Different Phtoreceptor Pigments in Plants are Activated by Different Wavelengths....

i received this handout in my class, introduction to the physiology of how plants sense their enviroment...

i thought it was interesting and i thought i would share.... this reinforces the idea that MH is better-suited for veg, and HPS for flowering. (and a combination the best.)

Different Phtoreceptor Pigments in Plants are Activated by Different Wavelengths of Solar Radiation


There are phtoreceptors in plants that are specifically activated by UV light, by blue light (mostly MH), by red light (mostly HPS) and by far-red light. The best-known blue-light phtoreceptors are the phototropins (which induce phtotropism) and cryptochromes (which induce a variety of growth responses.) The best known red light phtoreceptors are the chlorophylls (which induce phtosynthesis) and the phytochromes (which regulate a variety of phtomorphogenic responses, including flowering, seed germination, and anthocyanin synthesis, and stem elongation.)

It's neat to understand why things work the way they do. Thanks for the info.

vedddy eenteresting... Thanx for the share peace..

Sack's First Outdoor Grow
LQQK see.. All threads new updates today 10/17/05
Sack's Bubbledust Outdoor Grow
Sack's Cappuccino OD Grow
Sack's Limon OD Grow

sack :friends:

You and your Fancy Book Learnin'

You and your Fancy Book Learnin'

Damn Bart!

Your clearing out those Cob Webs in my head. I actually remember all that from Class. See Mom pot does'nt make you Stupid. Keep it up!

~GB~

Isn't science wonderful!
NoS

i worked with the researcher who discovered the blue-light receptor that she named "cryptochrome" because it was so darn hard to find......a pun on the word "cryptic"....phytochrome (the red-light receptor) was discovered much earlier.

Sometimes you will still see the category of light-absorbing pigments still referred to as "phytochromes" but when used specifically the word refers to the receptors which capture red-light at and around 660 nm......

Scientists postulate that there are specific photoreceptor molecules for UV light and even one for Green light but such molecules have yet to be discovered.....we still have a long way to go with plants as compared to animals.....-gp

very cool guinea,

thanks everyone for stoppin by, if you guys enjoy this info, i dont mind postin up more.

take care,
bartender187

cryptochrome to tha dome!

cryptochrome to tha dome!

photoregulatory signal regulation

My research interests concern the mechanism by which plants respond to light. Plants use several different photoreceptors to enable them to sense the quality and quantity of light in the surrounding environment. In response to this information they adjust their growth and development accordingly. We are interested in the nature of these photoreceptors and the signaling mechanisms utilized to initiate specific responses – such responses include (at the molecular level) membrane depolarization, synthesis of pigments, changes in gene expression (and at the developmental level) seed germination, stem elongation, and flowering.

Our studies involve the model plant Arabidopsis thaliana, and we utilize a combination of genetic, molecular, and biochemical approaches. Several years ago we characterized cryptochrome, a photoreceptor that selectively senses blue and UV-A light. Interest in this photoreceptor has recently been heightened by the finding that related cryptochrome photoreceptors are responsible for the entrainment of circadian rhythms in animals, including humans.

The above paragraphs provide a summary of the research in which i participated. Researchers discovered and isolated certain plants which did not respond to either red light or blue light. These plants are termed "knockout mutants" because they are lacking a certain gene that either codes for the red-light receptor (phytochrome) or the blue-light receptor (cryptochrome).

The final discovery of cryptochrome and its corresponding gene was a triumph for researchers who had postulated its existence for decades. Its acceptance by the scientific community did not happen overnight and was preceeded by a chorus of competing theories. The phytochrome mafia claimed that the red-light receptor actually overlapped somehow into the blue-light spectrum and claimed that phytochrome was the only molecule of photoreception. The auxin gang claimed that their favorite plant hormone was somehow implicated in the reception of blue light and corresponding changes in plant morphology. However, in the end, the elusive blue-light receptor was discovered and everyone celebrated.



G R A P H