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FlowersModerator: BioTeam
23 posts • Page 1 of 2 • 1, 2
FlowersWhy are petals [in flowers]coloured?The leaves are green because they have chlorophyll so what about petals?Do they have any pigment like that?
"The roots of education is bitter, but the fruit is sweet" Aristotle
Re: Flowers
As far as I know, no flower petals have any chlorophyll.
The color of the petal of the flower comes mainly from chromoplasts with are stuffed with caroten pigments. Vacuoles also contribue because they accumulate antocian pigments
"I have no intention of stopping anytime soon. I want to understand the universe and answer the big questions, that is what keeps me going" - Stephen Hawking
Phycocyanin is a blue pigment that make the algae coloured blue...
Q: Why are chemists great for solving problems?
A: They have all the solutions.
I am rather sure that many orchids have both green petals and sepals... how green they turn out often depends on the culture (temperature/light), so chlorophyll can be present in the petals, though the lip usually has a bit more color.
Also read somewhwere that karoten actually also can produce a bit of energy, not much but a little... Another curious thing was that we once pollinated a white phalaenopsis, the other flowers droppend and the pollinated flower turned light greeen (not botrytis but uniformly light green), as if the plant knew that energy would now be needed to produce seed... didnt take any photos and I gave away the plant to make room.
for the seedling? I dont believe orchids in general put a lot of energy into each seed, that is why germination needs a fungus to supply the embryo with sugar. Orchid seeds are esentially produced with no lunch bag for the embryo, I only seem to recall that some "primitive" types of orchids have seeds of a size that allows a little reserve to be included. But orchids make so many seeds that though each seed doesnt contain a lot of energy then it takes a lot to make them all. But usually pollinated orchid flowers dont do this, it was just this one white phalaenopsis that did it. But it left me curious.
When it comes to other plants I am totally ignorant and would like to hear if other had seen it happen. It really was just a side comment only briefly within the subject of the original post.
Re: Flowers
"The roots of education is bitter, but the fruit is sweet" Aristotle
Main pigments in flowers:
Anthocyanins -- red, purple, and blue colors; water soluble. Flavones -- pale yellow colors; water soluble. Carotenes -- yellow, orange, and red colors; oil or fat soluble. From: http://www.shieldsgardens.com/DLPlace/pigments.html
I beleive both anthocyanins and flavones are types of flavonoids just variations of the same molekulare structure (less or more O and H and some sugar added). Both I beleive are found in the vaculoes.
What is also really interesting is how these components react to pH levels. Many anthocyanins are extreemly sensitive and can change from red to "blue" because of the pH which is controlled by another process in the flower. So when trying to control color in breeding programs it is important to know what you are working with and what you want to achieve. Eg not all genes related to color are passe equally, mithocondrial dna actually is very important when breeding for yellows in some genus'. But I am really an ignorant on this area, but I have been fighting to write an article about the subject for a while (it is too long and needs trimming and to be made easy to understand), so I might need the help of some of you guys with some of the details... One of the biggest problems is that I am writing it another language than english (in danish, which is my mother tongue), so I dont know the words for the various terms, since most of my reference articles are in english. A little knowledge is a dangerous thing...
Caroten only has a role in photoprotection becuase it can not release energy like chlorophil can. It accepts energy from tripletic chlorophil and can only lose it under the form of heat. It can not give an electron to oxygen(like chlorophil can) to form singletic oxygen which attacks the double organic bonds Thus caroten can not produce energy at all, except for caloric energy which is not used but also not harmful I appologise if this is too much info regards, Andrew "I have no intention of stopping anytime soon. I want to understand the universe and answer the big questions, that is what keeps me going" - Stephen Hawking
23 posts • Page 1 of 2 • 1, 2
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