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1.
Using gene targeting by homologous recombination in Ceratodon purpureus, we were able to knock out four phytochrome photoreceptor genes independently and to analyze their function with respect
to red light dependent phototropism, polarotropism, and chlorophyll content. The strongest phenotype was found in knock-out
lines of a newly described phytochrome gene termed CpPHY4 lacking photo- and polarotropic responses at moderate fluence rates. Eliminating the atypical phytochrome gene CpPHY1, which is the only known phytochrome-like gene containing a putative C-terminal tyrosine kinase-like domain, affects red
light-induced chlorophyll accumulation. This result was surprising, since no light dependent function was ever allocated to
this unusual gene.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Accession number for CpPHY4: EU122393. 相似文献
2.
A virus collection was used to identify a pathogen suitable for laboratory use with the model legume Lotus japonicus. Several Lotus species or L. japonicus accessions were tested and various degrees of susceptibility to the Arabis mosaic virus derived from barley (ArMV-ba) were found. Virus multiplication and persistence in Lotus tissue were examined, as well as plant responses to it. Sensitivity to the virus among the accessions and species is discussed
in light of their geographical origin.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
3.
Eric D. Brenner Philip Feinberg Suzan Runko Gloria M. Coruzzi 《Plant molecular biology》2009,70(5):523-533
BMAA is a cycad-derived glutamate receptor agonist that causes a two- to three-fold increase in hypocotyl elongation on Arabidopsis seedlings grown in the light. To probe the role of plant glutamate receptors and their downstream mediators, we utilized
a previously described genetic screen to identify a novel, BMAA insensitive morphology (bim) mutant, bim409. The normal BMAA-induced hypocotyl elongation response observed on wild-type seedlings grown in the light is impaired in
the bim409 mutant. This BMAA-induced phenotype is light-specific, as the bim409 mutant exhibits normal hypocotyl elongation in etiolated (dark grown) plants (+ or − BMAA). The mutation in bim409 was identified to be in a gene encoding the Proteosomal
Regulatory Particle AAA-ATPase-3 (RPT3). Possible roles of the proteosome in Glu-mediated signaling in plants is discussed.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
4.
Chloroplast photorelocation movement in green plants is generally mediated by blue light. However, in cryptogam plants, including
ferns, mosses, and algae, both red light and blue light are effective. Although the photoreceptors required for this phenomenon
have been identified, the mechanisms underlying this movement response are not yet known. In order to analyze this response
in more detail, chloroplast movement was induced in dark-adapted Adiantum
capillus-veneris gametophyte cells by partial cell irradiation with a microbeam of red and/or blue light. In each case, chloroplasts were
found to move toward the microbeam-irradiated area. A second microbeam was also applied to the cell at a separate location
before the chloroplasts had reached the destination of the first microbeam. Under these conditions, chloroplasts were found
to change their direction of movement without turning and move toward the second microbeam-irradiated area after a lag time
of a few minutes. These findings indicate that chloroplasts can move in any direction and do not exhibit a polarity for chloroplast
accumulation movement. This phenomenon was analyzed in detail in Adiantum and subsequently confirmed in Arabidopsis
thaliana palisade cells. Interestingly, the lag time for direction change toward the second microbeam in Adiantum was longer in the red light than in the blue light. However, the reason for this discrepancy is not yet understood.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
5.
In background white light, supplementary far-red (max 700 nm) is an order of magnitude less effective than supplementary far-red (max 739 nm) in the stimulation of stem extension in Sinapis alba. The relationship between phytochrome photoequilibrium and extension rate increase for the two supplementary far-red treatments is, however, very similar. This evidence indicates that phytochrome cycling is not involved in the phytochrome control of stem extension in light-grown Sinapis alba and that the response to supplementary far-red light is not fluence rate (irradiance) dependent.Abbreviations Pfr
far-red absorbing form of phytochrome
-
the phytochrome photoequilibrium (Pfr/Ptotal) 相似文献
6.
7.
