Matsubara, ShizueGilmore, AdamOsmond, C Barry2015-12-132015-12-130310-7841http://hdl.handle.net/1885/92620This study investigated the chloroplast pigment content of the Australian mistletoe Amyema miquelii (Lehm. ex Miq.) Tiegh. over diurnal periods in sun- and shade-acclimated leaves. Amyema miquelii exhibited the typical higher plant complement of neoxanthin, the xanthophyll cycle pigments, lutein, chlorophylls a and b and β carotene. Substantial levels of lutein epoxide were also present. Interestingly, diurnal light exposure elicited a decrease in lutein epoxide that paralleled the decrease in violaxanthin. Compared with shade-acclimated leaves, sun leaves exhibited reduced lutein epoxide and violaxanthin levels and higher chlorophyll a/b ratios. It is clear that the pools of violaxanthin and lutein epoxide respond in parallel to both diurnal light changes and sun-shade acclimation, although there seemed to be some differences in the recovery characteristics. These results raise a question as to whether lutein and lutein epoxide cycling may provide an auxiliary means of energy dissipation for some species.Keywords: Energy dissipation; Pigments; Chloroplasts; Plants (botany); acclimation; diurnal variation; light intensity; pigment; Amyema; Amyema miquelii; Embryophyta; Viscum album20012015-12-12