Commercial Uses of Plant Hormones

This lesson covers: 

1. Controlling fruit ripening with ethene
2. The use of auxins in rooting powders and micropropagation
3. The use of synthetic auxins as weedkillers
4. Other commercial applications of plant hormones

Controlling fruit ripening with ethene

Ethene, a natural plant hormone, plays a crucial role in the ripening of climacteric fruits such as bananas, apples, and tomatoes. These fruits are unique because they continue to ripen after being harvested.

Steps of controlling fruit ripening:

1. In the commercial sector, climacteric fruits are picked when they are unripe.
2. They are then exposed to ethene gas in a controlled environment.
3. This triggers and synchronises their ongoing ripening process.

Benefits of using ethene gas to control ripening:

1. Ensures that the fruits ripen uniformly.
2. Reduces the likelihood of spoilage and damage during transportation and storage.
3. Helps the fruits reach the market in an ideal state for consumption.

The use of auxins in rooting powders and micropropagation

Auxins are a group of plant hormones that play a vital role in the growth and development of plants. One of the key functions of auxins like indole-3-acetic Acid (IAA) is promoting root growth.

Commercial uses of auxins for root growth:

1. Rooting powders that contain auxins stimulate root cell development when they are applied to plant cuttings, greatly increasing the success rate of plant propagation.
2. Auxins are essential in micropropagation to mass produce genetically identical plants from small tissue samples, ensuring consistency and quality in crops.

The use of synthetic auxins as weedkillers

Synthetic auxins are a class of herbicides that mimic the action of natural auxin hormones but with exaggerated effects. They are used to target and eliminate broad-leaf weeds in agricultural fields.

This process occurs as follows:

1. When weeds absorb synthetic auxins, they experience an accelerated and unsustainable growth rate.
2. This leads to their death.
3. This selective action is beneficial as it doesn't harm nearby narrow-leaf crops like wheat or rice.
4. This allows those plants to thrive without competition from weeds.

Advantages of using synthetic auxins as weedkillers:

1. Simple and cheap to produce
2. Low toxicity to mammals
3. Selective, affecting only broad-leaf plants

Other commercial uses of plant hormones

Plant hormones find a variety of other applications in commercial settings.

These commercial applications include:

• Using auxins  stimulate fruit development without fertilisation, to prevent the formation of seeds in fruit.
• Using ethene to promote the dropping of fruits before harvest, easing the harvesting process.
• Using cytokinins to extend the shelf-life of produce by slowing down the ageing processes.
• Using gibberellins to improve the size and shape of fruits, enhancing their market appeal and value.