Ethylene's influence isn't limited to just fruits; it also affects certain vegetables. Many vegetables, such as tomatoes, capsicums, and aubergines, are botanically fruits but are culinarily treated as vegetables. When these "vegetables" are exposed to ethylene, they exhibit ripening attributes similar to climacteric fruits. This includes colour changes, softening, and flavour development. However, it's essential to note that not all vegetables respond to ethylene in the same manner. Some, like leafy greens, may deteriorate faster in the presence of ethylene. Therefore, understanding ethylene's role is crucial in storage and transportation to prevent unintentional spoilage.

Yes, not all fruits depend on ethylene for their ripening. While climacteric fruits like bananas, tomatoes, and apples are ethylene-dependent, there's another category called non-climacteric fruits. Examples of non-climacteric fruits include grapes, citrus fruits, and strawberries. These fruits do not show a spike in ethylene production during ripening. Their ripening is more gradual and does not exhibit the accelerated rates seen in climacteric fruits upon ethylene exposure. This difference also affects post-harvest practices, as exposing non-climacteric fruits to ethylene doesn't significantly alter their ripening pace.

Releasing ethylene continuously would be inefficient and counterproductive for plants. Ethylene production is energy-intensive, and constant release would waste the plant's precious resources. Additionally, perpetual ethylene release might lead to premature ripening of fruits, even when conditions aren't optimal. The positive feedback mechanism ensures that ethylene production is ramped up only when fruits are ready to ripen. This strategic, timed release ensures that the fruits mature rapidly when the time is right, optimising the chances of attracting seed dispersers and ensuring successful seed dispersal and plant propagation.

Ethylene stands out among phytohormones due to its gaseous state. Most phytohormones, like auxins, gibberellins, and cytokinins, are solid or liquid. Ethylene's gaseous nature allows it to diffuse rapidly across tissues, making its effect on ripening almost instantaneous. Furthermore, it can move between fruits, leading to synchronised ripening among closely packed fruits. Its simple molecular structure also means it can be synthesised relatively easily within plant tissues, ensuring a quick response when needed. While all phytohormones play vital roles in various plant processes, ethylene's unique state and its pivotal role in rapid fruit ripening differentiate it from its counterparts.

Yes, ethylene can and is used to ripen fruits artificially. In commercial agriculture, fruits are often harvested when they are still green and then transported to market areas. Before these fruits are sold, they can be exposed to ethylene gas in controlled ripening chambers. This ensures that the fruits ripen uniformly and are ready for consumption by the time they reach the consumer. While this process allows for better transportation and shelf-life, it's worth noting that artificially ripened fruits might not have the same nutritional profile or flavour as naturally ripened ones. Some countries also have regulations against certain artificial ripening agents, so it's essential to use ethylene judiciously and responsibly.