Multiple Consequences Induced by Epidermally-Located Anthocyanins in Young, Mature and Senescent Leaves of Prunus

Anthocyanic morphs are generally less efficient in terms of carbon gain, but, in turn, aremore photoprotected than anthocyanin-less ones. To date, mature leaves of differentmorphs or leaves at different developmental stages within the same species havegenerally been compared, whereas there is a lack of knowledge regarding different stagesof development of red vs. green leaves. Leaves (1-, 7-, and 13-week-old) of red- (RLP)and green-leafed (GLP) Prunus in terms of photosynthetic rate, carbon metabolism andphotoprotective mechanisms were compared to test whether anthocyanin-equippedleaves perform better than anthocyanin-less leaves and whether photoprotectionis the primary role of epidermally-located anthocyanins, using for the first time arecently-developed parameter of chlorophyll fluorescence (qPd). GLP leaves had a higherphotosynthetic rate in 1- and 7-week-old leaves, but RLP leaves performed better atan early stage of senescence and had a longer leaf lifespan. Anthocyanins contributedto leaf photoprotection throughout the leaf development, but were tightly coordinatedwith carotenoids. Besides photoprotecting, we propose that epidermal anthocyaninsmay be principally synthetized to maintain an efficient carbon-sink strength in young andsenescent leaves, thus extending the RLP leaf lifespan.