Hi,
CrakerJax explained some time ago something:
The molecule that plants use to protect themselves from the dangers of getting too much sun during photosynthesis has now been revealed by a combination of ultrafast spectroscopy and plant genetics. Plants rely on sunlight to generate chemical energy via photosynthesis. It's been known for more than two decades that plants protect themselves from excess light, which can lead to oxidative damage to chlorophyll and other key photosynthetic pigments. But the biophysical mechanism of this protective process--known as feedback de-excitation--has remained mysterious.
Chemist Graham R. Fleming, plant biologist Krishna K. Niyogi, and coworkers at Lawrence Berkeley National Laboratory and the University of California, Berkeley, have now shown that zeaxanthin, a carotenoid known to be produced by plants in response to bright sunlight, is responsible for the protective effect [Science, 307, 433 (2005)].
Using femtosecond spectroscopic techniques and plant genetics, the team shows that exposing spinach leaves to intense light triggers the formation of zeaxanthin cation radicals. These cation radicals form when zeaxanthin binds to potentially dangerous photoexcited chlorophyll molecules. The zeaxanthin gives up an electron to the excited chlorophyll, yielding a chlorophyll anion radical and a zeaxanthin cation radical. These products subsequently undergo charge recombination, allowing the excited-state energy of chlorophyll to be safely dissipated as heat.
The study is "a major advance in understanding how feedback de-excitation works at the molecular level," comments Robert E. Blankenship of Arizona State University. It "points the way to studies in which this mechanism might be manipulated for practical uses," he adds, such as protecting artificial photosynthetic systems used for solar energy generation from light-induced damage.
Could genetics removed in a few years the memory of the plant that for hundread of thousands of years had?
Twelve12 on anothe site said something that makes some sence. Is there a logical reason why 24/0 is better? Is there science fact that 24/0 is better? I am asking becouse I can;t seem to find it
"It is safe to assume that you know about day and night and circadian rhythms and the bodies biological clock, well plants have them too. There is such thing as a time keeping protein and repressor proteins. In plants this protein is sensitive to light on the 24 hour cycle of light to dark, this protein in plants is called TOC, here is the latest information on it. At dawn repressor genes are activated by light witch over the course of the day slows the production of TOC and therefore decreases concentration, at night when there is no light to produce repressors, TOC levels rise and are circulated through the plant, especially near meristematic tissue where ALL plant growth occurs. It is this oscillation of TOC and repressors over the 18/6 cycle that keep hormones in regulation for vegetative growth.
During the 12/12 cycle- TOC and its repressors are at a certain chemical equilibrium(keep in mind the concentration and therefore times in cycle are different for all plants, cannabis seems to like 12/12 for its hormone equilibrium for flowering) anyways 12/12 TOC levels stimulate the production of flowering hormones- confused yet, hormones are coming up. Just like an athlete using steroids, never using your god given testosterone means you'll have stunted testosterone production when you kick the steroids. Same in plants, if you leave it on 24/0 cycle, you'll never achieve the proper hormone regulation for flowering, well you will get better vegetative growth,and buds too, just not nearly as potent as if you had done it the way natures intends, so remember, light and dark, cycles of TOC regulate expression of hormones, mainly gibberellins and ethylene."