Reversal of Inhibitors of Seed Germination by Red Light pins Kinetin

1965 ◽  
Vol 18 (1) ◽  
pp. 41-43 ◽  
Author(s):  
A. A. Khan ◽  
N. E. Tolbert
Keyword(s):  
Seed Germination ◽  
Red Light

scholarly journals The counteracting effect of potassium cyanide in sodium azide-inhibited germination of Paulownia tomentosa  Steud. seeds

2005 ◽  
Vol 57 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Suzana Zivkovic ◽  
Dragoljub Grubisic ◽  
Zlatko Giba ◽  
Radomir Konjevic
Keyword(s):  
Seed Germination ◽  
Light Pulse ◽  
Sodium Azide ◽  
Incubation Medium ◽  
Red Light ◽  
Potassium Cyanide ◽  
Inhibitory Effect ◽  
Escape Time ◽  
Paulownia Tomentosa ◽  
Respiratory Inhibitors

The effect of some respiratory inhibitors on light-induced Paulownia tomentosa Steud. seed germination was studied. Millimolar solution of sodium azide was sufficient to completely prevent germination induced by a 5-min red light pulse. The inhibitory effect of azide was absent if seeds were rinsed before phytochrome activation by light. Sodium azide was effective only if present in the period of Pfr activity. The escape time from azide inhibition compared to the escape from far-red light action, was delayed for about 24 hours. When azide was applied after phytochrome activation, its effect depended on how long it was present in the incubation medium. The removal of azide allowed full restoration of germination by another red light pulse and the far-red escape time did not differ from the escape of untreated, i.e. water-imbibed seeds. Potassium cyanide alone did not produce any effect in light-stimulated germination of these seeds. However, it counteracted the inhibitory effect of azide in light-stimulated germination, if applied simultaneously at a concentration three times higher.

scholarly journals Arabidopsis chloroplast J protein DJC75/CRRJ mediates nitrate-promoted seed germination in the dark

2020 ◽  
Vol 125 (7) ◽  
pp. 1091-1099
Author(s):  
Huai-Syuan Ciou ◽  
Yu-Lun Tsai ◽  
Chi-Chou Chiu
Keyword(s):  
Arabidopsis Thaliana ◽  
Seed Germination ◽  
Germination Rate ◽  
Red Light ◽  
Phytochrome B ◽  
Biosynthetic Gene ◽  
Unknown Mechanism ◽  
J Domain ◽  
Domain Protein ◽  
J Protein

Abstract Background and Aims Nitrate can stimulate seed germination of many plant species in the absence of light; however, the molecular mechanism of nitrate-promoted seed germination in the dark remains largely unclear and no component of this pathway has been identified yet. Here, we show that a plastid J-domain protein, DJC75/CRRJ, in arabidopsis (Arabidopsis thaliana) is important for nitrate-promoted seed germination in the dark. Methods The expression of DJC75 during imbibition in the dark was investigated. The seed germination rate of mutants defective in DJC75 was determined in the presence of nitrate when light cues for seed germination were eliminated by the treatment of imbibed seeds with a pulse of far-red light to inactivate phytochrome B (phyB), or by assaying germination in the dark with seeds harbouring the phyB mutation. The germination rates of mutants defective in CRRL, a J-like protein related to DJC75, and in two chloroplast Hsp70s were also measured in the presence of nitrate in darkness. Key Results DJC75 was expressed during seed imbibition in the absence of light. Mutants defective in DJC75 showed seed germination defects in the presence of nitrate when light cues for seed germination were eliminated. Mutants defective in CRRL and in two chloroplast Hsp70s also exhibited similar seed germination defects. Upregulation of gibberellin biosynthetic gene GA3ox1 expression by nitrate in imbibed phyB mutant seeds was diminished when DJC75 was knocked out. Conclusions Our data suggest that plastid J-domain protein DJC75 regulates nitrate-promoted seed germination in the dark by upregulation of expression of the gibberellin biosynthetic gene GA3ox1 through an unknown mechanism and that DJC75 may work in concert with chloroplast Hsp70s to regulate nitrate-promoted seed germination. DJC75 is the first pathway component identified for nitrate-promoted seed germination in the dark.

Contrasting seed germination responses to red and far-red light in Leptospermum scoparium and Melicytus ramiflorus

2000 ◽  
Vol 27 (11) ◽  
pp. 1069
Author(s):  
Helen Herron ◽  
John Clemens ◽  
Dennis H. Greer
Keyword(s):  
Seed Germination ◽  
Red Light ◽  
Green Light ◽  
Photon Flux ◽  
Short Term ◽  
Short Term Exposure ◽  
Subsequent Exposure ◽  
R:Fr Ratio ◽  
Leptospermum Scoparium

