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The pollen grains reflect UV-beta to shield their chromosomes stored in the pollen from UV-alpha which is important for making sure of reproductive success. [10] The technique of UV coloration has evolved in other species as well for various reasons. Similarly, carnivorous plants reflect and absorb UV to attract prey to it. [10]
The photomorphogenesis of plants is often studied by using tightly frequency-controlled light sources to grow the plants. There are at least three stages of plant development where photomorphogenesis occurs: seed germination, seedling development, and the switch from the vegetative to the flowering stage (photoperiodism). [2]
UV-B resistance 8 (UVR8) also known as ultraviolet-B receptor UVR8 is an UV-B – sensing protein found in plants and possibly other sources. [2] It is responsible for sensing ultraviolet light in the range 280-315 nm and initiating the plant stress response. It is most sensitive at 285nm, near the lower limit of UVB.
A postzygotic mutation (or post-zygotic mutation) is a change in an organism's genome that is acquired during its lifespan, instead of being inherited from its parent(s) through fusion of two haploid gametes. Mutations that occur after the zygote has formed can be caused by a variety of sources that fall under two classes: spontaneous mutations ...
Photoexcitation is the first step in a photochemical process where the reactant is elevated to a state of higher energy, an excited state.The first law of photochemistry, known as the Grotthuss–Draper law (for chemists Theodor Grotthuss and John W. Draper), states that light must be absorbed by a chemical substance in order for a photochemical reaction to take place.
Cyanobacteria photosystem II, dimer, PDB 2AXT. Photoinhibition occurs in all organisms capable of oxygenic photosynthesis, from vascular plants to cyanobacteria. [14] [15] In both plants and cyanobacteria, blue light causes photoinhibition more efficiently than other wavelengths of visible light, and all wavelengths of ultraviolet light are more efficient than wavelengths of visible light. [14]
Each absorbed photon causes the formation of an exciton (an electron excited to a higher energy state) in the pigment molecule. The energy of the exciton is transferred to a chlorophyll molecule ( P680 , where P stands for pigment and 680 for its absorption maximum at 680 nm) in the reaction center of photosystem II via resonance energy transfer .
Photoprotection is the biochemical process that helps organisms cope with molecular damage caused by sunlight.Plants and other oxygenic phototrophs have developed a suite of photoprotective mechanisms to prevent photoinhibition and oxidative stress caused by excess or fluctuating light conditions.