Review on; Nature and Mechanism of Sensing and Responding to Excess Light by Higher Plants

Abstract

Plants are the basis for the survival of living things in nature. They can prepare their own food through photosynthesis. Hence, they are the bottom of food chain. Sun light helps to maintain the planet’s surface temperature through photosynthesis, it is the process that plants use to change carbon dioxide (CO₂), and water (H₂O) through light energy using Rubisco enzyme into sugars which help to maintain plant growth, development through continuous supply of energy (ATP) on the leaf chlorophyll. On the other hand, sunlight also provides critical information about the environment information for proper plant development and the measurement of daylength that is used by plants to regulate movement. Plants absorb too much light more than they can actually use in photosynthesis. To control photo-inhibition/ photo-oxidative injury and adapt to their environmental conditions, all plants have developed different mechanisms to scenes and respond too much light stimuli directly and indirectly. Phytochromes, phototropin, neochrome, and cryptochrome dependent signals for chloroplast movement and gene expression responses are considered as direct sensing and responding mechanism through photoreceptors. Additionally, plants can sense excess light through biochemical and metabolic signals indirectly.