Summary
A major problem associated with cereal biotechnology remains the extreme difficulty of reliably and efficiently regenerating plants from protoplasts. Because of the assumed inverse correlation between levels of the modified nucleotide 5-methylcytosine in a gene and the degree of transcription, we report here on experiments to determine whether exposure of maize and tobacco cultures to the 5-methylcytosine analogue 5-Azacytidine (5-Azt) induces gene de-methylation and, as such, enhances tissue culture response, for example by increasing protoplast division frequency. The results show that whilst 5-Azt may be of use in expanding leaf areas capable of producing callus as well as increasing the amount of callus produced, in all other aspects 5-Azt is strongly inhibitory to growth at all but the lowest concentrations. Molecular analysis shows that no readily discernible changes in gene methylation status can be found, regardless of 5-Azt concentration or the gene probe used. Differences can, however, be found in methylation status between callus and developmentally determined tissues, irrespective of 5-Azt treatment. The results suggest that, apart from a very limited role, 5-Azt has no obvious use in tissue culture.
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Communicated by I. Potrykus
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Brown, P.T.H., Yoneyama, K. & Lörz, H. An investigation into the role of 5-Azacytidine in tissue culture. Theoret. Appl. Genetics 78, 321–328 (1989). https://doi.org/10.1007/BF00265291
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DOI: https://doi.org/10.1007/BF00265291