NMR on Plants |
Our group has a long standing track record in NMR experiments on plants. In 1994 we developed NMR suitable climate chambers for 11.7 T and 7 T NMR machines in cooperation with the group of Prof. Zimmermann. Intact plants can be kept in these chambers under controlled environmental conditions. Light intensity, humidity, CO2 concentration, temperature and other parameters can be adjusted and freely varied.
Within the last decade NMR coils for use on almost any part of a plant from roots over stem to the leaves have been developed. Experiments could be performed on seeds, seedlings at various stages of their development, small fully developed plants, liana and truncated twigs. NMR experiments could even be combined with other techniques such as xylem pressure probe or Scholander bomb.
Plant experiments demand a lot of adaptation of hardware as well as pulse sequences compared to measurements on animals or humans for the following reasons: Plant tissue usually has very short T2, T2* and quite long T1 relaxation times. Air filled spaces often cause problems due to strongly varying magnetic field inhomogeneities. The electric conductivity of plant tissue is generally very low compared to animal tissue which results in very different loading of coils. Flow velocities of water and metabolites in plants are up to 1000 times lower than in animals.
The most prominent NMR results for plants at present are: Flow velocities in xylem and phloem can be measured with high accuracy under normal and stress conditions. Water distribution in plants can be mapped under drought stress and osmotic stress. Distribution of sugars, lipids and secondary metabolites in plant stems can be detected. Metabolism studies on plants are possible using 13C and 19F labeled substrates. Salinity stress can be monitored using 23Na NMR.
Contact:
Thomas Schulze-Till