Regulation of Ethylene Synthesis of Harvested Banana Fruit by 1 -Methylcyclopropene

Treatment with 1-methylcyclopropene (1-MCP), a potent inhibitor of ethylene action, delayed the decrease in fruit firmness and the time in peaks of respiration and ethylene production rates, 1-aminocyclopropane-1-carboxylic acid (ACC) concentration, and ACC oxidase (ACO) activity of banana fruit, but exogenous ethylene treatment was not able to induce fruit ripening when the fruit was treated with 200 nL/L of 1 MCP. Furthermore, 1-MCP treatment delayed expression of ACC synthase (ACS) and ACO genes, two ripening- related genes in ethylene synthesis. These results demonstrated that ripening process of banana fruit was delayed at a physiological level by 1-MCP, while ethylene synthesis could be regulated at suppressed transcript levels of ACS and ACO genes.
Obrada s 1-metilciklopropenom (1-MCP), snažnim inhibitorom djelovanja etena, usporava snizivanje čvrstoće banane i vrijeme dostizanja maksimalne respiracije, brzine proizvodnje etena, zatim koncentraciju 1-aminociklopropan-1-karboksilne kiseline (ACC) i aktivnosti ACC oksidaze (ACO). Me|utim, egzogena obrada etenom nije mogla inducirati sazrijevanje ploda ako su banane bile obrađene s 200 nL/L 1-MCP. Nadalje, obrada s 1-MCP usporila je ekspresiju ACC sintaze (ACS) te ACO gena, jer oba gena sudjeluju u sintezi etena tijekom sazrijevanja. Ovi rezultati pokazuju da je proces sazrijevanja banana usporen na fiziološkoj razini, dok se sinteza etena može regulirati prigušivanjem razine transkripcije ACS i ACO gena s 1-MCP.