Consequences of administration of indoleacetic acid 



SiEGEL, S. M. (1955). The biochemistry of Hgnin formation. Physiol. Plant. 8, 20. 

 SiEGEL, S. M., and Galston, A. W. (1953). Experimental coupling of indoleacetic 



acid to pea root protein in vivo and in vitro. Proc. Nat. Acad. Sci., Wash. 39, 1111. 

 SiEGEL, S. M., and Galston, A. W. (1955). Peroxide genesis in plant tissues and its 



relation to indoleacetic acid destruction. Arch. Biochem. Biophys. 54, 102. 

 SwEDiN, B., and Theorell, H. (1940). Dioxymaleic acid oxidase action of per- 

 oxidases. Nature, 145, 7 1 . 

 Tang, Y. W., and Bonner, J. (1947). The enzymatic inactivation of indoleacetic 



acid. I. Some characteristics of the enzyme contained in pea seedlings. Arch. 



Biochem. 13, 1 1. 

 Tonhazy, N., and Pelczar, M. J., Jr. (1954). Oxidation of indoleacetic acid by an 



extracellular enzyme from Polyponis versicolor and a similar oxidation catalyzed by 



nitrite. Science, 120, 141. 

 Torrey. J. (1953). The effect of certain metabolic inhibitors on vascular tissue 



differentiation in isolated pea roots. Amer. J. Bot. 40, 525. 

 Wagenknecht, a. C., and Burris, R. H. (1950). Indoleacetic acid inactivating 



enzymes from bean roots and pea seedlings. Arch. Biochem. 25, 30. 



Note added in proof 



Since this manuscript was prepared for publication, several articles have appeared which 

 bear on the subject matter discussed here. 



(1) Auxin-protein formation in pea extracts has been independently demonstrated (Marre, 

 1955) with naphthylacetic acid. 



(2) The formation of indoleacetylaspartic acid in pea seedlings has been unequivocally 

 shown (Andreae and Good, 1955). This compound, which predominates over free lAA 

 in the brei of I AA-treated tissues, resembles in several respects the I AA-complex split from 

 the lA.A-protein by the action of Coenzyme A. 



(3) The fate of lAA exposed to various lAA oxidase preparations has been further in- 

 vestigated. In pea brei. 3-indolealdehyde has been isolated as a minor product of the 

 reaction (Racusen, 1955). In Oniphalia enzyme preparations, there is some evidence of 

 oxindole formation (Ray and Thimann, 1955 ^ 



(4) The role of naturally- occurring phenols in the peroxidative destruction of lAA has 

 been investigated (Kenten, 1955). 



(5) The in vivo significance of auxin destruction in Osmunda has been challenged (Briggs 

 et al., 1955a, b) on the basis that auxin translocation occurs readily through tissues 

 which, when converted to a brei, rapidly inactivate lAA. 



(6) The xylogenic action of lAA has been confirmed in cultured callus tissues (Wetmore, 

 1955). 



(7) Indirect confirmation of the induction of lAA oxidase activity by auxin has been obtained 

 (Aberg and Jonsson, 1955). 



REFERENCES 



Aberg, B.. and Jonsson, E. (1955). Studies on plant growth regulators. XI. Experiments 



with pea roots, including some observations on the destruction of indoleacetic acid by 



different types of roots. LantbrHogsk. Ann. 21, 401. 

 Andreae, W. A., and Good, N. E. (1955). The formation of indoleacetylaspartic acid in 



pea seedlings. Plant Physiol. 30, 380. 

 Briggs, W. R., Morel, G., Steeves, T. A., Sussex, I. M., and Wetmore, R. H. (1955a). 



Enzvmatic auxin inactivation bv extracts of the fern Osmunda cinnamomea L. Plant 



Physiol. 30, 143. 

 Briggs, VV. R., Steeves, T. A., Sussex, I. M., and Wetmore, R. H. (1955b). A comparison 



of auxin destruction bv tissue extracts and intact tissues of the fern Osmunda cinnamomea L. 



Plant Physiol. 30, 148. ' 

 Kenten, R. H. (1955). The oxidation of indolyl-3-acetic acid by waxpod bean root sap 



and peroxidase systems. Biochem. J. 59, 110. 

 Marre, E. (1955). Spectrophotometric demonstration of the formation of auxin-protein 



complexes by the sulfhvdrvl groups in vegetable enzvme preparations. R. C. Accad. 



Lincei, 18, 88. 

 Racusen, D. (1955). Formation of indole- 3-aldehvde by indoleacetic oxidase. Arch. 



Biochem. Biophys. 58, 508. 

 Ray, p. M., and Thimann, K. V. (1955). Steps in the oxidation of indoleacetic acid. 



Science, 122, 187. 

 Wetmore, R. H. (1955). Differentiation of xylem in plants. Science, 121, 626. 



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