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1.
2.
Mirta Tkalec Tatjana Prebeg Vibor Roje Branka Pevalek-Kozlina Nikola Ljubešić 《Acta Physiologiae Plantarum》2008,30(6):881-890
Although duckweed Lemna minor L. is a known accumulator of cadmium, detailed studies on its physiological and/or defense responses to this metal are still
lacking. In this study, the effects of 10 μM CdCl2 on Lemna minor were monitored after 6 and 12 days of treatment, while growth was estimated every 2 days. Cadmium treatment resulted in progressive
accumulation of the metal in the plants and led to a decrease in the growth rate to 54% of the control value. The metal also
considerably impaired chloroplast ultrastructure and caused a significant reduction in pigment content, i.e., at day 12, by
30 and 34% for chlorophylls a and b, and by 25% for carotenoids. During cadmium treatment, the contents of malondialdehyde and endogenous H2O2 progressively increased (rising 77 and 46% above the controls by day 12), indicating that cadmium induced considerable oxidative
stress. On the other hand, higher activities of pyrogallol peroxidase (PPX), ascorbate peroxidase (APX) and catalase (CAT),
as well as the induction of a new APX isoform, in cadmium-treated plants, clearly showed activation of an antioxidative response.
At day 6, only PPX activity was significantly above the controls (15%), while, at day 12, PPX, APX and CAT activities were
increased (74, 78 and 63%). Cadmium also led to accumulation of the heat shock protein 70 (HSP70) and induced an additional
isoform of this protein. The obtained results suggest that cadmium (10 μM) is phytotoxic to Lemna minor, inducing oxidative stress, and that antioxidative enzymes and HSP70 play important roles in the defense against cadmium
toxicity.
M. Tkalec and T. Prebeg contributed equally to this work 相似文献
3.
Gui-Li Yang Yang Fang Ya-Liang Xu Li Tan Qi Li Yang Liu Fan Lai Yan-Ling Jin An-Ping Du Kai-Ze He Xin-Rong Ma Hai Zhao 《Plant molecular biology》2018,98(4-5):319-331
The Lemnaceae, known as duckweed, the smallest flowering aquatic plant, shows promise as a plant bioreactor. For applying this potential plant bioreactor, establishing a stable and efficient genetic transformation system is necessary. The currently favored callus-based method for duckweed transformation is time consuming and genotype limited, as it requires callus culture and regeneration, which is inapplicable to many elite duckweed strains suitable for bioreactor exploitation. In this study, we attempted to establish a simple frond transformation system mediated by Agrobacterium tumefaciens for Lemna minor, one of the most widespread duckweed species in the world. To evaluate the feasibility of the new transformation system, the gene CYP710A11 was overexpressed to improve the yield of stigmasterol, which has multiple medicinal purposes. Three L. minor strains, ZH0055, D0158 and M0165, were transformed by both a conventional callus transformation system (CTS) and the simple frond transformation system (FTS). GUS staining, PCR, quantitative PCR and stigmasterol content detection showed that FTS can produce stable transgenic lines as well as CTS. Moreover, compared to CTS, FTS can avoid the genotype constraints of callus induction, thus saving at least half of the required processing time (CTS took 8–9 months while FTS took approximately 3 months in this study). Therefore, this transformation system is feasible in producing stable transgenic lines for a wide range of L. minor genotypes. 相似文献
4.
Duckweeds, quick-growing aquatic plants, have been recently recognized as promising hosts for the large-scale production of recombinant proteins and as an ideal biomass feedstock for biofuel production. These possible wide-spread industrial uses of duckweeds intensified research aimed at understanding the mechanisms that control duckweed growth. Here, we describe how the hormone cytokinin affects growth. We performed a number of standard cytokinin growth- and physiological-response assays using sterile-grown colonies of Lemna gibba and Spirodela polyrhiza. Similar to land plants, cytokinin inhibited root elongation in duckweeds. Surprisingly, and in contrast to land plants, cytokinin promoted growth of aerial organs in both duckweed species, suggesting that the cytokinin growth response fundamentally differs between aquatic and land plants. 相似文献
5.
