Journal of Experimental Botany, Vol. 52, No. 90001, pp. 419-426,
March 2001
© 2001 Oxford University Press
Flavonoids induced in cells undergoing nodule organogenesis in white clover are regulators of auxin breakdown by peroxidase
Genomic Interactions Group, Research School of Biological Sciences, Australian National University, GPO Box 475, Canberra, ACT 2601, Australia
It was tested whether flavonoids that specifically accumulate in cells undergoing early nodule organogenesis could affect auxin turnover by a peroxidase to explain local changes in auxin distribution that occur during nodule formation in white clover (Trifolium repens cv. Haifa). A fluorometric assay was developed to determine the kinetics of indoleacetic acid (IAA) breakdown rates by a horseradish peroxidase in vitro. Three flavonoid compounds, which had previously been localized and identified, were purified from root tissue and their tissue concentrations estimated. A derivative of 7,4'-dihydroxyflavone (DHF), as well as free DHF, strongly inhibited auxin breakdown by peroxidase at concentrations estimated in the root tissue. Formononetin, an isoflavonoid accumulating in nodule primordia, accelerated auxin breakdown by peroxidase at concentrations estimated to be present in the roots. These results suggest that local changes in flavonoid accumulation could regulate local auxin levels during nodule organogenesis. The results are consistent with previous observations on the localization of auxin during nodule organogenesis. A model for the interaction of flavonoids with peroxidases is proposed to explain changes auxin during nodule development. A similar mechanism could be involved in lateral root and root gall formation.
Key words: Auxin, flavonoids, lateral root formation, nodulation, organogenesis.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  N Wuyts, G Lognay, R Swennen, and D De Waele Nematode infection and reproduction in transgenic and mutant Arabidopsis and tobacco with an altered phenylpropanoid metabolism J. Exp. Bot., August 1, 2006; 57(11): 2825 - 2835. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Lazar and H. M. Goodman From The Cover: MAX1, a regulator of the flavonoid pathway, controls vegetative axillary bud outgrowth in Arabidopsis PNAS, January 10, 2006; 103(2): 472 - 476. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. P. Lohar, N. Sharopova, G. Endre, S. Penuela, D. Samac, C. Town, K. A.T. Silverstein, and K. A. VandenBosch Transcript Analysis of Early Nodulation Events in Medicago truncatula Plant Physiology, January 1, 2006; 140(1): 221 - 234. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. A. Peer, A. Bandyopadhyay, J. J. Blakeslee, S. N. Makam, R. J. Chen, P. H. Masson, and A. S. Murphy Variation in Expression and Protein Localization of the PIN Family of Auxin Efflux Facilitator Proteins in Flavonoid Mutants with Altered Auxin Transport in Arabidopsis thaliana PLANT CELL, July 1, 2004; 16(7): 1898 - 1911. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Chaban, F. Waller, M. Furuya, and P. Nick Auxin Responsiveness of a Novel Cytochrome P450 in Rice Coleoptiles Plant Physiology, December 1, 2003; 133(4): 2000 - 2009. [Abstract] [Full Text]
|
|
|
|
 |
|
 T. Akashi, Y. Sawada, N. Shimada, N. Sakurai, T. Aoki, and S.-i. Ayabe cDNA Cloning and Biochemical Characterization of S-Adenosyl-L-Methionine: 2,7,4'-Trihydroxyisoflavanone 4'-O-Methyltransferase, a Critical Enzyme of the Legume Isoflavonoid Phytoalexin Pathway Plant Cell Physiol., February 15, 2003; 44(2): 103 - 112. [Abstract] [Full Text] [PDF]
|
|