Effects of red light (R) and far-red light (FR), and selected photon flux densities (PFD) of photosynthetically active radiation (PAR) on seed germination in the photoblastic, primary colonising species Leptospermum scoparium J. R. et G. Forst. and the late secondary successional Melicytus ramiflorus J. R. et G. Forst. were studied. A continuous R dose response curve forL. scoparium germination was developed, unifying data from experiments using long-term exposure to PAR with those following short-term exposure to R. The threshold R dose needed to effect germination was ~0.1 mmol m –2 , and the response was saturated at 1000 mmol m –2 . Stimulation of germination by R was reversed by a subsequent exposure to FR. These features are consistent with a low-fluence response mediated by phytochrome B. FR reversal of germination was achieved at a dose two orders of magnitude lower than that of R required to induce initial germination. However, when both R and FR were provided simultaneously, the FR dose needed to even partially inhibit germination (34% compared to > 95% in controls) was two orders of magnitude higher than the R dose (R:FR ratio = 0.007). Germination in L. scoparium was also stimulated in up to 12% of seed upon diurnal exposure to FR, or by green light (~2 mol m –2 ), indicating a very-low-fluence response mediated by phytochrome A also operating in this species. In contrast, seed germination in M. ramiflorus was relatively unresponsive to R, and secondary dormancy was induced by high PFD (515 mol m –2 s –1 ).

Quantitative trait loci associated with lettuce seed germination under different temperature and light environments

Genome ◽  
2008 ◽  
Vol 51 (11) ◽  
pp. 928-947 ◽  
Author(s):  
Eiji Hayashi ◽  
Natsuyo Aoyama ◽  
David W. Still
Keyword(s):  
Quantitative Trait Loci ◽  
Seed Germination ◽  
Path Analysis ◽  
Quantitative Trait ◽  
Germination Rate ◽  
Red Light ◽  
Seed Maturation ◽  
Lettuce Seed ◽  
Factors Affecting ◽  
Trait Loci

Temperature and light are primary environmental cues affecting seed germination. To elucidate the genetic architecture underlying lettuce ( Lactuca sativa L.) seed germination under different environmental conditions, an F8 recombinant inbred line population consisting of 131 families was phenotyped for final germination and germination rate. Seeds were imbibed in water at 20 °C under continuous red light (20-Rc), 20 °C continuous dark (20-Dc), 31.5 °C continuous red light (31.5-Rc), 31.5 °C continuous dark (31.5-Dc), or 20 °C far-red light for 24 h followed by continuous dark (20-FRc-Dc). Thirty-eight quantitative trait loci (QTL) were identified from two seed maturation environments: 10 for final germination and 28 for germination rate. The amount of variation attributed to an individual QTL ranged from 9.3% to 17.2% and from 5.6% to 26.2% for final germination and germination rate, respectively. Path analysis indicated that factors affecting germination under 31.5-Rc or 31.5-Dc are largely the same, and these appear to differ from those employed under 20-FRc-Dc. QTL and path analysis support the notion of common and unique factors for germination under diverse temperature and light regimes. A highly significant effect of the seed maturation environment on subsequent germination capacity under environmental stress was observed.

scholarly journals Germination and seed conservation of a pioneer species, Tecoma stans (Bignoniaceae), from tropical dry forest of Colombia

2018 ◽  
Vol 66 (2) ◽  
pp. 918
Author(s):  
Jhon Alexander Vargas-Figueroa ◽  
Alba Marina Torres-González
Keyword(s):  
Seed Germination ◽  
White Light ◽  
Germination Rate ◽  
Red Light ◽  
Tropical Dry Forest ◽  
Seed Storage ◽  
Dry Forest ◽  
Storage Behavior ◽  
Mean Germination Time ◽  
Seed Storage Behavior

Seed germination and seed longevity under different environmental conditions are fundamental to understand the ecological dynamics of a species, since they are decisive for its success within the ecosystem. Taking this into account, seed germination and seed storage behavior of a pioneer species of tropical dry forest (Tecoma stans) were studied in the laboratory, to establish the effect of different environmental conditions on a local tree population. Two seed lots collected in July 2011, from Cali (Colombia), were evaluated under three alternating temperatures (20/30, 20/25, 25/30 ºC; 16/8 h) and four light qualities (12-hour white light photoperiod, darkness, and 15 minutes of red light -R and far red light -FR). Final germination was recorded for all treatments; for white light treatment the daily germination was recorded to calculate mean germination rate, mean germination time, and two synchronization indices. To assess the effect of light quality on physiological variables, a destructive germination test was carried out. For this test, another seed lot was evaluated under the same light conditions using an alternating temperature of 20/30 °C - 16/8 h, recording germination during six days for every treatment. In addition, seeds were stored at two different moisture contents (7.7, 4.1 %) and three storage temperatures (20, 5, -20 ºC), during two time periods (one and three months); a seed germination test was conducted for each treatment. Four replicates of 35 seeds per treatment were used for all experiments. Germination was high (GP > 90 %) with all alternating temperatures under white light, whereas under R, FR, and darkness germination was evenly successful at low temperatures, but at higher temperature, half of the seeds entered into secondary dormancy (GP= 45-65 %). However, mean germination rate and synchronization under R and FR decreased significantly in comparison to white light treatment and, consequently, mean germination time increased. Seed storage behavior of this species is orthodox due to the high germination (GP > 90 %) obtained under all treatments. In conclusion, T. stans seeds have a negative germination response at high incubation temperatures in the absence of white light, entering into a secondary dormancy. In contrast, an environment with a lower temperature and without white light delays the germination, but at the end seeds are able to reach the same germination values. This seed dependence on incident light in limiting conditions suggests a physiological mechanism on the seed tissues of this species, probably mediated by phytochromes. Finally, the orthodox seed storage behavior of T. stans is a reason to include this species in ex situ seed conservation programs for restoration and recovery of the tropical dry forest; however, long-term studies should be conducted in order to evaluate the maintenance of this characteristic throughout longer periods of time. Rev. Biol. Trop. 66(2): 918-936. Epub 2018 June 01. 

