Slow turnover of the D1 reaction center protein of photosystem II in leaves of high mountain plants

The D1 reaction center protein of photosystem II usually exhibits a rapid turnover in light. The D1 protein turnover was compared in three species of alpine plants, Homogyne alpina, Ranunculus glacialis, Soldanella alpina, and in the lowland plant Taraxacum officinale by radioactive labeling in light and subsequent chase experiments. The D1 protein of alpine plants could also be recognized by its more rapid labeling, relative to other membrane proteins. However, compared to T. officinale the turnover of the D1 protein was considerably slower in the alpine plants. The potential advantage of a slow D1 turnover for adaptation to the environmental conditions of high mountain plants is discussed.