Abstract
Three‐year‐old active and dormant sycamore plants were treated with labelled auxin solution applied to the outer bark or the inner xylem in order to establish the rate of transport of radioactive materials in longitudinal and radial directions. The velocity of auxin transport in the vertical direction within the bark was 0.4–0.6 cm/h in active plants and 0.1–0.2 cm/h in dormant plants. It was found that auxin can move from bark to xylem or vice versa. Autoradiography shows that radial transport takes place within the rays. Auxin is translocated from xylem to bark at a higher rate and in greater amounts than in the reverse direction both in active and dormant plants, but the radial transport from bark to xylem in dormant plants is greater than in active plants. The slower the vertical transport within the bark the faster the radial one in the centripetal direction. On the other hand, the rate of the transport in the centrifugal direction was found to be slower for dormant plants. A higher level of auxin may be maintained in the cambium of active plants because of the centrifugal movement of auxin within the xylem.
Original language | English |
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Pages (from-to) | 61-69 |
Number of pages | 9 |
Journal | New Phytologist |
Volume | 73 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1974 |
Externally published | Yes |