Ethylene

Also an unexpected and unusual plant hormone. Allegedly explains why when bananas were transported in vehicles with gas lamps (which gave off the gas) they ripened quicker. Since it is gaseous, fruits that use this molecule to ripen affect each other in a positive feedback sort of way. Produced by the fruit from a strange cyclic intermediate : 1-aminocyclopropane-1-carboxylic acid, which is made using SAM(S-adenosyl methionine). This decomposes to ethylene, catalyzed by an oxidase.

The Ethylene FAQ (really, frequently asked questions about ethylene?) says:

" Ethylene can promote ripening in tomatoes, bananas, citrus, pineapples, dates, persimmons, pears, apples, melons, mangos, avocados, papayas and jujubes"

Other C2H4 questions may be answered at http://store.yahoo.com/catalyticgenerators/index.html.

Apples give off ethylene, at least the Golden Delicious variety does it.
This is why when you want your kakis (persimmons, whatever) to ripen, you put them in a closed container with an apple. Try it at home ! It works !

Of course, this makes much more sense if you consider that kakis are picked in October when they are about as eatable as cannonballs ...

Eth"yl*ene (?), n. [From Ethyl.] Chem.

A colorless, gaseous hydrocarbon, C2H4, forming an important ingredient of illuminating gas, and also obtained by the action of concentrated sulphuric acid in alcohol. It is an unsaturated compound and combines directly with chlorine and bromine to form oily liquids (Dutch liquid), -- hence called olefiant gas. Called also ethene, elayl, and formerly, bicarbureted hydrogen.

<-- is effective in hastening the ripening of certain fruits. -->

Ethylene series Chem., the series if unsaturated hydrocarbons of which ethylene is the type, and represented by the general formula CnH2n.

 

© Webster 1913.