Microbial xylanases and their inhibition by specific proteins in cereals

Abstract

Arabinoxylans (AXs) belong to the components of plant cells which are mainly degraded by microbial xylanases during colonization of grain by phytopathogens. For the defence, cereals contain proteinaceous xylanase inhibitors (XIs), namely xylanase inhibitor protein (XIP), Triticum aestivum xylanase inhibitor (TAXI) and thaumatin-like xylanase inhibitor (TLXI). Their presence in cereals in high levels can be a serious problem in different industrial applications. XIs regulate AX hydrolysis and participate in plant defence mechanisms. XIs have various specificity against microbial xylanases from the glycoside hydrolase (GH) families of GH10 and GH11. Therefore, this review brings new information about the function of XIs as defence responses to pathogen infection of plants and as a problem in plant material processing in different industrial applications.