| Principal Investigator |
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Junichi Ueda, Ph.D.
(Osaka Prefecture University) |
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| Objective |
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Auxin, one of the plant hormones, is characteristics of its ability
to move unidirectionally in stems from the tip to base along the vector
of gravity, or basipetally, on Earth (This movement is called "auxin
polar transport").
This experiment aims to identify the role of gravity in auxin polar transport.
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| Experiment outline |
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Seeds of maize and pea are germinated and allowed to grow in orbit.
Stem segments cut from the seedlings are put into small plastic tubes containing
14C-labeled IAA in an agar medium at the bottom of the tubes. After an
appropriate incubation, the stem segments are frozen and brought back to
Earth, where auxin polar transport is measured. Since auxin is labeled
with radioisotope, the transport is readily determined. In addition, auxin
polar transport activities in stem segments prepared from the seedlings
which have already grown on Earth are also measured after launching in
order to clarify the effect of the zero-gravity on auxin polar transport
by comparing with those on Earth.
(note) Auxin, one of the plant hormones, is a chemical substance that controls
the growth and development of plants.
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| The cut stems are put into contact with an agar medium
containing Auxin. |
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| Expected effects |
: |
Auxin, which is considered to regulate the growth and development of
plants, moves in stem from the tip to base along the vector of gravity
on Earth. In this experiment, the data in relation to the regulating mechanism
of auxin polar transport by gravity will be obtained as well as basic information
of the plant growth under the zero-gravity. |
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