A comparison of the effects of 1,4-naphthoquinone and 2-hydroxy-1,4-naphthoquinone (lawsone) on indole-3-acetic acid (IAA)-induced growth of maize coleoptile cells
| Autor: | Michał Ludynia, Waldemar Karcz, Małgorzata Rudnicka |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
0301 basic medicine Physiology Medium pH Plant Science 1 4-Naphthoquinone 01 natural sciences Lawsone 03 medical and health sciences chemistry.chemical_compound Acid growth Auxin Hydrogen peroxide Membrane potential chemistry.chemical_classification biology Growth rate 030104 developmental biology Coleoptile chemistry Biochemistry Catalase Oxidative stress biology.protein Biophysics Indole-3-acetic acid Agronomy and Crop Science 010606 plant biology & botany Naphthoquinones |
| Popis: | The effects of 1,4-naphthoquinone (NQ) and 2-hydroxy-1,4-naphthoquinone (NQ-2-OH) on indole-3-acetic acid (IAA)-induced growth, medium pH changes and membrane potential ( Em) in maize (Zea mays L.) coleoptile cells were determined. In addition, the redox cycling properties of both naphthoquinones were also compared. The dose-response curves constructed for the effects of NQ and NQ-2-OH on endogenous and IAA-induced growth differ in shape. It was found that NQ was by 10–50% more effective in inhibiting IAA-induced growth in maize coleoptile segments than NQ-2-OH. Simultaneous measurements of growth and external medium pH indicated that NQ and NQ- 2-OH reduced or eliminated proton extrusion at all of the concentrations used, excluding NQ at 1 μM. It was found that both naphthoquinones at concentrations higher than 10 μM caused the depolarisation of the membrane potential ( Em). Additionally, compared to the controls, NQ- and NQ-2-OH-exposure of coleoptile segments, at concentrations higher than 10 μM, caused an elevation of the hydrogen peroxide ( H2O2) production and plasma membrane redox activity. The highest catalase activity was observed at 10 μM NQ and it was ca. 18-fold greater (at 4 h) than in the control medium. Moreover, it was also found that NQ and NQ-2-OH, at all concentrations studied, increased the malondialdehyde content of coleoptile segments at 4 h of the experiment. The data presented here are discussed taking into account the “acid growth hypothesis” of auxin action and the mechanisms by which naphthoquinones interact with biological systems. |
| Databáze: | OpenAIRE |
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