Suberin as an Extra Barrier to Grass Digestibility: a Closer Look to Sugarcane Forage

Suberin is a lipid-phenolic biopolymer present in the cell walls of specialized plant cell types. Due to its insolubility and impermeability, suberin forms an important barrier to the transport of water, ions and gases in certain plant tissues, such as the root endodermis, the periderm and the bundle sheath of C4 plants. In sugarcane forage, supplied in tropical countries as complement to animal livestock, the cell walls of most tissues that build up the stem are progressively suberized. Suberin biochemical features and significant content in the stem make this biopolymer an extra factor influencing sugarcane biomass recalcitrance, decreasing digestibility. Here, we summarize the latest data on the biosynthesis, transport and deposition of suberin in plants, with a special focus on sugarcane forage, and discuss how this biopolymer affects biomass digestibility.