Open AccessCytokinin/auxin balance in crown gall tumors is regulated by specific loci in the T-DNA
Author(s) -
Donna E. Akiyoshi,
Roy O. Morris,
Rebecca Hinz,
Barbara Sue Mischke,
Tsune Kosuge,
David Garfinkel,
Milton P. Gordon,
Eugene W. Nester
Publication year - 1983
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.80.2.407
Subject(s) - biology , agrobacterium tumefaciens , mutant , cytokinin , auxin , ti plasmid , octopine , microbiology and biotechnology , gall , genetics , gene , botany , transgene
Insertion of the transposon Tn5 into the T-region of the octopine Ti plasmid ofAgrobacterium tumefaciens gives rise to crown gall tumors having altered morphology. Three loci within the T-DNA that control tumor morphology have been detected [Garfinkel, D. J., Simpson, R. B., Ream, L. W., White, F. F., Gordon, M. P. & Nester, E. W. (1981)Cell 27, 143-153]. They influence tumor size (tml ), production of roots (tmr ), or production of shoots (tms ). Cytokinin and auxin levels in such mutant tumors were examined by HPLC/radioimmunoassay and HPLC/fluorescence assay, respectively. Free indoleacetic acid levels (in pmol/g) were: uninfected tobacco stem tissues, 128; wild-type A348 tumors, 295;tml mutant tumors, 307;tmr mutant tumors, 129; andtms mutant tumors, 70. Averagetrans -ribosylzeatin levels were correspondingly: 0.97, 48, 40, 0.54, and 1,400 pmol/g.trans -Ribosylzeatin/indoleacetic acid ratios were as high as 24 in shoot-producing tumors and as low as 0.003 in root-producing tumors. The evidence strongly suggests that tumor phytohormone levels are determined by genes in the T-DNA.