Differential centrifugation experiments showed that the 13-fold increase in total acid ribonuclease (RNase) activity arising during the 48 h following mechanical damage to potato leaves was associated, in about equal proportions, with the sedimentable and supernatant fluid fractions of cell homogena
Increase in ribonuclease activity following mechanical damage to leaf and tuber tissues ofSolanum tuberosumL.
โ Scribed by D. Pitt; Mary Galpin
- Publisher
- Springer-Verlag
- Year
- 1971
- Tongue
- English
- Weight
- 710 KB
- Volume
- 101
- Category
- Article
- ISSN
- 0032-0935
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โฆ Synopsis
Major increases occurred in the capacity of damaged potato leaf and tuber tissues to hydrolyse ribonucleic acid whilst relatively minor increases were found in the activity of acid phosphomonoesterase and acid phosphodiesterase. Partial purification of homogenates by gel filtration on Sephadex G-100 revealed that much of the increased capacity to degrade ribonucleic acid following damage was due to increased ribonuclease activity. Although appreciable differences in the elution patterns of tuber homogenates subjected to gel filtration were observed before and after the breaking of dormancy the increased ribonuclease activity following damage was a constant feature. Actinomycin D had a relatively small effect on preventing these increases in phosphate-ester hydrolase activities whilst the effect of cycloheximide was very pronounced. Isopycnic equilibrium centrifugation experiments, using deuterium oxide as a density label, provided no evidence that the increased enzyme activity following damage was due to synthesis of new enzyme.
๐ SIMILAR VOLUMES
The pattern of changes in RNase activity in damaged potato leaves incubated in the presence of [14C]leucine followed closely that of leaves incubated in the absence of the radioisotope, but the levels of activity during time course experiments were consistently lower. Contributions of other nucleoly