To narrow the differences between the results obtained from radionuclides and heavy metal ecotoxicity investigations in the laboratory and in the abandoned uranium mines, a few standardised plant bioassay procedures were selected from the literature for testing with Lemna gibba L. The bioassay procedures were tested in situ and ex situ. The laboratory culturing was performed in batch and semicontinuous modes. The results revealed that most of the standardised plant bioassay procedures require modification for the L. gibba bioassay to predict the actual effects under field conditions. L. gibba performed relatively better in the field than laboratory batch cultures despite that the batch cultures had many-fold higher nutrient concentrations than in the field. For instance, the phosphorus concentration of the mine tailing water was 0.13 ± 0.09 μg l−1 in the field, while the literature range for phosphorus in the laboratory culture media is 13.6–40 mg l−1. L. gibba growth in the laboratory batch culture was influenced by speciation changes due to consumption of nutrients, CO2 and O2 phase exchanges, and excretion of organic substances by the test plants. Semicontinuous culture modes performed significantly better than batch cultivation even after 10× dilution of the nutrient solution. The growth behaviour revealed that L. gibba exhibited intrapopulation and probiotic interaction for best performance. Growth performance of L. gibba was influenced by the anions that balanced essential cations despite equal cation concentration in the culture media; e.g., the best growth was observed in culture media that had more SO42− than Cl−. Water samples from the field had higher SO42− concentrations than Cl−. The test vessel material, sterilisation and axenic culturing procedures also influenced the sensitivity of the bioassay. These, for instance, and a few others are neither described nor reported in most standard Lemna tests or the literature. Thus, this work presents results of a series of tests conducted on the selected methods. Common and possible errors and corrective measures in assigning L. gibba bioassay from laboratory population levels to field community levels are discussed. 相似文献
6.
Photosynthetic parameters were measured in two invasive weeds, Mikania micrantha and Chromolaena odorata, grown in soil under full, medium, and low irradiance and full, medium, and low water supply. Both species showed significantly
higher net photosynthetic rate, quantum yield of PS 2 photochemistry and photochemical quenching coefficient under high than
low irradiance. For M. micrantha, low irradiance caused decreased chlorophyll content (Chl), Chl a/b ratio and maximum photochemical efficiency of PS 2 (Fv/Fm), while drought decreased Chl content and Fv/Fm and increased nonphotochemical quenching (NPQ). However, these parameters were much less affected in C. odorata except that Chl content and NPQ slightly increased under drought and high irradiance. High irradiance increased xanthophyll
pools in both species, especially M. micrantha under combination with drought. 相似文献
7.
Li J Jain M Vunsh R Vishnevetsky J Hanania U Flaishman M Perl A Edelman M 《Plant cell reports》2004,22(7):457-464
The development of tissue culture systems in duckweeds has, to date, been limited to species of the genus Lemna. We report here the establishment of an efficient tissue culture cycle (callus induction, callus growth and plant regeneration) for Spirodela oligorrhiza Hegelm SP, Spirodela punctata 8717 and Lemna gibba var. Hurfeish. Significant differences were found among the three duckweed species pertaining to carbohydrate and phytohormone requirements for callus induction, callus growth and frond regeneration. In vitro incubation with poorly assimilated carbohydrates such as galactose (S. oligorrhiza SP and L. gibba var. Hurfeish) and sorbitol (S. punctata 8717) as sole carbon source yielded high levels of callus induction on phytohormone-supplemented medium. Sorbitol is required for optimal callus growth of S. oligorrhiza SP and S. punctata 8717, while sucrose is required for callus growth of L. gibba var. Hurfeish. Sucrose either alone (S. oligorrhiza SP, L. gibba var. Hurfeish) or in addition to sorbitol (S. punctata 8717) is required for frond regeneration.Abbreviations
ABA:
(±)-Abscisic acid
-
BA:
N6-Benzyladenine
-
2,4-D
2,4-Dichlorophenoxyacetic acid
-
Dicamba:
3,6-Dichloro-2-methoxybenzoic acid
-
2iP:
N6-(2-Isopentenyl)adenine
-
NAA:
-Naphthaleneacetic acid
-
PCA:
p-Chlorophenoxy acetic acid
-
Picloram:
4-Amino-3,5,6-trichloropicolinic acid
-
TDZ:
Thidiazuron
Communicated by A. AltmanJ. Li and M. Jain contributed equally to the research reported in this article. 相似文献
8.
