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UltravioletPhotography

Flying a kite?


DaveO

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This will probably not fly like a kite but go down like a lead balloon.

 

Do the anthers always come out UV-black. My impression is that they do but I haven't seen as many as the founders of this forum.

 

The allied question is - are they black because they contain UV absorbers, of which there are many to choose from in the vegetable kingdom. Then this leads to asking if pollinators can easily detect UV-black which they learn to use to orient themselves to the "goodies" that the flower offers.

 

I'm only a chemist so what would I know about such stuff?

 

So, is this what UV signatures are all about??

 

Dave :wacko:

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Hi Dave,

 

If I understand the term anther correct, I'm not a botanist, it can include visible pollen.

If that is correct the answer to your first question is no. There are even UV-white reflecting pollen.

 

post-150-0-63104800-1545115201.png

 

post-150-0-63403400-1545115181.png

 

post-150-0-04994600-1545115153.png

 

post-150-0-71056900-1545115752.png

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Hi Ulf,

 

Your shots, except perhaps the first one, show what I see on a lot of my UV shots of Australian native wildflowers. Dyer et al (Proc Roy Soc B (2012) 279 3606-3615) says we parted company with the other continental landmasses about 34 million years ago, so what we see that looks like your flora must be convergent evolution with a completely different suite of pollinators. Your images confirm what I'm trying to say, they all show UV-black centres so if an insect could zoom in on those in UV it would have found the location of the pollen and nectar. You have blue filaments supporting the anthers in some cases just like ours. Perhaps we could write some papers together, with Birna & Andrea if we could find a place to publish.

 

Dave

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Thanks Steve.

 

They are just small cropped screenclips from my FastRawViewer without any special processing. No artistic intention at all. Just to show Dave the colors.

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This will probably not fly like a kite but go down like a lead balloon.

 

Do the anthers always come out UV-black. My impression is that they do but I haven't seen as many as the founders of this forum.

 

The allied question is - are they black because they contain UV absorbers, of which there are many to choose from in the vegetable kingdom. Then this leads to asking if pollinators can easily detect UV-black which they learn to use to orient themselves to the "goodies" that the flower offers.

 

I'm only a chemist so what would I know about such stuff?

 

So, is this what UV signatures are all about??

 

Dave :wacko:

 

Dave, I don't think the reason for the center of a flower to be dark is just to have insects, like bees center in to get the pollen.

 

But you could test this. Just sequence the genome for your favorite 5 flowers that grow easily or see if a sets are available on pubmed.

Then pull down the proteins in the dark part and the light parts of the flower to see what the major constituents are. I am not sure if the same protein, just different sugar tags are used or if there are truelly different proteins that make up the color difference. You could also look at mRNA expression levels between the yellow and dark parts to see if there is significant difference.

Once that is teased out, which no doubt would be a publication on its own. Then you need to eliminate the dark region in some flowers. To make a series of albino flowers.

Once that is done, you can then watch to see if the insects ignore them, avoid them or don't have any preference.

My assumption is the the insects would have no preference. I would be more interested in if this modification some how altered the flower to be more sensitive or less sensitive to UV damage. As this maybe a natural sunscreen to protect the flower during pollination period.

 

Anyway that all should take you less than 30 years and you would get at least 4 papers from it. So you should get to work.

 

David :P

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David :D .

You forgot the crucial stage - separating all the various biomolecules from the witches brew in any one part of the plant (by HPLC or some such) then checking the UV spectrum each one. There's another 20 years at least.

 

Here was my "Road to wherever" moment

 

http://www.ultravioletphotography.com/content/index.php/topic/1105-yellow-pigments-of-australian-acacias/page__hl__%2Bacacia+%2Blongifolia__fromsearch__1

 

Merry Xmas

Dave

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So then you agree with me?

I would only suggest that if the flower color had absolutely nothing to do with insects interacting with them.

The highest comparative expression between uv dark and not would tell you the main target. You may not need to subdivide further.

 

But, I don't think that would take too long these days. I also have a chemistry background, partially. Analytical and Biochemistry would mix in there with flowers and you may get some fun results.

Just like the identification of wine. The small molecules are actually quite few and the mixtures are not too complicated.

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I was thinking about your response Dave. I may not have been clear in my proposed research project, or I am asking a different question.

 

I am not asking, what is the chemical that makes up the color difference in UV. If that is the question then yes, HPLC, LC-MS or better yet a MALDI MS protocol would work best to ID the chemicals. Then you would also need NMR to structurally characterize, as 400MHz machines are cheap and you would get a better idea of the structure.

 

My question is does an insect home in on the UV portion of the flower? Does it need it, or does it not even care?

To address this question a Genetics approach is best. As you don't exactly care what the chemical or thing is that makes up the difference.

You would look for expression differences between the UV dark area and UV bright areas. Look for just more than 2 fold expression using RNA. Biological systems uses enzymes to catalyze rapidly reactions that chemists would use gold or platinum for. So you would be looking for a protein enzyme, if the difference ended up being a 5 branched sugar rather than a linear sugar on the UV light area. You should see more expression of that enzyme or family in your screen.

Then with you sequence you would compare and align it to known sequences to try and id the enzyme or family.

Then align with structural databases to see if you can guess the role. Is it an acetylase or does it methylate, ete.

