Question:
Does Gravity effect the direction in which a plant grows?
Replies:
Eric,
Yes, plants do respond gravity. Living things that are sensitive to
gravity are said to be geotropic. Plant stems are negatively geotropic
and the roots are positively geotropic.
Some scientists think this tropism is caused by plant growth hormones
known as auxins. Auxins can speed up or slow down the growth of certain
areas of a plant. If a plant stem falls and continues growing it is
thought that the stem bends upward when auxins are pulled to the bottom
side of the stem by gravity. The bottom side then grows faster than the
top side which causes it to bend upward. As the stem becomes upright
again the auxins even out and the stem then grows straight. Sounds
confusing, doesn't it! Most general botany books have information which
may be clearer than my account. General botany books may be found in
most libraries. Good luck?
Wayne Vanderploeg
Yes. Plants grow against the pull of gravity.
Richard Barrans Jr., Ph.D.
I am not a plant type, but check the word geotropism. It is the effect
of gravity on plants.
Dr. Myron
Most plants have a negative reaction to gravity, that is they grow opposite
the pull of gravity in order to get up above the soil.
J. Elliott
Yes, but it depends on which part of the plant you are asking about. Roots
are programmed to grow toward gravity (they are positively gravitropic) and
stems grow away from gravity (negatively gravitropic). Even if you turn the
plant sideways, it will "know" where it is in space.
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