serval:BIB_8B888CBCE302
Contrasting growth responses in lamina and petiole during neighbor detection depend on differential auxin responsiveness rather than different auxin levels.
10.1111/nph.13449
25963518
000360376400024
de Wit
M.
author
Ljung
K.
author
Fankhauser
C.
author
article
2015
New Phytologist
1469-8137
0028-646X
journal
208
1
198-209
Foliar shade triggers rapid growth of specific structures that facilitate access of the plant to direct sunlight. In leaves of many plant species, this growth response is complex because, although shade triggers the elongation of petioles, it reduces the growth of the lamina. How the same external cue leads to these contrasting growth responses in different parts of the leaf is not understood. Using mutant analysis, pharmacological treatment and gene expression analyses, we investigated the role of PHYTOCHROME INTERACTING FACTOR7 (PIF7) and the growth-promoting hormone auxin in these contrasting leaf growth responses. Both petiole elongation and lamina growth reduction are dependent on PIF7. The induction of auxin production is both necessary and sufficient to induce opposite growth responses in petioles vs lamina. However, these contrasting growth responses are not caused by different auxin concentrations in the two leaf parts. Our work suggests that a transient increase in auxin levels triggers tissue-specific growth responses in different leaf parts. We provide evidence suggesting that this may be caused by the different sensitivity to auxin in the petiole vs the blade and by tissue-specific gene expression.
Arabidopsis/growth & development
Arabidopsis/metabolism
Arabidopsis Proteins/metabolism
DNA-Binding Proteins/metabolism
Darkness
Gene Expression
Indoleacetic Acids/metabolism
Light
Plant Leaves/growth & development
Plant Leaves/metabolism
eng
60_published
Publication types: Journal Article ; Research Support, Non-U.S. Gov't Publication Status: ppublish
University of Lausanne
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