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1.
BMC Plant Biol ; 21(1): 387, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34416853

RESUMO

BACKGROUND: The plant body in duckweed species has undergone reduction and simplification from the ancient Spirodela species towards more derived Wolffia species. Among the five duckweed genera, Wolffia members are rootless and represent the smallest and most reduced species. A better understanding of Wolffia frond architecture is necessary to fully explore duckweed evolution. RESULTS: We conducted a comprehensive study of the morphology and anatomy of Wolffia globosa, the only Wolffia species in China. We first used X-ray microtomography imaging to reveal the three-dimensional and internal structure of the W. globosa frond. This showed that new fronds rapidly budded from the hollow reproductive pocket of the mother fronds and that several generations at various developmental stages could coexist in a single W. globosa frond. Using light microscopy, we observed that the meristem area of the W. globosa frond was located at the base of the reproductive pocket and composed of undifferentiated cells that continued to produce new buds. A single epidermal layer surrounded the W. globosa frond, and the mesophyll cells varied from small and dense palisade-like parenchyma cells to large, vacuolated cells from the ventral to the dorsal part. Furthermore, W. globosa fronds contained all the same organelles as other angiosperms; the most prominent organelles were chloroplasts with abundant starch grains. CONCLUSIONS: Our study revealed that the reproductive strategy of W. globosa plants enables the rapid accumulation of biomass and the wide distribution of this species in various habitats. The reduced body plan and size of Wolffia are consistent with our observation that relatively few cell types are present in these plants. We also propose that W. globosa plants are not only suitable for the study of structural reduction in higher plants, but also an ideal system to explore fundamental developmental processes of higher plants that cannot be addressed using other model plants.


Assuntos
Lilianae/anatomia & histologia , Lilianae/crescimento & desenvolvimento , Lilianae/genética , Folhas de Planta/anatomia & histologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/genética , Evolução Biológica , China , Lilianae/ultraestrutura , Folhas de Planta/ultraestrutura
2.
Int J Biol Macromol ; 188: 595-608, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34389388

RESUMO

Phosphate transporters (PHTs) mediate the uptake and translocation of phosphate in plants. A comprehensive analysis of the PHT family in aquatic plant is still lacking. In this study, we identified 73 PHT members of six major PHT families from four duckweed species. The phylogenetic analysis, gene structure and protein characteristics analysis revealed that PHT genes are highly conserved among duckweeds. Interaction network and miRNA target prediction showed that SpPHTs could interact with the important components of the nitrate/phosphate signaling pathway, and spo-miR399 might be a central regulator that mediates phosphate signal network in giant duckweed (Spirodela polyrhiza). The modeled 3D structure of SpPHT proteins shared a high level of homology with template structures, which provide information to understand their functions at proteomic level. The expression profiles derived from transcriptome data and quantitative real-time PCR revealed that SpPHT genes are respond to exogenous stimuli and remarkably induced by phosphate starvation, phosphate is absorbed from aquatic environment by the whole duckweed plant. This study lays the foundation for further functional studies on PHT genes for genetic improvement and the promotion of phosphate uptake efficiency in duckweeds.

3.
Int J Mol Sci ; 22(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203933

RESUMO

Natural resistance-associated macrophage proteins (Nramps) are specific metal transporters in plants with different functions among various species. The evolutionary and functional information of the Nramp gene family in Spirodela polyrhiza has not been previously reported in detail. To identify the Nramp genes in S. polyrhiza, we performed genome-wide identification, characterization, classification, and cis-elements analysis among 22 species with 138 amino acid sequences. We also conducted chromosomal localization and analyzed the synteny relationship, promoter, subcellular localization, and expression patterns in S. polyrhiza. ß-Glucuronidase staining indicated that SpNramp1 and SpNramp3 mainly accumulated in the root and joint between mother and daughter frond. Moreover, SpNramp1 was also widely displayed in the frond. SpNramp2 was intensively distributed in the root and frond. Quantitative real-time PCR results proved that the SpNramp gene expression level was influenced by Cd stress, especially in response to Fe or Mn deficiency. The study provides detailed information on the SpNramp gene family and their distribution and expression, laying a beneficial foundation for functional research.


