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1.
World J Microbiol Biotechnol ; 35(12): 180, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31728755

RESUMO

Derived from RNA, 5'-ribonucleotides, especially Inosine-5'-monophosphate (IMP) and guanosine-5'-monophosphate (GMP), can enhance the umami taste of soy sauce. In this study, the RNA content of three different salt-tolerant yeasts was examined. The most valuable strain was subjected to atmospheric and room-temperature plasma (ARTP) mutagenesis, which improved its RNA content by 160.54%. Regular fermentation with RNA-enhanced strain failed to increase the amount of 5'-ribonucleotides in the soy sauce due to hydrolysis by phosphatase. A two-stage fermentation strategy was then carried out. Aroma compounds were mainly synthesized in the first stage, and RNA-enriched biomass was massively produced in the second stage followed by heat treatment to inactivate phosphatase. After the proposed strategy was applied, IMP and GMP in the soy sauce reached 68.54 and 89.37 mg/L, respectively. Moreover, the amounts of key aroma compounds and organic acids significantly increased. Results may provide new insights for improving the quality of soy sauce through microorganism breeding and fermentation control.


Assuntos
Mutagênese , Gases em Plasma , RNA , Tolerância ao Sal/genética , Tolerância ao Sal/efeitos da radiação , Alimentos de Soja , Zygosaccharomyces/genética , Zygosaccharomyces/efeitos da radiação , Cruzamento , Fermentação , Microbiologia de Alimentos , Cloreto de Sódio , Paladar , Temperatura Ambiente , Zygosaccharomyces/fisiologia
2.
Plant Biol (Stuttg) ; 20(5): 808-816, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29888486

RESUMO

We studied the resistance of Parmotrema austrosinense to UV-B stress. We focused on the effects of a high dose UV-B radiation on the content of chlorophylls, carotenoids and UV-B screening compounds. Photosynthetic parameters were measured by chlorophyll fluorescence (potential and effective quantum yields, photochemical and non-photochemical quenching) and evaluated in control and UV-B-treated lichens. Lichens from two different locations in Cordoba, Argentina, were selected: (i) high altitude and dry plots at (Los Gigantes) and (ii) lowland high salinity plots (Salinas Grandes). UV-B treatment led to a decrease in the content of photosynthetic pigments and UV-B screens (absorbance decrease in 220-350 nm) in the samples from Salinas Grandes, while in Los Gigantes samples, an increase in UV-B screen content was observed. Chlorophyll fluorescence parameters showed a UV-B-induced decline in FV /FM , ΦPSII and qP indicating limitation of primary photosynthetic processes in photosystem II (PSII) of symbiotic alga, more pronounced in Salinas Grandes samples. Protective mechanism of PSII were activated by the UV-B treatment to a higher extent in samples from Salinas Grandes (NPQ 0.48) than in Los Gigantes samples (NPQ 0.26). We concluded that site-related characteristics, and in particular different UV-B radiation regimen, had a strong effect on resistance of the photosynthetic apparatus of P. austrosinense to UV-B radiation.


Assuntos
Líquens/efeitos da radiação , Fotossíntese/efeitos da radiação , Raios Ultravioleta , Altitude , Carotenoides/análise , Carotenoides/metabolismo , Clorofila/análise , Clorofila/metabolismo , Ecossistema , Fluorescência , Líquens/química , Líquens/metabolismo , Tolerância ao Sal/efeitos da radiação
3.
J Dairy Sci ; 100(6): 4290-4293, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28390720

RESUMO

Lactococcus lactis is a culture widely used in salt-containing dairy products. Salt hinders bacterial growth, but exposure to environmental stress may protect cells against subsequent stress, including salt. The objective of this study was to evaluate the salt tolerance of L. lactis R-604 after exposure to various stresses. The culture was subjected to 10% (vol/vol) ethanol for 30 min, mild heat at 52°C for 30 min, 15 mM hydrogen peroxide for 30 min, or UV light (254 nm) for 5 min and compared with a control. Starting with 5 log cfu/mL for all treatments, growth was determined in M17 broth with 5 NaCl concentrations (0, 1, 3, 5, and 7% wt/vol). Plating was conducted daily for 5 d. Salt tolerance was enhanced with mild heat exposure before growth in M17 broth with 5% (wt/vol) NaCl on d 3, 4, and 5, and with exposure to hydrogen peroxide and ethanol stresses before growth in M17 broth with 5% (wt/vol) NaCl on d 4 and 5. Exposure of this culture to mild heat, hydrogen peroxide, or ethanol before growth in M17 broth containing 5% (wt/vol) salt can enhance its survival, which could be beneficial when using it in salt-containing dairy products.


