The stimulant involved in the germination of Striga hermonthica
| Autor: | Alexander Todd, A. W. Johnson, Eric Robinson, R. F. C. Brown |
|---|---|
| Rok vydání: | 1949 |
| Předmět: |
Striga hermonthica
Residue (complex analysis) biology General Engineering Germination Striga Carbohydrate Sorghum biology.organism_classification chemistry.chemical_compound Horticulture chemistry visual_art Acetone visual_art.visual_art_medium General Earth and Planetary Sciences Charcoal General Environmental Science |
| Zdroj: | Proceedings of the Royal Society of London. Series B - Biological Sciences. 136:1-12 |
| ISSN: | 2053-9193 |
| DOI: | 10.1098/rspb.1949.0001 |
| Popis: | The seeds of Striga hermonthica will only germinate readily when they have been exposed to a chemical stimulant released from a potential host root, and the purpose of the investigation has been the examination of the chemical nature of the stimulant. Crude concentrates have been prepared by growing roots of intact seedlings of Sorghum vulgare in water to which charcoal has been added, removing the charcoal and then eluting it with 70% acetone. A residue is obtained which when redissolved in water promotes the germination of the parasite seed. It has been shown that the concentrate contains carbohydrates and particularly pentoses although aldopentoses appear to be absent. At the same time the effects on germination of a large variety of sugars has been tested and a relatively weak effect has been observed with certain samples of seed with D-fructose, D-fructose-1:6-diphosphate and with L-sorbose. The most powerful stimulation, however, has been given by D-xyloketose. This carbohydrate has given germination with all samples of seed with which it has been tested and at concentrations lower than with the crude concentrate. Maximum germination has been recorded with D-xyloketose at a concentration of 1 x 10 -6 mg./ml. and some stimulation at 1 x 10 -7 mg./ml. Fresh preparations of the concentrate and of D-xyloketose are also similar in the important respects that when stored at 5 to 15°C the activities of both disappear completely within 72 hr., and that they are both completely inactivated by heating at 60°C for 60 min. Thus it is highly probable that the stimulating action of the crude concentrate is due to a substance which is either similar to or identical with D-xyloketose. |
| Databáze: | OpenAIRE |
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