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Search: authors:"Jan Kępczyński"

9 papers found.
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Exogenous putrescine increases the responsiveness of thermodormant Avena fatua L. caryopses to karrikinolide and gibberellic acid

A natural feature of freshly harvested Avena fatua L. caryopses is primary dormancy which, however, was relieved partially by putrescine (Put) (10−2 M) and completely by karrikinolide (KAR1) (3 × 10−9 M) or gibberellic acid (GA3) (10−5 M). The sensitivity of A. fatua caryopses to these stimulators was adversely affected by supraoptimal temperature (SOT) (30 °C). A reduced ...

Plant-derived smoke induced activity of amylases, DNA replication and β-tubulin accumulation before radicle protrusion of dormant Avena fatua L. caryopses

Florets of Avena fatua (wild oat) did not germinate at temperatures from 5 to 35 °C, nor did caryopses at 5 and above 15 °C. Smoke–water (SW) was found to partly or substantially induce dormant florets and caryopses to germinate at temperatures from 10 to 25 °C, whereby almost all caryopses germinated at 15 and 20 °C. When florets were dry-stored at 25 °C for 4 months, their ...

Gibberellin-like effects of KAR1 on dormancy release of Avena fatua caryopses include participation of non-enzymatic antioxidants and cell cycle activation in embryos

Main conclusion The induction of dormancy release and germination of Avena fatua caryopses by KAR 1 involves ABA degradation to phaseic acid. Both, KAR 1 and GA 3 , control the AsA–GSH cycle, DNA replication and accumulation of β-tubulin in embryos before caryopses germination. Abstract Avena fatua caryopses cannot germinate in darkness at 20 °C because of dormancy, but ...

Participation of GA3, ethylene, NO and HCN in germination of Amaranthus retroflexus L. seeds with various dormancy levels

Amaranthus retroflexus seeds were dormant at 25 °C in the darkness and in the light, and also at 35 °C in the darkness. GA3 and ethylene partially removed dormancy at 35 °C in the darkness and at 25 °C in the light. Dormancy was removed by 1–5 days of treatment with nitric oxide or cyanide. The effect of NO and HCN was inhibited by cPTIO, thus the effect of HCN was NO dependent. ...

Response of Amaranthus retroflexus L. seeds to gibberellic acid, ethylene and abscisic acid depending on duration of stratification and burial

Freshly harvested, dormant seeds of Amaranthus retroflexus were unable to germinate at 25 and 35 °C. To release their dormancy at the above temperatures, the seeds were stratified at a constant temperature (4 °C) under laboratory conditions or at fluctuating temperatures in soil or by outdoor burial in soil. Fully dormant, or seeds stratified or buried (2006/2007 and 2007/2008) for ...

Interaction of karrikinolide and ethylene in controlling germination of dormant Avena fatua L. caryopses

Caryopses of Avena fatua L. are dormant after harvest and germinate poorly at 20 °C. Dormancy was released by after-ripening the dry caryopses in the dark at 25 °C for 3 months. Karrikinolide (butenolide, 3-methyl-2H-furo[2,3-c]pyran-2-one, KAR1), in contrast to exogenous ethylene and the precursor of ethylene biosynthesis 1-aminocyclopropane-1-carboxylic acid (ACC), completely ...

Regulation of ethylene biosynthesis at the level of 1-aminocyclopropane-1-carboxylate oxidase (ACO) gene

Ethylene, a gaseous plant hormone regulates essentially all physiological processes during the plant’s life cycle. The practical implications of ethylene biosynthesis regulation for plant improvement have supported the continuous basic research on dissecting the structure of genes encoding ethylene biosynthetic enzymes, their differential expression patterns, and mechanisms ...

Necessity of gibberellin for stimulatory effect of KAR1 on germination of dormant Avena fatua L. caryopses

Avena fatua L. florets (caryopses enclosed by lemma and palea) were partially dormant at 10–20 °C and did not germinate at temperatures outside this range. After-ripening florets at 25 °C for 12 weeks completely removed dormancy. Caryopses (florets without lemma and palea) were able to germinate totally at 20 °C. Karrikinolide (KAR1) and gibberellic acid (GA3) applied at 10–25 °C ...

Releasing primary dormancy in Avena fatua L. caryopses by smoke-derived butenolide

The effect of smoke and smoke-derived butenolide in releasing dormancy of caryopses (referred to as seeds) of the economically important weed Avena fatua L. was studied. Seeds of A. fatua are dormant after harvest. Both smoke-water and butenolide, applied continuously, removed dormancy in darkness at 15, 20 and 25°C and slightly at 30°C. Butenolide was very active at a ...