1/7/2016 M.Yaseen k 2

Presented to:

Dr.Touqeer Ahamad Yasir sb

Presented by:

Muhammad Yaseen Kanju

Ultraviolet Stress in

Plant

Ultraviolet: Ultraviolet (UV) light is electromagnetic

radiation with a wavelength shorter than that of visiblelight but longer than X-rays.

The range between visible light 400 nm and 780 nm.

The photon energies from 3 eV to 124 eV.

Ultraviolet UV light is found in sunlight.

This is emitted by electric arcs and specialized lights such as mercury lamps and black lights.

It can cause chemical reactions.

A large fraction of UV, including all that reaches the surface of the Earth is classified as non-ionizing radiation.

Ultraviolet The higher energies of the ultraviolet spectrum from

wavelengths about 120 nm to 10 nm.

Extreme ultraviolet are ionizing but due to this effect these wavelengths are absorbed by nitrogen.

The even more strongly by dioxygen and thus have an extremely short path length through air.

Ultraviolet Effect on Plant Reduction of cell and leaves area.

Reduction in photosynthesis.

Impact on metabolism.

Effect on root and shoot growth

Ultraviolet Effect on Plant Reduced the grain size.

Less movement of nutrients.

Retards growth.

Lower yield under low water potential

Type of Ultraviolet Ultraviolet A

One of the three types of invisible light rays.

Ultraviolet A .

Ultraviolet B .

Ultraviolet C .

UV A and UV B stress Increasing solar UV-B is not merely an environmental

stress for plants.

Solar UV-B can cause plant morphogenetic effects which can in turn of plants and the structure of a vegetation.

In addition, UV-B radiation affect the production of various secondary metabolites.

Such as flavonoids, tannins and lignin.

UV A and UV B stress Recent measurements of ozone levels have led to

concern that the stratospheric ozone layer.

The depleted as a result of contamination with man-made chlorofluorocarbons.

The amounts of solar UV-B radiation reaching the Earth's surface is increasing harmful effect.

UV A and UV B stress Harmful to living organisms, damaging DNA,

proteins, lipids and membranes in plant.

Plants, which use sunlight for photosynthesis and are unable to avoid exposure to enhanced levels of UV-B radiation are at risk.

Ultraviolet C Although ultraviolet C is the most dangerous type of

ultraviolet light.

In terms of its potential to harm life on earth.

It cannot penetrate earth's protective ozone layer.

Therefore it poses no threat to human animal or plant life on earth

UV A and UV B stressSensitive to UV A Sensitive to UV B

Soybean.

Faba bean

Clover.

Pea.

Cucumber

Cotton.

Rice

Wheat.

Maize

Tomato.

Target Sites in Plants

• Photosynthesis and Respiration

• Photosynthesis is sensitive to increased UV-B

effects on photosynthesis is not clear.

• Many studies

• The have demonstrated detrimental effects of UV-B

radiation on photosynthesis under laboratory

conditions in plants .

Target Sites in Plants

• Krupp and radiation, but the environmental relevance of UV-B.

• Kickert 1989.

• Groth and Krupa, 2000.

• .

Target Sites in Plants• Reddy et al. 2003 but the action spectrum of the UV-B

effect does not suggest a specific target molecule.

• Renger et al. 1989.

• Fedina et al 2010.

• Teramura and Sullivan, 1994.

Target Sites in Plants At the whole-plant level, the effect of UV-B stress is

usually perceived as a decrease in photosynthesis

and growth.

• This is associated with alterations in

carbon and nitrogen metabolism .

• Julkunen-Tiitto et al 2005.

• Lidon 2012.

Target sites in plants:• Nucleic acids:

DNA is the noteable target.

• Jiang and Taylor 1993.

•

Amino acids.

Proteins:.

Target sites in plants Plant growth regulators.

Lipids.

Cell Membranes.

Photosynthesis disrupt.