Seasonal variation in transcript abundance in cork tissue analyzed by real time RT-PCR

Abstract

The molecular processes underlying cork biosynthesis and differentiation are mostly unknown. Recently, a list of candidate genes for cork biosynthesis and regulationwas made available opening newpossibilities for molecular studies in cork oak (Quercus suber L.). Based on this list, we analyzed the seasonal variation inmRNAabundance in cork tissue of selected genes by real time reverse-transcriptase polymerase chain reaction (RT-PCR). Relative transcript abundance was evaluated by principal component analysis and genes were clustered in several functional subgroups. Structural genes of suberin pathways such as CYP86A1, GPAT and HCBT, and regulatory genes of the NAMand WRKY families showed highest transcript accumulation in June, a crucial month for cork development. Other cork structural genes, such as FAT and F5H, were significantly correlated with temperature and relative humidity. The stress genes HSP17.4 and ANNwere strongly positively correlated to temperature, in accord with their protective role