halophyte
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BACKGROUND: Many areas throughout the world are simultaneously contaminated by high concentrations of soluble salts and by high concentrations of heavy metals that constitute a serious threat to human health. The use of plants to extract or stabilize pollutants is an interesting alternative to classical expensive decontamination procedures. However, suitable plant species still need to be identified for reclamation of substrates presenting a high electrical conductivity. SCOPE: Halophytic plant species are able to cope with several abiotic constraints occurring simultaneously in their natural environment. This review considers their putative interest for remediation of polluted soil in relation to their ability to sequester absorbed toxic ions in trichomes or vacuoles, to perform efficient osmotic adjustment and to limit the deleterious impact of oxidative stress. These physiological adaptations are considered in relation to the impact of salt on heavy metal bioavailabilty in two types of ecosystem: (1) salt marshes and mangroves, and (2) mine tailings in semi-arid areas. CONCLUSIONS: Numerous halophytes exhibit a high level of heavy metal accumulation and external NaCl may directly influence heavy metal speciation and absorption rate. Maintenance of biomass production and plant water status makes some halophytes promising candidates for further management of heavy-metal-polluted areas in both saline and non-saline environments.
- MeSH
- biodegradace MeSH
- chlorid sodný metabolismus MeSH
- halotolerantní rostliny metabolismus MeSH
- hornictví MeSH
- látky znečišťující půdu metabolismus MeSH
- mokřady MeSH
- pouštní klima MeSH
- regenerace a remediace životního prostředí * MeSH
- těžké kovy metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Echinophora spinosa (Apiaceae) is a psammophilous species growing along Mediterranean coastal sand dunes. This species secretes essential oils made up of monoterpenoids, phenylpropanoids, and polyacetylenes, which may represent effective, eco-friendly and safe active ingredients for the preparation of green insecticides. Based on this, in the present study, we selected a French accession of E. spinosa growing on the coastal dunes of Corsica, extracting the essential oils from aerial parts and roots by hydrodistillation. The essential oils were analyzed by GC-MS for chemical composition and screened for their insecticidal activity on three target insects, Culex quinquefasciatus, Spodoptera littoralis, and Musca domestica. The essential oil from roots was dominated by the phenylpropanoid myristicin and the monoterpene hydrocarbon terpinolene, with a minor contribution of (Z)-falcarinol. The oil from the aerial parts was characterized by monoterpenes, mainly p-cymene, a-phellandrene, and α-pinene. The root essential oil exhibited promising toxicity on the target insects, with special reference to C. quinquefasciatus larvae (LC50 = 15.7 mg L-1), while on M. domestica and S. littoralis, it showed LD50 of 38.3 μg adult-1 and 55.6 μg larva-1, respectively. Based on our findings, E. spinosa can be viewed as a new potential crop to produce insecticidal essential oils in arid salty areas. However, synergistic and antagonistic effects of the major constituents of both oils tested here deserve future research. Further studies on the efficacy of stable formulations of the E. spinosa root essential oil, with special reference to micro- and nanoformulations, are ongoing.
- MeSH
- Apiaceae * MeSH
- halotolerantní rostliny MeSH
- insekticidy * MeSH
- larva MeSH
- monoterpeny MeSH
- oleje prchavé * MeSH
- ostrovy MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Francie MeSH
- ostrovy MeSH
Plant precursor miRNAs (pre-miRNA) have conserved evolutionary footprints that correlate with mode of miRNA biogenesis. In plants, base to loop and loop to base modes of biogenesis have been reported. Conserved structural element(s) in pre-miRNA play a major role in turn over and abundance of mature miRNA. Pre-miR396c sequences and secondary structural characteristics across Oryza species are presented. Based on secondary structure, twelve Oryza pre-miR396c sequences are divided into three groups, with the precursor from halophytic Oryza coarctata forming a distinct group. The miRNA-miRNA* duplex region is completely conserved across eleven Oryza species as are other structural elements in the pre-miRNA, suggestive of an evolutionarily conserved base-to-loop mode of miRNA biogenesis. SNPs within O. coarctata mature miR396c sequence and miRNA* region have the potential to alter target specificity and association with the RNA-induced silencing complex. A conserved SNP variation, rs10234287911 (G/A), identified in O. sativa pre-miR396c sequences alters base pairing above the miRNA-miRNA* duplex. The more stable structure conferred by the 'A10234287911' allele may promote better processing vis-à-vis the structure conferred by 'G10234287911' allele. We also examine pri- and pre-miR396c expression in cultivated rice under heat and salinity and their correlation with miR396c expression.
