Hormones promote growth within plants. Plant hormones are unequally distributed throughout the stems and roots, which results in parts of the plant growing in a particular direction.
Gibberellins, which are a group of plant hormones responsible for growth and development, are important for initiating seed germinationThe process where seeds sprout and begin to grow.. Low concentrations can be used to increase the speed of germination, and they stimulate cell elongationBecoming longer. and cause plants to grow taller.
They are naturally produced by seeds.
Gibberellins can be used to:
end seed dormancy
promote flowering
increase fruit size
Seed dormancyHibernation for seeds which stops when they germinate. must be broken for seeds to germinate, and this can be done by using gibberellins.
Controlling fruit ripening
ethene The simplest alkene, consisting of two carbon atoms joined by a double bond, surrounded by four hydrogen atoms. is a hydrocarbonA compound that contains hydrogen and carbon only. gas which speeds up ripening in bananas and other fruit. It also controls cell division during plant growth.
In the food industry fruit is often picked unripe and then transported. This prevents fruit from over-ripening on the journey. It is ripened during storage by adding ethene and then taken to the shops.
The effect of ethene released from bananas is clearly visible if you keep them in a bowl with other fruit, as it causes other fruits to ripen very quickly.