Plant pathogenesis-related proteins in class 10 (PR- 10) have well-defined structures , but the physiological function unclear . The discovery that the plant hormone binding protein from the group of cytokines ( CSBP ) belong to a group of structurally PR- 10 , suggesting that the binding of hydrophobic ligands of the general biological role of this entire class. This is confirmed by the structure of lupine protein complexes LLPR - 10.2B of cytokinins .