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.

scholarly journals Light Gradient-Based Screening of Arabidopsis thaliana on a 384-Well Type Plant Array Chip

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 191
Author(s):  
Youn-Hee Park ◽  
Je-Kyun Park
Keyword(s):  
Arabidopsis Thaliana ◽  
White Light ◽  
Solid Medium ◽  
Red Light ◽  
Phytochrome B ◽  
Wild Type ◽  
Light Gradient ◽  
Gradient Based ◽  
Light Effects ◽  
Germination And Growth

Arabidopsis thaliana (Arabidopsis), as a model for plant research, is widely used for various aspects of plant science. To provide a more sophisticated and microscopic environment for the germination and growth of Arabidopsis, we report a 384-well type plant array chip in which each Arabidopsis seed is independently seeded in a solid medium. The plant array chip is made of a poly(methyl methacrylate) (PMMA) acrylic material and is assembled with a home-made light gradient module to investigate the light effects that significantly affect the germination and growth of Arabidopsis. The light gradient module was used to observe the growth pattern of seedlings according to the intensity of the white light and to efficiently screen for the influence of the white light. To investigate the response to red light (600 nm), which stimulates seed germination, the light gradient module was also applied to the germination test. As a result, the germination results showed that the plant array chip can be used to simultaneously screen wild type seeds and phytochrome B mutant seeds on a single array chip according to the eight red light intensities.

Response of the photosynthetic apparatus to UV-A and red light in the phytochrome B-deficient Arabidopsis thaliana L. hy3 mutant

2016 ◽  
Vol 54 (3) ◽  
pp. 321-330 ◽  
Author(s):  
V. D. Kreslavski ◽  
F. J. Schmitt ◽  
C. Keuer ◽  
T. Friedrich ◽  
G. N. Shirshikova ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Red Light ◽  
Photosynthetic Apparatus ◽  
Phytochrome B

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 The J-domain protein Rme-8 interacts with Hsc70 to control clathrin-dependent endocytosis in Drosophila

2004 ◽  
Vol 164 (7) ◽  
pp. 1055-1064 ◽  
Author(s):  
Henry C. Chang ◽  
Michael Hull ◽  
Ira Mellman
Keyword(s):  
Caenorhabditis Elegans ◽  
Genetic Data ◽  
Dominant Negative ◽  
Pleiotropic Effects ◽  
Endocytic Pathway ◽  
Common Pathway ◽  
Strong Resemblance ◽  
J Domain ◽  
Domain Protein ◽  
J Protein

By screening for mutants exhibiting interactions with a dominant-negative dynamin, we have identified the Drosophila homologue of receptor-mediated endocytosis (Rme) 8, a J-domain–containing protein previously shown to be required for endocytosis in Caenorhabditis elegans. Analysis of Drosophila Rme-8 mutants showed that internalization of Bride of sevenless and the uptake of tracers were blocked. In addition, endosomal organization and the distribution of clathrin were greatly disrupted in Rme-8 cells, suggesting that Rme-8 participates in a clathrin-dependent process. The phenotypes of Rme-8 mutants bear a strong resemblance to those of Hsc70-4, suggesting that these two genes act in a common pathway. Indeed, biochemical and genetic data demonstrated that Rme-8 interacts specifically with Hsc70-4 via its J-domain. Thus, Rme-8 appears to function as an unexpected but critical cochaperone with Hsc70 in endocytosis. Because Hsc70 is known to act in clathrin uncoating along with auxilin, another J-protein, its interaction with Rme-8 indicates that Hsc70 can act with multiple cofactors, possibly explaining its pleiotropic effects on the endocytic pathway.

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>

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

scholarly journals Ecophysiology of seed germination in Mediterranean geophytes. 1. Muscari spp

2002 ◽  
Vol 12 (3) ◽  
pp. 193-201 ◽  
Author(s):  
Maria A. Doussi ◽  
Costas A. Thanos
Keyword(s):  
Seed Germination ◽  
White Light ◽  
Mediterranean Climate ◽  
Germination Rate ◽  
Red Light ◽  
Rainfall Regime ◽  
Light Conditions ◽  
Rainy Period ◽  
Germination Characteristics ◽  
The Mediterranean

Ecophysiological aspects of seed germination were investigated in four Mediterranean geophytes of the genus Muscari (Liliaceae): M. comosum (tassel hyacinth), M. neglectum (common grape hyacinth), M. commutatum and M. weissii. Experiments were performed at constant temperatures in the dark and under temperature and light conditions simulating those prevailing in nature during November–January, i.e. well into the rainy season of the Mediterranean climate. In all species, no primary dormancy was revealed, and germination occurred in a rather narrow range of cool temperatures (optimum at 10 or 15°C) and at a remarkably slow rate; both germination characteristics seem to be associated with autumn/winter seed germination and seedling establishment. Such a postulated strategy is ecologically advantageous within an unpredictable rainfall regime, known to prevail during the start of the rainy period of the Mediterranean climate. This strategy may also explain the spread of germination of M. comosum seeds over two consecutive years, observed by Theophrastus. Far-red light, simulating light conditions under a dense canopy, resulted in only a slight delay of germination compared to dark controls. Diurnal white light, qualitatively simulating natural daylight, caused a significant decrease of the germination rate in all four species studied. Moreover, white light was found to suppress considerably final seed germination (photoinhibition) in M. weissii and M. neglectum; in the latter species, prolonged imbibition under white light also led to the induction of secondary dormancy.

Seed stratification and germination strategy in the Mediterranean pines Pinus brutia and P. halepensis

1995 ◽  
Vol 5 (3) ◽  
pp. 151-160 ◽  
Author(s):  
Antonis Skordilis ◽  
Costas A. Thanos
Keyword(s):  
Seed Germination ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Red Light ◽  
Pinus Brutia ◽  
Temperature Range ◽  
Promotive Effect ◽  
Germination Behaviour ◽  
Mediterranean Pine ◽  
Of Greece

AbstractThe ecophysiology of germination in Pinus brutia and P. halepensis was studied in seeds collected from different areas of Greece. In regard to the temperature range of germination, both P. halepensis and the southern provenance (Lasithi, Crete) of the East Mediterranean pine, P. brutia, follow a typical Mediterranean pattern. In the latter species, dramatic differences in the degree of dormancy were noted among the three provenances investigated; in all seed lots however, 20°C was clearly the optimal temperature for germination. Stratification resulted in a considerable promotion of P. brutia seed germination. Nevertheless, the inductive effect of stratification was shown to differ among the three provenances used, escalating from a simple increase of germination rate (in the southern seed lot from Lasithi, Crete) through a broadening of the temperature range of germination (in the intermediate lot from Thasos Island) to, finally, a dramatic release from a particularly deep dormancy (in the northern lot from Soufli). These deeply dormant seeds of the latter provenance displayed an absolute stratification requirement; prolonged illumination or seed coat scarification could not substitute for the promotive effect of prechilling. A considerable interaction between far-red light and stratification was revealed in the dormant seeds of P. brutia (Soufli provenance); far-red pulses during stratification could either cancel or diminish the germination promotion induced by low temperatures. The differences observed in the germination behaviour among the various P. brutia provenances may be attributed to a variable ecophysiological strategy in regard to the temporal pattern of seedling emergence and establishment. According to the variants of this strategy, seed germination is timed to occur during either spring (in regions with relatively cold and moist climates), or autumn and early winter (in southern, mild and dry areas) or both (in intermediate conditions).

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