The stimulative action of applied gibberellins (GA) on seed germination has been reported for a large number species in the past three decades. Applied GA often replaces need environmental stimuli like specific temperature pretreatment or light. Therefore, it suggested that endogenous GAs are essential intermediates stimulation germination. Endogenous have identified seeds limited species, but most evidence regulatory role is entirely circumstantial. use isogenic mutants with lesions...

Ethylene, a gaseous plant hormone regulates essentially all physiological processes during the plant's life cycle. The practical implications of ethylene biosynthesis regulation for improvement have supported continuous basic research on dissecting structure genes encoding biosynthetic enzymes, their differential expression patterns, and mechanisms underlying transcriptional activity. ACC oxidase (ACO) is involved in final step production tissues. In various plants several ACO isoforms been...

The role of endogenous ethylene during germination non‐dormant seeds Amaranthus caudatus L. was investigated. readily germinated in water and darkness at 24°C. Application or its precursor I‐aminocyclopropane‐I‐carboxylic acid (ACC) slightly increased the rate germination. Both compounds effectively antagonized osmotic inhibition by polyethyleneglycol. aminoethoxyvinylglycine (AVG) reduced production 90% but did not inhibit However, inhibited 2,5‐norbornadiene, a competitive inhibitor...

The information on the involvement of hormones in release dormancy grass caryopses is still insufficient. main aim present study was to deepen our understanding mechanism Avena fatua L. by after-ripening relation abscisic acid (ABA) and gibberellins (GAs). florets during dry storage resulted removal caryopses, allowing their germination at 20 30 °C. Sensitivity ABA paclobutrazol (PAC), a GAs biosynthesis inhibitor, decreased as period extended. After-ripening increased content embryos total...

The induction of dormancy release and germination Avena fatua caryopses by KAR 1 involves ABA degradation to phaseic acid. Both, GA 3 , control the AsA–GSH cycle, DNA replication accumulation β-tubulin in embryos before germination. cannot germinate darkness at 20 °C because dormancy, but karrikinolide-1 (KAR1), a compound plant-derived smoke, gibberellic acid (GA3) induced an almost complete radicle protrusion through coleorhiza was preceded increased water uptake, rupture coat, embryo size...

Plant-derived smoke, its water extract—the smoke (SW), and karrikin (KAR1) present in the stimulate seed germination plants from fire-prone fire-free areas, including weeds cultivated plants. There are also plants, seeds of which can respond only to but not KAR1, vice versa. Smoke and/or KAR1 be applied horticulture, agriculture, revegetation. This review describes effects on weed focuses mainly recent knowledge about physiological role these factors dormancy release Avena fatua caryopses....

The dormancy release by KAR

Siliqua development was studied in the wild type line Landsberg erecta and GA‐sensitive mutant ga‐1 of Arabidopsis thaliana (L.) Heynh. Reciprocal crosses between ga‐l mutant, self pollinations either parent have shown that siliqua growth is determined by endogenous GAs originating from maternal tissues embryo. The pollinated or cross‐pollinated with pollen showed reduced growth, which to a large extent could be overcome exogenously applied GAs. siliquae possessed very ent ‐kaurene...

The effect of polyethylene glycol (PEG‐6000), abscisic acid (ABA), 2‐chloroethylphosphonic (ethephon) and 1‐aminocyclopropane‐1‐carboxylic (ACC) on the germination Amaranthus caudatus L. seeds was examined. Both PEG‐6000 ABA inhibited rate percentage seed germination. potentiated PEG. Ethephon highly effective in reversing inhibitory PEG or combinations both. ACC relieved inhibition by combined Aminoethoxyvinylglycine (AVG) increased caused ABA. seems to be related more less ethylene...

The effect of smoke and smoke-derived butenolide in releasing dormancy caryopses (referred to as seeds) the economically important weed Avena fatua L. was studied. Seeds A. are dormant after harvest. Both smoke-water butenolide, applied continuously, removed darkness at 15, 20 25°C slightly 30°C. Butenolide very active a concentration 10−8 M. M also able remove 20°C when for 12 or 24 h 4°C 3 20°C. Sensitivity decreased with longer preincubation times water. This compound less effective light...

