%0 Journal Article
%T The Dormancy Marker DRM1/ARP Associated with Dormancy but a Broader Role In Planta
%A Georgina M. Rae
%A Karine David
%A Marion Wood
%J Developmental Biology Journal
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/632524
%X Plants must carefully regulate their development in order to survive a wide range of conditions. Of particular importance to this is dormancy release, deciding when to grow and when not to, given these varying conditions. In order to better understand the growth release mechanism of dormant tissue at the molecular and physiological levels, molecular markers can be used. One gene family that has a long association with dormancy, which is routinely used as a marker for dormancy release, is DRM1/ARP (dormancy-associated gene-1/auxin-repressed protein). This plant-specific gene family has high sequence identity at the protein level throughout several plant species, but its function in planta remains undetermined. This review brings together and critically analyzes findings on the DRM1/ARP family from a number of species. We focus on the relevance of this gene as a molecular marker for dormancy, raising questions of what its role might actually be in the plant. 1. Introduction Plants are sessile; therefore, a number of mechanisms are elegantly managed in the plant to ensure its survival and optimisation in its given setting. Integral to this is the temporal and spatial determination of growth in relation to the surroundings. This growth may be vegetative, such as axillary budbreak and branch development, or floral, including flower and fruit development. To achieve this, cell division, cell elongation, or a combination of the two has been shown to play a pivotal role in plant growth regulation. Dormancy is a means of ensuring a plant¡¯s long-term survival and is defined as the ¡°transitory delay of visible growth that occurs in plant meristematic tissues¡± [1]. An example of this occurs in perennials over winter. When temperatures are low and daylight hours are limited, plants protect themselves by ceasing growth, waiting for the more favourable conditions of spring in which they focus their resources on growing and reproducing. As such, the key decisions around when to release dormant tissue from dormancy (dormancy release/shoot outgrowth/shoot branching) are an important mechanism for plant biologists to understand. Both perennial and annual plants (e.g., Arabidopsis) also undergo a type of dormancy known as apical dominance or paradormancy, where endogenous signals/hormones from the apical bud are received by lower axillary meristems, preventing their bud outgrowth. This phenomenon was first described in 1934 [2], when it was shown that axillary buds of decapitated plants were released from dormancy due to a lack of auxin flow down the stem. Since then, the
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