Assuntos
Lactococcus lactis/fisiologia , Tolerância ao Sal/fisiologia , Estresse Fisiológico , Animais , Meios de Cultura , Etanol/farmacologia , Temperatura Alta , Peróxido de Hidrogênio/farmacologia , Lactococcus lactis/efeitos dos fármacos , Lactococcus lactis/efeitos da radiação , Tolerância ao Sal/efeitos dos fármacos , Tolerância ao Sal/efeitos da radiação , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/efeitos da radiação , Raios Ultravioleta
4.
Sci Rep ; 7: 41236, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28145449

RESUMO

Within the chloroplasts reactive oxygen species (ROS) are generated during photosynthesis and stressful conditions. Excessive ROS damages chloroplasts and reduces photosynthesis if not properly detoxified. In this current study, we document that chloroplasts produce melatonin, a recently-discovered plant antioxidant molecule. When N-acetylserotonin, a substrate for melatonin synthesis, was fed to purified chloroplasts, they produced melatonin in a dose-response manner. To further confirm this function of chloroplasts, the terminal enzyme for melatonin synthesis, N-acetylserotonin-O-methyltransferase (ASMT), was cloned from apple rootstock, Malus zumi. The in vivo fluorescence observations and Western blots confirmed MzASMT9 was localized in the chloroplasts. A study of enzyme kinetics revealed that the Km and Vmax of the purified recombinant MzASMT9 protein for melatonin synthesis were 500 µM and 12 pmol/min·mg protein, respectively. Arabidopsis ectopically-expressing MzASMT9 possessed improved melatonin level. Importantly, the MzASMT9 gene was found to be upregulated by high light intensity and salt stress. Increased melatonin due to the highly-expressed MzASMT9 resulted in Arabidopsis lines with enhanced salt tolerance than wild type plants, as indicated by reduced ROS, lowered lipid peroxidation and enhanced photosynthesis. These findings have agricultural applications for the genetic enhancement of melatonin-enriched plants for increasing crop production under a variety of unfavorable environmental conditions.


Assuntos
Arabidopsis/fisiologia , Cloroplastos/metabolismo , Melatonina/biossíntese , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/efeitos da radiação , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Biomassa , Cloroplastos/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Proteínas de Fluorescência Verde/metabolismo , Cinética , Luz , Malondialdeído/metabolismo , Malus/genética , Malus/efeitos da radiação , Fotossíntese/efeitos da radiação , Filogenia , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Proteínas de Plantas/genética , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Espécies Reativas de Oxigênio/metabolismo , Tolerância ao Sal/efeitos dos fármacos , Tolerância ao Sal/efeitos da radiação , Regulação para Cima/genética , Regulação para Cima/efeitos da radiação
5.
Genes Genet Syst ; 91(5): 245-256, 2017 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-27582185

RESUMO

A high-salt environment represents environmental stress for most plants. Those that can grow and thrive in such an environment must have membrane transport systems that can respond effectively. Plant roots absorb Na+ from the soil, and the plant must maintain Na+ homeostasis to survive salt stress. A major mechanism by which salt-tolerant plants adapt to salt stress is through modulation of ion transport genes. We have subjected a population of rice plants to mutagenesis, and identified lines with both single-nucleotide polymorphisms (SNPs) in membrane transport genes and altered responses to salt stress. Primers labeled with FAM or HEX fluorescent dyes were designed for nine target genes encoding membrane transport proteins that are believed to regulate salt stress tolerance. A TILLING (Targeting Induced Local Lesions IN Genome) assay was performed on 2,961 M2 rice mutant lines using electrophoresis. After the TILLING assay, a total of 41 mutant lines containing SNPs in the target genes were identified and screened. The average number of mutations per gene was 1/492 kb in lines having SNPs, and the percentage of mutation sites per total sequence was 0.67. Among the 41 lines, nine had altered sequences in the exon region of the genes. Of these nine lines, seven were tolerant to salt stress after exposure to 170 mM NaCl for three weeks, while the other two lines were not more salt-tolerant than the control lines. Furthermore, five mutant lines containing SNPs in the coding region of OsAKT1, OsHKT6, OsNSCC2, OsHAK11 and OsSOS1 showed changed expression levels for each gene. We conclude that variation in membrane transport genes, such as expression levels and protein structures, may affect the rice plant's tolerance to salt stress. These mutations represent traits that may be selected for large rice mutant populations, permitting efficient acquisition of salt-tolerant lines.


