Redirection of auxin flow in Arabidopsis thaliana roots after infection by root-knot nematodes.
Plant-parasitic root-knot nematodes induce the formation of giant cells within the plant root, and it has been recognized that auxin accumulates in these feeding sites. Here, we studied the role of the auxin transport system governed by AUX1/LAX3 influx proteins and different PIN efflux proteins during feeding site development in Arabidopsis thaliana roots. Data generated via promoter-reporter line and protein localization analyses evoke a model in which auxin is being imported at the basipetal side of the feeding site by the concerted action of the influx proteins AUX1 and LAX3, and the efflux protein PIN3. Mutants in auxin influx proteins AUX1 and LAX3 bear significantly fewer and smaller galls, revealing that auxin import into the feeding sites is needed for their development and expansion. The feeding site development in auxin export (PIN) mutants was only slightly hampered. Expression of some PINs appears to be suppressed in galls, probably to prevent auxin drainage. Nevertheless, a functional PIN4 gene seems to be a prerequisite for proper nematode development and gall expansion, most likely by removing excessive auxin to stabilize the hormone level in the feeding site. Our data also indicate a role of local auxin peaks in nematode attraction towards the root.
Department of Molecular Biotechnology, Ghent University (UGent), Coupure links 653, B-9000 Ghent, Belgium.
Tina
T
Kyndt
Department of Plant Sciences, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
Aska
A
Goverse
Department of Molecular Biotechnology, Ghent University (UGent), Coupure links 653, B-9000 Ghent, Belgium.
Annelies
A
Haegeman
Department of Plant Sciences, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
Sonja
S
Warmerdam
Department of Molecular Biotechnology, Ghent University (UGent), Coupure links 653, B-9000 Ghent, Belgium.
Cecilia
C
Wanjau
Department of Molecular Biotechnology, Ghent University (UGent), Coupure links 653, B-9000 Ghent, Belgium.
Mona
M
Jahani
INRA, Univ. Nice Sophia Antipolis, CNRS, UMR 1355-7254 Institut Sophia Agrobiotech, 06900 Sophia Antipolis, France.
Gilbert
G
Engler
INRA, Univ. Nice Sophia Antipolis, CNRS, UMR 1355-7254 Institut Sophia Agrobiotech, 06900 Sophia Antipolis, France.
Janice
J
de Almeida Engler
Department of Molecular Biotechnology, Ghent University (UGent), Coupure links 653, B-9000 Ghent, Belgium godelieve.gheysen@ugent.be.
Godelieve
G
Gheysen
D000818:Animals; D017360:Arabidopsis / Q000469:parasitology* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000502:physiology; D007210:Indoleacetic Acids / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000502:physiology; D018613:Microscopy, Confocal; D010937:Plant Growth Regulators / Q000378:metabolism / Q000502:physiology*; D018517:Plant Roots / Q000469:parasitology* / Q000502:physiology; D014431:Tylenchoidea / Q000502:physiology*
C100794:AUX1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; C531125:LAX3 protein, Arabidopsis; D026901:Membrane Transport Proteins; D010937:Plant Growth Regulators
AUX1; Arabidopsis; LAX3; PIN; auxin; galls; root-knot nematode.