Assuntos
Araceae/genética , Cádmio/toxicidade , Proteínas de Transporte de Cátions/genética , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Família Multigênica , Proteínas de Plantas/genética , Estresse Fisiológico/genética , Motivos de Aminoácidos , Sequência de Aminoácidos , Araceae/efeitos dos fármacos , Proteínas de Transporte de Cátions/química , Proteínas de Transporte de Cátions/metabolismo , Cromossomos de Plantas/genética , Sequência Conservada , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas/genética , Estresse Fisiológico/efeitos dos fármacos , Sintenia/genética
4.
Genomics ; 113(4): 1761-1777, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33862182

RESUMO

WRKY is one of the largest transcription factor families across higher plant species and is involved in important biological processes and plant responses to various biotic/abiotic stresses. However, only a few investigations on WRKYs have been conducted in aquatic plants. This study first systematically analyzed the gene structure, protein properties, and phylogenetic relationship of 693 WRKYs in nine aquatic and two wetland plants at the genome-wide level. The pattern of WRKY groups in two aquatic ferns provided new evidence for the origin and evolution of WRKY genes. ARE cis-regulatory elements show an unusual high frequency in the promoter region of WRKY genes, indicating the adaptation to the aquatic habitat in aquatic plants. The WRKY gene family experienced a series of gene loss events in aquatic plants, especially group III. Further studies were conducted on the interaction network of SpWRKYs, their target genes, and non-coding RNAs. The expression profile of SpWRKYs under phosphate starvation, cold, and submergence conditions revealed that most SpWRKYs are involved in the response to abiotic stresses. Our investigations lay the foundation for further study on the mechanism of WRKYs responding to abiotic stresses in aquatic plants.

5.
Int J Mol Sci ; 22(2)2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-33466729

RESUMO

Plants adapt to environmental changes by regulating their development and growth. As an important interface between plants and their environment, leaf morphogenesis varies between species, populations, or even shows plasticity within individuals. Leaf growth is dependent on many environmental factors, such as light, temperature, and submergence. Phytohormones play key functions in leaf development and can act as molecular regulatory elements in response to environmental signals. In this review, we discuss the current knowledge on the effects of different environmental factors and phytohormone pathways on morphological plasticity and intend to summarize the advances in leaf development. In addition, we detail the molecular mechanisms of heterophylly, the representative of leaf plasticity, providing novel insights into phytohormones and the environmental adaptation in plants.


Assuntos
Aclimatação , Reguladores de Crescimento de Plantas/metabolismo , Fenômenos Fisiológicos Vegetais , Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Desenvolvimento Vegetal , Reguladores de Crescimento de Plantas/genética , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Plantas/anatomia & histologia , Plantas/genética
6.
Front Immunol ; 11: 1857, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32973766

RESUMO

Vibriosis is a commonly found bacterial disease identified among fish and shellfish cultured in saline waters. A multitude of Vibrio species have been identified as the causative agents. LamB, a member of outer membrane protein (OMPs) family of these bacteria is conserved among all Vibrio species and has been identified as an efficient vaccine candidate against vibriosis. Rootless duckweed (Wolffia) is a tiny, edible aquatic plant possessing characteristics suitable for the utilization as a bioreactor. Thus, we attempted to express a protective edible vaccine antigen against fish vibriosis in nuclear-transformed Wolffia. We amplified LamB gene from virulent Vibrio alginolyticus and it was modified to maximize the protein expression level and translocate the protein to the endoplasmic reticulum (ER) in plants. It was cloned into binary vector pMYC under the control of CaMV 35S promoter and introduced into Wolffia globosa by Agrobacterium-mediated transformation. Integration and expression of the LamB gene was confirmed by genomic PCR and RT-PCR. Western blot analysis revealed accumulation of the LamB protein in 8 transgenic lines. The cross-protective property of transgenic Wolffia was evaluated by orally vaccinating zebrafish through feeding fresh transgenic Wolffia and subsequently challenging with virulent V. alginolyticus. High relative percent survival (RPS) of the vaccinated fish (63.3%) confirmed that fish immunized with transgenic Wolffia were well-protected from Vibrio infection. These findings suggest that Wolffia expressed LamB could serve as an edible plant-based candidate vaccine model for fish vibriosis and feasibility of utilizing Wolffia as bioreactor to produce edible vaccines.


