Abstract
BackgroundPlants primed by humic acids showed physiological and molecular response against different abiotic stresses without the presence of stressor agents (salinity, drought, heavy metal toxicity). It is plausible that humic acids themselves can act as chemical priming substances in plants. We hypothesized that humic acids can trigger the weak acids stress response in cell plants acidifying the cytosol and thus eliciting the transduction signalling response cascade.MethodsThe dose–response curves of maize seedlings roots with different concentrations of humic, acetic and salicylic acids determined the most active and inhibitory concentration. These data were further used to evaluate changes on intracellular pH using BCECF-AM probe (2,7-bis(2-carboxyethyl)-5(and 6)-carboxyfluorescein, acetoxymethyl ester) and differential transcription level of genes related to weak stress response in plants by qPCR real time.ResultsHumic acids like short chain organic acids decrease the intracellular pH showed by the increased fluorescence of BCECF probe. The drop in cytosolic pH promoted by humic acids was not transient. We observed a high level of protein kinases related to cell energy-sensing and transcription factors associated to transduction of stress signalling.ConclusionThe humic acids can be considered as a chemical priming agent, since in the appropriate concentration they can induce the typical plant abiotic stress response of weak acids inducing plant acclimation and enhancing the abiotic stress tolerance.
Highlights
Plants primed by humic acids showed physiological and molecular response against different abiotic stresses without the presence of stressor agents
The shoulders at 82 ppm derive from the carbon 4 involved in the glycosidic bond with the most deshielded di-O-alkyl anomeric carbon centred at 104.7 ppm in glucose units [35]
The broad bands extended along the aryl-C interval (116–140 ppm) involve the un-substituted and C-substituted phenyl units of different aromatic components, while the signals shown in the phenolic region (140–160 ppm) are indicative of O-bearing carbon 3, 4, and 5 in the aromatic ring of lignin derivatives, carbon 3 and 5 being coupled to methoxyl substituent
Summary
Plants primed by humic acids showed physiological and molecular response against different abiotic stresses without the presence of stressor agents (salinity, drought, heavy metal toxicity). It is plausible that humic acids themselves can act as chemical priming substances in plants. Humic acids can be used as natural chemical prime agent. (2020) 7:31 drought, heavy metal toxicity and humic substances themselves [12]. These seedlings showed general physiological adjustment and transcriptomic analysis unveil specific gene response against abiotic stress [12] in typical acclimation behaviour [13]. The main mechanisms underpinning the priming activity of humic acids on plant seedlings remain unclear
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Chemical and Biological Technologies in Agriculture
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
