Am. Del Hierro et al., Chloroplast movements in leaves of two evergreen sclerophyllous plants (Ilex aquifolium and Prunus laurocerasus), PL BIOSYST, 134(3), 2000, pp. 297-304
Chloroplast movements provide a means for fine-tuning the absorption of rad
iation in leaves. Since evergreen sclerophylls may experience very differen
t light levels during the seasons and at different locations either at the
periphery or in the interior of a forest, such a mechanism must theoretical
ly be of great importance for them. Detailed field and laboratory studies o
n sclerophylls are however lacking. We provide first evidence that chloropl
asts in the leaf mesophyll of Loth Ilex aquifolium (holly) and Prunus lauro
cerasus (cherry laurel) may be stimulated by low light intensities. Even at
winter temperatures close to freezing, chloroplasts move to a position a h
ere light absorption is increased. Effects of temperature, light pretreatme
nt and light quality for the induction of movement are described.