Barley Cbf3 Gene Identification, Expression Pattern, and Map Location

Abstract

Although cold and drought adaptation in cereals and other plants involve the induction of a large number of genes, inheritance studies in Triticeae (wheat [Triticum aestivum], barley [Hordeum vulgare], and rye [Secale cereale]) have revealed only a few major loci for frost or drought tolerance that are consistent across multiple genetic backgrounds and environments. One might imagine that these loci could encode highly conserved regulatory factors that have global effects on gene expression; therefore, genes encoding central regulators identified in other plants might be orthologs of these Triticeae stress tolerance genes. The CBF/DREB1 regulators, identified originally in Arabidopsis as key components of cold and drought regulation, merit this consideration. We constructed barley cDNA libraries, screened these libraries and a barley bacterial artificial chromosome library using rice (Oryza sativa) and barley Cbf probes, found orthologs of ArabidopsisCBF/DREB1 genes, and examined the expression and genetic map location of the barley Cbf3 gene,HvCbf3. HvCbf3 was induced by a chilling treatment. HvCbf3 is located on barley chromosome 5H between markers WG364b and saflp58 on the barley cv Dicktoo × barley cv Morex genetic linkage map. This position is some 40 to 50 cM proximal to the winter hardiness quantitative trait locus that includes the Vrn-1H gene, but may coincide with the wheat 5A Rcg1 locus, which governs the threshold temperature at which cor genes are induced. From this, it remains possible that HvCbf3 is the basis of a minor quantitative trait locus in some genetic backgrounds, though that possibility remains to be thoroughly explored.

Low levels of linkage disequilibrium in wild barley ( Hordeum vulgar e ssp. spontaneum ) despite high rates of self-fertilization

“…The sequence from the enzymatic Pepc locus was reported in Morrell et al (17); 5ЈPepc is an additional 2,017 bp adjacent to, and immediately upstream from, that region. C-repeat binding factor 3 (Cbf3) is a functional, nonenzymatic locus that shows increased expression when plants are exposed to low temperatures (18). The dehydrin loci, Dhn1, Dhn4, and Dhn7, all show increased expression during dehydration (19).…”

From Laboratory to Field. Using Information from Arabidopsis to Engineer Salt, Cold, and Drought Tolerance in Crops

“…The orthologous genes of CBF have been found in most crop plants examined so far, including canola (B. napus), soybean (Glycine max), broccoli (Brassica oleracea), tomato, alfalfa (Medicago sativa), tobacco (Nicotiana tabacum), cherry (Prunus avium), strawberry (Fragaria spp. ), wheat, rye (Secale cereale), corn (Zea mays), rice, and barley (Jaglo et al, 2001;Choi et al, 2002;Gao et al, 2002;Owens et al, 2002;Dubouzet et al, 2003;Francia et al, 2004;Shen et al, 2003aShen et al, , 2003bVagujfalvi et al, 2003;Xue, 2003). Many of the putative orthologs have been functionally tested, indicating conservation of the pathway in those plant species.…”

The Role of Dreb Transcription Factors in Abiotic Stress Tolerance of Plants

“…in Arabidopsis, expression of DREB1A was induced by cold, while DREB2A was induced by dehydration and salt stress (39 (30). in barley, a DREB1A homolog cBF3 was induced by cold stress (12). A homolog of DREB2-type gene found in wheat was induced by cold, while dehydration and salt stress had small effects on its expression (57).…”

“…in the same way, several cBFs (cBF1, cBF2, cBF3 and cBF4) were isolated from Arabidopsis (19,21,43). Several cBF homologs have also been reported from a wide range of plants including barley (12,59), canola (30), Bell pepper (24), soybean (37), tobacco (49), tomato (30) and wheat (66). typically the DReB1 and DReB2 genes are induced by cold and dehydration stress, respectively.…”