Production and metabolism of indole acetic acid in roots and root nodules of Phaseolus mungo.
The mature root nodules of Phaseolus mungo (L.), a leguminous pulse, contain higher amount of indole acetic acid (IAA) than non-nodulated roots. The tryptophan pool present in the mature nodule and young roots might serve as a precursor for the IAA production. Presence of IAA metabolising enzymes - IAA oxidase and peroxidase - indicate the metabolism of IAA in the nodules and roots. In culture, the symbiont, isolated from the nodules, produced a high amount of IAA, when tryptophan was supplied in the medium as a precursor. The symbiont preferred l-isomer over the dl- or d-isomer of tryptophan for IAA production. The important physiological implication of the IAA production in the legume-Rhizobium symbiosis is discussed.
Ghosh
Sisir
S
Department of Botany, The University of Burdwan, Golapbag, Burdwan-713104, West Bengal, India.
Basu
P S
PS
D007210:Indoleacetic Acids / Q000378:metabolism*; D027805:Phaseolus / Q000382:microbiology*; D018517:Plant Roots / Q000382:microbiology*; D012231:Rhizobium / Q000254:growth & development / Q000378:metabolism*
D007210:Indoleacetic Acids