Cornus colour and carotenoid pigments

Discussion in 'Plants: Science and Cultivation' started by cshillibeer, Jan 29, 2012.

  1. cshillibeer

    cshillibeer Member

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    Am I right in assuming that carotenoid pigments are the reason Cornus species have yellow and red bark? I (more or less) understand the photosynthetic function in leaves of biological pigments, but do they serve a similar purpose (if any at all) in the bark?
     
  2. Michael F

    Michael F Esteemed Contributor Forums Moderator 10 Years of Activity

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    Other options to consider include thermoregulation, UV light resistance, and (if combined with toxins) browse prevention (as a visual warning to unpalatability).
     
  3. cshillibeer

    cshillibeer Member

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    Thanks for that information. So is it carotenoid? Do you know of any papers on the topic?
     
  4. Lysichiton

    Lysichiton Active Member

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    I don't know what the actual pigments are in Cornus bark. The Cornus stolinifera stems are showing nicely red around here right now.

    There is no photosynthetic function carried out by these bark pigments, to my knowledge. Beta-carotene is part of the photosynthetic "machinery", but this is intracellular in conjunction with the initial capture of light energy mediated by the green pigment, chlorophyll.

    However, you'd get a better answer from someone whose plant physiology knowledge is more current that mine.

    Michael F. - what ARE the functions of these bark pigments? The explanations in your post don't sound like a good story to me? The most prominent bark colours that I am noticing around here are Salix spp. & Cornus stolinifera, I don't think that either of these are very toxic & I have seen both of them grazed or bark-stripped by animals in the past.
     
  5. Michael F

    Michael F Esteemed Contributor Forums Moderator 10 Years of Activity

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    In Salix spp., prominent bark colours only occur in human-selected cultivars, so you could argue the function is to be pleasing to humans, with humans as the driving force of their evolution. As far as I know, the colours are natural in Cornus stolonifera; if they are not toxic, then seek some other reason. But maybe Homo sapiens-related evolution is active here too.
     
  6. Ron B

    Ron B Esteemed Contributor 10 Years of Activity

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    Many willows that have not been selected by humans have colorful new shoots on a routine basis.
     
  7. Daniel Mosquin

    Daniel Mosquin Renowned Contributor UBC Botanical Garden Forums Administrator Forums Moderator 10 Years of Activity

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