Changes in Transcript and Protein Expression Levels in the Barley - Cochliobolus sativus Interaction

Spot blotch, caused by Cochliobolus sativus, is an important barley disease which causes extensive grain yield losses worldwide. In order to investigate the molecular responses to the C. sativus infection, leaf transcriptome and proteome before and after fungus inoculation in a resistant barley genotype, were compared using cDNA-AFLP and 2-D PAGE techniques. A notable number of transcripts and proteins exhibiting significant differential accumulations were detected compared to the non-inoculated controls. Functional annotation of the transcripts and proteins revealed a wide range of pathways including cell wall fortification, metabolism, signal transduction and defence. Spearman correlations of the relative abundances for those genes represented by both an mRNA and a protein showed a weak (r(s) = 0.4; P < 0.001) relationship, indicating that post-transcriptional processes play a critical role in regulating the protein level during infection. Taken together, our study suggested that a joint analysis of the transcriptomic and proteomic of barley data can provide useful insights that may not be deciphered from individual analysis of mRNA or protein expressions.