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1.
Heliyon ; 7(1): e06082, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33553752

RESUMO

Brasenia schreberi J. F. Gmel, a perennial floating-leaved macrophyte with high economic value as an aquatic vegetable, has been listed as first-class endangered species in China, mainly due to its habitat loss. Protected cultivation is a potential strategy to meet the demand of both plant conservation and vegetable market, whereas pre-experiments are still needed before series of parameters can be properly set for the large-scale growth of the plants indoor. Light quality is one of the major factors controlling the development of plants and consequently becomes an important factor when planting B. schreberi indoor. This experiment used three artificial light sources to investigate the response of B. schreberi seedlings to different light qualities, including the red-blue LED light (red: blue = 5:1, RB-LED), the white LED light (W-LED) and the white fluorescent (W-Fluo). Our results indicated that the responses of B. schreberi towards varied light qualities differed from those of most terrestrial plants. The total leaf number of the RB-LED treatment was the highest; the number of the submerged leaf and the rolled leaf of the RB-LED treatment was higher than that of the other two treatments, but the number of floating leaves was the lowest. Both the specific leaf weight and the pigment contents per unit leaf area were the lowest in the RB-LED treatment. Quantum yield of PSⅡ (Φ PSⅡ), electron transport rate (ETR) and photochemical quenching (qP) measured through light induction curves followed the sequence from high to low as W-Fluo > W-LED > RB-LED, whereas the trend of non-photochemical quenching (NPQ) reversed. The maximum potential ETR (P s) and maximum ETR (ETRm) derived from ETR curves further verified the trends.

2.
J Exp Bot ; 71(19): 5865-5879, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-32649744

RESUMO

Asparagine-linked glycosylation (N-glycosylation) is one of the most important protein modifications in eukaryotes, affecting the folding, transport, and function of a wide range of proteins. However, little is known about the roles of N-glycosylation in the development of stomata in plants. In the present study, we provide evidence that the Arabidopsis stt3a-2 mutant, defective in oligosaccharyltransferase catalytic subunit STT3, has a greater transpirational water loss and weaker drought avoidance, accompanied by aberrant stomatal distribution. Through physiological, biochemical, and genetic analyses, we found that the abnormal stomatal density of stt3a-2 was partially attributed to low endogenous abscisic acid (ABA) and auxin (IAA) content. Exogenous application of ABA or IAA could partially rescue the mutant's salt-sensitive and abnormal stomatal phenotype. Further analyses revealed that the decrease of IAA or ABA in stt3a-2 seedlings was associated with the underglycosylation of ß-glucosidase (AtBG1), catalysing the conversion of conjugated ABA/IAA to active hormone. Our results provide strong evidence that N-glycosylation is involved in stomatal development and participates in abiotic stress tolerance by modulating the release of active plant hormones.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ácido Abscísico , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Secas , Regulação da Expressão Gênica de Plantas , Glicosilação , Ácidos Indolacéticos , Estômatos de Plantas/metabolismo , Estresse Fisiológico
3.
Plant Cell ; 31(12): 2996-3014, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31604812

RESUMO

The conversion of etioplasts into chloroplasts in germinating cotyledons is a crucial transition for higher plants, enabling photoautotrophic growth upon illumination. Tight coordination of chlorophyll biosynthesis and photosynthetic complex assembly is critical for this process. ORANGE (OR), a DnaJ-like zinc finger domain-containing protein, was reported to trigger the biogenesis of carotenoid-accumulating plastids by promoting carotenoid biosynthesis and sequestration. Both nuclear and plastidic localizations of OR have been observed. Here, we show that Arabidopsis (Arabidopsis thaliana) OR physically interacts with the transcription factor TCP14 in the nucleus and represses its transactivation activity. Through this interaction, the nucleus-localized OR negatively regulates expression of EARLY LIGHT-INDUCIBLE PROTEINS (ELIPs), reduces chlorophyll biosynthesis, and delays development of thylakoid membranes in the plastids of germinating cotyledons. Nuclear abundance of OR decreased upon illumination. Together with an accumulation of TCP14 in the nucleus, this derepresses chloroplast biogenesis during de-etiolation. TCP14 is epistatic to OR and expression of ELIPs is directly regulated by the binding of TCP14 to Up1 elements in the ELIP promoter regions. Our results demonstrate that the interaction between OR and TCP14 in the nucleus leads to repression of chloroplast biogenesis in etiolated seedlings and provide new insights into the regulation of early chloroplast development.plantcell;31/12/2996/FX1F1fx1.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Clorofila/biossíntese , Cloroplastos/metabolismo , Cotilédone/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/efeitos da radiação , Núcleo Celular/metabolismo , Núcleo Celular/efeitos da radiação , Cotilédone/genética , Estiolamento , Regulação da Expressão Gênica de Plantas/genética , Germinação , Proteínas de Choque Térmico HSP40/genética , Proteínas de Choque Térmico HSP40/efeitos da radiação , Iluminação , Plastídeos/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Plântula/metabolismo , Tilacoides/metabolismo , Fatores de Transcrição/genética , Regulação para Cima
4.
J Agric Food Chem ; 67(15): 4300-4310, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30908022

