Ice mass accumulation in plant tissues
Abstract
Freezing events significantly impair plant life. Biophysical aspects of freezing are less studied than molecular responses but are fundamental to the understanding of freezing resistance. During harmless freezing of plant tissues ice accumulates extracellularly and cells usually freeze dehydrate. How ice growth is controlled and how cellular water is segregated to the ice is not understood. As plants consist in large part of water, the amount of ice formed must be considerable. While reduction of water content is part of cold acclimation, spring and alpine plants survive freezing with high water content. Hardly anything is known about how the growing ice masses are managed. There is, however, recent evidence that ice accumulates in predetermined spaces. Some of them seem to pre-exist, others are formed by tissue rupture. We hypothesize that 1) The spatial confinement of ice masses must be managed by targeted ice segregation at specific loci. 2) Ice masses show a temperature dependent growth and 3) ice mass growth is regulated by ice affecting molecules that locally promote or inhibit ice mass formation, facilitate targeted ice segregation and affect ice crystal morphology. With a new set of new and innovative methods we tackle the biophysical and chemical aspects of ice growth in plant tissue: (1) A new cryo-microscope using reflected-polarised-light (CMrpl) allows an unambiguous and rapid visualisation of ice masses and the analysis of ice crystal shape and their attachment to cell walls. (2) Recent results obtained with a new calorimeter (µDSC 7 Evo) uncover till now invisible very slight freezing processes in leaves. 3) By GC-MS molecular components of ice crystals and by RAMAN microscopy also molecular components of cell walls and cell lumina close to ice will be revealed.
freezing resistance mechanism ice nucleation low temperature stress freezing cytorrhysis frost hardening
Publikationen
Project staff
Notburga Gierlinger
Assoc. Prof. Priv.-Doz. Mag. Dr. Notburga Gierlinger
burgi.gierlinger@boku.ac.at
Tel: +43 1 47654-80338
BOKU Project Leader
01.08.2021 - 31.07.2025
BOKU partners
External partners
University of Innsbruck
A.Univ.-Prof.Mag.Dr. Gilbert NEUNER
partner