类胡萝卜素裂解双加氧酶(carotenoid cleavage dioxygenase, CCD)家族成员能催化类胡萝卜素裂解生成挥发性芳香物质并参与植物激素的合成。为探究茶树CsCCD基因家族成员生物学功能及基因表达模式,采用生物信息学手段进行了茶树全基因组CsCCD基因家族成员的鉴定,预测分析了其基因结构、保守基序、染色体定位、蛋白的理化性质、进化特性、互作网络、启动子顺式作用元件,并通过RT-qPCR测定了茶树不同叶位、乌龙茶加工过程中光照处理下CsCCD的相对表达量。共鉴定出11个茶树CsCCD基因家族成员,含有1–11个外显子、0–10个内含子不等;平均氨基酸个数为519 aa,平均分子质量为57 643.35 Da;聚类分析显示,CCD1、CCD4、CCD7、CCD8和NCED5个亚族各自聚成一类。茶树CsCCD基因家族主要含有胁迫响应元件、激素响应元件、光响应元件与多因素响应元件,且以光响应元件最多(142个)。进一步对茶树CsCCD基因在茶树不同叶位及乌龙茶加工过程中LED补光晾青过程的表达模式分析发现,CsCCD1、CsCCD4在成熟叶中表达量高于嫩叶及嫩茎,且随做青... 相似文献
8.
Zane Duxbury Martin Schliep Raymond J. Ritchie Anthony W. D. Larkum Min Chen 《Photosynthesis research》2009,101(1):69-75
Chromatic photoacclimation and photosynthesis were examined in two strains of Acaryochloris marina (MBIC11017 and CCMEE5410) and in Synechococcus PCC7942. Acaryochloris contains Chl d, which has an absorption peak at ca 710 nm in vivo. Cultures were grown in one of the three wavelengths (525 nm, 625 nm and
720 nm) of light from narrow-band photodiodes to determine the effects on pigment composition, growth rate and photosynthesis:
no growth occurred in 525 nm light. Synechococcus did not grow in 720 nm light because Chl a does not absorb effectively at this long wavelength. Acaryochloris did grow in 720 nm light, although strain MBIC11017 showed a decrease in phycobilins over time. Both Synechococcus and Acaryochloris MBIC11017 showed a dramatic increase in phycobilin content when grown in 625 nm light. Acaryochloris CCMEE5410, which lacks phycobilins, would not grow satisfactorily under 625 nm light. The cells adjusted their pigment composition
in response to the light spectral conditions under which they were grown. Photoacclimation and the Q
y peak of Chl d could be understood in terms of the ecological niche of Acaryochloris, i.e. habitats enriched in near infrared radiation.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
9.
Using a physicochemical method, the distribution of endogenous indole-3-acetic acid (IAA) was measured in the peripheral and central cell layers, as well as in the illuminated and shaded sides of phototropically stimulated radish hypocotyls (Raphanus sativus var. hortensis f. gigantissimus Makino). The IAA was evenly distributed over the illuminated and shaded sides in the first and second positive phototropic curvatures induced by a pulse or a continuous unilateral illumination with blue light. Also, no net exchange of the IAA between the peripheral and central cell layers was observed during these curvatures. These results suggest that phototropism of radish hypocotyls cannot be described by the Cholodny-Went theory. 相似文献
10.
Treatment of the whole of aSinapis alba plant with supplementary far-red light (FR), in back-ground white light (WL), induces a rapid increase in stem extension rate. This rapid increase is regulated by the light environment of the stem itself. Supplementary FR to the stem increases extension rate after a lag period of 10–15 min. A lag period of 3–4 h follows FR irradiation of the leaf, before an increase in extension rate is detectable. When the stem is given supplementary FR, the change in extension rate which is induced increases with increasing FR fluence rate, and with decreasing phytochrome photoequilibrium. There is no difference between the effects of supplementary FR max 719 nm and supplementary FR max 739 nm for these relationships. The increase in extension rate induced by supplementary FR is reversed by an increase in the fluence rate of red light (R). These data indicate that the response is controlled by phytochrome photoequilibrium.Abbreviations B
blue light
- FR
far-red light
- R
red light
- WL
white light
- Pfr
far-red absorbing form of phytochrome
- Pr
red absorbing form of phytochrome
- Ptot
total phytochrome level (=Pr+Pfr); -Pfr/Ptot, measured
- ER
difference in stem extension rate, before and after treatment 相似文献
11.
