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Boron-Toxicity Tolerance in Barley Arising from Efflux Transporter Amplification

2007; American Association for the Advancement of Science; Volume: 318; Issue: 5855 Linguagem: Inglês

10.1126/science.1146853

1095-9203

Tim Sutton, Ute Baumann, Julie E. Hayes, Nicholas C. Collins, Bu-Jun Shi, Thorsten Schnurbusch, Alison Hay, Gwenda M. Mayo, Margaret Pallotta, Mark Tester, Peter Langridge,

Plant Stress Responses and Tolerance

Both limiting and toxic soil concentrations of the essential micronutrient boron represent major limitations to crop production worldwide. We identified Bot1, a BOR1 ortholog, as the gene responsible for the superior boron-toxicity tolerance of the Algerian barley landrace Sahara 3771 (Sahara). Bot1 was located at the tolerance locus by high-resolution mapping. Compared to intolerant genotypes, Sahara contains about four times as many Bot1 gene copies, produces substantially more Bot1 transcript, and encodes a Bot1 protein with a higher capacity to provide tolerance in yeast. Bot1 transcript levels identified in barley tissues are consistent with a role in limiting the net entry of boron into the root and in the disposal of boron from leaves via hydathode guttation.