied with a range of phosphorus concentrations. In short-term pot trials (26 days), transgenic barley expressing TaALMT1 (GP-ALMT1) was more efficient than a non-transformed sibling line (GP) at taking up phosphorus on acid soil, but the genotypes did not differ when the soil was limed. Differences in phosphorus uptake efficiency on acid soil could be attributed not only to the differential effects of aluminium toxicity on root growth between the genotypes, but also to differences in phosphorus uptake per unit root length. Although GP-ALMT1 out-performed GP on acid soil, it was still not as efficient at taking up phosphorus as plants grown on limed soil. GP-ALMT1 plants grown in acid soil possessed substantially smaller rhizosheaths than those grown in limed soil, suggesting that root hairs were shorter. This is a probable reason for the lower phosphorus uptake efficiency. When grown to maturity in large pots, GP-ALMT1 plants produced more than twice the grain as GP plants grown on acid soil and 80% of the grain produced by limed controls. Expression of TaALMT1 in barley was not associated with a penalty in either total shoot or grain production in the absence of Al3+, with both genotypes showing equivalent yields in limed soil. These findings demonstrate that an important crop species can be genetically engineered to successfully increase grain production on an acid soil.