Upstream of gene expression: what is the role of microtubules in cold signalling?

Cold stress is a major abiotic stress, restricting plant growth and development. Therefore, gene expression in response to cold stress and during cold acclimation has been studied intensively, including the ICE-CBF-COR pathway, as well as the modulation of this cascade by secondary messengers, for instance mitogen-activated protein kinase (MAPK) cascades. In contrast, the early events of cold perception and cold adaption have received far less attention. This is partially due to the fact that cold is a physical signal, which requires the conceptual framework to be adjusted. In this review, we address the role of microtubules in cold sensing, and propose a model whereby microtubules, while not being part of signalling itself, act as modulators of cold sensitivity. The purpose of this model is to derive implications for future experiments that will help to provide a more complete understanding of cold adaptation.