scholarly journals The Effects of Light Color on Seed Germination of Markhamia stipulata (Wall.) Seem

2017 ◽  
Vol 3 (4) ◽  
pp. 233
Author(s):  
Sri Ulie Rahmawati ◽  
Arief Noor Rachmadiyanto
Keyword(s):  
Seed Germination ◽  
Germination Rate ◽  
Block Design ◽  
Red Light ◽  
Botanical Garden ◽  
Dark Light ◽  
Significant Difference ◽  
Length Width ◽  
Light Color ◽  
And Control

<p class="Els-body-text"><em>Markhamia stipulata </em>(Wall.) Seem. (Bignoniaceae) is one of collections in Bogor Botanical Garden that potential as a medicine. Information about germination of these species were not known yet. This research was aimed to examine the effect of light color on germination process of <em>Markhamia stipulata</em> (Wall.) Seem. The research method used a Randomized Complete Block Design (RCBD) that consist of three treatments (red light, far red light, dark) and one control (open air) with four replications for each group. Each group consist of 10 seeds. Precentage of seed germination; seedling height; cotyledon width; length, width and number of leaves were measured. The result showed that seed germination start at third day after sowing.  Germination rate and germination rate coefficcient showed there is no significant difference between all treatments even though far red light showed highest number (100 %; 0.755).  However, light color influence on seedling growth. Far red light showed affect on internodes distance. Dark light showed affect on leaves and cotyledon size. Red light and control showed similarity.</p><p> </p><div><p class="Els-keywords"><strong>Keywords:</strong> dark; far red light<em>, </em><em>Markhamia stipulata</em> (Wall.) Seem; red light; seed germination</p></div>

scholarly journals Germination responses of seeds of Desmodium triflorum

2018 ◽  
Vol 4 (2) ◽  
pp. 19 ◽  
Author(s):  
Niroj Paudel ◽  
Prakash Deep Rai
Keyword(s):  
Seed Germination ◽  
Blue Light ◽  
White Light ◽  
Red Light ◽  
Light Condition ◽  
Dark Condition ◽  
Percentage Germination ◽  
Negative Effect

<p class="abstract"><strong>Background:</strong> Germination of <em>Desmodium triflorum</em> is used for the scarification using the acid is valuable for the different light condition.</p><p class="abstract"><strong>Methods:</strong> The sample was collected as four month of interval of time and the seed is treated with acids with different time.  </p><p class="abstract"><strong>Results:</strong> seeds scarified with sulfuric acids for 10 min before sowing had better germination than those scarified for 5 and 15 min. Among them light qualities, red and white light had slightly promoted effect whereas blue light and dark condition had slightly negative effect on seed germination.</p><p><strong>Conclusions:</strong> In comparison to blue light and dark condition, red light and white light were promoted to percentage germination indicating the role of phytochrome in seed germination of <em>Desmodium triflorum</em>. </p>

Phytochromes and seed germination

1998 ◽  
Vol 8 (3) ◽  
pp. 317-329 ◽  
Author(s):  
Jorge J. Casal ◽  
Rodolfo A. Sánchez
Keyword(s):  
Seed Germination ◽  
Red Light ◽  
High Irradiance ◽  
Phytochrome B ◽  
Phytochrome A ◽  
Germination Inhibition ◽  
Growth Capacity ◽  
Small Family ◽  
Recent Advances ◽  
Signalling Process

AbstractThe control of seed germination by red and far-red light is one of the earliest documented phytochrome-mediated processes Phytochrome is now known to be a small family of photoreceptors whose apoproteins are encoded by different genes Phytochrome B (phyB) is present in dry seeds and affects germination of dark imbibed seeds but other phytochromes could also be involved Phytochrome A (phyA) appears after several hours of imbibition and mediates very-low-fluence responses PhyB and other phytochromes different from phyA mediate the classical low-fluence responses The phytochrome involved in high-irradiance responses of seed germination (inhibition of germination under continuous far-red) has not been unequivocally established, although phyA is the most likely candidate Phytochrome can affect embryo growth capacity and/or the constraint imposed by the tissues surrounding the embryo At least in some species, gibberellins participate in the signalling process In the field, phyA has been implicated in the perception of light during soil cultivations, and phyB would be involved in the perception of red/far-red ratios associated with the presence of gaps in the canopy This review describes recent advances in phytochrome research, particularly those derived from the analysis of germination in specific mutants, and their connection with traditional observations on phytochrome control of seed germination

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