Plant Hormones (Uses of Auxin, Gibberellin and Ethene)

• Auxin is a growth hormone.
• Adding auxin to plant hormones in a tissue culture could allow us to grow lots of plant clones.
• If we add rooting power (that contains auxin) to soil with cuttings then the plants will produce roots and create a new plant.
• We can use auxin to kill weeds as if you add enough auxin you can completely disrupt a plant's growth patterns, which causes it to die. Most weeds are broad leaves plants but most commercial plants are narrow-leaved. This means that we can make selective weed killers that we can spray everywhere but only kill the weeds.
• Gibberellin can induce flowering, grow larger fruit and control dormancy.
• By exposing seeds to gibberellin farmers can induce germination at times of the year when it wouldn't usually happen. This means they can grow multiple crops per year and have all crops grow at the same time.
• Normally flowering requires certain conditions, gibberellin can induce it on demand. It can make more flowers and bigger flowers too.
• Gibberellin can grow larger fruits by making seedless fruit grow larger.
• Ethene is used to stimulate the ripening of fruit.
• Most of our fruit is shipped for weeks before it gets to us. This way we can pick unripe fruit, and then expose it to ethene to ripen it is ready for sale.
• We often block plants own production of ethene during transportation.
• Ethene works by stimulating an enzyme that causes the fruit to ripen.