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 dark 25 °C for 3 months. Karrikinolide (butenolide, 3-methyl-2H-furo[2,3-c]pyran-2-one, KAR1), contrast to exogenous ethylene precursor biosynthesis 1-aminocyclopropane-1-carboxylic acid (ACC), completely overcame dormancy. The effect KAR1 not affected aminoethoxyvinylglycine (AVG), α-aminoisobutyric (AIB) CoCl2, inhibitors ACC synthase oxidase,...

Abstract The effect and involvement of ethylene in germination partially after‐ripened apple ( Malus domestica Borkh. cv. Antonovka) embryos were studied. requirement for was shown by the use a rhizobitoxine analog 8‐hydroxy‐quinoline sulphate which are inhibitors biosynthesis, mercuric perchlorate, trap endogenously produced ethylene. Excised found to produce progressively greater amounts with increasing periods after‐ripening. Inhibition or abscisic acid accompanied inhibition formation...

Florets of Avena fatua (wild oat) did not germinate at temperatures from 5 to 35 °C, nor caryopses and above 15 °C. Smoke–water (SW) was found partly or substantially induce dormant florets 10 25 whereby almost all germinated 20 When were dry-stored °C for 4 months, their dormancy, that markedly completely, respectively, removed Floret caryopsis SW demand decreased with time dry storage. Paclobutrazol, a gibberellin biosynthesis inhibitor, completely antagonized the stimulatory effect on...

A very small percentage, below 10%, of Amaranthus retroflexus seeds were germinated at 25 °C in the light and thus considered to be primary dormant. Nitric oxide (NO) applied for only 5 h stimulated germination these non-deep physiologically dormant seeds. Likewise, ethephon, ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC) gibberellic (GA3) induced dormancy release. The stimulatory effect NO, ACC, GA3 on was associated with increased ethylene production prior radicle protrusion. nitric...

Molecular studies of primary and secondary dormancy in Avena fatua L., a serious weed cereal other crops, are intended to reveal the species-specific details underlying molecular mechanisms which turn may be useable management. Among others, quantitative real-time PCR (RT-qPCR) data comparative gene expression analysis give some insight into involvement particular wild oat genes release, maintenance or induction by unfavorable conditions. To assure obtaining biologically significant results...

Germination of primary dormant wild oat caused by KAR1 or GA3 is associated with ACC accumulation and increased ethylene production shortly before radicle protrusion as a result the non-transcriptional transcriptional activation ACS ACO enzymes, respectively. Response to both compounds involves modulation sensitivity through receptor genes. Harvested Avena fatua caryopses are and, therefore, germinated poorly at 20 °C. Karrikin 1 (KAR1), which action probably requires endogenous gibberellins...

Journal Article Requirement of Ethylene for Growth Callus and Somatic Embryogenesis in Medicago sativa L. Get access JAN KEPCZYNSKI, KEPCZYNSKI 4 1Department Plant Physiology, University SzczecinFelczaka 3a, 71—412, Szczecin,Poland 4To Whom correspondence should be addressed. Abbreviation: 2,4-D=dichlorophenoxyacetic acid. Search other works by this author on: Oxford Academic PubMed Google Scholar BRYAN D. McKERSIE, McKERSIE 2Crop Science Department, Guelph, GuelphOntario, Canada NIG 2WI...

Amaranthus caudatus L. seed germination was studied under different levels of water deficit induced by PEG 6000 in laboratory conditions.PEG at osmotic potentials -0.2 to -0.3 MPa 24°C darkness delayed and reduced final percentage.PEG solutions potential lower than almost totally blocked germination.Ethephon much more effective GA 3 reversing PEG-caused inhibition A. germination.PEG decreased α-amylase activity after 14 h incubation.It β-amylase 20 h, caused an increase total dehydrogenase...

Avena fatua L. florets (caryopses enclosed by lemma and palea) were partially dormant at 10–20 °C did not germinate temperatures outside this range. After-ripening 25 for 12 weeks completely removed dormancy. Caryopses (florets without able to totally 20 °C. Karrikinolide (KAR1) gibberellic acid (GA3) applied 10–25 or markedly induced germination of caryopses, respectively. Both caryopses more sensitive KAR1 than GA3. To obtain similar effects, 1,000 10,000 times lower concentrations GA3...