Molecular basis for the auxin-independent phenotype of crown gall tumor tissues.

The transfer of specific Ti (tumor-inducing) plasmid sequences, the T-DNA, from Agrobacterium tumefaciens to a wide range of plants results in the formation of crown gall tumors. These tissues differ from most plant cells in that they can be grown in vitro in the absence of added phytohormones. Here, data are presented that offer an explanation for the auxin-independent phenotype of crown gall tissues. It is shown that crude cell-free extracts prepared from three bacterial species harboring pTiA6 gene 1 could convert L-tryptophan to indole-3-acetamide; control extracts lacking gene 1 could not carry out the reaction. Other reports indicate that the pTiA6 gene 2 product can convert indole-3-acetamide to indole-3-acetic acid, a naturally occurring auxin of plants. It is concluded that the auxin-independent phenotype of crown gall tissue involves the introduction of Ti plasmid sequences encoding a two-step pathway for auxin synthesis.

[1]  G. Schröder,et al.  Tumour genes in plants: T‐DNA encoded cytokinin biosynthesis , 1985, The EMBO journal.

[2]  D. Inzé,et al.  Tobacco plants transformed with the Agrobacterium T‐DNA gene 1 contain high amounts of indole‐3‐acetamide , 1985 .

[3]  R. Amasino,et al.  T-DNA of Agrobacterium tumefaciens encodes an enzyme of cytokinin biosynthesis. , 1984, Proceedings of the National Academy of Sciences of the United States of America.

[4]  S. G. Rogers,et al.  Identification of a cloned cytokinin biosynthetic gene. , 1984, Proceedings of the National Academy of Sciences of the United States of America.

[5]  M. Thomashow,et al.  Crown gall oncogenesis: evidence that a T-DNA gene from the Agrobacterium Ti plasmid pTiA6 encodes an enzyme that catalyzes synthesis of indoleacetic acid. , 1984, Proceedings of the National Academy of Sciences of the United States of America.

[6]  M. Van Montagu,et al.  The complete nucleotide sequence of the TL‐DNA of the Agrobacterium tumefaciens plasmid pTiAch5. , 1984, The EMBO journal.

[7]  D. Garfinkel,et al.  Nucleotide sequence of the tms genes of the pTiA6NC octopine Ti plasmid: two gene products involved in plant tumorigenesis. , 1984, Proceedings of the National Academy of Sciences of the United States of America.

[8]  E. Weiler,et al.  The T-region of Ti plasmids codes for an enzyme synthesizing indole-3-acetic acid. , 1984, European journal of biochemistry.

[9]  J. Brosius,et al.  Vectors bearing a hybrid trp-lac promoter useful for regulated expression of cloned genes in Escherichia coli. , 1983, Gene.

[10]  R. O. Morris,et al.  Cytokinin/auxin balance in crown gall tumors is regulated by specific loci in the T-DNA. , 1983, Proceedings of the National Academy of Sciences of the United States of America.

[11]  D. Sciaky,et al.  Variation in hormone autonomy and regenerative potential of cells transformed by strain A66 of agrobacterium tumefaciens , 1982, Cell.

[12]  L. Willmitzer,et al.  The TL‐DNA in octopine crown‐gall tumours codes for seven well‐defined polyadenylated transcripts , 1982, The EMBO journal.

[13]  M. Van Montagu,et al.  Genetic Identification of functions of TL‐DNA transcripts in octopine crown galls , 1982, The EMBO journal.

[14]  D. Garfinkel,et al.  Genetic analysis of crown gall: Fine structure map of the T-DNA by site-directed mutagenesis , 1981, Cell.

[15]  P. Hooykaas,et al.  Grown gall plant tumors of abnormal morphology, induced by Agrobacterium tumefaciens carrying mutated octopine Ti plasmids; analysis of T-DNA functions. , 1981, Gene.

[16]  D. Helinski,et al.  Suppression of Co1E1 replication properties by the Inc P-1 plasmid RK2 in hybrid plasmids constructed in vitro. , 1979, Journal of molecular biology.

[17]  T. Kosuge,et al.  The rôle of indole-3-acetic acid accumulation by alpha methyl tryptophan-resistant mutants of Pseudomonas savastanoi in gall formation on oleanders , 1978 .

[18]  T. Kosuge,et al.  Microbial synthesis and degradation of indole-3-acetic acid. I. The conversion of L-tryptophan to indole-3-acetamide by an enzyme system from Pseudomonas savastanoi. , 1966, The Journal of biological chemistry.

[19]  H. Sprince.  A modified Ehrlich benzaldehyde reagent for detection of indoles on paper chromatograms , 1960 .

[20]  J. Kaper,et al.  On the metabolism of tryptophan by Agrobacterium tumefaciens. , 1958, Biochimica et biophysica acta.

[21]  W. Mccrea.  De Broglie on Quantum Theory , 1954, Nature.

[22]  A. C. Braun,et al.  CROWN GALL PRODUCTION BY BACTERIA-FREE TUMOR TISSUES. , 1941, Science.