barley (Hordeum vulgare L.) dehydrin multigene family: sequences, allele types, chromosome assignments, and expression characteristics of 11 Dhn genes of cv Dicktoo

• Published in: Theoretical and applied genetics Vol. 98; no. 8; pp. 1234 - 1247
• Main Authors: Choi, D.W, Zhu, B, Close, T.J
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.06.1999; Berlin Springer Nature B.V
• Subjects: abscisic acid; Acids; alleles; Allelomorphism; amino acid sequences; Barley; Biological and medical sciences; chromosome mapping; Chromosomes; Classical genetics, quantitative genetics, hybrids; Cold; cultivars; desiccation; dhn genes; DNA; DNA primers; DNA sequencing; exons; Fundamental and applied biological sciences. Psychology; genbank/af043086; genbank/af043087; genbank/af043088; genbank/af043089; genbank/af043090; genbank/af043091; genbank/af043092; genbank/af043093; genbank/af043094; genbank/af043095; genbank/af043096; gene copy number; Gene expression; gene location; Genetic aspects; Genetic engineering; genetic regulation; Genetics of eukaryotes. Biological and molecular evolution; Hordeum vulgare; introns; linkage (genetics); messenger RNA; molecular sequence data; multigene family; nucleotide sequences; Nucleotide sequencing; Physiological aspects; Plant genetics; plant proteins; Proteins; Pteridophyta, spermatophyta; regulatory sequences; restriction mapping; Salinity; Vegetals; Japan; Genetic mapping; Monocotyledones; Hordeum vulgare; Nucleotide sequence; Chromosome; Dehydration; Cereal crop; Stress; Molecular evolution; Allele; Gramineae; Drought resistance; Angiospermae; Multigene family; Spermatophyta; Gene duplication; Cultivar
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s001220051189

Dehydrins (LEA D11 proteins) have been identified in both higher and lower plants, and are associated with tolerance to, or response to the onset of, low temperature or dehydration. Several studies have suggested that specific alleles of Dhn genes may contribute to a number of phenotypic traits, including the emergence of seedlings in cool or saline soils and the frost tolerance of more-mature plants. However, an incomplete collection of the Dhn multigene family in any system and nucleic acid cross-hybridization between Dhn gene-family members have limited the precision of these studies. We attempted to overcome these impediments by determining the nucleotide sequences of the entire Dhn multigene family in barley and by developing gene-specific probes. We identified 11 unique Dicktoo Dhn genes. Seven appear to be alleles of Dhn genes identified previously in other barley cultivars. Another, Dhn9, appears to be orthologous to a Triticum durum Dhn gene. A statistical analysis of the total collection of genomic clones brings the estimated size of the barley Dhn gene family to 13. Allelic differences in the protein-coding regions appear to result principally from duplications of entire phi-segments or single amino-acid substitutions, suggesting that polypeptide structural constraints have been a strong force in the evolution of Dhn alleles. Chromosome mapping by PCR with wheat-barley addition lines established the presence of Dhn genes in four barley chromosomes (3H, 4H, 5H, 6H). RT-PCR demonstrated that the Dhn genes are differentially regulated under dehydration, low temperature and ABA treatment, consistent with putative regulatory elements located upstream of the respective Dhn coding regions. This whole-genome, gene-specific study unifies what previously seemed to be disparate-mapping, expression, and genetic-variation data for Dhn genes in the Triticeae and other plant systems.