Annotated maps of the IGH, IGK, and IGL loci in the gray, short-tailed opossum Monodelphis domestica were generated from analyses of the available whole genome sequence for this species. Analyses of their content and organization
confirmed a number of previous conclusions based on characterization of complementary DNAs encoding opossum immunoglobulin
heavy and light chains and limited genomic analysis, including (a) the predominance of a single immunoglobulin heavy chain
variable region (IGHV) subgroup and clan, (b) the presence of a single immunoglobulin (Ig)G subclass, (c) the apparent absence
of an IgD, and (d) the general organization and V gene complexity of the IGK and IGL light chain loci. In addition, several unexpected discoveries were made including the presence of a partial V to D, germline-joined
IGHV segment, the first germline-joined Ig V gene to be found in a mammal. In addition was the presence of a larger number
of IGKV subgroups than had been previously identified. With this report, annotated maps of the major histocompatibility complex,
T-cell receptor, and immunoglobulin loci have been completed for M. domestica, the only non-eutherian mammalian species for which this has been accomplished, strengthening the utility of this species
as a model organism.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
12.
Hawaiian lobeliads have radiated into habitats from open alpine bogs to densely shaded rainforest interiors, and show corresponding
adaptations in steady-state photosynthetic light responses and associated leaf traits. Shaded environments are not uniformly
dark, however, but punctuated by sunflecks that carry most of the photosynthetically active light that strikes plants. We
asked whether lobeliads have diversified in their dynamic photosynthetic light responses and how dynamic responses influence
daily leaf carbon gain. We quantified gas exchange and dynamic light regimes under field conditions for ten species representing
each major Hawaiian sublineage. Species in shadier habitats experienced shorter and less numerous sunflecks: average sunfleck
length varied from 1.4 ± 1.7 min for Cyanea floribunda in shaded forest understories to 31.2 ± 2.1 min for Trematolobelia kauaiensis on open ridges. As expected, the rate of photosynthetic induction increased significantly toward shadier sites, with assimilation
after 60 s rising from ca. 30% of fully induced rates in species from open environments to 60% in those from densely shaded
habitats. Uninduced light use efficiency—actual photosynthesis versus that expected under steady-state conditions—increased
from 10 to 70% across the same gradient. In silico transplants—modeling daily carbon gain using one species’ photosynthetic
light response in its own and other species’ dynamic light regimes—demonstrated the potential adaptive nature of species differences:
understory Cyanea pilosa in its light regimes outperformed gap-dwelling Clermontia parviflora, while Clermontia in its light regimes outperformed Cyanea. The apparent crossover in daily photosynthesis occurred at about the same photon flux density where dominance shifts from
Cyanea to Clermontia in the field. Our results further support our hypothesis that the lobeliads have diversified physiologically across light
environments in Hawaiian ecosystems and that those shifts appear to maximize the carbon gain of each species in its own environment.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
13.
Primula nutans Georgi is widely distributed in hummock-and-hollow wetlands on the Qinghai-Tibetan Plateau. To assess the ecophysiology of
this species in responding to microenvironments, we examined the photosynthetic characteristics and individual carbon gain
of plants growing in different microsites from a hummock-and-hollow wetland on the Qinghai-Tibetan Plateau and under laboratory
conditions. Plants from wetland hummock microsites showed significantly higher light-saturated photosynthetic CO2 uptake (A
max) than those from microsites in hollows at a controlled temperature of 15°C in leaf chamber. Leaf dark respiration rate (R) was only significantly higher in plants from hummocks than hollows at the measuring temperature of 35°C. Optimum temperature
for A
max was 15°C for all plants in the field despite different microsites. In plants growing under laboratory conditions differing
in light and temperature, both A
max and R were significantly higher under higher growth light (photosynthetic photon flux density, PPFD: 800 or 400 μmol m−2 s−1) than low light of 90 μmol m−2 s−1. No statistically significant differences in A
max and R existed in plants differing in growing temperatures. Estimates derived from the photosynthetic parameters of field plants,
and microsite environmental measures including PPFD, air temperature and soil temperature showed that the optimum mean daily
temperature for net daily carbon gain was around 10°C and the net daily carbon gain was largely limited under lower daily
total PPFD. These results suggest that the differences in A
max and R in P. nutans are strongly affected by growing light regimes but not by temperature regimes.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
14.
