Plant & Animal Genomes XIII Conference

January 15-19, 2005
Town & Country Convention Center
San Diego, CA

Functional Genomics Of Malting In Barley

Nora L. Lapitan¹ , Anna-Maria Botha-Oberholster¹ , Blake Cooper² , Jolanta Menert² , Timothy J. Close³ , Christopher Lawrence⁴

¹  Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO 80523

²  Busch Agricultural Resources, Inc., Fort Collins, CO, 80524

³  University of California, Riverside CA, 92521

⁴  Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA, 24061

Malting is a complex process that involves many enzymes. The overall goal of this project is to isolate specific gene sequences and allelic variation, particularly, single nucleotide polymorphisms (SNPs) of structural and regulatory genes involved with the malting process. Results will be presented on: 1) identification of allelic variants in beta-amylase gene, Bmy1; 2) transcriptional profiling of gene expression during malting using Affymetrix ® Barley Gene Chips; and 3) development of ESTs from cDNA libraries enriched for genes expressed during malting. Twenty cDNA libraries were constructed from malt tissues of selected malting barley cultivars representing 2-row and 6-row classes. SNPs were identified for Bmy1 at amino acid positions 115, 165, and 430. The association of these SNPs with malting quality parameters was determined. RNA expression patterns in different stages of micromalting (i.e, steeping, germination, kilning) in the cultivar ‘Morex’ was studied through hybridization of RNA against the 22K Barley1 Affymetrix ® GeneChip probe array. A subset of candidate genes that appear to be important in malting was identified. Expression patterns of these genes were then compared among the 6-row cultivars, ‘Morex’ and ‘Legacy’, and the 2-row cultivars, ‘Harrington’ and ‘Merit.’ ESTs were developed from a cDNA library made by suppression subtractive hybridization of RNA from malted tissues with RNA from dry seed. Sequence annotation of a small subset of ESTs from the enriched libraries validated some of the candidate genes identified on the array. Interestingly, novel sequences not reported previously for barley were found.