Ethylene promotes fruit ripening. This mango on the verge of ripening is influenced by the effects of ethylene. Because ethylene is a gas, the signal to ripen spreads from to fruit. The ripening processes includes the enzymatic breakdown of cell walls, which softens the fruit, and the conversion of starches and acids to sugar, which makes the fruit sweet. Ethylene also opposes some auxin effects and promotes or inhibits growth and development of roots, leaves, and flowers , depending on species.