Özet:
Boron is a necessary nutrient for plants and animals, however excess of it causes toxicity. Previously, Atr1
and Arabidopsis Bor1 homolog were identified as the boron efflux pump in yeast, which lower the cytosolic
boron concentration and help cells to survive in the presence of toxic amount of boron. In this study,
we analyzed ATR1 paralogs, YMR279c and YOR378w, to understand whether they participate in boron
stress tolerance in yeast. Even though these genes share homology with ATR1, neither their deletion rendered
cells boron sensitive nor their expression was significantly upregulated by boron treatment. However,
expression of YMR279, but not YOR378w, from the constitutive GAPDH promoter on a high copy
plasmid provided remarkable boron resistance by decreasing intracellular boron levels. Thus our results
suggest the presence of a third boron exporter, YMR279c, which functions similar to ATR1 and provides
boron resistance in yeast.