Impact of copper on reactive oxygen species,lipid peroxidation and antioxidants in <Emphasis Type="Italic">Lemna minor</Emphasis> 总被引:2,自引:2,他引:0
S. K. Panda 《Biologia Plantarum》2008,52(3):561-564
Lemna minor L. treated with 20, 50, or 100 μM CuSO4 accumulated Cu and reactive oxygen species (hydrogen peroxide and superoxide radical) in frond and root cells. The time-course
analysis of lipid peroxidation showed high increment in malondialdehyde production only after 12 and 48 h of Cu treatment.
Guaiacol peroxidase and superoxide dismutase activities decreased after 48 h while glutathione reductase activity enhanced
48 h after Cu-treatment. Ascorbate and glutathione contents increased with the increasing Cu stress. 相似文献
9.
Chlorophyll (Chl) fluorescence of warm day/cool night temperature exposed Phalaenopsis plants was measured hourly during 48 h to study the simultaneous temperature and irradiance response of the photosynthetic
physiology. The daily pattern of fluorescence kinetics showed abrupt changes of photochemical quenching (qP), non-photochemical quenching (NPQ) and quantum yield of photosystem II electron transport (ΦPSII) upon transition from day to night and vice versa. During the day, the course of ΦPSII and NPQ was related to the air temperature pattern, while maximum quantum efficiency of PSII photochemistry (Fv/Fm) revealed a rather light dependent response. Information on these daily dynamics in fluorescence kinetics is important with
respect to meaningful data collection and interpretation. 相似文献
10.
Calycanthus chinensis is an endangered plant of the national second-grade protection of China restricted in a small area in Zhejiang Province.
We studied parameters of photosynthesis, chlorophyll (Chl) contents, and Chl fluorescence (minimum fluorescence, F0, maximum fluorescence, Fm, variable fluorescence, Fv, and Fv/Fm) of C. chinensis and Chimonanthus praecox. C. chinensis had lower compensation irradiance but higher saturation irradiance than C. praecox. Hence C. chinensis has more advantage in obtaining and utilizing photon energy and higher Chl content, and is more adaptive to higher temperature
and propitious to thermal dissipation than C. praecox. In addition, C. chinensis produces abundant, well-preserved seed with a higher germination rate and a wider adaptability to temperature than C. praecox. Thus C. chinensis is prone to survival and viability, and gets rid of the endangered plant species of the national second-grade protection
of China. 相似文献
11.
Chloroplast rpS16 gene intron sequences were determined and characterized for twenty-five Lemnaceae accessions representing nine duckweed species. For each Lemnaceae species nucleotide substitutions and for Lemna minor, Lemna aequinoctialis, Wolffia arrhiza different indels were detected. Most of indels were found for Wolffia arrhiza and Lemna aequinoctialis. The analyses of intraspecific polymorphism resulted in identification of several gaplotypes in Lemna gibba and Lemna trisulca. Lemnaceae phylogenetic relationship based on rpS16 intron variability data has revealed significant differences between Lemna aequinoctialis and other Lemna species. Genetic distance values corroborated competence of Landoltia punctata separations from Spirodela into an independent generic taxon. The acceptability of rpS16 intron sequences for phylogenetic studies in Lemnaceae was shown. 相似文献
12.
