BAK1 and infection: RxLRs and CRLs were more expressed in Castanea crenata and elicitins and NLPs in Castanea sativa. Considering the low number of potential PRR genes overexpressed in C. sativa after infection and the undetected BAK1, it is likely that elicitins and NLPs have a significant role in the cellular decline of this chestnut species.