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Re: Green Light
> Date: Fri, 13 Mar 1998 18:39:16 -0700 (MST)
> From: "Roger S. Miller" <rgrmill at rt66_com>
> Subject: Re: Aquatic Plants Digest V3 #137
> On Fri, 13 Mar 1998, Dr. Dave wrote:
> > Plants can utilize green light for photosynthesis. This occurs because,
> > even though chlorophyll does not absorb green light, accessory pigments
> > do. The energy captured by the accessory pigments is then magically
> > transferred to the applicable photosystem. Take a look at Barry James'
> > book on P. 21 and you will clearly see what Im talking about.
> I have a few plant books, but not that one.
> Do you have a sense for how common that adaptation is? My understanding
> is that most plants show so little response to green light (~530 nm) that
> it is called "safelight" in plant growth research. The researcher can
> work by it, but the plants show minimal response to it.
> Whatley and Whatley's "Light and Plant Life" is a nice (but slightly old)
> discussion on the response of plants to different wavelengths of light.
> Roger Miller
> Date: Sat, 14 Mar 1998 16:44:17 +1000
> From: David Aiken <d.aiken at eis_net.au>
> Subject: Re: Green Light
> On 14/3/98 Dave wrote:
> >Plants can utilize green light for photosynthesis. This occurs because,
> >even though chlorophyll does not absorb green light, accessory pigments
> >do. The energy captured by the accessory pigments is then magically
> >transferred to the applicable photosystem. Take a look at Barry James'
> >book on P. 21 and you will clearly see what Im talking about.
> I can accept it all except for the "magically" at the end of line 3. <g>
> David Aiken
Sorry to differ with some of you, but, I think that plants uses green
light at a minimum or not at all. I cant quote directly but I'll try to repeat a
few of the points that have been made. Someone said that accessory chlorophyll can
capture green light and transfer the energy. My biology book says different. If I
remember correctly, there are 2 accessory chlorophyll, a and b, or is it b and c?
Anyway, these can accept other spectrums that the main chlorophyll cannot, but
these spectrums do not include green (the spectrum is mostly blue and red, if I
remember correctly). From a logical point, if these accessory pigments do use the
green spectrum, then it will not be reflected at all, and leaves will not appear
so. Someone, possibly the same person, said that some plants that grow in the
understories where green light is more abundant have adapted to use it. This is
reasonable, but aquarium plants are NOT rain forest plants, well, maybe some are
but... and if they HAVE adapted to use green light then their leaves would not
appear green. I have only recently heard of this Amano guy (im still pretty new at
this), but why do people think that this guy can't be wrong? Sure he can grows
pretty plants, but that doesnt not make the spectrum of light he uses to be
beneficial. Someone said that he probably uses a wide spectrum of green to show
his plants better, this I agree with- logical. Probably he uses lots of green
because he can afford to. Conclusion: green plants do not use green green light!