Yuri T. Yamamoto Nirmala Rajbhandari Xiaohong Lin Ben A. Bergmann Yufuko Nishimura Anne-Marie Stomp 《In vitro cellular & developmental biology. Plant》2001,37(3):349-353
Summary We developed efficient genetic transformation protocols for two species of duckweed, Lemna gibba (G3) and Lemna minor (8627 and 8744), using Agrobacterium-mediated gene transfer. Partially differentiated nodules were co-cultivated with Agrobacterium tumefaciens harboring a binary vector containing β-glucuronidase and nptII expression cassettes. Transformed cells were selected and allowed to grow into nodules in the presence of kanamycin. Transgenic
duckweed fronds were regenerated from selected nodules. We demonstrated that transgenic duckweed could be regenerated within
3 mo. after Agrobacterium-mediated transformation of nodules. Furthermore, we developed a method for transforming L. minor 8627 in 6 wk. These transformation protocols will facilitate genetic engineering of duckweed, ideal plants for bioremediation
and large-scale industrial production of biomass and recombinant proteins. 相似文献
13.
Kuppusamy Sathishkumar Kadarkarai Murugan Giovanni Benelli Akon Higuchi Aruliah Rajasekar 《Annals of microbiology》2017,67(1):91-98
Bioreduction of the very toxic hexavalent chromium ion [Cr(VI)] to the non-toxic trivalent chromium ion [Cr(III)] is a key remediation process in chromium-contaminated sites. In this study, we investigated the bioreduction of Cr(VI) by Pseudomonas stutzeri L1 and Acinetobacter baumannii L2. The optimum pH (5–10), temperature (27, 37 and 60 °C) and initial chromium Cr(VI) concentration (100–1000 mg L?1) for Cr(VI) reduction by strains L1 and L2 were determined using the diphenylcarbazide method. In the presence of L1 and L2, the bioreduction rate of Cr(VI) was 40–97 and 84–99%, respectively. The bioreduction of Cr(VI) by L2 was higher, reaching up to 84%—than that by L1. The results showed that strain L2 was able to survive even if exposed to 1000 mg L?1 of Cr(VI) and that this tolerance to the effects of Cr(VI) was linked to the activity of soluble enzyme fractions. Overall, A. baumannii L2 would appear to be a potent Cr(VI)-tolerant candidate for the bioremediation of chromium (VI)-contaminated wastewater effluent. 相似文献
14.
The effects of shade on the growth, leaf photosynthetic characteristics, and chlorophyll (Chl) fluorescence parameters of
Lycoris radiata var. radiata were determined under differing irradiances (15, 65, and 100% of full irradiance) within pots. The HI plants exhibited a
typical decline in net photosynthetic rate (P
N) during midday, which was not observed in MI- and LI plants. This indicated a possible photoinhibition in HI plants as the
ratio of variable to maximum fluorescence (Fv/Fm) value was higher and the minimal fluorescence (F0) was lower in the, and LI plants. Diurnal patterns of stomatal conductance (g
s) and transpiration rate (E) were remarkably similar to those of P
N at each shade treatments, and the intercellular CO2 concentration (C
i) had the opposite change trend. Under both shading conditions, the light saturation point, light compensation point and photon-saturated
photosynthetic rate (P
max) became lower than those under full sunlight, and it was the opposite for the apparent quantum yield (AQY). The higher the
level of shade, the lower the integrated daytime carbon gain, stomatal and epidermis cell densities, specific leaf mass (SLM),
bulb mass ratio (BMR), leaf thickness, and Chl a/b ratio. In contrast, contents of Chls per dry mass (DM), leaf area ratio (LAR), leaf mass ratio (LMR), leaf length, leaf area
and total leaf area per plant increased under the same shade levels to promote photon absorption and to compensate for the
lower radiant energy. Therefore, when the integrated daytime carbon gain, leaf area and total leaf area per plant, which are
the main factors determining the productivity of L. radiata var. radiata plant, were taken into account together, this species may be cultivated at about 60∼70% of ambient irradiance to promote
its growth. 相似文献
15.