RESUMO

Carotenoids are essential phytonutrients for the human body. Higher plants usually synthesize and accumulate carotenoids in their leaves, flowers, and fruits. Most carotenoids have either two ß-rings on both ends or ß- and ε-rings separately on two ends of their molecules and are synthesized from the acyclic lycopene as the precursor. Lycopene ß- and ε-cyclases (LCYB and LCYE, respectively) catalyze the ß- and ε-cyclization of lycopene, respectively, and regulate the metabolic flux from lycopene to its downstream ß,ß-branches (by LCYB alone) and ß,ε-branches (by LCYE and LCYB). In this study, we identified and characterized genes for two LCYBs (CaLCYB1 and CaLCYB2), one LCYE (CaLCYE1), and a capsanthin/capsorubin synthase (CaCCS1) which is also able to ß-cyclize lycopene from the red pepper ( Capsicum annuum var. conoides) genome. By quantifying transcript abundances of these genes and contents of different carotenoid components in ripening fruits, we observed a correlation between the induction of both CaLCYBs and the accumulation of carotenoids of the ß,ß-branch during ripening. Although capsanthin was accumulated in ripened fruits, our quantification demonstrated a strong induction of CaCCS1 at the breaker stage, together with the simultaneous repression of CaLCYE1 and the decrease of lutein content, suggesting the involvement of CaCCS1 in competing against CaLCYE1 for synthesizing carotenoids of the ß,ß-branch. Our results provide important information for future metabolic engineering studies to manipulate carotenoid biosynthesis and accumulation in fruits.


Assuntos
Capsicum/metabolismo , Carotenoides/metabolismo , Licopeno/química , Licopeno/metabolismo , Capsicum/genética , Capsicum/crescimento & desenvolvimento , Ciclização , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Liases Intramoleculares/genética , Liases Intramoleculares/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
5.
Sci Rep ; 8(1): 17955, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30560901

RESUMO

Brasenia schreberi J. F. Gmel. (Cabombaceae), a perennial freshwater macrophyte characterized by a thick mucilage on all underwater organs and especially young buds, has been widely cultivated as an aquatic vegetable in China for many years but is now listed as an endangered species due to anthropogenic impacts and habitat loss. Recent studies have demonstrated that different B. schreberi populations in China have low levels of genetic diversity but significantly different mucilage contents (MucC). Considering the importance of mucilage on both economic and ecological aspects, we examined mucilage-environment relationships in three B. schreberi cultivation sites. The results indicated that water permanganate index (CODMn), total N (TNw), electrical conductivity (ECw), dissolved oxygen (DOw), sediment organic carbon (SOC) and total N (TNs) were significant factors, which explained 82.2% of the variation in mucilage accumulation. The MucC and mucilage thickness (MucT) as well as single bud weight (SBW) of B. schreberi showed negative relationships with CODMn, TNw and ECw but positive relationships with SOC and TNs. Besides, high temperature may have a negative impact on mucilage accumulation of the species. Our study demonstrated that the mucilage accumulation of B. schreberi required good water quality and nutrient-enriched sediments, suggesting that habitat conservation, especially the quality of water, is important for maintaining B. schreberi populations.


