Shoot control of root development and nodulation is mediated by a receptor-like kinase.
In legumes, root nodule organogenesis is activated in response to morphogenic lipochitin oligosaccharides that are synthesized by bacteria, commonly known as rhizobia. Successful symbiotic interaction results in the formation of highly specialized organs called root nodules, which provide a unique environment for symbiotic nitrogen fixation. In wild-type plants the number of nodules is regulated by a signalling mechanism integrating environmental and developmental cues to arrest most rhizobial infections within the susceptible zone of the root. Furthermore, a feedback mechanism controls the temporal and spatial susceptibility to infection of the root system. This mechanism is referred to as autoregulation of nodulation, as earlier nodulation events inhibit nodulation of younger root tissues. Lotus japonicus plants homozygous for a mutation in the hypernodulation aberrant root (har1) locus escape this regulation and form an excessive number of nodules. Here we report the molecular cloning and expression analysis of the HAR1 gene and the pea orthologue, Pisum sativum, SYM29. HAR1 encodes a putative serine/threonine receptor kinase, which is required for shoot-controlled regulation of root growth, nodule number, and for nitrate sensitivity of symbiotic development.
Krusell
Lene
L
Laboratory of Gene Expression, Department of Molecular Biology, University of Aarhus, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark.
Madsen
Lene H
LH
Sato
Shusei
S
Aubert
Grégoire
G
Genua
Aratz
A
Szczyglowski
Krzysztof
K
Duc
Gérard
G
Kaneko
Takakazu
T
Tabata
Satoshi
S
de Bruijn
Frans
F
Pajuelo
Eloisa
E
Sandal
Niels
N
Stougaard
Jens
J
D000483:Alleles; D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D025461:Feedback, Physiological; D020869:Gene Expression Profiling; D017343:Genes, Plant / Q000235:genetics; D000070116:Lotus / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009586:Nitrogen Fixation / Q000235:genetics; D018532:Pisum sativum / Q000201:enzymology / Q000235:genetics; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D018520:Plant Shoots / Q000201:enzymology / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D012231:Rhizobium / Q000502:physiology; D013559:Symbiosis / Q000235:genetics
D017346:Protein Serine-Threonine Kinases