Diurnal regulation of scent emission in rose flowers 总被引:3,自引:0,他引:3
Previous studies have shown diurnal oscillation of scent emission in rose flowers with a peak during the day (Helsper in Planta
207:88–95, 1998; Picone in Planta 219:468–478, 2004). Here, we studied the regulation of scent production and emission in
Rosa hybrida cv. Fragrant Cloud during the daily cycle and focused on two terpenoid compounds, germacrene D and geranyl acetate, whose
biosynthetic genes have been characterized by us previously. The emission of geranyl acetate oscillated during the daily light/dark
cycle with a peak early in the light period. A similar daily fluctuation was found in the endogenous level of this compound
and in the expression of its biosynthetic gene, alcohol acetyl transferase (RhAAT). The rhythmic expression of RhAAT continued under conditions of constant light or darkness, indicating regulation by the endogenous circadian clock. However,
the accumulation and emission of geranyl acetate ceased under continuous light. Our results suggest that geranyl acetate production
is limited by the level of its substrate geraniol, which is suppressed under constant light conditions. The emission of germacrene
D also oscillated during the daily cycle with a peak early in the light period. However, the endogenous level of this compound
and the expression of its biosynthetic gene germacrene D synthase (RhGDS) were constant throughout the day. The diurnal oscillation of germacrene D emission ceased under continuous light, suggesting
direct regulation by light. Our results demonstrate the complexity of the diurnal regulation of scent emission: although the
daily emission of most scent compounds is synchronized, various independently evolved mechanisms control the production, accumulation
and release of different volatiles.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
15.
We studied the short-term impact of sediment load on the photosynthetic performance of Saccharina latissima sporophytes exposed to ultraviolet radiation (UVR). The algae were collected from different sediment-influenced environments
in Svalbard in August 2007. Initial optimum quantum yield (F
v/F
m) of sediment-covered sporophytes was significantly higher compared to sediment-free sporophytes. Experimental sediment coating
on blade discs had a photoprotective function by screening out 92% of the weighted UV-B (UVery) treatment. No UVR-induced photoinhibition was observed in sediment-coated blade discs while sediment removal caused a reduction
in F
v/F
m not only after 12-h UVR exposure but also after 6-h recovery in low white light compared to the initial value. Thus, sediment
coating has a short-term functional significance in mitigating the negative effect of UVR on photosynthesis of an important
kelp species and set a baseline for further studies.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
16.
Archaea have recombination proteins similar to those of eukaryote, but many have not been characterized. Here, the characterization
of a Rad55 homologue from Sulfolobus tokodaii (stRad55A) was reported. StRad55A protein preferred binding to ssDNA and had ssDNA-dependent ATPase activity. In addition,
UV light could induce the expression of this protein, which was different from RadB, a RadA paralog found in euryarchaeota.
Most importantly, stRad55A could release the suppression of excessive stSSB (single strand DNA binding protein from S. tokodaii) on the strand exchange catalyzed by stRadA (RadA homologue from S. tokodaii), by interacting directly with both stRadA and stSSB. StRad55A may function as a mediator to accelerate the displacement
of stSSB by stRadA.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
17.
Bo Joakim Eriksson Noel N. Tait Graham E. Budd Michael Akam 《Development genes and evolution》2009,219(5):249-264
As the putative sister group to the arthropods, onychophorans can provide insight into ancestral developmental mechanisms
in the panarthropod clade. Here, we examine the expression during segmentation of orthologues of wingless (Wnt1) and engrailed, two genes that play a key role in defining segment boundaries in Drosophila and that appear to play a role in segmentation in many other arthropods. Both are expressed in segmentally reiterated stripes
in all forming segments except the first (brain) segment, which only shows an engrailed stripe. Engrailed is expressed before segments are morphologically visible and is expressed in both mesoderm and ectoderm. Segmental wingless expression is not detectable until after mesodermal somites are clearly distinct. Early engrailed expression lies in and extends to both sides of the furrow that first demarcates segments in the ectoderm, but is largely
restricted to the posterior part of somites. Wingless expression lies immediately anterior to engrailed expression, as it does in many arthropods, but there is no precise cellular boundary between the two expression domains analogous
to the overt parasegment boundary seen in Drosophila. Engrailed stripes extend along the posterior part of each limb bud, including the antenna, while wingless is restricted to the distal tip of the limbs and the neurectoderm basal to the limbs.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
18.
