Abstract

Control dormant seeds that imbibed water for 16 hr germinated 100% after 10 µ 1/1 C₂H₄ was applied for 24 hr. Dormant seeds that imbibed cycloheximide (100 µ g/ml), 6-methylpurine (50 µ g/ml) and 6-azauracil (50 µ g/ml) for 16 hr did not germinate at either 24 or 48 hr after 10 µ 1/1 ethylene treatment. Both protein- and nucleic acid-synthesis ihhibitors prevented germination induced by ethylene in these dormant seeds.

Imbibition of 20 μ M ABA by dormant seeds prevented germination, but this effect was reversed by ethylene. Tracer studies with 14C- amino acids indicate that ABA does not inhibit total protein synthesis, but it does inhibit emergence in the absence of ethylene. In the presence of ABA plus ethylene, emergence occurred, but no change in total protein synthesis was detected. At 8 weeks after harvest, both germination and incorporation of 2^–14C-uracil into RNA were inhibited by ABA and stimulated by ethylene. By 17 weeks after harvest, only the inhibition of germination and its reversal by ethylene were notable. However, at 17 weeks after harvest, ethylene enhanced RNA synthesis when germination and protein synthesis were inhibited by cycloheximide. Development of isocitritase activity in the seeds was inhibited by ABA and the inhibition was reversed by ethylene, indicating that de novo synthesis of protein is inhibited by ABA and activated by ethylene in these seeds. The opposite effects of ABA and ethylene on germination, RNA synthesis and isocitritase activity suggest that germination is controlled at the level of RNA and/or protein synthesis in these seeds. The prevention of germination of dormant seeds in the presence of ethylene by protein- and RNA-synthesis ihhibitors supports this suggestion, but the data do not preclude an action of ABA or ethylene prior to detectable affects on RNA or protein synthesis.

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Keywords: Dormancy, abscisic acid, cycloheximide, 6-methylpurine, protein synthesis, RNA synthesis

How to Cite:

Ketring, D., (1975) “Physiology of Oil Seeds. V. Germination of NC-13 Virginia-type Peanut Seeds in the Presence of Inhibitors and Ethylene^1,2”, Peanut Science 2(2), p.73-77. doi: https://doi.org/10.3146/i0095-3679-2-2-9

Author Notes

¹Cooperative investigations of the Southern Region, Agricultural Research Service, U. S. Department of Agriculture and Texas Agricultural Experiment Station, Texas A&M University, College Station, Texas.

²Mention of a trademark name or a proprietary product does not constitute endorsement by the United States Departmet of Agriculture or Texas A&M University and does not imply its approval to the exclusion of other products that also may be suitable.

⁴Abbreviations: CH: cycloheximide; 6-MP; 6-methylpurine; 6-AZU:6-azauracil; Act D: actinomycin D; ABA:-abscisic acid; GA:gibberellic acid.