Cytokinin-Induced Ethylene Biosynthesis in Nonsenescing Cotton Leaves
AUTOR(ES)
Suttle, Jeffrey C.
RESUMO
The influence of cytokinins on ethylene production was examined using cotton leaf tissues. Treatment of intact cotton (Gossypium hirsutum L. cv LG 102) seedlings with both natural and synthetic cytokinins resulted in an increase in ethylene production by excised leaves. The effectiveness of the cytokinins tested was as follows: thidiazuron ≫ BA ≫ isopentyladenine ≥ zeatin ≫ kinetin. Using 100 micromolar thidiazuron (TDZ), an initial increase in ethylene production was observed 7 to 8 hours post-treatment, reached a maximum by 24 hours and then declined. Inhibitors of 1-aminocyclopropane-1-carboxylic acid (ACC) synthesis and its oxidation to ethylene reduced ethylene production 24 hours post-treatment; however, by 48 hours only inhibitors of ACC oxidation were effective. The increase in ethylene production was accompanied by a massive accumulation of ACC and its acid-labile conjugate. TDZ treatment resulted in a significant increase in the capacity of tissues to oxidize ACC to ethylene. Endogenous levels of methionine remained constant following TDZ treatment. It was concluded that the stimulation of ethylene production in cotton leaves following cytokinin treatment was the result of an increase in both the formation and oxidation of ACC.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1056235Documentos Relacionados
- Cytokinin-induced mRNAs in cultured soybean cells.
- Cytokinin-induced Growth Responses by Fenugreek Cotyledons
- Cytokinin-Induced Wall Extensibility in Excised Cotyledons of Radish and Cucumber 1
- Polyribosome Formation in Relation to Cytokinin-induced Cell Division in Suspension Cultures of Glycine max [L.] Merr. 1
- Differential Expression of the Arabidopsis Nia1 and Nia2 Genes1 : Cytokinin-Induced Nitrate Reductase Activity Is Correlated With Increased Nia1 Transcription and mRNA Levels