COLD-SPECIFIC INDUCTION OF A DEHYDRIN GENE FAMILY MEMBER IN BARLEY

An interval on barley (Hordeum vulgare L.) chromosome 7 accounting for significant quantitative trait locus effects for winter hardiness wer e detected in a winter (Dicktoo) x spring (Morex) barley population (P .M. Hayes, T. Blake, T.H.H. Chen, S. Tragoonrung, F. Chen, A. Pan, and B. Liu [1993] Genome 36: 66-71). Two members of the barley dehydrin g ene family, Dhn1 and Dhn2, were located within the region defining the winter hardiness quantitative trait locus effect (A. Pan, P.M. Hayes, F. Chen, T. Blake, T.H.H. Chen, T.T.S. Wright, I. Karsai, Z. Bedo [19 94] Theor Appl Genet 89: 900-910). To investigate the possible role of Dhn1 and Dhn2 in winter hardiness, we examined the expression pattern of six barley dehydrin gene family members in shoot tissue in respons e to cold temperature. Incubation of 3-week-old barley plants at 2 deg rees C resulted in a rapid induction of a single 86-kD polypeptide tha t was recognized by an antiserum against a peptide conserved in the de hydrin gene family. Northern blot analysis confirmed the induction of an mRNA corresponding to Dhn5. The expression patterns of cold-induced dehydrins in shoot tissue for Dicktoo and Morex were identical under the conditions studied, in spite of the known phenotypic differences i n their winter hardiness. These results, together with the allelic str ucture of selected high- and low-survival lines, suggest that the Dick too alleles at the Dhn1 and Dhn2 may not be the primary determinants o f winter hardiness in barley.