Assuntos
Espécies em Perigo de Extinção , Meio Ambiente , Mucilagem Vegetal/biossíntese , Estreptófitas/fisiologia , Análise de Variância , China , Desenvolvimento Vegetal , Estações do Ano , Temperatura , Água
6.
Front Plant Sci ; 8: 2140, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29312395

RESUMO

Chlorophylls and carotenoids not only function in photosynthesis and photoprotection but are also involved in the assembly of thylakoid membranes and the stabilization of apoproteins in photosystems. In this study, we identified a nuclear gene required for chlorophyll and carotenoid metabolism, namely, DWARF AND YELLOW 1 (DY1). Growth of the loss-of-function dy1 mutant was severely retarded, and the seedlings of this mutant accumulated significantly less amounts of both chlorophylls and carotenoids in cotyledons and rosette leaves, although genes related to pigment metabolism did not show corresponding fluctuation at the transcriptional level. In chloroplasts of the dy1 leaves, thylakoids were loosely packed into grana. The dy1 mutant also possessed severely impaired photosynthetic and photoprotective abilities. DY1 encodes a chloroplast stroma protein that is highly conserved in vascular plants. Our results demonstrated that after the full-length DY1 (53 kDa) was imported into the chloroplast and its N-terminal transit peptide was processed, the C-terminal end of this premature DY1 (42 kDa) was also removed during the maturation of rosette leaves, resulting in a 24-kDa mature peptide. Our blue native PAGE and Western blot analyses showed the presence of both premature and mature forms of DY1 in protein complexes. The involvement of DY1 in chloroplast development is discussed.

7.
Front Plant Sci ; 7: 360, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27047527

RESUMO

The biosynthesis of chlorophylls and carotenoids and the assembly of thylakoid membranes are critical for the photoautotrophic growth of plants. Different factors are involved in these two processes. In recent years, members of the DnaJ-like zinc finger domain proteins have been found to take part in the biogenesis and/or the maintenance of plastids. One member of this family of proteins, PSA2, was recently found to localize to the thylakoid lumen and regulate the accumulation of photosystem I. In this study, we report that the silencing of PSA2 in Arabidopsis thaliana resulted in variegated leaves and retarded growth. Although both chlorophylls and total carotenoids decreased in the psa2 mutant, violaxanthin, and zeaxanthin accumulated in the mutant seedlings grown under growth condition. Lower levels of non-photochemical quenching and electron transport rate were also found in the psa2 mutant seedlings under growth condition compared with those of the wild-type plants, indicating an impaired capability to acclimate to normal light irradiance when PSA2 was silenced. Moreover, we also observed an abnormal assembly of grana thylakoids and poorly developed stroma thylakoids in psa2 chloroplasts. Taken together, our results demonstrate that PSA2 is a member of the DnaJ-like zinc finger domain protein family that affects light acclimation and chloroplast development.

8.
Bot Stud ; 56(1): 31, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28510840

RESUMO

BACKGROUND: Asparagine (N)-linked glycosylation is one of the most crucial post-translational modifications, which is catalyzed in the lumen of the endoplasmic reticulum (ER) by the oligosaccharyltransferase (OST) in eukaryotic cells. Biochemical and genetic assay leads to the identification of the nine subunits (Ost 1-6, Stt3, Swp1 and Wbp1) of the yeast OST and in which Stt3p is proposed playing a central and conserved role in N-glycosylation. Two STT3 isoform genes, STT3A and STT3B, exist in the plant and mammal genomes. OST with different catalytic STT3 isoforms has different enzymatic properties in mammals. The mutation of STT3A in Arabidopsis thaliana causes a salt hypersensitive phenotype the inhibited root growth and swollen root tips suggesting protein N-glycosylation is indispensable for plant growth and development. Spartina alterniflora is widely used for shoreline protection and tidal marsh restoration due to the strong salt tolerance although the exact molecular mechanism is little known. To explore the possible biological roles of N-glycosylation in plant adaptive resistance to salinity stress, we cloned the STT3 genes from S. alterniflora and heterogenously expressed them in Arabidopsis mutant to observe the functional conservation. RESULTS: SaSTT3A and SaSTT3B genes were cloned from Spartina alterniflora. SaSTT3A genomic sequences spanned over 23 exons and 22 introns, while SaSTT3B had 6 exons and 5 introns. The gene structures of both genes were conserved among the analyzed plant species. Subcellular localization and transmembrane structure prediction revealed that these two genes had 13 and 11 transmembrane helices respectively. The functional complementation in which the cDNA of SaSTT3A and SaSTT3B driven by CaMV 35S promoter completely or partially rescued Arabidopsis stt3a-2 mutant salt-sensitive phenotype, indicating STT3A functions conservatively between glycophyte and halophyte and N-glycosylation might be involved in plant resistance to salinity. CONCLUSIONS: Two STT3 isoform genes, SaSTT3A and SaSTT3B, were cloned from S. alterniflora and they were evolutionally conserved at gene structure and coding sequences compared with their counterparts. Moreover, SaSTT3 genes could successfully rescue Arabidopsis stt3a-2 salt-sensitive phenotype, suggesting there exists a similar N-glycosylation process in S. alterniflora. Here we provided a first piece of evidence that the N-glycosylation might be involved in salt tolerance of halophyte.