 

Using that you would then mutate the flower to create an albino, using RNA interference to block the pathway to prevent the UV pattern. You can use general mutagens, RNAi, or if lucky you knock out the gene in the plant or even add a conditional knock out. A conditional knock out would decrease the expression of that enzyme when you add something. You can use chemicals, heat, or cold. This may be needed if the gene ended up being essential or has many roles.

 

Then test it out with insects to see if they care.

 

This actually may not be too complicated, but I don't know if all the genetic tools would be accessible in your selected plants. You may need to select plant that the tools have been set up with. Like canola.

 

I hope that is more clear.

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My answer was as a 1960s chemist before all this genome stuff was even a gleam in anyone's eye. I think we agree but I sort of get tangled up halfway through what I am writing.

 

My guess (far too basic to call it anything else) is that UV absorbing molecules evolved in their own good time and the flowers which expressed them survived UV assaults better than those without. Then along came insects (or perhaps they were there before) and some of those insects could detect UV, perhaps for quite different reasons such as navigation, and so they could detect UV dark areas and one day found that was helping to guide them to whatever they were seeking.

 

The elephant is the fact that our flora evolved without honey bees which is what almost all researchers use to study bee-vision which probably doesn't matter but I have been caught out too many times in the past with that assumption. Most of our bees are solitary which makes training them harder than with a hive of domesticated bees.

 

I think after all your work you would conclude that your bees don't care - however another elephant is in the paddock where our native orchids live and are attracted by pheromone-like molecules.

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  • 2 weeks later...

.....if pollinators can easily detect UV-black which they learn to use to orient themselves to the "goodies" that the flower offers?

 

UV-absorbing areas of a flower (or anything else which is UV-absorbing) are dark or black only in a reflected UV photograph. To any animal or insect which has a visual UV receptor, reflected UV is a color and absorbed UV is the complement of that color. There are no "UV-dark" or "UV-bright" areas seen by such an animal or bee. (See poster in next post).

 

The floral pigments of various kinds are responsible for the UV-absorbing or UV-reflecting areas. Those pigments are known. Aside from providing color benefits to the flower, the pigments also supply other chemical benefits. (We recently had a topic along these lines, but I don't recall where it was.)

 

**********

 

Plants have multiple strategies for pollination*. Motion, wind, water, bees, moths, bats, birds, mice (other animals), beetles, other insects (wasps, flies, etc.) and let's not forget self-pollination and also no-pollination-needed-at-all. Some plants have evolved pollinator lures such as pattern, color, fragrance, shape or mimicry. But some do not use any of those lures. Thus, the fact that some UV-absorbing bull's-eye flowers and their pollinating insects might have co-evolved (as it is currently thought) to "recognize" one-another, well, that is only one tiny part of the story. Although for us, of course, this is a particularly interesting part of the story because of our love of reflected UV photography.

 

*Corresponding statement: Pollinators have multiple strategies for finding food. Detecting UV-patterning is only one such strategy. :)

 

**********

 

So keep in mind, please, that we must distinguish between the UV-reflected view, the human view and the bee's view of a particular flower.

I made a poster for this. I'll go find it and put the link here:

 

****

 

Do the anthers always come out UV-black?

I don't know!

A prowl through the botanical section some day might provide some examples.

 

My question is does an insect home in on the UV portion of the flower?

Some do. Some do not. :D

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Poster showing Human View, Camera View and Bee View of a Bull's-eye Flower

 

In the next post I have anothe poster which will show you that the bee (as a particular case) does not see Dandelion anthers as UV-dark or U-black.

 

The reference is missing off this copy so here it is.

What Does the Honeybee See?

by Adrian Horridge, 2009, AusNatU e-Press

***********************

 

FlowerBeeVee_Template09Fed2018.jpg

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Anthers, if UV-absorbing, are only UV-black to the UV-camera. To an insect or other animal with UV-vision, the anthers are some kind of color. That color may not be human visible however.

 

**************

 

beeChart20170221_final_8x11.jpg

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As a rest from going round in ever decreasing circles I sometimes go back to old references and find that I can now see them without the paywall that was there when they were first published - at least that what I think happens.

 

Here is a case in point: how to colour a flower

http://rspb.royalsocietypublishing.org/content/283/1830/20160429

 

Follow the link to the supplementary material and you will find reflectance curves for 12 plant species - I'm sure i couldn't see those before. You can see quite different responses in UV for flowers which all look yellow to our eyes. Anybody have a spectrometer/spectrophotometer they no longer need?

 

Dave

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Andrea,

I think we can now add mold or types of fungi to your list. Apparently there are fungi networks that connect many types of plants and allow for different types of communication. These are hidden under the soil.

I will have to see if I can find a good reference.

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Dave, I really enjoyed looking through the Australian bee website. Such lovely bees! Particularly endearing is that Teddy Bear Bee.
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Thanks Andrea,

 

Here's an interesting article on Aussie stingless bees:Free flying stingless bees

https://www.researchgate.net/publication/260149697_Behavioural_evidence_of_colour_vision_in_free_flying_stingless_bees

 

It turns out that it was much more difficult to work with these bees than with honeybees. They tended to die if they were marked to identify individual bees, they didn't fly at all if only one bee was introduced into the experimental apparatus, they need to be in a group of at least five bees.

 

The mind boggles thinking about working with solitary Aussie bees, like Teddy Bear Bees or Blue-banded Bees. I doubt such studies will ever be funded or carried out.

 

Dave

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