At least that is the rumor.. so far I have seen signs of spring but with the snow forecast for tomorrow the stupid groundhog is being proved correct. One of the best parts of spring are the flowers! The white, snowy landscape (or in a city the gray/blackish disgusting slush) gives way to brightly colored flowers of all shapes and sizes! The trees were awake at Boos school this last week, little red buds glittering like rubies.. spring is coming :)
Now to link this to all the tags in this post.. My course this semester is plant development seminar. Seminar courses are usually student led, students take turns presenting a current journal article on the topic. Mine is coming up in 2 weeks and the topic is.. FLOWERING! :-D
The study I have chosen to present is Phloem long-distance delivery of FLOWERING LOCUS T (FT) to the apex by Yoo, et al. The Plant Journal (2013) 75:456-468. Which I apologize is not open access so you can only read the abstract unless you have a subscription to the journal. This article is REALLY cool and full of a ton of things I knew nothing about before I started reading it!
Takehome message of the paper: FT/FTL2 are produced in the companion cells and transferred into sieve elements where it is transported to the shoot apical meristem and initiates flowering.
Say what?! Ok.... ummm.. let us try to break all of that down into normal people speak.
First those FT/FTL2 thingies are simply acronyms for proteins called FLOWERING LOCUS T which has been shown to be the signal that changes the shoot from vegetative (leaves/growing) into reproductive, aka FLOWERS! :)
Next, plants have a vascular system that consists of phloem and xylem. Phloem is for nutrients and it has several different types of cells. The two important for this paper are companion cells and sieve elements. Companion cells have all of the organelles and cell machinery required for making proteins, like the FT. Sieve elements are conduits, they move things around.
Lastly, meristems are stem cells of the plant world. They create new cells that can become any type of plant cell. Meristems are where plants grow.
We can put these all together to say that leaves sense the environment, in this case how long the sun is up. When the right amount of light is perceived, the companion cells start making FT protein. FT protein moves into the sieve elements via diffusion and travels up to the above ground growing point(s), the shoot apical meristem. This meristem shifts from normal growing conditions to flowering conditions and POOF a flower appears :)
That's all I have figured out so far.. good thing I have almost 2 weeks to finish figuring this out! :-D