Goulas Estelle, Le Dily Frédérik, Ozouf Jérôme, Ourry Alain
Unité Mixte de Recherche de Physiologie et Biochimie Végétales (UMR INRA-UCBN), Institut de Biochimie et Biologie Appliquée, Université de Caen Basse-Normandie, Esplanade de la Paix, F-14032 Caen cedex, France.
J Plant Physiol. 2003 Aug;160(8):893-902. doi: 10.1078/0176-1617-00937.
The ability of white clover (Trifolium repens L.) to undergo cold acclimation is an important determinant of its persistence in mixed swards since growth rate at low temperatures sustains higher clover contents at the start of spring. During a re-growth period following defoliation, a gradual exposure of the root system (cv. Grasslands Huia) led to some physiological and morphological changes of cold-adaptive significance, similar to those developed by clover ecotypes originating in northern areas of Europe. Thus, cold exposure of the root system resulted in small-leaved prostrate forms of white clover after one month of re-growth. Similarly, cold exposure increased the ability of plants to store nitrogen since the application of low temperatures to the root system enhanced soluble protein accumulation in roots and in stolons. More specifically, cold exposure of the roots induced gene expression of a vegetative storage protein (17.3 kDa VSP) in both organs. These results demonstrate that the root system of clover plants should be a site of perception of the low-temperature stimulus, and gave rise to the question of the transduction of the cold signal from the roots to the aerial parts. On the basis of this study and taking into account molecular aspects concerning the clover VSP, it is suggested that this protein could participate in cold acclimation in addition to its role in nitrogen storage.
白三叶（Trifolium repens L.）进行冷驯化的能力是其在混播草地中持久性的一个重要决定因素，因为低温下的生长速率能在春季开始时维持较高的三叶草含量。在刈割后的再生期，根系（品种为Grasslands Huia）逐渐暴露会导致一些具有冷适应意义的生理和形态变化，类似于源自欧洲北部地区的三叶草生态型所产生的变化。因此，根系经冷处理后，再生一个月的白三叶会呈现小叶匍匐形态。同样，冷处理增强了植物储存氮的能力，因为对根系施加低温会提高根和匍匐茎中可溶性蛋白质的积累。更具体地说，根系冷处理诱导了这两个器官中一种营养储存蛋白（17.3 kDa VSP）的基因表达。这些结果表明，三叶草植物的根系应该是低温刺激的感知部位，并引发了冷信号从根系向地上部分传导的问题。基于这项研究并考虑到与三叶草VSP相关的分子层面，表明这种蛋白质除了在氮储存中发挥作用外，还可能参与冷驯化。
