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.

Evaluation of Chalcone Derivatives as Photosynthesis and Plant Growth Inhibitors

“…Although most chalcone derivatives show no activity on aerial part dry biomass reduction, compounds 6a and 6j demonstrated similar or better results on the I. grandifolia root biomass experiment compared to other synthetic compounds described in the literature [46–53] . For example, the α,β‐unsaturated carbonyl compounds such as the enaminopyran‐2,4‐dione derivatives reduced the root dry biomass by an average of 32 % to 83 % at 500 μM, [49] and the pyridazin‐3(2 H )‐one derivatives reduced the root dry biomass by an average of 28 to 76 % at 200 μM [54] .…”