Natural Variation in Banana Varieties Highlights the Role of Melatonin in Postharvest Ripening and Quality

Abstract

This study aimed to investigate the role of melatonin in postharvest ripening and quality in various banana varieties with contrasting ripening periods. During the postharvest life, endogenous melatonin showed similar performance with ethylene in connection to ripening. In comparison to ethylene, melatonin was more correlated with postharvest banana ripening. Exogenous application of melatonin resulted in a delay of postharvest banana ripening. Moreover, this effect is concentration-dependent, with 200 and 500 μM treatments more effective than the 50 μM treatment. Exogenous melatonin also led to elevated endogenous melatonin content, reduced ethylene production through regulation of the expression of MaACO1 and MaACS1, and delayed sharp changes of quality indices. Taken together, this study highlights that melatonin is an indicator for banana fruit ripening in various varieties, and the repression of ethylene biosynthesis and postharvest ripening by melatonin can be used for biological control of postharvest fruit ripening and quality.

Melatonin delays leaf senescence of Chinese flowering cabbage by suppressing ABFs‐mediated abscisic acid biosynthesis and chlorophyll degradation

“…Melatonin retards leaf senescence in several plants including barley and detached apple leaves . In addition, melatonin is effective in maintaining the quality of postharvest fruits such as peach, banana, and litchi . For harvested green leafy vegetables such as Chinese flowering cabbage, leaf senescence is the most important factors affecting its shelf‐life and nutritional value during the postharvest storage and distribution.…”

“…15,16 In addition, melatonin is effective in maintaining the quality of postharvest fruits such as peach, banana, and litchi. [41][42][43] For harvested green leafy vegetables such as Chinese flowering cabbage, leaf senescence is the most important factors affecting its shelflife and nutritional value during the postharvest storage and distribution. In this work, we found that exogenous application of melatonin-alleviated senescence changes in Chinese flowering cabbage, with melatonin treatment maintaining a higher value of Fv/Fm and total chlorophyll content, while inhibiting the expression of chlorophyll catabolic and senescence marker genes.…”

Melatonin promotes ripening of grape berry via increasing the levels of ABA, H2O2, and particularly ethylene

“…By contrast, exogenous application of melatonin delays postharvest senescence in banana, strawberry, and peach fruits 16 – 18 . Therefore, melatonin treatment is proposed to positively regulate fruit ripening but negatively regulate fruit senescence, although the two processes are intrinsically linked 15 , 16 . However, melatonin also regulates fruit metabolism or abiotic resistance via interaction with other signaling molecules.…”

“…Melatonin promotes ripening and improves quality of climacteric tomato fruit during postharvest life 14 , and further proteomics analysis provides insights into the physiological and molecular mechanisms underlying melatonin-mediated tomato fruit ripening 15 . In banana, another typical climacteric fruit, melatonin is also an indicator for fruit ripening in various varieties 16 . By contrast, exogenous application of melatonin delays postharvest senescence in banana, strawberry, and peach fruits 16 – 18 .…”

“…In banana, another typical climacteric fruit, melatonin is also an indicator for fruit ripening in various varieties 16 . By contrast, exogenous application of melatonin delays postharvest senescence in banana, strawberry, and peach fruits 16 – 18 . Therefore, melatonin treatment is proposed to positively regulate fruit ripening but negatively regulate fruit senescence, although the two processes are intrinsically linked 15 , 16 .…”