In tobacco leaves inoculated with tobacco mosaic virus (TMV), changes in chlorophyll (Chl) and carotenoid contents, parameters
of slow Chl fluorescence kinetics, i.e. the maximum quantum yield of photosystem (PS2) photochemistry Fv/Fm, the effective quantum yield of photochemical energy conversion in PS2 Φ2, ratio of quantum yields of photochemical and concurrent non-photochemical processes in PS2 Fv/F0, non-photochemical quenching (NPQ), and photochemical activities of isolated chloroplasts from systemically infected tobacco
leaves were investigated. We compared two successive stages of infection, the first in the stage of vein clearing at 9th day post inoculation (dpi) and the second at 22nd dpi when two different regions, i.e. light- (LGI) or dark-green (DGI) islands in the infected leaf were apparent and symptoms were fully developed. These two
different regions were measured separately. The Chl and carotenoid contents in infected leaves decreased with a progression
of infection and were lowest in LGI in the second stage. Also the ratio of Chl a/b declined in similar manner. The maximum quantum yield of PS2 photochemistry Fv/Fm, was decreased in the following order: first stage, DGI, and LGI. The same is true for the ratio Fv/F0. The decrease of Φ2 in infected leaves declined as compared to their controls. On the contrary, NPQ increased in infected leaves, the highest
value was found in the first infection stage. Photochemical activities of the whole electron transport chain in isolated chloroplasts
dramatically declined with the progression of symptoms, the lowest value was in LGI. Similarly, but to a lesser extent, the
activity of PS2 in isolated chloroplasts decreased in infected leaves. Generally, the most marked impairment of the photosynthetic
apparatus was manifested in the LGI of infected leaves. 相似文献
16.
The effects of different spectral region of excitation and detection of chlorophyll (Chl) a fluorescence at room temperature on the estimation of excitation energy utilization within photosystem (PS) 2 were studied
in wild-type barley (Hordeum vulgare L. cv. Bonus) and its Chl b-less mutant chlorina f2 grown under low and high irradiances [100 and 1 000 μmol(photon) m−2 s−1]. Three measuring spectral regimes were applied using a PAM 101 fluorometer: (1) excitation in the red region (maximum at the wavelength of 649 nm) and detection in the far-red region beyond 710 nm, (2) excitation in the blue region (maximum at the wavelength of 461 nm) and detection beyond 710 nm, and (3) excitation in the blue region and detection in the red region (660– 710 nm). Non-photochemical quenching of maximal (NPQ)
and minimal fluorescence (SV0), determined by detecting Chl a fluorescence beyond 710 nm, were significantly higher for blue excitation as compared to red excitation. We suggest that
this results from higher non-radiative dissipation of absorbed excitation energy within light-harvesting complexes of PS2
(LHC2) due to preferential excitation of LHC2 by blue radiation and from the lower contribution of PS1 emission to the detected
fluorescence in the case of blue excitation. Detection of Chl a fluorescence originating preferentially from PS2 (i.e. in the range of 660–710 nm) led to pronounced increase of NPQ, SV0, and the PS2 photochemical efficiencies (FV/FM and FV′/FM′), indicating considerable underestimation of these parameters using the standard set-up of PAM 101. Hence PS1 contribution to the minimal fluorescence level in the irradiance-adapted state may reach up to about 80 %. 相似文献
17.
Composition of microelements and photosynthetic pigment content (chlorophylls (Chl) a and b) were monitored in growing needles of spruce (Picea abies (L.) Karst.) and Siberian fir (Abies sibirica Ledeb.) during spring-autumn vegetation period. The dynamics of fresh weight and needle length for the first-year needles
of spruce and fir revealed a number of shared and species-specific features in growth patterns of photosynthetic organs. In
the beginning of growth period (in May), the needles elongated rapidly, while June–July were marked by the increase in needle
weight. In P. abies the needle weight accumulated rapidly (specific growth rates μmax up to 0.20 day−1) over a short period (14 days), while in A. sibirica the needle weight increased slower (μmax ≤ 0.11 day−1) but over a longer period (≥30 days). The dynamics of Chl a and Chl b content and their ratio were identical in needles of both species over the growth period, although changes in Chl a were pronounced stronger than those in Chl b. In spring (May), a relatively high total Chl content per needle dry weight was noted. In summer (June–August), the total
Chl content declined appreciably. In autumn (September–November), the total chlorophyll content in first-year needles increased
slightly. Microelements were classified into two groups according to seasonal dynamics of their relative content in first-year
needles. The first group includes Ba, Mn, Zn, B, Cu, Co, Cr, Pb, and Mo, whose relative content had a distinctive maximum
in July, coincident with the peak in Chl content. The second group comprises Ni, V, Ag, Be, Cd, and As, whose relative content
was minimal at this period. Seasonal changes in microelement composition were similar for the two conifer species examined,
which is likely due to different physiological values of various microelements for photosynthetic organs. 相似文献
18.
