Effect of gibberellin on protein and non-structural carbohydrate in dormant Avena fatua caryopses

Keng, J. C. W.; Foley, Michael

doi:10.1016/0168-9452(87)90218-4

Cited by 5 publications

(2 citation statements)

References 15 publications

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“…However, the breaking of dormancy by soluble sugars suggests that D M73 embryos may not possess a block in the utiiization of these sugars (Foley 1992). Sugar accumulation in D embryos has been investigated in relation to GA-induced breaking of dormancy of intact caryopses (Keng and Foley 1987). It has not been investigated in a systematic manner using cultured excised embryos.…”

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Carbohydrate status in dormant and afterripened excised wild oat embryos

Foley¹,

Bancal²,

Nichols³

1992

Physiol Plant

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1992. Carbohydrate status in dormant and afterripened excised wild oat embryos. -Physioi. Plant. 85; 461^66.Germination and carbohydrate concentrations were determined in excised dormant and afterripened wild oat (Avena fatua L. line M73) embryos cultured on N6 medium with and without 88 mM fructose (Fru). Without Fru dormant embryos began to germinate after approximately 2 weeks, and the germination rate was greater at 12 than 16'*C. With addition of Fru 80% of dormant embryos germinated in 3 days. More than 80% of afterripened embryos germinated within 1 day on N6 with or without additional sugars. Therefore, relative to afterripened embryos, true embryo dormancy exists in line M73. Concentrations of starch and soluble sugars were initially similar in dormant and afterripened embryos. Culturing dormant and afterripened embryos on medium with Fru resulted in concentrations of glucose (Glu), sucrose (Sue), Fru and maltose (Mal) that were the same or higher than the initial levels. The concentration of starch in embryos initially increased slightly then remained constant or declined, except in dormant embryos on Fru-amended medium, where starch accumulated to 34 |ig Glu equivalents (mg fresh weight)"' at 52 h. Raffinose (Raf) and stachyose (Stach) concentrations declined over time in all embryos. Carbohydrate concentrations in afterripened embryos on medium without Fm decreased to nearly undetectable levels by 52 h. Soluble sugar concentrations in dormant embryos on medium without Fru also declined by 52 h, but changes were not as extensive as those in afterripened embrj'os without Fru. In 52 h Raf and Stach were nearly depleted in all afterripened embryos, aod in dormant embryos cultured on Fru-containing medium but not in dormant embryos without Fru. The concentration of Stach in dormant embryos without Frti declined 60% at 12 to 18 days coinciding with the potential for germination. The results demonstrate that a decline in Stach concentration is associated with the poteotial for germination of dormant (D) excised embryos. The mechanism of dormancy-breaking associated with the Raf family oligosaccharides remains to be determined.

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Carbohydrate status in dormant and afterripened excised wild oat embryos

Foley¹,

Bancal²,

Nichols³

1992

Physiol Plant

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“…Esta enzima aumenta com a concentração de GA 3 (Simpson & Naylar, 1962). O ácido giberélico promove a síntese de RNA e proteínas, ambos no embrião e tecidos do endosperma (Keng & Foley, 1987). Assim, pelos resultados dessas pesquisas o GA 3 parece estimular a produção de açúcares (hexoses) à partir da degradação de amido, via mecanismos de glicólise, ciclo de Krebs e cadeia de transporte de elétrons.…”

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Determinação de inibidores da germinação no espermoderma de sementes de café (Coffea arabica L.)

Pereira¹,

Oliveira²,

Lúcia³

et al. 2002

Rev. bras. sementes

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E ANA LÚCIA PEREIRA KIKUTI 5 RESUMO -Sementes de café apresentam germinação lenta, aumentando consequentemente o período de formação das mudas. A causa dessa germinação lenta, ainda não está elucidada. Aparentemente, a difusão de gases e da água tem papel secundário comparadas ao efeito de inibidores presentes. A presente pesquisa foi desenvolvida no Setor de Sementes do Departamento de Agricultura e no Laboratório de Química da Universidade Federal de Lavras. Em uma pesquisa preliminar, utilizando sementes de alface como indicadora de inibidores e extrato aquoso de espermoderma ("película prateada"), ficou evidenciada a presença de inibidores nesse tecido. Em uma segunda etapa o extrato aquoso da película prateada foi submetido a um fracionamento, em teste in vitro. Observou-se, por meio desse teste, que a fração ativa encontrava-se na fase metanólica, a qual foi concentrada sob vácuo e eluída através de coluna de sílica gel com metanol, água destilada e HCl 0,1M. Após concentração sob vácuo da fração ativa originou-se um sólido branco, que se mostrou homogêneo segundo análise por cromatografia em camada fina com placas de sílica gel. Por meio de análise de espectrometria de infravermelho, de massas e de ressonância magnética nuclear de 1 H e de 13 C, atribuiu-se a tal sólido a estrutura da cafeína. Conclui-se que o espermoderma pode contribuir para a lenta germinação das sementes de café, possivelmente devido à presença de cafeína.Termos para indexação: sementes, café, germinação, inibidores. GERMINATION INHIBITORS DETERMINATION IN THE SPERMODERM OF COFFEE (Coffea arabica L.) SEEDSABSTRACT -Coffee seeds present slow germination, increasing hence the period of formation of seedlings. The cause that slow germination is not elucidated yet. Apparently, the diffusion of gases and water has a secondary role as compared with the effect of inhibitors present. The present research work was developed in the Seed Sector of the Agriculture Department and in the Chemistry Department of the Universidade Federal de Lavras. In a previous research by utilizing lettuce seeds as an indicator of inhibitors and aqueous extract of spermoderm (silvery film), the presence of inhibitors in this tissue was evidenced. In a second step, the aqueous step of the silvery film was submitted to a fractionating, in vitro test. It was observed by means of that test, that the active fraction was in the methanol phase, which was concentrated under vacuum and eluted through gel silica column with methanol, distilled water and 0.1M HCl. After concentration under vacuum, of active fraction gave rised to a white solid, which showed itself homogenous according to the thin layer chromatography analysis with gel silica plates. By means of the infrared, mass and 1 H and 13 C nuclear magnetic resonance spectrometry, the caffeine structure was ascribed to such a solid. It follows that spermoderm may contribute to the slow germination of coffee seeds, possibly due to the presence of caffeine.

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