Brown rot gene expression and regulation in acetylated and furfurylated wood: A complex picture

The aim of this study was to investigate Rhodonia placenta expression patterns of genes involved in the depolymerisation during the non-enzymatic phase in acetylated (W_Ac) and furfurylated wood (W_FA). During the 98-day-long exposure, W_Ac [22.6% weight per cent gain (WPG) on average] and W_FA (69% WPG on average) lost no more than 3% mass while the untreated wood (W_Un) reached 41% mass loss (ML) in 55 days. Expression of six genes putatively involved in the non-enzymatic degradation process were investigated. In conclusion, expression levels of alcohol oxidase Ppl118723 (AlOx1) and laccase Ppl111314 (Lac) were significantly higher in the modified wood materials (W_Mod) than in W_Un, which is in accordance with previous results and may be explained by the absence of the degradation products that have been proposed to down-regulate the non-enzymatic degradation process. However, copper radical oxidase Ppl156703 (CRO1) and a putative quinate transporter Ppl44553 (PQT) were expressed at significantly lower levels in W_Mod than in W_Un while quinone reductase Ppl124517 (QRD) and glucose oxidase Ppl108489 (GOx) were expressed at similar levels as in W_Un. These results suggest that gene regulation in W_Mod is more complex than a general up-regulation of genes involved in the non-enzymatic degradation phase.