J. D. García-García J. S. Rodríguez-Zavala R. Jasso-Chávez D. Mendoza-Cozatl Rafael Moreno-Sánchez 《Archives of microbiology》2009,191(5):431-440
Photosynthetic Euglena gracilis grown with different K2CrO4 concentrations was analyzed for its ability to take up, retain and reduce Cr(VI). For comparison, cells were also exposed
to CrCl3. Cellular Cr(VI) uptake at pH 7.2 showed a hyperbolic saturation pattern with K
m of 1.1 mM, V
m of 16 nmol (h × 107 cells)−1, and K
i sulfate of 0.4 mM. Kinetic parameters for sulfate uptake were similar, K
m = 0.83 mM, V
m = 15.9 nmol (h × 107cells)−1 and K
i chromate = 0.3 mM. The capacity to accumulate chromium depended on the ionic species, external concentration and pH of the incubation
medium. Cr(VI) or Cr(III) accumulation was negligible in the acidic (pH 3.5) culture medium, in which Cr(VI) was abiotically
reduced to Cr(III). At pH 7.2 Cr(VI) was fully stable and high accumulation (>170 nmol/1 × 107 cells at 1 mM K2CrO4) was achieved; surprisingly, Cr(III) accumulation was also significant (>35 nmol/1 × 107 cells at 1 mM CrCl3). Cr(VI) was reduced by cells at pH 7.2, suggesting the presence of an external reductive activity. Cr(VI) induced an increased
cysteine and glutathione content, but not in phytochelatins suggesting that chromium accumulation was mediated by monothiol
compounds. 相似文献
19.
Jagesh K. Tiwari Poonam D. Sarkar SK. Pandey Jai Gopal S. Raj Kumar 《Plant Cell, Tissue and Organ Culture》2010,103(2):175-187
Interspecific potato somatic hybrids between Solanum tuberosum L. (di)haploid C-13 and 1 endosperm balance number non-tuberous wild species S. etuberosum Lindl. were produced by protoplasts electrofusion. The objective was to transfer virus resistance from this wild species
into the cultivated potatoes. Post-fusion products were cultured in VKM medium followed by regeneration of calli in MS13 K medium at 20°C under a 16-h photoperiod, and regenerants were multiplied on MS medium. Twenty-one somatic hybrids were
confirmed by RAPD, SSR and cytoplasm (chloroplast/mitochondria) type analysis possessing species-specific diagnostic bands
of corresponding parents. Tetraploid nature of these somatic hybrids was determined through flow cytometry analysis. Somatic
hybrids showed intermediate phenotypes (plant, leaves and floral morphology) to their parents in glass-house grown plants.
All the somatic hybrids were male-fertile. ELISA assay of somatic hybrids after artificial inoculation of Potato virus Y (PVY)
infection reveals high PVY resistance. 相似文献
20.
Temperature response curves of chlorophyll a fluorescence parameters were used to assess minimum sub-zero temperature assuring functioning of photosynthetic photochemical
processes in photosystem II (PS II) of Antarctic lichens. Umbilicaria Antarctica and Xanthoria elegans were measured within the temperature range from −20 to +10°C by a fluorometric imaging system. For potential (F
V/F
M) and actual (Φ
II) quantum yields of photochemical processes the minimum temperature was found to be between −10 and −20°C. Non-photochemical
quenching (NPQ) of absorbed excitation energy increased with temperature drop reaching maximum NPQ at −15°C. Image analysis
revealed intrathalline heterogeneity of chlorophyll a fluorescence parameters with temperature drop. Temperature response of Φ
II exhibited an S-curve with pronounced intrathalline differences in X. elegans. The same relation was linear with only limited intrathalline difference in U. antarctica. The results showed that Antarctic lichen species were well adapted to sub-zero temperatures and capable of performing primary
photosynthesis at −15°C. 相似文献