The osmotin protein is involved in both monocot and dicot plant responses to biotic and abiotic stress. To determine the biological activity of osmotin, the gene was amplified from tobacco genomic DNA, fused with the hexahistidine tag motif and successfully expressed in Escherichia coli, after which the recombinant osmotin was purified and renatured. Various activities were then tested, including hemolytic activity, toxicity against human embryonic kidney cells, and the antifungal activity of the recombinant osmotin. We found that osmotin had no adverse effects on human kidney cells up to a concentration of 500 μg.ml(-)(1). However, the purified osmotin also had significant antimicrobial activity, specifically against fungal pathogens causing candidiasis and otitis, and against the common food pathogens. Using the osmotin-Agrobacterium construct, the osmotin gene was inserted into tobacco plants in order to facilitate the isolation of recombinant protein. Using qPCR, the presence and copy number of the transgene was detected in the tobacco plant DNA. The transgene was also quantified using mRNA, and results indicated a strong expression profile, however the native protein has been never isolated. Once the transgene presence was confirmed, the transgenic tobacco plants were grown in high saline concentrations and monitored for seed germination and chlorophyll content as indicators of overall plant health. Results indicated that the transgenic tobacco plants had a higher tolerance for osmotic stress. These results indicate that the osmotin gene has the potential to increase crop tolerance to stresses such as fungal attack and unfavorable osmotic conditions.
- MeSH
- geneticky modifikované rostliny * genetika růst a vývoj metabolismus MeSH
- halotolerantní rostliny * genetika růst a vývoj metabolismus MeSH
- lidé MeSH
- rostlinné proteiny * biosyntéza genetika MeSH
- tabák * genetika růst a vývoj metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The role of microorganisms in litter degradation in arid and semi-arid zones, where soil and water salinization is one of the main factors limiting carbon turnover and decay, remains obscure. Heterostachys ritteriana (Amaranthaceae), a halophyte shrub growing in arid environments such as "Salinas Grandes" (Córdoba, Argentina), appears to be the main source of organic matter in the area. Little is known regarding the microorganisms associated with H. ritteriana, although they are a potential source of enzymes such as cellulolytic ones, which might be important in biotechnological fields such as bioethanol production using ionic liquids. In the present study, by studying the microbiota growing on H. ritteriana leaf litter in "Salinas Grandes," we isolated the cellulolytic fungus Fusarium equiseti LPSC 1166, which grew and degraded leaf litter under salt stress. The growth of this fungus was a function of the C substrate and the presence of NaCl. Although in vitro the fungus used both soluble and polymeric compounds from H. ritteriana litter and synthesized extracellular β-1,4 endoglucanases, its activity was reduced by 10% NaCl. Based on these results, F. equiseti LPSC 1166 can be described as a halotolerant cellulolytic fungus most probably playing a key role in the decay of H. ritteriana leaf litter in "Salinas Grandes."
