Boron-toxicity tolerance in barley arising from efflux transporter amplification.
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.
Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Private Mail Bag 1, Glen Osmond, South Australia 5064, Australia. tim.sutton@acpfg.com.au
Tim
T
Sutton
Ute
U
Baumann
Julie
J
Hayes
Nicholas C
NC
Collins
Bu-Jun
BJ
Shi
Thorsten
T
Schnurbusch
Alison
A
Hay
Gwenda
G
Mayo
Margaret
M
Pallotta
Mark
M
Tester
Peter
P
Langridge
D000595:Amino Acid Sequence; D001483:Base Sequence; D001692:Biological Transport; D001895:Boron / Q000378:metabolism / Q000633:toxicity*; D001896:Boron Compounds / Q000378:metabolism* / Q000633:toxicity*; D002874:Chromosome Mapping; D017343:Genes, Plant; D001467:Hordeum / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D037121:Plant Lectins / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D040641:Quantitative Trait Loci; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D014158:Transcription, Genetic
D001896:Boron Compounds; D026901:Membrane Transport Proteins; D037121:Plant Lectins; D010940:Plant Proteins; D001895:Boron