Investigation of barley brittle stem mutants

The barley brittle stem mutants, fs2, designated X054 and M245, have reduced levels of cellulose compared with their isogenic parents Ohichi and Shiroseto. A custom-designed microarray, based on Agilent technology and including genes involved in cell wall metabolism, was used to compare transcript levels in the mutant and parental lines. For both mutants, the microarray revealed a marked decrease in mRNA for the HvCesA4 cellulose synthase gene in specific zones of stem internodes, and this was confirmed by quantitative PCR. Genes expression was measured for the upper and lower zones from the 4th internodes of stems. Plant were at Zadocks developmental stage 49. Gene expression was compared between mutants and their wildtype parents.