- MeSH
- biodegradace MeSH
- celulosa metabolismus MeSH
- Chenopodiaceae mikrobiologie MeSH
- chlorid sodný metabolismus MeSH
- fungální proteiny genetika metabolismus MeSH
- Fusarium enzymologie genetika metabolismus MeSH
- glykosidhydrolasy genetika metabolismus MeSH
- listy rostlin mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
A comprehensive understanding of the relationship between arbuscular mycorrhizal (AM) fungi and coastal saline soil organic carbon (SOC) is crucial for analysis of the function of coastal wetlands in soil carbon sequestration. In a field experiment, the temporal and spatial dynamics of AM fungi, glomalin-related soil protein (GRSP) - which is described as a N-linked glycoprotein and the putative gene product of AM fungi, SOC, and soil aggregates were investigated in halophyte Kosteletzkya virginica rhizosphere soil of coastal saline areas of North Jiangsu, China. Soil samples were collected from a depth of up to 30 cm in two plantation regions from August 2012 to May 2013. Results showed K. virginica formed a strong symbiotic relationship to AM fungi. AM colonization and spore density were the highest in the 10-20 cm soil layer of Jinhai farm in August 2012, because of the presence of numerous fibrous roots in this soil layer. The total GRSP and SOC were the highest in the 0-10 cm soil layer in May 2013 and November 2012, respectively. Correlation coefficient analysis revealed that AM colonization and spore density were positively correlated with total GRSP. Meanwhile, total GRSP was significantly positively correlated with large macroaggregates (>3 mm), SOC, total P, Olsen P, and soil microbial biomass carbon (SMBC), but negatively correlated with microaggregates (<0.25 mm), soil EC, total N, and pH. SOC was positively correlated with spore density, large macroaggregates, small macroaggregates (2-0.25 mm), alkaline N, and SMBC and negatively correlated with microaggregates, EC, pH, and total K. Although it may be a statistical artifact, we found an interesting phenomenon that there was no significant correlation between soil aggregates and AM colonization or spore density. Hence, total GRSP is a vital source of saline soil C pool and an important biological indicator for evaluating coastal saline SOC pool and soil fertility, while AM colonization or spore density may not be.
- MeSH
- časoprostorová analýza MeSH
- fungální proteiny metabolismus MeSH
- geologické sedimenty chemie mikrobiologie MeSH
- glykoproteiny metabolismus MeSH
- koloběh uhlíku MeSH
- mykorhiza metabolismus MeSH
- půdní mikrobiologie * MeSH
- sekvestrace uhlíku * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Čína MeSH
The review is focused on plant proteome response to salinity with respect to physiological aspects of plant salt stress response. The attention is paid to both osmotic and ionic effects of salinity stress on plants with respect to several protein functional groups. Therefore, the role of individual proteins involved in signalling, changes in gene expression, protein biosynthesis and degradation and the resulting changes in protein relative abundance in proteins involved in energy metabolism, redox metabolism, stress- and defence-related proteins, osmolyte metabolism, phytohormone, lipid and secondary metabolism, mechanical stress-related proteins as well as protein posttranslational modifications are discussed. Differences between salt-sensitive (glycophytes) and salt-tolerant (halophytes) plants are analysed with respect to differential salinity tolerance. In conclusion, contribution of proteomic studies to understanding plant salinity tolerance is summarised and discussed.
- Publikační typ
- časopisecké články MeSH
Halotolerant bacteria get adapted to a saline environment through modified physiological/structural characteristics and may provide stress tolerance along with enhanced growth to the host plants by different direct and indirect mechanisms. This study reports on multiple halotolerant plant growth-promoting rhizobacteria isolated from the coastal soils in Bangladesh, in fields where the halophytic wild rice Oryza coarctata is endemic. The aim was to find halotolerant bacteria for potential use as biofertilizer under normal/salt-stressed conditions. In this study, eight different strains were selected from a total of 20 rhizobacterial isolates from the saline-prone regions of Debhata and Satkhira based on their higher salt tolerance. 16S rRNA gene sequencing results of the rhizobacterial strains revealed that they belonged to Halobacillus, Bacillus, Acinetobactor, and Enterobactor genera. A total of ten halotolerant rhizobacteria (the other 2 bacteria were previously isolated and already reported as beneficial for rice growth) were used as both single inoculants and in combinations and applied to rice growing in pots. To investigate their capability to improve rice growth, physiological parameters such as shoot and root length and weight, chlorophyll content at the seedling stage as well as survival and yield at the reproductive stage were measured in the absence or presence (in concentration 40 or 80 mmol/L) of NaCl and in the absence or presence of the rhizobacteria. At the reproductive stage, only 50% of the uninoculated plants survived without setting any grains in 80 mmol/L NaCl in contrast to 100% survival of the rice plants inoculated with a combination of the rhizobacteria. The combined halotolerant rhizobacterial inoculations showed significantly higher chlorophyll retention as well as yield under the maximum NaCl concentration applied compared to application of single species. Thus, the use of a combination of halotolerant rhizobacteria as bioinoculants for rice plants under moderate salinity can synergistically alleviate the effects of stress and promote rice growth and yield.
