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Gibberellins inhibit adventitious rooting in hybrid aspen and Arabidopsis by affecting auxin transport
Author(s) -
Mauriat Mélanie,
Petterle Anna,
Bellini Catherine,
Moritz Thomas
Publication year - 2014
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12478
Subject(s) - arabidopsis , auxin , gibberellin , cutting , polar auxin transport , hypocotyl , biology , strigolactone , botany , shade avoidance , microbiology and biotechnology , mutant , gene , biochemistry
Summary Knowledge of processes involved in adventitious rooting is important to improve both fundamental understanding of plant physiology and the propagation of numerous plants. Hybrid aspen ( Populus tremula × tremuloïdes ) plants overexpressing a key gibberellin ( GA ) biosynthesis gene ( At GA 20ox1 ) grow rapidly but have poor rooting efficiency, which restricts their clonal propagation. Therefore, we investigated the molecular basis of adventitious rooting in Populus and the model plant Arabidopsis. The production of adventitious roots ( AR s) in tree cuttings is initiated from the basal stem region, and involves the interplay of several endogenous and exogenous factors. The roles of several hormones in this process have been characterized, but the effects of GA s have not been fully investigated. Here, we show that a GA treatment negatively affects the numbers of AR s produced by wild‐type hybrid aspen cuttings. Furthermore, both hybrid aspen plants and intact Arabidopsis seedlings overexpressing At GA 20ox1 , Ptt GID 1.1 or Ptt GID 1.3 genes (with a 35S promoter) produce few AR s, although AR s develop from the basal stem region of hybrid aspen and the hypocotyl of Arabidopsis. In Arabidopsis, auxin and strigolactones are known to affect AR formation. Our data show that the inhibitory effect of GA treatment on adventitious rooting is not mediated by perturbation of the auxin signalling pathway, or of the strigolactone biosynthetic and signalling pathways. Instead, GA s appear to act by perturbing polar auxin transport, in particular auxin efflux in hybrid aspen, and both efflux and influx in Arabidopsis.