Evaluation of p-benzoquinones derivatives as post-emergent plant growth inhibitor

Abstract

Eight p-benzoquinones derivatives (1-8) were synthesized and evaluated as photosynthesis and plant growth (dry biomass) inhibitors through semi in vivo and in vivo assay. The photosynthetic parameters provided by the JIP-test were based on the major steps of the photosynthetic process: photon absorption (ABS), energy capture (TR), electron transport (ET) and reduction of photosystem II (PS II) final acceptors (RE). Compounds 6, 7 and 8 decresead the PI(abs) parameter by 82, 75, 42% and incresead the ET0/CS0 parameter by 37, 20 and 25%, respectively. These results suggested that 6-8 inhibit the electron transport chain at PS II in both semi in vivo and in vivo assays. Futhermore, compounds 6 and 7 reduced the plant growth by 52 and 77%, respectively. Therefore, the derivatives of p-benzoquinone not only demonstrated appreciable activity as inhibitors of photosynthesis by acting on the electron transport chain on the acceptor side of PS II, but also inhibit the plant growth.