Department of Botany, University of Burdwan, Golapbag, Burdwan-713104
The mature root nodules of Psophocarpus tetragonolobus, a leguminous climber, contained higher levels of indole acetic acid (IAA), gibberellica acid like (GA), cytokinin like (CK) and abscisic acid (ABA) like substances than uninfected roots. The levels of tryptophan was also higher in the nodules. The presence of IAA metabolising enzymes indicates the metabolism of IAA in the nodules. The symbiont from the nodules, a Rhizobium sp., produced high amount of IAA in culture when supplemented with trypotophan. For IAA production, the bacteria preferred the L-isomer over the DL-or D-isomer of tryptophan.
