Pressurized gas transport in two Japanese alder species in relation to their natural habitats |
| |
Authors: | Wolfgang Grosse Angela Schulte Hiroko Fujita |
| |
Institution: | 1. Botanical Institute, University of Cologne, Gyrhofstrasse 15, D-5000, K?ln 41, Germany 2. Botanic Garden, Faculty of Agriculture, Hokkaido University, West 8, North 3, Chuo-ku, 060, Sapporo, Japan
|
| |
Abstract: | Oxygen uptake measurements have shown that pressurized gas transport, resulting from the physical effect of thermo-osmosis
of gases, improves oxygen supply to the roots of the seedlings in two alder speciesAlnus japonica (Thunb.) Steud. andAlnus hirsuta (Spach) Rupr., which are both native in Japan. When gas transport conditions were established by irradiation of the tree
stems the internal aeration was increased to a level nearly equal to the oxygen demand of the root system in leafless seedlings
ofA. hirsuta, but was higher inA. japonica so that excess oxygen was excreted into the environment. An increase of superoxide dismutase (SOD) activity, which protects
plants from toxic oxygen radicals and post-anoxic injury, has been observed in root tissues ofA. japonica when the seedlings were flooded for 3 days. The increase of SOD activity, in concert with high gas transport rates, may enable
this tree species to grow in wet sites characterized by low oxygen partial pressure in the soil and by varying water tables.
A less effective gas transport, flood-induced reduction of SOD activity in root tissues, and reduced height growth in waterlogged
soil may be responsible for the fact thatA. hirsuta is unable to inhabit wettland sites. |
| |
Keywords: | Alnus japonica Alnus hirsuta flood-tolerance root aeration superoxide dismutase |
本文献已被 SpringerLink 等数据库收录! |
|