The red alga Acrosymphyton purpuriferum (J. Ag.) Sjöst. (Dumontiaceae) is a short day plant in the formation of its tetrasporangia. Tetrasporogenesis was not inhibited by 1 h night-breaks when given at any time during the long (16 h) dark period (tested at 2 h intervals). However, tetrasporogenesis was inhibited when short (8 h) main photoperiods were extended beyond the critical daylength with supplementary light periods (8 h) at an irradiance below photosynthetic compensation. The threshold irradiance for inhibition of tetrasporogenesis was far lower when supplementary light periods preceded the main photoperiod than when they followed it (<0.05 μmol·m−2·s−1 vs. 3 μmol·m−2·s−1). The threshold level also depended on the irradiance given during the main photoperiod and was higher after a main photoperiod in bright light than after one in dim light (threshold at 3 μmol·m−2·s−1 after a main photoperiod at ca. 65 μmol·m−2·s−1 vs. threshold at <0.5 μmol·m−2·s−1 after a main photoperiod at ca. 35 μmol·m−2·s−1). The spectral dependence of the response was investigated in day-extensions (supplementary light period (8 h) after main photoperiod (8 h) at 48 μmol·m−2·s−1) with narrow band coloured light. Blue light (λ= 420 nm) was most effective, with 50% inhibition at a quantum-dose of 2.3 mmol·m−2. However, yellow (λ= 563 nm) and red light (λ= 600 nm; λ= 670 nm) also caused some inhibition, with ca. 30% of the effectiveness of blue light. Only far-red light (λ= 710 nm; λ= 730 nm) was relatively ineffective with no significant inhibition of tetrasporogenesis at quantum-doses of up to 20 mmol·m−2. 相似文献
19.
The reproductive characteristics and pollination system of Rhododendron semibarbatum were investigated at two sites in Honshu, Japan. This species is protandrous, partially self-incompatible at postzygotic
stages, and requires outcrossing via pollinator visitation for effective seed production. The effective pollinators were two
bumblebee species: males of Bombus ardens at Miyama, and workers of Bombus honshuensis at Agematsu. The flowers possess two staminodes ornamented with whitish hairs, which do not reflect UV light, on the filaments.
Nectar was secreted continuously during the flowering period, and nectar production rate differed between the sites. Visitation
by B. ardens males was more frequent and varied among and within days, whereas that by B. honshuensis workers was less frequent and constant throughout the observation period. A single visit by a B. ardens male was more effective for seed production than visitation by a B. honshuensis worker, resulting in pollen limitation in the latter case. Differences in resource requirements between the two pollinators,
representing different castes, might affect their behavior, resulting in B. ardens males contributing to more effective seed production.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
20.
Recently we reported that Catalase-1 (CAT-1) played an important role in protecting conidial viability in Neurospora crassa, and interacted with a light signal transducer, nucleoside diphosphate kinase-1 (NDK-1). To disclose the functional interaction
between CAT-1 and NDK-1 at the genetic level, we created CAT-1 and NDK-1 double mutants, cat-1;ndk-1-1 and cat-1;ndk-1-2, by crossing single mutants of cat-1
RIP
and ndk-1
P72H
previously isolated in our laboratory. The double mutant strains grew normally, but showed increased CAT-2 activity. In cat-1
RIP
, NDK activity was increased when dCDP was used as a substrate. ndk-1
P72H
, cat-1;ndk-1-1, and cat-1;ndk-1-2 were more sensitive to riboflavin than the wild type and cat-1
RIP
under strong light (100 μE m−2 s−1). The pull-down experiment suggests that His-tagged NDK-1 is bound to [32P]NADH. However, his-tagged NDK-1P72H was not bound to [32P]NADH. The double mutants showed much lower conidial viability and lost all conidial germination ability much more rapidly
than cat-1
RIP
, when they were cultured under continuous light for more than 2 weeks. These results indicate that the interaction of CAT-1
with NDK-1 plays an important role in supporting the survival of conidia under oxidative and light-induced stress including
singlet oxygen, and confirm our former conclusion that reactive oxygen species play an important role in light signal transduction
via NDK-1 at the genetic level.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献