Steroid Phytohormones in Coal Deposits: a Geochemical Bridge between Ancient and Modern Plants

Samples of coal and peat of different ages from the deposits of Belarus were first studied for the content of plant steroid hormones (brassinosteroids) using independent methods of enzyme immunoassay and HPLC-MS/MS. The quantitative determination of brassinosteroids showed that all the studied samples contained phytohormones of the main natural groups (brassinolide, 24-epibrassinolide, and 28-homobrassinolide), except for brassinolide in the oldest sample. The measured content of brassinosteroids corresponded to that characteristic of modern plant objects, and the composition of brassinosteroids varied depending on the depth of occurrence and other factors. The data obtained may indicate a high stability of plant steroid hormones and their supposed role as bioregulators over a long period of plant evolution.