Applications

Tentoxin is a naturally occurring phytotoxic cyclic tetrapeptide that is excreted by the fungi Alternaria alternata and Alternaria tenuis. It induces chlorosis in germinating seedlings of many dicotyledonous plants. Tentoxin has been postulated to inhibit cyclic photophosphorylation by acting as an energy transfer inhibitor at the terminal steps of ATP synthesis and to target the F1 moiety of photosynthetic H⁺-ATPases. A kinetic analysis of the action of tentoxin on the chloroplast F1 H⁺-ATPase (CF1) portion of chloroplast ATP synthase has been reported.