Transport auxin

A. M. Hirsch, R. V. Bhuvaneswari, J. G. Torrey and T. Bisseling, Early nodulin genes are induced in alfalfa root outgrowths elicited by auxin transport inhibitors. Proc. Natl. Acad. Sci. U.S.A. 86 1244-1248 (1989). 

Another area in which Arabidopsis genetics is proving to be useful is the study of the proposed role of flavonoids in regulating auxin transport. Several years ago, Jacobs and Rubery published the first evidence that flavonoids could specifically compete with naphthylphthalamic acid for binding to the auxin efflux carrier in etiolated zucchini hypocotyls.35 This finding was somewhat controversial, however, and no additional evidence for the connection between flavonoids and auxin transport was reported for some time. Brown et al. have now used Arabidopsis flavonoid mutants to generate new evidence in support of a role for flavonoids in the regulation of polar auxin movement.6 These experiments took... 

JACOBS, M., RUBERY, P.H., Naturally occurring auxin transport regulators, Science, 1988,241,346-349. 

Orlova I, Marshall-Colon A, Schnepp J, Wood B, Varbanova M, Fridman E, Blakeslee JJ, Peer WA, Murphy AS, Rhodes D, Pichersky E, Dudareva N (2006) Reduction of benzoid synthesis in petunia flowers reveals multiple pathways to benzoic acid and enhancement in auxin transport. Plant Cell 18 3458-3475... 

None of these had pronounced herbicidal activity but rather PGR activity. Compound % for example, has been shown to be an auxin transport inhibitor, a property probably shared by the other members of this class also. A structure activity analysis for this group of compounds has been reported by Katekar ( ) ... 

Further studies are required to fully elucidate the role of flavonoids in auxin regulation in vivo to determine, for example, whether changes in the synthesis or deposition of specific flavonoids within the cell act to change the rate or direction of auxin transport. There is the question of how such different organs or developmental outcomes as nodules, lateral roots,... 

Palme, K. and Galweiler, L., PIN-pointing the molecular basis of auxin transport, Curr. Opin. Plant Biol, 2, 375, 1999. 

Lomax, T.L., Muday, G.K., and Rubery, P., Auxin transport, in Plant Hormones Physiology, Biochemistry, and Molecular Biology, Davies, P.J., Ed., Kluwer Academic Press, Norwell, The Netherlands, 1995, 509. 

Brown, D.E. et al., Elavonoids act as negative regulators of auxin transport in vivo in Arabidopsis, Plant Physiol, 126, 524, 2001. 

Murphy, A., Peer, W.A., and Taiz, L., Regulation of auxin transport by aminopeptidases and endogenous flavonoids, Planta, 211, 315, 2000. 

Thus, the presence of a silatrane group in the phytohormone molecule prolongs its effect or facilitates the auxin transport through the biomembranes. 

Besseau S, Hoffmann L, Geoffroy P, Lapierre C, Pollet B, Legrand M. 2007. Flavonoid accumulation in arabidopsis repressed in lignin synthesis affects auxin transport and plant growth. Plant Cell 19 148-162. 

FLAVONOID-AUXIN TRANSPORT INTERACTION AND MODULATION OF PLANT GROWTH... 

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