title: Studying microstructure and microstructural changes in plant tissues by advanced diffusion magnetic resonance imaging techniques.
abstract: As sessile organisms, plants must respond to the environment by adjusting their growth and development. Most of the plant body is formed post-embryonically by continuous activity of apical and lateral meristems. The development of lateral adventitious roots is a complex process, and therefore the development of methods that can visualize, non-invasively, the plant microstructure and organ initiation that occur during growth and development is of paramount importance. In this study, relaxation-based and advanced diffusion magnetic resonance imaging (MRI) methods including diffusion tensor (DTI), q-space diffusion imaging (QSI), and double-pulsed-field-gradient (d-PFG) MRI, at 14.1 T, were used to characterize the hypocotyl microstructure and the microstructural changes that occurred during the development of lateral adventitious roots in tomato. Better contrast was observed in relaxation-based MRI using higher in-plane resolution but this also resulted in a significant reduction in the signal-to-noise ratio of the T2-weighted MR images. Diffusion MRI revealed that water diffusion is highly anisotropic in the vascular cylinder. QSI and d-PGSE MRI showed that in the vascular cylinder some of the cells have sizes in the range of 6-10 μm. The MR images captured cell reorganization during adventitious root formation in the periphery of the primary vascular bundles, adjacent to the xylem pole that broke through the cortex and epidermis layers. This study demonstrates that MRI and diffusion MRI methods allow the non-invasive study of microstructural features of plants, and enable microstructural changes associated with adventitious root formation to be followed.
authors.affiliation: School of Chemistry, The Sackler Faculty of Exact Sciences, and.
authors.forename: Darya
authors.initials: D
authors.lastname: Morozov
authors.affiliation: Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Ramat Aviv, Tel Aviv 66978, Israel.
authors.forename: Iris
authors.initials: I
authors.lastname: Tal
authors.affiliation: Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Ramat Aviv, Tel Aviv 66978, Israel.
authors.forename: Odelia
authors.initials: O
authors.lastname: Pisanty
authors.affiliation: Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Ramat Aviv, Tel Aviv 66978, Israel.
authors.forename: Eilon
authors.initials: E
authors.lastname: Shani
authors.affiliation: School of Chemistry, The Sackler Faculty of Exact Sciences, and.
authors.forename: Yoram
authors.initials: Y
authors.lastname: Cohen
mesh_terms: D038524:Diffusion Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D018546:Hypocotyl / Q000166:cytology* / Q000648:ultrastructure; D018551:Solanum lycopersicum / Q000166:cytology* / Q000648:ultrastructure; D018517:Plant Roots / Q000166:cytology* / Q000648:ultrastructure
keywords: Adventitious roots; Solanum lycopersicum.; auxin; diffusion MRI (DWI); diffusion tensor imaging (DTI); double-pulsed-field-gradient (d-PGSE) MRI; hypocotyl structure; magnetic resonance imaging (MRI); microstructure; plant development; q-space diffusion MRI (QSI); tomato