|BURTON, CHARLOTTE - Former ARS Employee|
|HONG, ZONGLIE - University Of Idaho|
|JACKSON, ERIC - Former ARS Employee|
Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/17/2014
Publication Date: 3/1/2014
Citation: Hu, G., Burton, C., Hong, Z., Jackson, E. 2014. Identification and characterization of a partially functional mutation of the cellulose-synthase-like (CslF6) gene in barley (Hordeum vulgare L.). Journal of Cereal Science. 59:189-195.
Interpretive Summary: The soluble fiber known as beta-glucan is an important component of barley because it affects the process of malting in barley and the suitability of barley as feed for certain animals. We identified and characterized a mutant in the barley called m351. The mutant showed a low beta-glucan content in grain of 1.5% compared to about 4% in normal barley. In addition to the low beta-glucan, other changes include crude fiber and fructans compared to the corresponding ‘wild-type’, non-mutant plants. Otherwise, the chemical composition of m351 seed is nearly identical to that of the wild-type. Our study showed that the mutation is located on chromosome 7H. Molecular studies showed that the mutant is due to the partial function of the gene called CslF6, which is involved in beta-glucan biosynthesis. This study complemented the functional evaluations of the CslF6 gene in previous studies. Since low beta-glucan is an important character in barley for malting and feed uses, this mutant allele could be used to breed improved barley varieties.
Technical Abstract: The chemical induced barley mutant m351 was first selected for its low level of mixed-linkage (1,3), (1,4) beta-D-glucan (MLG) in an effort to find barley lines with varied grain MLG contents. The MLG decrease in m351 was associated with thinned endosperm cell walls and increased levels of fructans and crude fiber, but maintained the same plant characteristics under field conditions as the wild-type. The mutation was mapped to a genetic locus flanked by two SSR markers, Bmag369 and Bmag564, on chromosome 7H. Molecular cloning of the m351 locus revealed its identity as a new allele of the CslF6 gene, encoding the enzyme for MLG biosynthesis. The m351 mutant allele substitutes alanine for threonine at position 849 in the amino acid sequence. The resultant protein has some functionality based on MLG level in grain and it affects multiple metabolic pathways based on analysis of chemical changes in m351 grain composition. The metabolic changes associated with MLG reduction in m351are the first report of a partially functional CslF6 gene in cereal grains. The results contribute to better understanding of the functional effects of the CslF6 gene and the mutant has potential implications in grain end-use quality improvement