Auxin controls Arabidopsis adventitious root initiation by regulating jasmonic acid homeostasis.
Vegetative shoot-based propagation of plants, including mass propagation of elite genotypes, is dependent on the development of shoot-borne roots, which are also called adventitious roots. Multiple endogenous and environmental factors control the complex process of adventitious rooting. In the past few years, we have shown that the auxin response factors ARF6 and ARF8, targets of the microRNA miR167, are positive regulators of adventitious rooting, whereas ARF17, a target of miR160, is a negative regulator. We showed that these genes have overlapping expression profiles during adventitious rooting and that they regulate each other's expression at the transcriptional and posttranscriptional levels by modulating the homeostasis of miR160 and miR167. We demonstrate here that this complex network of transcription factors regulates the expression of three auxin-inducible Gretchen Hagen3 (GH3) genes, GH3.3, GH3.5, and GH3.6, encoding acyl-acid-amido synthetases. We show that these three GH3 genes are required for fine-tuning adventitious root initiation in the Arabidopsis thaliana hypocotyl, and we demonstrate that they act by modulating jasmonic acid homeostasis. We propose a model in which adventitious rooting is an adaptive developmental response involving crosstalk between the auxin and jasmonate regulatory pathways.
Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umea, Sweden.
Laurent
L
Gutierrez
Gaëlle
G
Mongelard
Kristyna
K
Floková
Daniel I
DI
Pacurar
Ondrej
O
Novák
Paul
P
Staswick
Mariusz
M
Kowalczyk
Monica
M
Pacurar
Hervé
H
Demailly
Gaia
G
Geiss
Catherine
C
Bellini
D000596:Amino Acids / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D006706:Homeostasis; D018546:Hypocotyl / Q000235:genetics / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D008025:Ligases / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D054883:Oxylipins / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development* / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D000596:Amino Acids; D029681:Arabidopsis Proteins; C092776:CONSTANS protein, Arabidopsis; D003517:Cyclopentanes; D004268:DNA-Binding Proteins; D007210:Indoleacetic Acids; D054883:Oxylipins; D014157:Transcription Factors; C011006:jasmonic acid; C525277:GH3.5 protein, Arabidopsis; D008025:Ligases