We report the synthesis of twelve indole derivatives bearing nitro or amide groups via Fischer indole methodology followed by reduction/acetylation and amidation reactions. After thorough characterization, these indoles were subjected to a number of studies in order to evaluate their bioactive potential as photosynthesis and plant growth inhibitors. Firstly, these molecular hybrids were evaluated as photosystem II (PSII) inhibitors through chlorophyll a (Chl a) fluorescence measurement. In this study, 6‐chloro‐8‐nitro‐2,3,4,9‐tetrahydro‐1H‐carbazole (15a) and 5‐chloro‐2,3‐dimethyl‐7‐nitro‐1H‐indole (15b) showed the best results by reducing the phenomenological parameters of reaction centers ABS/RC, TR0/RC and ET0/RC of PSII. Electron chain blockage by these compounds may lead to diminished ATP synthesis and CO2 fixation which interrupt the plant development. The compounds 15a and 15b both act as postemergent herbicides, reducing the dry biomass of Ipomoea grandifolia and Senna alata weeds by an average of 40% and 37%, respectively, corroborating the fluorescence results. Additionally, the molecular docking study revealed that the presence of strong electron‐withdrawing groups at the indole phenyl ring is important for the ligand’s interaction with the binding pocket of protein D1 on PSII. The optimization of these molecular features is the goal of our research group in further understanding and development of new potent herbicides.

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Endophytic fungi are an important class of microorganisms, able to interact with a host plant via a mutualistic mechanism without visible symptoms of the fungal colonization. The synergy between endophytic fungi and their host plant can promote morphological, physiological and biochemical changes through the expression of bioactive metabolites. This work aims to correlate metabolic changes in the Combretum lanceolatum plant metabolome with its endophytic fungi Diaporthe phaseolorum (Dp) and Trichoderma spirale (Ts), and to discover corresponding metabolite‐biomarkers, with the principal focus being on its primary metabolism. The 1H‐NMR metabolomic analysis of qualitative and quantitative changes was performed through multivariate statistical analysis and the identification of primary metabolites was achieved on the Madison Metabolomics Consortium Database. The presence of Dp significantly impacted the plant's metabolic pathways, improving the biosynthesis of primary metabolites such as threonine, malic acid and N‐acetyl‐mannosamine, which are precursors of special metabolites involved in plant self‐defence. This work represents a valuable contribution to advanced studies on the metabolic profiles of the interaction of plants with endophytes.

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.

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.

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The aim of this work was to identify and quantify the metabolites present in the roots of Combretum lanceolatum inoculated with its endophytic fungi. The metabolomics was accomplished using the 1H nuclear magnetic resonance (NMR) spectral data and evaluated via rNMR software and Madison Metabolomics Consortium Database (MMCD). The principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) showed that plants inoculated with Trichoderma spirale (Ts) present differentiation and discrimination over the time as compared to control. Seven days after Ts fungal inoculation, 15 metabolites were identified at different concentrations comparing to the control plants. The plants inoculated with Ts fungus present the metabolites spermidine and pantothenate in higher concentrations and 3-hydroxybutyric acid and β-alanine in lower concentrations as compared to control plants, indicating any response to biotic stress. These metabolites are involved in various plant processes, including secondary metabolites biosynthesis, energy metabolism and self-defense. Therefore, this work demonstrates the diversification of primary metabolites composition influenced by endophytes inoculation.