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Growth at Zero Gravity

  1. Feb 11, 2004 #1
    Hi Folks
    I am not sure if this is the right place to post but here it comes :

    Plants, trees, corn etc. all grow upwards, that is in the oppsite direction of the local gravitational field (here disregarding the effect of the sunlight).
    If I grow say wheat on a spinning old fashion record player, in total darkness, I should see the wheat growing in direction of the center, with an angle determined by the angular frequenzy and the distance from the center, I am about to perform that experiment.

    I was then wondering if anyone knew what would happen if wheat was grewn in zero gravity AND in darkness ??
    Does anyone know of experiments performed ?

    Zero Gravity

  2. jcsd
  3. Feb 11, 2004 #2


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    Staff: Mentor

    Plants grow straight up for stability, but they are actually fuller on the southern side due to the greater sunlight.

    The turntable experiment would need to be performed with a light source moving with the turntable otherwise the wheat wouldn't grow. And because of that, I'm not sure a zero gravity/zero light experiment would work.

    It would be interesting to observe seed gestation while suspended in a tank (zero gravity or neutral boyancy) though.
  4. Feb 12, 2004 #3
    Hi Russ
    Thanks for your comment.
    The wheat will grow in zero light, at least for a week or so.
    Haven't you done the experiment in primary school, where you seed grass, one in darkness and one in sunlight, observing that the one growing in darkness grows faster, trying to grow up into the light ?

    The interresting thing is How does the plant cells know which direction is up ? How do they "feel" the direction og gravity ?
    So this brings us back to the experiment in zero gravity / zero light, how would they grow there ?

  5. Feb 13, 2004 #4
    If I recall correctly from last year's biology plants don't know which way's up and which way's down. But the plant growth hormone (Axin or something like that) gathers at the bottom of the seed (pulled down by gravity) and that causes the plant to "know" which way's up. The plants roots then grow where the most concentration of the hormone was and its stalk where there was less of the hormone.
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