Ecology, Environment and Conservation Paper

PLANTS UNDER RADIATION STRESS -A REVIEW

Gurpreet Kaur, Parmil Singh and Jagmeet Kaur

Abstract

Light intensity and quality are integral part of the environment that affect the physiology of cells and growth and development of the whole plant. Excessive, deficient and inappropriate spectral distributions of light can be defined as stress to the integrated plant system, having deleterious effects. More than required quantities of photosynthetically active radiations i.e. PAR (400-700 nal) and increased absorption of UV-radiations produce radiation stress in plants. The biosphere receives solar radiations at wavelength ranging from 290 nm - 3000 nm. Ultraviolet spectrum can be divided into three regions UV-A (320-400 nm), UV-B (280-320 nm) and UV-C (200-280 nm). Studies of ultraviolet radiations on plants mainly focus on UV-B radiations because UV-C is completely absorbed by the atmosphere and UV-A has no detrimental impact on plant architecture and functions. Leaves are the perception sites for incoming radiations. UV stress is a complex oxidative stress inducing the production of various Reactive Oxygen Species (ROS) in plants, these generated ROS serve to modify metabolism and gene expression so that plant may evolve mechanisms to respond to adverse environmental conditions.