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Energy dissipation and photosynthetic electron flow during the transition from juvenile red to mature green leaves in mango (Mangifera indica L.)

Abstract Leaf colouration during development from juvenile red to mature green leaves is a genetically controlled process in mango (Mangifera indica L.). This study aimed to determine the pigmentation pattern and electron transport flow in both red and green leaves under varied light intensity. In this study, 5- and 10-day old juvenile red and mature green leaves, respectively, were used. Three different photosynthetic active radiation levels (600 ± 5, 1000 ± 5 and 1200 ± 5 µmol m−2 s−1) were chosen to examine chlorophyll a fluorescence (O-J-I-P) transients. The vacuole of spongy cells in mesophyll contained anthocyanin in the juvenile leaf and rapidly degraded during the colour transition from red to green. A significant difference in chlorophyll, carotenoid and anthocyanin pigments was observed in both leaf types. The O-J-I-P parameters revealed that light intensity has a greater influence on the PSII electron transport chain than on PSI. Furthermore, the PSI of both leaves appeared to be more tolerant than that in PSII. The red leaf performed more energy dissipation than the green leaf after elevated light intensity exposure. O-J-I-P transients can be used as a sensitive, non-destructive method for measuring energy dissipation induced by intense radiation in plants.