The aim of the present study is to extend the applicability of MRI measurements similar
to those used in human diagnostics to the examination of water barriers in living
plants, thus broadening their use in natural sciences. The cucumber, Cucumis sativus,
and Phillyrea angustifolia, or false olive, were chosen as test plants. The MRI measurements
were carried out on three samples of each plant in the same position vis-a-vis the
MRI apparatus using a Siemens Avanto MRI scanner. Two different relaxation times were
employed, T1 capable of histological mapping, and T2, used for the examination of
water content. In the course of the analysis, it was found that certain histological
formations and branching cause modifications to the intensity detected with relaxation
time T2. Furthermore, these positions can also be found in T1 measurements. A monotonic
correlation (cucumber: ρ = 0.829; false olive: ρ = –0.84) was observed between the
T1 and T2 measurements. In the course of the statistical analysis of the signal intensities
of the xylems it was concluded that they cannot be regarded as independent in a statistical
sense; these changes rather depend on the anatomic structure of the plant, as the
intensity profile is modified by nodes, leaves and branches. This serves as a demonstration
of the applicability of MRI to the measurement of well know plant physiological processes.
The special parametrization required for this equipment, which is usually used in
human diagnostics, is also documented in the present study.
