Ethylene Biosynthesis during Aerenchyma Formation in Roots of Maize Subjected to Mechanical Impedance and Hypoxia
| Autor: | Page W. Morgan, Wayne R. Jordan, Malcolm C. Drew, Chuanjiu He, Scott A. Finlayson |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Ethylene
ATP synthase Physiology Mechanical impedance Substrate (chemistry) chemistry.chemical_element Plant Science Biology Hypoxia (medical) Oxygen Aerenchyma formation chemistry.chemical_compound chemistry Biochemistry Genetics biology.protein Biophysics medicine Elongation medicine.symptom Research Article |
| Zdroj: | Plant Physiology. 112:1679-1685 |
| ISSN: | 1532-2548 0032-0889 |
| Popis: | Germinated maize (Zea mays L.) seedlings were enclosed in modified triaxial cells in an artificial substrate and exposed to oxygen deficiency stress (4% oxygen, hypoxia) or to mechanical resistance to elongation growth (mechanical impedance) achieved by external pressure on the artificial substrate, or to both hypoxia and impedance simultaneously. Compared with controls, seedlings that received either hypoxia or mechanical impedance exhibited increased rates of ethylene evolution, greater activities of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase, ACC oxidase, and cellulase, and more cell death and aerenchyma formation in the root cortex. Effects of hypoxia plus mechanical impedance were strongly synergistic on ethylene evolution and ACC synthase activity; cellulase activity, ACC oxidase activity, or aerenchyma formation did not exhibit this synergism. In addition, the lag between the onset of stress and increases in both ACC synthase activity and ethylene production was shortened by 2 to 3 h when mechanical impedance or impedance plus hypoxia was applied compared with hypoxia alone. The synergistic effects of hypoxia and mechanical impedance and the earlier responses to mechanical impedance than to hypoxia suggest that different mechanisms are involved in the promotive effects of these stresses on maize root ethylene biosynthesis. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|