Molecular analysis and spatial expression pattern of a low-temperature-specific barley gene, blt101.

A cDNA clone of the previously unreported low-temperature-induced gene blt101 was isolated after a differential screen of a cDNA library prepared from low-temperature (6 degrees C day/2 degrees C night) grown barley shoot meristems. Southern blot analysis of barley ditelosomic addition lines was used to assign this single-copy gene to the long arm of chromosome 4. Analysis of steady-state levels of blt101 mRNA showed the induction of this transcript in shoot meristems upon transfer of barley (cv. Igri) plants from control (20 degrees C/15 degrees C) to low (6 degrees C/2 degrees C) temperature treatment. Further, the high level of this transcript is maintained at low temperatures but is reduced on transfer from low to control temperatures. The gene is not induced by drought or by foliar application of ABA. Analysis of segregating doubled haploid lines shows that there is no specific association of this gene with either spring/winter growth habit or frost hardiness. Examination of the spatial expression pattern revealed ubiquitous expression of blt101 in low-temperature (6 degrees C/2 degrees C) grown barley shoot meristems, mature leaves and roots.