With the exception of the reduced length of root hairs, no
notable differences in shoot or root growth and overall development were observed for api mutant BC2 plants prior to
inoculation. The api mutant phenotype, characterized by small and noninvaded nodular outgrowths, was clearly visible as early as 3 days postinoculation. The rhizobial infection was also defective at the earlier stage of infection thread (IT) initiation in root hairs, as well as later during IT growth in the small percentage of nodules which overcome the primordium invasion block. Nodulated api plants are not self-sufficient for nitrogen fixation. Neither modulating ethylene biosynthesis nor reducing ethylene sensitivity in a skl genetic background alters the basic api phenotype, suggesting that API function is not closely linked to ethylene metabolism or signaling.
Single gene targeted?
yes
Extra Information
Epistasis analyses show that API functions downstream of
BIT1/ERN1 and LIN and upstream of NIP/LATD and the DNF genes.
Mutagenesis Method
EMS
Mutant Class
Nod+-
Allelism
not allelic to nip-3
The earliest development stage known to be affected
Formation of an infection thread
Wildtype Line
Jemalong A17
References:
Authors
Year
Title
Locator
Teillet A, Garcia J, de Billy F, Gherardi M, Huguet T, Barker DG, de Carvalho-Niebel F and Journet EP
2008
api, A Novel Medicago truncatula Symbiotic Mutant Impaired in Nodule Primordium Invasion
