Responses To Environment Stresses by Plants

If there are adverse changes in the environment they affects the plant harmfully the factors, which change normal conditions of light, CO2, nutrients, temperature etc, causes stresses on plants.

              Stresses defined as "An environment factor that cause adverse affects on growth, reproduction of an organism".

              Plants have different methods to cope with the stresses. The common stresses of plants are these:

Response to Drought Condition:

1. When there is shortage of water in the soil then plant cope with deficiency of water in different ways plants reduce the rate of transpiration by closing their stomata in this way water loss can be prevented.
2. When there is shortage of water, plants produce abscesses and this hormone helps to close the Stomata.
3. When there is shortage of water in soil, plants develop deep roots system to absorb more water.
4. The growth of shallow roots is prevented.
5. In desert plants, where there is deficiency of water, leaves are changes into spines to prevent the low water.
6. The position of leaves, such that less amount of light falls on them.

Response to Oxygen Deficiency: Plants have different adaptations to cope with the deficiency of oxygen. The plants, which grow in water, these adaptations. Some plants develop aerial roots to absorb oxygen from the air. In same plants there are air tube provide oxygen to submerged roots.

Response to Salt Stress: Some plants grow in soil, which contain large amount of salt, there plants are called Halophytes. The plants contain more amount of salt has high osmotic pressure due to this plant losses water by ex osmosis, there plants absence salt to prevent the loss of water. These plants have salt glands in the leaves, which remove the excess salt from in this way halophytes can survive in salty places, other plants cannot survive for long in salt environment.

Response to Heat Stress: 
    If there is high temperature in the environment it can harm and kill the plant because at high temperature enzymes denature and metabolic reaction decrease.
Plants have different mechanism to cop with heat stress.

1. Transpiration produces cooling effect in plants by evaporation.
2. Plants growing in hot places can tolerate the heat stress.
3. At high temperature cells of plants form heat shock protein. These proteins surround the enzymes protect them from denaturing.

Response to Cold Stress: When temperature is very low, it harms the plant body at low temperature fluidity of cell membrane, plasma membrane changes into solid structure.
        The lipids of membrane become locked into crystalline structure as a result, transport of material through membrane become difficult.
          So plants have different methods to cop  with cold stress.

1. At low temperature cell syntheses unsaturated fatty acids, which prevent the ice formation in plasma membrane.
2. At low temperature cell cell contains some solute in the cytoplasm, which allow the Cytosol to supper without ice formation. The ice crystals may form in cell wall e.g. polymers of fructose.

Response to Herb ivory: Herb ivory is a process of eating plant by animals. These plants are commonly eaten by animals face this stress plants show following methods to cop with this stress.

1. Some of these plants develop thorn.
2. Some plants become tasteless or toxic.