A transcriptomic-based comparison of barley cultivars differing with respect to their low temperature acclimation capacity

The PhD thesis is focused on a transcriptomics-based comparison of barley cultivars differing with respect to their low temperature acclimation capacity, with a particular focus on genes transcribed in the leaf and crown. The crown was of interest because of its importance for the winter survival of the plant. To involve both the first and the second phase of hardening, the test plants were exposed first to +3řC for 21 days, followed by - 3řC for one day. Freezing damage was assessed by measuring electrolyte leakage (Papers 2 and 3), using a modified version of a protocol developed by Prášil and Zámečník (1998). The same protocol was adapted to evaluate crown regrowth (Paper 2); for this purpose, the plants were cooled, then replanted and cut above the crown, and their survival rate calculated over the following week. Each RNA sample was queried by hybridization to an Affymetrix 22 K Barley1 GeneChip Genome Array (Close et al. 2004). The data were statistically analysed with the help of the software packages R, MAS 5.0 (Ihaka & Gentleman 1996) (Papers 2 and 3), Gene Spring GX 7.3 (Agilent Technologies, Santa Clara CA) and MapMan (Thimm et al. 2004; Usadel et al. 2005) (Paper 2), the "Self-Organizing Maps" algorithm (Kohonen et al. 1996) (Paper 3) and MIPS FunCat (Ruepp et al. 2004) (Paper 2). Paper..