10.6084/m9.figshare.1278874 Md N. Uddin Md N. Uddin Randall W. Robinson Randall W. Robinson Domenic Caridi Domenic Caridi Phytotoxicity induced by <i>Phragmites australis</i>: an assessment of phenotypic and physiological parameters involved in germination process and growth of receptor plant Taylor & Francis Group 2014 activated carbon gallic acid oxidative damage Phragmites australis physiological processes phytotoxicity 2014-01-02 00:00:00 Journal contribution https://tandf.figshare.com/articles/journal_contribution/Phytotoxicity_induced_by_i_Phragmites_australis_i_an_assessment_of_phenotypic_and_physiological_parameters_involved_in_germination_process_and_growth_of_receptor_plant/1278874 <p>This study investigated the possible phytotoxicity induced by <i>Phargmites australis</i> on phenotypic and physiological parameters of recipient plants with identification of major inhibitors in the donor plant. This was achieved using aqueous extracts of different organs and root exudates of <i>P. australis</i> in laboratory and greenhouse experiments with <i>Lactuca sativa</i> as the model test plant. The observed reduced liquid imbibition and altered resource mobilization in seeds of <i>L. sativa</i>, in particular an insufficient carbohydrate supply, demonstrated that the onset of germination might be negatively affected by phytotoxicity. Dose-response studies pointed out that oxidative stress through reactive oxygen species production could potentially cause the observed germination and seedling growth reductions. The osmotic effects by mannitol solution on germination as well as growth and physiology at a level of −0.57 and −0.45 bar, respectively, demonstrated that the results from aqueous plant extracts were partially induced by the osmotic potential on and above those levels. Overall, the relative strength of inhibition on measured parameters was the highest in leaf extract, followed by rhizome, root, stem, and inflorescence. Root exudates of <i>P. australis</i> also had negative impacts by reducing germination and growth of plant. High-performance liquid chromatography (HPLC) analysis revealed gallic acid, a potent phytotoxin, as a major compound with an order of leaf >inflorescence>rhizome>root>stem.</p>