Effects of phytohormones on thermal denaturation profiles of Cymbidium DNA: indication of differential DNA replication.

AUTOR(ES)

Nagl, W

RESUMO

Protocorm pieces of the orchid Cymbidium were aseptically cultured either without phytohormones, or with one of the growth promoting substances, auxin cytokinin, and gibberellin. The derivative melting profiles of the extracted DNA's differ from each other with respect to the size of various AT- and GC- rich fractions. Evidence has been obtained for the increase of the more AT--rich fractions in auxin-treated cultures, while gibberellin stimulated the expansion of the GC-rich fractions. These results are consistent with earlier cytological and cytochemical findings and indicate the involvement of hormone-controlled differential DNA replication in the development of Cymbidium protocorms in vitro.

Documentos Relacionados

• Thermal denaturation of calf thymus DNA: existence of a GC-richer fraction
• The thermal denaturation of DNA: average length and composition of denatured areas
• Human mitochondrial DNA: analysis of 7S DNA from the origin of replication.
• The effect of nucleotide substitution on DNA denaturation profiles.
• Application of higher derivative techniques to analysis of high-resolution thermal denaturation profiles of reassociated repetitive DNA.