Assuntos
Antígenos de Bactérias/imunologia , Araceae/imunologia , Vacinas Bacterianas/imunologia , Doenças dos Peixes/prevenção & controle , Vibrioses/veterinária , Animais , Antígenos de Bactérias/administração & dosagem , Proteínas da Membrana Bacteriana Externa/administração & dosagem , Proteínas da Membrana Bacteriana Externa/imunologia , Vacinas Bacterianas/administração & dosagem , Plantas Geneticamente Modificadas , Vibrioses/prevenção & controle , Peixe-Zebra
7.
Bioresour Technol ; 317: 124029, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32916457

RESUMO

Duckweed is a potential biomass source for alternative energy production. This work reports the effects of trophic modes on growth rates, biomass accumulation, and removal rates of pollutant by duckweed. Glucose, fructose, galactose, sucrose, and maltose all supported heterotrophic and mixotrophic growth of duckweed. The mixotrophic growth rate was 4.98 and 6.22 times higher than those in heterotrophic and photoautotrophic conditions, respectively. Notably, mixotrophy produced more biomass than the simple sum of the biomass accumulation during heterotrophy and photoautotrophy. Mixotrophy was also superior in starch and protein production, as well as in removal rates of nutrients and organic carbon from the growth medium. However, the starch content of duckweed grown heterotrophically was 2.06 times higher than in mixotrophy, suggesting a combination of mixotrophy and heterotrophy as an effective strategy for starch-rich biomass production. This study thus provides a paradigm for future studies supporting duckweed-based biomass production and organic wastewater treatment.


Assuntos
Araceae , Poluentes Ambientais , Biomassa , Carbono , Processos Heterotróficos
8.
Opt Express ; 28(6): 8843-8852, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32225502

RESUMO

We demonstrate a novel Er:LuSGG active gain medium emitting laser wavelength at 2795 nm for the first time. The Er:LuSGG crystal is grown successfully by the Czochralski method with high crystalline and optical quality. The spectra properties, including absorption and fluorescence emission cross-section are presented in contrast with similar Er-doped garnet crystals. The fluorescence lifetimes of the upper (4I11/2) and lower (4I13/2) laser levels are 1.75 and 4.64 ms, respectively. Under 973 nm laser diode pumping, a maximum output power of 789 mW in continuous-wave mode, corresponding to optical-to-optical efficiency of 20.2% and slope efficiency of 24.4%, is achieved with high laser beam quality. The results show that the Er:LuSGG is a promising MIR laser material operated at 2.8 µm.

9.
Plant Cell Rep ; 39(6): 737-750, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32146519

RESUMO

KEY MESSAGE: This is the first report of a highly efficient Agrobacterium tumefaciens-mediated transformation protocol for Acanthaceae and its utilization in revealing important roles of cytokinin in regulating heterophylly in Hygrophila difformis. Plants show amazing morphological differences in leaf form in response to changes in the surrounding environment, which is a phenomenon called heterophylly. Previous studies have shown that the aquatic plant Hygrophila difformis (Acanthaceae) is an ideal model for heterophylly study. However, low efficiency and poor reproducibility of genetic transformation restricted H. difformis as a model plant. In this study, we reported successful induction of callus, shoots and the establishment of an efficient stable transformation protocol as mediated by Agrobacterium tumefaciens LBA4404. We found that the highest callus induction efficiency was achieved with 1 mg/L 1-Naphthaleneacetic acid (NAA) and 2 mg/L 6-benzyladenine (6-BA), that efficient shoot induction required 0.1 mg/L NAA and 0.1 mg/L 6-BA and that high transformation efficiency required 100 µM acetosyringone. Due to the importance of phytohormones in the regulation of heterophylly and the inadequate knowledge about the function of cytokinin (CK) in this process, we analyzed the function of CK in the regulation of heterophylly by exogenous CK application and endogenous CK detection. By using our newly developed transformation system to detect CK signals, contents and distribution in H. difformis, we revealed an important role of CK in environmental mediated heterophylly.


