THIOPHENE SYNTHESIS AND DISTRIBUTION IN YOUNG DEVELOPING PLANTS OF TAGETES-PATULA AND TAGETES ERECTA

Thiophene synthesis and accumulation were investigated in organs of Tagetes patula and T. erecta. Thiophene accumulation started rapidly in germinating seedlings of both species. Roots and hypocotyls were the major thiophene accumulating organs and 5-(3-buten-1-ynyl)-2,2'-bithienyl (BBT) and 5-(4-acetoxy-1-butynyl)-2,2'-bithienyl (BBTOAc) were the major accumulated compounds. Higher thiophene concentrations were reached in Tagetes patula than in T. erecta. Accumulation patterns for individual thiophenes were different within organs, between organs and between both species. Within hypocotyls of Tagetes patula, thiophene concentrations were high in the epidermis and the vascular tissue and low in the parenchymatic tissues of cortex and pith. Synthesis of thiophenes was high in the roots and hypocotyls and very low in the leaves. Transport of thiophenes from the roots into the shoot occurred, but the rate of transport was too low to explain the high concentrations in the hypocotyl. It is concluded that for the main part thiophenes are accumulated where they are synthesized.