Seasonal changes in photosynthesis, phenolic content, antioxidant activity, and anatomy of apical and basal leaves of Aristotelia chilensis

Abstract

Aristotelia chilensis (Mol.) Stuntz is an evergreen species endemic to Chile. It grows in open areas or under tree canopy, and its leaves emerge in early spring and summer. The objective of this study was to determine changes in photosynthetic parameters, total phenol content (TPC), antioxidant activity, and anatomy of apical and basal leaves of A. chilensis during the year. Photosynthesis performance was determined by measuring electron transport rate (ETR), the quantum efficiency of photosystem II (Fv/Fm), photochemical quenching (qP), and non-photochemical quenching (NPQ) with a fluorimeter. Leaf extracts were analysed to determine TPC and antioxidant activity. The maximum ETR and qP were recorded in spring and summer when the photosynthetically active radiation (PAR) at midday was higher (1901 and 1968 µmol m -2 s -1 , respectively) than in other parts of a year. The Fv/Fm had typical physiological values in both types of leaves (about 0.8 in all the seasons). Also the NPQ was not influenced by the kind of leaves and season of the year. In concordance, the basal spring leaves had the highest TPC values. In contrast, the highest values of antioxidant activity were recorded in basal winter leaves followed by basal spring leaves. The results suggested that an increase in PAR (spring) positively affected the antioxidant activity and TPC, which correlated with higher ETR and qP values. The apical leaves showed morphological adaptations during the year and areas of intercellular spaces and palisade parenchyma were larger than in the basal leaves.

Anti-Inflammatory Chilean Endemic Plants

“…Studies have demonstrated that A. chilensis aqueous extract exhibits anti-inflammatory effects and immunomodulatory activity related to atopic-like dermatitis [ 113 ]. Several epidemiological studies on human health have underlined the beneficial role of phenolic compounds in preventing arteriosclerosis, cardiovascular diseases, arthritis, diabetes, neurodegenerative diseases, and cancers [ 113 , 114 ]. The berries have increased uses and are broadly selected to develop healthy or potential functional foods because of their biological attributes [ 110 ].…”

“…Furthermore, it has been described that this species has a high concentration of anthocyanin pigments, giving its berries a characteristic dark violet color [ 53 ]. The maqui fruit has four times more antioxidant properties than other berries [ 114 ]. A. chilensis is rich in poly-glycosylated derivatives with high antioxidant capacity, which suggests antiatherogenic properties.…”