Assuntos
Acanthaceae/genética , Agrobacterium tumefaciens/genética , Citocininas/isolamento & purificação , Transformação Genética , Acanthaceae/metabolismo , Calo Ósseo/efeitos dos fármacos , Calo Ósseo/crescimento & desenvolvimento , Proliferação de Células , Ácidos Naftalenoacéticos/farmacologia , Fenótipo , Reguladores de Crescimento de Plantas/farmacologia , Folhas de Planta , Brotos de Planta , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento
10.
Opt Express ; 26(22): 28421-28428, 2018 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-30470018

RESUMO

We demonstrate a laser diode (LD) end-pumped Er:YAP laser with dual-wavelength outputs of 2710 and 2728 nm. The maximum average powers of 739 and 738 mW are achieved in the continuous wave (CW) and pulse modes, which corresponds to optical-to-optical efficiencies of 10.1% and 12.3%, and the slope efficiencies of 12.1% and 13.8%, respectively. In addition, a comparison of laser performance on differently sized crystals indicates that the 1 × 1 × 5 mm3 Er:YAP crystal has a best cooling efficiency. This helps to decrease the thermal lensing effect, which contributes to improving laser efficiency and beam quality.

11.
Opt Lett ; 43(17): 4312-4315, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30160715

RESUMO

We demonstrate a 966 nm laser diode (LD) side-pumped Er,Pr:GYSGG laser crystal operated at 2.79 µm under a high repetition rate. The lifetimes of the upper level I11/24 and lower level I13/24 are 0.66 and 0.85 ms, respectively. The laser performance under different repetition rates and pulse widths is experimentally studied with the optimal cavity structure. A maximum output power of 8.86 W is achieved at 125 Hz and 200 µs pulse widths, corresponding to the slope efficiency of 14.8% and electrical-to-optical efficiency of 7.7%. With increasing frequency from 50 to 200 Hz, the slope efficiency varies from 24.7% to 11.7% operated at a 125 µs pulse width. Moreover, the Mx2/My2 factors of 7.52/7.59 and Θx/Θy far-field divergences of 16.1/16.5 mrad are also measured. The results indicate that a high-performance 2.79 µm laser could be realized on the Er,Pr:GYSGG radiation resistant crystal by deactivation and LD side-pumping.

12.
Opt Express ; 25(18): 21349-21357, 2017 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-29041434

RESUMO

We demonstrate the thermal analysis and laser performance of a GYSGG/Cr,Er,Pr:GYSGG composite crystal. The lifetime ratio of lower and upper levels of Er3+ in Cr,Er,Pr:GYSGG crystal is further reduced due to the optimized doping concentrations. The thermal effect of composite crystal is lower than that of Cr,Er,Pr:GYSGG crystal. A maximum pulse energy 342.8 mJ operated at 5 Hz and 2.79 µm is obtained on the composite crystal, corresponding to electrical-to-optical efficiency of 0.86% and slope efficiency of 1.08%. Under the same condition, these values on the Cr,Er,Pr:GYSGG crystal are only 315.8 mJ, 0.79% and 1.04%, respectively. Moreover, the composite crystal has also a relative high laser beam quality, exhibiting obvious advantage in reducing thermal effects and improving laser performances.

13.
Opt Lett ; 40(18): 4194-7, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26371894

RESUMO

We demonstrate the growth, spectroscopy, and laser performance of a 2.79 µm Cr,Er,Pr:GYSGG radiation-resistant crystal. The lifetimes for the upper laser level (4)I(11/2) and lower laser level (4)I(13/2) are 0.59 and 0.84 ms, respectively, which are due to the doping of the Pr(3+) ions. A maximum pulse energy of 278 mJ operated at 10 Hz and 2.79 µm is obtained when pumped with a flash lamp, which corresponds to the electrical-to-optical efficiency of 0.6% and a slope efficiency of 0.7%. A maximum average power of 2.9 W at 60 Hz is achieved, which corresponds to the electrical-to-optical efficiency of 0.4% and slope efficiency of 0.8%. Compared with a Cr,Er:YSGG crystal, the Cr,Er,Pr:GYSGG crystal can be operated at a higher pulse repetition rate. These results suggest that doping deactivator Pr(3+) ions can effectively decrease the lower laser level lifetime and improve the laser repetition rate. Therefore, the application fields and range of the Cr,Er,Pr:GYSGG laser can be extended greatly due to its properties of radiation resistance and high repetition frequency.


Assuntos
Lasers de Estado Sólido , Análise Espectral , Absorção de Radiação
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