9.
Anal Biochem ; 440(2): 130-6, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23747531

RESUMO

Isopentenyl diphosphate (IDP) and its isomer dimethylallyl diphosphate (DMADP) are building units for all isoprenoids; thus, intracellular pool sizes of IDP and DMADP play important roles in living organisms. Several methods have been used to quantify the amount of DMADP or the combined amount of IDP plus DMADP, but measuring the DMADP/IDP ratio has been difficult. In this study, a method was developed to measure the ratio of DMADP/IDP. Catalyzed by a recombinant IDP isomerase (IDI) together with a recombinant isoprene synthase (IspS), IDP was converted to isoprene, which was then detected by chemiluminescence. With this method, the in vitro equilibrium ratio of DMADP/IDP was found to be 2.11:1. IDP and DMADP pools were significantly increased in Escherichia coli transformed with methylerythritol 4-phosphate pathway genes; the ratio of DMADP/IDP was 3.85. An E. coli strain transformed with IspS but no additional IDI had a lower DMADP level and a DMADP/IDP ratio of 1.05. Approximately 90% of the IDP and DMADP pools in light-adapted kudzu leaves were light dependent and so presumably were located in the chloroplasts; the DMADP/IDP ratios in chloroplasts and cytosol were the same as the in vitro ratio (2.04 in the light and 2.32 in the dark).


Assuntos
Alquil e Aril Transferases/metabolismo , Isomerases de Ligação Dupla Carbono-Carbono/metabolismo , Hemiterpenos/metabolismo , Compostos Organofosforados/metabolismo , Proteínas Recombinantes/metabolismo , Alquil e Aril Transferases/genética , Isomerases de Ligação Dupla Carbono-Carbono/genética , Escherichia coli/genética , Folhas de Planta/enzimologia , Pueraria/enzimologia , Proteínas Recombinantes/genética , Transformação Genética
10.
Bioorg Med Chem ; 18(1): 314-9, 2010 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-19914835

RESUMO

Two series of thiazolidinone derivatives designing for potential EGFR and HER-2 kinase inhibitors have been discovered. Some of them exhibited significant EGFR and HER-2 inhibitory activity. Compound 2-(2-(5-bromo-2-hydroxybenzylidene)hydrazinyl)thiazol-4(5H)-one (12) displayed the most potent inhibitory activity (IC(50)=0.09 microM for EGFR and IC(50)=0.42 microM for HER-2), comparable to the positive control erlotinib. Docking simulation was performed to position compound 12 into the EGFR active site to determine the probable binding model. Antiproliferative assay results indicating that some of the thiazolidinone derivatives own high antiproliferative activity against MCF-7. Compound 12 with potent inhibitory activity in tumor growth inhibition would be a potential anticancer agent.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Receptores ErbB/antagonistas & inibidores , Receptor ErbB-2/antagonistas & inibidores , Tiazolidinas/química , Tiazolidinas/farmacologia , Antineoplásicos/síntese química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Receptores ErbB/química , Receptores ErbB/metabolismo , Humanos , Modelos Moleculares , Neoplasias/tratamento farmacológico , Ligação Proteica , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Receptor ErbB-2/metabolismo , Relação Estrutura-Atividade , Tiazolidinas/síntese química
11.
Bioorg Med Chem ; 18(1): 305-13, 2010 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-19914837

