Is Microtubule Disassembly a Trigger for Cold Acclimation?

Abstract

Cold acclimation was followed in three cultivars of winter wheat (Triticum aestivum L.) that differ in freezing tolerance, using root growth as the indicator. During acclimation (followed through 7 d at 4 degrees C), growth rate progressively recovered. The recovery was fast in the tolerant, slow in the sensitive cultivars. The development of freezing tolerance was followed by a challenging cold shock administered after various time intervals of acclimation. Acclimation proceeded faster in the tolerant cultivars. Microtubules were monitored during the acclimation period. A rapid, but transient partial disassembly in the tolerant cultivars preceded the formation of cold-stable microtubules and the recovery of growth rate. In contrast, this transient disassembly was absent in the sensitive cultivar. When a transient disassembly was artificially generated by a pulse-treatment with the antimicrotubular herbicide pronamide, this could induce freezing tolerance. The appearance of cold-stable microtubules was accompanied by a reduced abundance of type TUA1/2 alpha-tubulin isotypes. These findings are discussed with respect to a role of microtubule disassembly in the sensing of low-temperature stress.

Cytological insights into the desiccation biology of a model system: moss protonemata

“…Our findings that the removal of MTs with oryzalin before drying also prevents cell survival indicate that the controlled disassembly of MTs during drying is not only necessary, but may have a key role in the desiccation biology of protonemata. We envisage that MTs may have a sensory function in the response of protonemal cells to water stress, similar to that suggested for the MTs of wheat cells under cold stress (Abdrakhamanova et al, 2003).…”

Activation of Zoosporogenesis-Specific Genes in Phytophthora infestans Involves a 7-Nucleotide Promoter Motif and Cold-Induced Membrane Rigidity

“…Our previous study of the effect of inhibitors on zoosporogenesis-specific transcription supported the presence of four signaling mechanisms; these involved an inositol trisphosphateregulated Ca 2ϩ channel, an inositol trisphosphate-independent Ca 2ϩ channel, a diacylglycerol-dependent pathway, and a Ca 2ϩ -plus-phospholipid-independent pathway (46). Multiple membrane-associated effectors may therefore exist, and participants independent of the membrane such as cold-induced microtubule disassembly cannot be discounted (1). A logical next step in identifying such effectors could involve determining how the transcription factor that binds the GGACGAG cold box becomes activated.…”

Effect of n-butanol and cold pretreatment on the cytoskeleton and the ultrastructure of maize microspores when cultured in vitro

“…Unchanged microtubule cytoskeleton can be explained by the same factors: high level of PA might neutralized the eventual microtubule disassembly induced by cold stress through the activity of regulator proteins like MAP65-1. Early cold-induced disruption of microtubules and subsequent formation of new filaments were observed in cold tolerant wheat genotypes (Abdrakhamanova et al 2003), suggesting the dynamic behavior of microtubules during long-term cold exposure. Besides this, cold stress sensitivity of microtubule network in microspores may show developmental stage dependency according to recent publications (De Storme et al 2012;Barton et al 2014), in which cold treatment only affected microtubular organization during the telophase of meiosis.…”