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Models of long‐distance transport: how is carrier‐dependent auxin transport regulated in the stem?
Author(s) -
Renton Michael,
Hanan Jim,
Ferguson Brett J.,
Beveridge Christine A.
Publication year - 2012
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2012.04093.x
Subject(s) - auxin , polar auxin transport , microbiology and biotechnology , gravitropism , biophysics , biology , pisum , chemistry , botany , biochemistry , arabidopsis , mutant , gene
Summary• This paper presents two models of carrier‐dependent long‐distance auxin transport in stems that represent the process at different scales. • A simple compartment model using a single constant auxin transfer rate produced similar data to those observed in biological experiments. The effects of different underlying biological assumptions were tested in a more detailed model representing cellular and intracellular processes that enabled discussion of different patterns of carrier‐dependent auxin transport and signalling. • The output that best fits the biological data is produced by a model where polar auxin transport is not limited by the number of transporters/carriers and hence supports biological data showing that stems have considerable excess capacity to transport auxin. • All results support the conclusion that auxin depletion following apical decapitation in pea ( Pisum sativum ) occurs too slowly to be the initial cause of bud outgrowth. Consequently, changes in auxin content in the main stem and changes in polar auxin transport/carrier abundance in the main stem are not correlated with axillary bud outgrowth.