Variation in violaxanthin and lutein cycle components in two provenances of Acer grandidentatum L. exposed to contrasting light

摘要

The ability of ornamental plants to acclimate to contrasting light environments via photoprotection mechanisms such as the violaxanthin (V) and lutein (Lx) cycles determines their success in managed landscapes. This study investigated whether provenance of origin influenced V and Lx cycle components in Acer grandidentatum L. (bigtooth maple) exposed to contrasting light environments. Seven-year-old bigtooth maple plants from two provenances, Lost Maples State Natural Area, Texas (LMPTX) and GuadalupeMountains, Texas (GMTX) were subjected to unshaded conditions and 48 % shade. Regardless of light treatment, beta-carotene content of plants from the LMPTX provenance (1,181 mu g g~(-1)) was higher than those from GMTX (964 mu g g~(-1)). Lutein contentdeclined from day 5 to 10, but returned to day 5 levels at the end of the experiment at day 15. In contrast, more α-carotene accumulated at day 10 than at day 5. Although the conversion state of the xanthophyll pigment pool was unchanged, zeaxanthin washigher in unshaded than shaded bigtooth maple plants. Chlorophyll a and b decreased from day 5 to 10 and then increased on day 15. Light treatment did not cause photosystem II efficiency and relative water content to differ between the provenances, suggesting that they effectively acclimated to contrasting light conditions.