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As plants have evolved and adapted their UV coloration, pollinators have also fine-tuned their individual adaptations to maximize their ability to target flowers for food. [8] The dynamic relationship between the pollinators and the pollinated has led to novel mutations and in some cases novel species. [ 1 ]
Photolyase is particularly important in repairing UV induced damage in plants. The photolyase mechanism is no longer working in humans and other placental mammals who instead rely on the less efficient nucleotide excision repair mechanism , although they do retain many cryptochromes . [ 11 ]
In the absence of light, plants develop an etiolated growth pattern. Etiolation of the seedling causes it to become elongated, which may facilitate it emerging from the soil. A seedling that emerges in darkness follows a developmental program known as skotomorphogenesis (dark development), which is characterized by etiolation. Upon exposure to ...
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.
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.
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.
And so they do not swim to or away from the light, but swim down, [62] this means to the center of gravity. Thus this is a UV-induced positive gravitaxis . Positive phototaxis (swimming to the light from the surface) and positive gravitaxis (swimming to the center of gravity) are induced by different ranges of wavelengths and cancel out each ...
Similarly, short wave UV light works in the same way as ionizing radiation which can also induce mutations generating chromosomal rearrangements. When DNA absorbs short wave UV light, dimerizing and oxidative mutations can occur which can cause severe damage to the DNA sequence of an organism.