We investigated the allelopathic effects of Bidens pilosa L. and Mikania micrantha Kunth. on the germination and early seedling growth of Zea mays L. (Maize) and Phaseolus vulgaris L. (Common bean). It integrates laboratory bioassay data with In silico analyses to elucidate how specific allelochemicals may interfere with the regulatory pathways of the GID1 and PYL9 genes, which play crucial roles in controlling seed germination. Aqueous leaf extracts (2 %, 4 %, 6 %) were assessed under controlled conditions and significant phytochemicals were characterised using SwissADME, molecular docking, molecular dynamics (MD) and gmxMMPBSA free-energy analysis. Both species showed concentration-dependent inhibition but M. micrantha was more phytotoxic. Z. mays germination decreased to 35 % at a 6 % extract concentration, than 90% in control. SwissADME analysis indicated that highly lipophilic sesquiterpenes (logP ≈ 4–5; TPSA < 30 Ų) enhanced the membrane permeability, suggesting their potential as allelopathic agents. The docking results also showed strong binding of key compounds (Luteolin, apigenin, caryophyllene, cedrene and quercetin) to the ABA receptor (PYL2) and GA receptor (GID1), with affinities from - 8. 0 to -10. 1 kcal/mol. MD simulations confirmed stable ligand-receptor interactions for over 100 ns, while gmxMMPBSA analysis showed consistently favourable binding energies (-15 to -30 kcal/mol), confirming their capacity to disrupt hormonal signalling. This comprehensive approach showed that the allelopathic effects of B. pilosa and M. micrantha resulted from synergistic interactions between flavonoids and sesquiterpenes that disrupt ABA and GA mediated germination pathways. These findings suggested the potential of allelochemicals as natural candidates for sustainable weed management techniques.
Sailo et al. (2026) studied this question.