Effects of Red Light on Photosynthesis

[Dana Riddle]

Here's an interesting paper concerning red light's effect on zooxanthellae photosynthesis (Clade A, Favites abdita.) Light with lots of red slowed the rate of photosynthesis.

Spectral Effects on Symbiodinium Photobiology Studied with a Programmable Light Engine

The spectral light field of Symbiodinium within the tissue of the coral animal host can deviate strongly from the ambient light field on a coral reef and that of artificial light sources used in lab studies on coral photobiology. Here, we used a novel approach involving light microsensor...

journals.plos.org

 

[Peace River]

Here's an interesting paper concerning red light's effect on zooxanthellae photosynthesis (Clade A, Favites abdita.) Light with lots of red slowed the rate of photosynthesis.

Spectral Effects on Symbiodinium Photobiology Studied with a Programmable Light Engine

The spectral light field of Symbiodinium within the tissue of the coral animal host can deviate strongly from the ambient light field on a coral reef and that of artificial light sources used in lab studies on coral photobiology. Here, we used a novel approach involving light microsensor...

journals.plos.org

Interesting! Thanks for sharing!!!

 

[taricha]

Here's a flip side of the coin, from a cyanobacteria paper I was reading.
Blue light reduces photosynthetic efficiency of cyanobacteria through an imbalance between photosystems I and II

I need to give it another read-through, but my interpretation is that cyano doesn't distribute its antennae pigments equally between photosystems 1 and 2. So blue (450nm) light mostly only excites only one photosystem. Orange and Red provide full strength photosynthesis.
As anyone in the hobby might have expected, Red cyano does marginally better in Blue light than green cyano does, but they both struggle under monochromatic blue.

 

[jda]

Do we have any idea if this is the same in a coral as it is in the free-standing Symbiodinium culture that they used? If so, then which ones?

 

[Dana Riddle]

Let this sink in. Limited Chromatic Adaptation ability in Symbiodinium species/clades could be as important as Photoadaptation. I shudder at the thought.

 

[Dana Riddle]

Do we have any idea if this is the same in a coral as it is in the free-standing Symbiodinium culture that they used? If so, then which ones?

I scanned the paper several times and did not see that the Symbiodinium under culture was indeed isolated from the Favites coral. Or did I just miss it?

 

[Dana Riddle]

Here's a flip side of the coin, from a cyanobacteria paper I was reading.
Blue light reduces photosynthetic efficiency of cyanobacteria through an imbalance between photosystems I and II

I need to give it another read-through, but my interpretation is that cyano doesn't distribute its antennae pigments equally between photosystems 1 and 2. So blue (450nm) light mostly only excites only one photosystem. Orange and Red provide full strength photosynthesis.
As anyone in the hobby might have expected, Red cyano does marginally better in Blue light than green cyano does, but they both struggle under monochromatic blue.

I need to review Shirley Jeffrie's and Kirk's works. If I recall, cyano contains a photopigment in reaction centers that differs from those in zoox. Weren't things so much easier when we thought there was only one Symbiodinium species/type? LOL.

 

[jda]

I did not see where they got it at all either, which is why I asked. ...so I would kinda like to know since not all kinds of "coral" are the same nor are all types of "Symbiodinium."

 

[Dana Riddle]

I did not see where they got it at all either, which is why I asked. ...so I would kinda like to know since not all kinds of "coral" are the same nor are all types of "Symbiodinium."

I looked in my Symbiodinium data base and found 6 reports of zoox found in Favites, and only one report for Favites abdita (it contained Clade C1.) All others are of Clade C. Looks like the wrong clade was used in these procedures?
The list is available here:

https://www.advancedaquarist.com/2006/1/AAOLM-Feature-Article-D-Riddle-Jan06-CladeList.pdf

 

[jda]

If it is indeed from Favites, can we label this study as just for that coral, at least in this thread? If that? People will likely take this the wrong way, link you in all kinds of posts and think that red might slow the rate of photosynthesis for all corals. I fear that this might create a reefing urban legend that will take way too much effort to get back under control than just stemming it now.

When I read this, the whole thought that came to mind is "this looks like this could be just for this one strain and not so much a universal conclusion..." but I am not very smart.

 

[Dana Riddle]

If it is indeed from Favites, can we label this study as just for that coral, at least in this thread? If that? People will likely take this the wrong way, link you in all kinds of posts and think that red might slow the rate of photosynthesis for all corals. I fear that this might create a reefing urban legend that will take way too much effort to get back under control than just stemming it now.

When I read this, the whole thought that came to mind is "this looks like this could be just for this one strain and not so much a universal conclusion..." but I am not very smart.

Honestly, I didn't catch that the zoox clade might not have been isolated from the target coral, and glad you brought it up. I assumed the cultured strain had been originally isolated from Favites, which would make sense. It is quite possible that Clades A and C would respond differently to identical procedural protocols. I do agree that the result should not be considered as universally applicable. The PAM fluorometry work I did with Porites had a different outcome (high rate of electron transport and delayed non-photochemical quenching.)

 

[jda]

Thanks. Even if the clade was harvested from a target coral, there are so many other clades and corals that universal application seems premature - thank you for your opinion on this since I don't get it all. As you know, I am long of the opinion that every wave from about 350-850nm is important in some way, shape or form and that if you isolate one thing, or another, you can find contradictions for ever nanometer if you run a few different tests (like in your research) but in the whole, it all works together in cohesion.

I did find the article fascinating and probably one a thousand that might be necessary to fully understand this stuff. Thanks for posting it.