IDENTIFICATION OF POLYMERIC DYE-TOLERANT OREGANO (ORIGANUM VULGARE) CLONAL LINES BY QUANTIFYING TOTAL PHENOLICS AND PEROXIDASE-ACTIVITY

High phenolic-containing oregano clonal lines have been targeted as po tential plants for developing pollutant-tolerant rhizospheres that cou ld accelerate microbial degradation of pollutants such as polymeric dy es and related aromatic compounds. Seven tissue culture-generated oreg ano clonal lines were found to grow on hormone-free medium containing 0.01% of Poly R-478 or Poly S-119. The results showed that dye toleran ce was associated with changes in total phenolics and peroxidase activ ity in these clonal lines. The total phenolics of most clonal lines de creased in response to polymeric dyes, whereas the peroxidase activity increased. Clonal line O-5 pretreated with Pseudomonas exhibited a hi gher level of peroxidase activity compared to untreated O-5 in respons e to the dyes. These observations suggested that the peroxidase activi ty was inducible. Stereomicroscopic observations revealed that the pol ymeric dyes were sequestered within the growing axis of the roots. Thi s process may also enhance the polymerization of such dyes onto the ce ll wall.