RESUMO

Two series of novel N-benzyl-N-(X-2-hydroxybenzyl)-N'-phenylureas and thioureas (1a-18a; 1b-18b) as potential EGFR and HER-2 kinase inhibitors have been discovered. These compounds displayed good EGFR and HER-2 inhibitory activity and the SARs are also been studied. Especially compound 7b demonstrated significant EGFR and HER-2 inhibitory activity (IC(50)=0.08 microM for EGFR and IC(50)=0.35 microM for HER-2). Docking simulation was performed to position compound 7b into the EGFR active site to determine the probable binding conformation and antiproliferative assay results indicating that these series of urea and thioureas own high antiproliferative activity against MCF-7. Above all, thiourea 7b would be a potential anticancer agent deserves further research.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Compostos de Fenilureia/química , Compostos de Fenilureia/farmacologia , Tioureia/química , Tioureia/farmacologia , Antineoplásicos/síntese química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/química , Receptores ErbB/metabolismo , Humanos , Modelos Moleculares , Neoplasias/tratamento farmacológico , Compostos de Fenilureia/síntese química , Ligação Proteica , Conformação Proteica , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/metabolismo , Relação Estrutura-Atividade , Tioureia/síntese química
12.
Bioorg Med Chem ; 18(2): 880-6, 2010 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-20005116

RESUMO

A series of amide-coupled benzoic nitrogen mustard derivatives as potential EGFR and HER-2 kinase inhibitors were synthesized and reported for the first time. Some of them exhibited significant EGFR and HER-2 inhibitory activity. Of all the studied compounds, compounds 5b and 5t exhibited the most potent inhibitory activity, which was comparable to the positive control erlotinib. Docking simulation was performed to position compounds 5b and 5t into the EGFR active site to determine the probable binding model. Antiproliferative assay results indicated that some of the benzoic nitrogen mustard derivatives possessed high antiproliferative activity against MCF-7. In particular, compounds 5b and 5t with potent inhibitory activity in tumor growth inhibition may function as potential antitumor agents.


Assuntos
Amidas/farmacologia , Antineoplásicos/farmacologia , Compostos de Mostarda Nitrogenada/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Amidas/síntese química , Amidas/química , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Receptores ErbB/antagonistas & inibidores , Humanos , Modelos Moleculares , Simulação de Dinâmica Molecular , Estrutura Molecular , Compostos de Mostarda Nitrogenada/síntese química , Compostos de Mostarda Nitrogenada/química , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Receptor ErbB-2/antagonistas & inibidores , Estereoisomerismo , Relação Estrutura-Atividade
13.
Fundam Clin Pharmacol ; 23(4): 457-64, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19709323

RESUMO

Many traditional Chinese medicines have been used as immunomodulators that act as either immunosuppressants or immunostimulators. Recently, our lab successfully isolated a monomer telocinobufagin (TCB) from the chloroform extract of Chan Su (Venenum Bufonis). In the present paper, we evaluated the immunomodulatory effects of this compound in vitro. We found that TCB significantly stimulates splenocyte proliferation when administered alone or in combination with polyclonal T-cell mitogens concanavalin A (Con A) and lipopolysaccharide. Telocinobufagin markedly enhances natural killer cell and peritoneal macrophage activation. Telocinobufagin increases the percentage of CD4, CD8 positive cells within a population of splenocytes. Moreover, we found that the level of several Th1 cytokines, including interleukin-2 (IL-2), interleukin-12 (IL-12), interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha), are significantly increased after TCB treatment, while the level of the Th2 cytokine interleukin-4 (IL-4) is significantly decreased. As a result, the ratio of Th1/Th2 is significantly increased. Taken together, these results indicate that TCB has potential immune system regulatory effects and suggest that this compound could be developed as a novel immunotherapeutic agent to treat cancer and other immune-mediated diseases, and it may become a new immunomodulatory agent in many regions.


Assuntos
Bufanolídeos/farmacologia , Citocinas/efeitos dos fármacos , Fatores Imunológicos/farmacologia , Baço/efeitos dos fármacos , Animais , Bufanolídeos/administração & dosagem , Bufanolídeos/química , Bufanolídeos/isolamento & purificação , Proliferação de Células/efeitos dos fármacos , Concanavalina A/farmacologia , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Fatores Imunológicos/administração & dosagem , Fatores Imunológicos/isolamento & purificação , Lipopolissacarídeos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Baço/citologia , Baço/imunologia , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Células Th2/efeitos dos fármacos , Células Th2/imunologia
14.
J Integr Plant Biol ; 51(3): 308-15, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19261074

