Plant hormones have many agricultural uses

Plant hormones have many agricultural uses

1- They control of fruit production, ripening and dropping

2- Production of seedless fruits

3- Use as weed killers

4- Agricultural uses of plant hormones help keep food prices down and benefit the environment

5- Some consumers are concerned that synthetic plant hormones may have dangerous sid effects for humans

Plants mark the seasons by measuring photoperiod

1- Flowering, seed germination and dormancy are all seasonal phenomena in plants

2- Plants detect season by measuring photoperiod ( the relative lengths of day and night)

Plant defenses

Defenses against herbivores and infectious microbes have evolved in plants

1- Herbivores are organisms that feed on plants; many plant adaptations have evolved to defend against herbivores

-- Production of distasteful or poisonous compounds

-- Symbioses with organisms that defend plants

2- Plants have also evolved defenses against pathogens

-- The epidermis is the first line of defense against infection

-- Chemical defenses offer a way to fight pathogens that enter the plant

3- Plant chemicals can kill animal parasites

 

Tropisms orient plant growth toward or away from environmental stimuli

1- Tropisms are responses that cause plants to grow in response to environmental stimuli

-- Positive tropisms cause plants to grow toward a stimulus

-- Negative tropisms cause plants to grow away from a stimulus

2-  Plants respond to various environmental stimuli

- Phototropism—response to light

- Gravitropism—response to gravity

 

- Thigmotropism—response to touch (Responsible for coiling of tendrils and vines around objects).