I am a sucker for the purps, she's so striking. I don't know if I read it or just always guesed that it was anthocyanin. I've often guessed it's presence was a sign that the plant had a slow down in metabolic rate or needs, and so stored the anthocyanin as excess sugar to recover, if conditions change for the better. In LED applications, I think it's tied to the over excitation of the phytochrome 660nm peak, to which the plant has the same response, as light mediates so many plant functions, especially metabolic ones. So the plant thinks it's going bigger than it is, due to spectrum overdriving, and goes purple due to the overproduction of sugar. Of course, these are just my musings, I haven't read any of this to be true...just assumption and guesses.
lol.
Interesting discussion point about the pigmentation,
anthocyanin is the correct reason for why the plant turns purple. There are various speculations as to the nature of this, the most prominent being a genetic reasoning; that is, when the plant goes through the changes of flowering, it is evolutionary advantageous to become purple - in order to attract insect pollinators who view our world in a totally different wavelength. Bees, for example, base their vision on higher energy light (towards green, blue, and UV), this is similar in night time pollinators such as moths. When a moth comes across a purple flower top, it glows in contrast to the dark, making it easier to spot during the night. I suspect that when we have a flowering event, the plant responds to "temperature induced pigment production" that coincides with the need to reproduce or spread genes (via dire pollination), as a last resort at repopulation. In other words, an enzyme (protein) is produced from the DNA via temperature induction, which then goes on to catalyze the formation of special pigments (most likely from sugar carbon skeletons)
To clear up a misconception, anthocyanin is not a sugar itself (it's a pigment), but can be covalently linked to sugar (and indeed stored as a sugarized complex).
In contrast to the obvious evolutionary advantage for "going purple", I wonder the advantage of anthocyanin as a electron funnel as compared to chlorophyll in photosynthesis (I'm sure there are published studies). If you monitored the photosynthetic rate of a totally purple plant and compared it to a totally green plant, you could begin to debate about whether purple is a superior energy producer compared to green or not. Just guessing, but because a plant is purple - it means it is absorbing everything BUT purple, and thus the pigments are being excited by less energetic radiation. Comparing to a green plant, which absorbs everything BUT green (it must then be absorbing some high energy near-UV light), I would argue that the more near-UV light the plant can take in (to an extent), the more readily the pigments are excited, and thus increasing the electron funneling capacity and perhaps photosynthetic rate.
Good discussion point, brother
I think I can almost taste them from here...they are sooo purply, the smoke must be tasty.