RESUMO

Aquatic plants develop strong fragment propagation and colonization ability to endure the natural disturbances. However, detailed research of ability to endure the natural disturbances has been lacking to date. Therefore, reproduction (shoot) and colonization (root) of shoot fragments of Potamogeton crispus L. with or without apices were investigated for the effect of apical dominance, and the growth of decapitated shoot fragments at three lengths (2, 4, 6 cm) was compared. Meanwhile, fragment propagation at levels of bud position was studied for bud position effect after escaping from apical dominance. The results showed significant increases occurred in the outgrowth of lateral branches on fragments decapitated compared with the fragments with apices, implying that apical dominance exists. Different lengths of fragments showed little difference in biomass allocations, but significant differences were noted in their propagation. Meanwhile, the effect of bud position was verified, due to the significant difference of average reproduction per node among the three length groups. Thus, the present study has made progress in the current understanding of aquatic plant dispersion among natural systems and contributes to improve methods of in vitro propagation for re-implantation purposes.


Assuntos
Adaptação Fisiológica , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia , Potamogetonaceae/crescimento & desenvolvimento , Potamogetonaceae/fisiologia , Água , Agricultura , Biomassa , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/fisiologia
15.
Ying Yong Sheng Tai Xue Bao ; 20(10): 2370-6, 2009 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-20077692

RESUMO

Four nutrient levels, i.e., 0.5 mg N x L(-1) and 0.1 mg P x L(-1) (I), 1.5 mg N x L(-1) and 0.3 mg P x L(-1) (II), 4.5 mg N x L(-1) and 0.9 mg P x L(-1) (III), and 13.5 mg N x L(-1) and 2.7 mg P x L(-1) (IV), were installed to study the effects of water body's nutrient level, plant species combination, and their interactions on the biomass accumulation and allocation of invasive floating species Eichhornia crassipes, native rooted leaf-floating species Jussiaea stipulacea, and submerged plant Vallisneria spiralis. The total, root, stem, and leaf biomass of E. crassipes and J. stipulacea, either in monoculture or in mixed-culture, increased with increasing water body's nutrient level, their total biomass in treatments III and IV being averagely 54.47% and 102.63% higher than that in treatments I and II, respectively. Under different plant species combination, the total, root, stem, and leaf biomass of V. spiralis showed a declining trend with the increase of nutrient level, and the total biomass of V. spiralis in treatments III and IV was averagely 45.88% lower than that in treatments I and II. The results of two-way ANOVA showed that water body's nutrient level had significant positive effects on the biomass of E. crassipes and J. stipulacea but negative effects on that of V. spiralis, and the effects of plant species combination varied with target plant species.


Assuntos
Biomassa , Eutrofização , Desenvolvimento Vegetal , Plantas/classificação , Poluentes Químicos da Água/análise , Eichhornia/crescimento & desenvolvimento , Monitoramento Ambiental/métodos , Nitrogênio/análise , Fósforo/análise , Ulex/crescimento & desenvolvimento
16.
Ambio ; 36(4): 335-42, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17626472

RESUMO

Natural wetlands, occupying 3.8% of China's land and providing 54.9% of ecosystem services, are unevenly distributed among eight wetland regions. Natural wetlands in China suffered great loss and degradation (e.g., 23.0% freshwater swamps, 51.2% costal wetlands) because of the wetland reclamation during China's long history of civilization, and the population pressure and the misguided policies over the last 50 years. Recently, with an improved understanding that healthy wetland ecosystems play a vital role in her sustainable economic development, China started major efforts in wetland conservation, as signified by the policy to return reclaimed croplands to wetlands, the funding of billions of dollars to restore degraded wetlands, and the national plan to place 90% of natural wetlands under protection by 2030. This paper describes the current status of the natural wetlands in China, reviews past problems, and discusses current efforts and future challenges in protecting China's natural wetlands.


Assuntos
Conservação dos Recursos Naturais/história , Áreas Alagadas , China , Conservação dos Recursos Naturais/legislação & jurisprudência , Conservação dos Recursos Naturais/tendências , Ecossistema , Monitoramento Ambiental/história , Monitoramento Ambiental/métodos , Previsões , Geografia , História do Século XX , História do Século XXI , Poluição da Água/análise , Poluição da Água/prevenção & controle
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