Assuntos
Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/efeitos da radiação , Oryza/genética , Oryza/efeitos da radiação , Primers do DNA , Raios gama , Mutagênese , Mutação/efeitos da radiação , Fenótipo , Proteínas de Plantas/genética , Tolerância ao Sal/genética , Tolerância ao Sal/efeitos da radiação , Estresse Fisiológico/genética , Estresse Fisiológico/efeitos da radiação
6.
Sci Rep ; 6: 32890, 2016 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-27597726

RESUMO

The effects of moderate salinity on the responses of woody plants to UV-B radiation were investigated using two Populus species (Populus alba and Populus russkii). Under UV-B radiation, moderate salinity reduced the oxidation pressure in both species, as indicated by lower levels of cellular H2O2 and membrane peroxidation, and weakened the inhibition of photochemical efficiency expressed by O-J-I-P changes. UV-B-induced DNA lesions in chloroplast and nucleus were alleviated by salinity, which could be explained by the higher expression levels of DNA repair system genes under UV-B&salt condition, such as the PHR, DDB2, and MutSα genes. The salt-induced increase in organic osmolytes proline and glycine betaine, afforded more efficient protection against UV-B radiation. Therefore moderate salinity induced cross-tolerance to UV-B stress in poplar plants. It is thus suggested that woody plants growing in moderate salted condition would be less affected by enhanced UV-B radiation than plants growing in the absence of salt. Our results also showed that UV-B signal genes in poplar plants PaCOP1, PaSTO and PaSTH2 were quickly responding to UV-B radiation, but not to salt. The transcripts of PaHY5 and its downstream pathway genes (PaCHS1, PaCHS4, PaFLS1 and PaFLS2) were differently up-regulated by these treatments, but the flavonoid compounds were not involved in the cross-tolerance since their concentration increased to the same extent in both UV-B and combined stresses.


Assuntos
Folhas de Planta/crescimento & desenvolvimento , Populus/crescimento & desenvolvimento , Tolerância ao Sal/efeitos da radiação , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Raios Ultravioleta/efeitos adversos , Adaptação Fisiológica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/efeitos da radiação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Populus/efeitos dos fármacos , Populus/efeitos da radiação , Estresse Fisiológico/efeitos da radiação
7.
Plant Cell Rep ; 35(9): 1943-54, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27295265

RESUMO

KEY MESSAGE: Here we report the enhancement of tolerance to salt stress in Brassica rapa (Chinese cabbage) through the RNAi-mediated reduction of GIGANTEA ( GI ) expression. Circadian clocks integrate environmental signals with internal cues to coordinate diverse physiological outputs. The GIGANTEA (GI) gene was first discovered due to its important contribution to photoperiodic flowering and has since been shown to be a critical component of the plant circadian clock and to contribute to multiple environmental stress responses. We show that the GI gene in Brassica rapa (BrGI) is similar to Arabidopsis GI in terms of both expression pattern and function. BrGI functionally rescued the late-flowering phenotype of the Arabidopsis gi-201 loss-of-function mutant. RNAi-mediated suppression of GI expression in Arabidopsis Col-0 and in the Chinese cabbage, B. rapa DH03, increased tolerance to salt stress. Our results demonstrate that the molecular functions of GI described in Arabidopsis are conserved in B. rapa and suggest that manipulation of gene expression through RNAi and transgenic overexpression could enhance tolerance to abiotic stresses and thus improve agricultural crop production.


Assuntos
Brassica rapa/genética , Brassica rapa/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Tolerância ao Sal/genética , Arabidopsis/genética , Brassica rapa/efeitos da radiação , Relógios Circadianos/genética , Relógios Circadianos/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Técnicas de Silenciamento de Genes , Genes de Plantas , Hidroponia , Luz , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Interferência de RNA , Tolerância ao Sal/efeitos dos fármacos , Tolerância ao Sal/efeitos da radiação , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética
8.
J Biosci Bioeng ; 117(5): 617-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24331982

RESUMO

In order to increase the value of freshwater algae as raw ingredients for health foods and feed for seawater-based farmed fish, we sought to breed high-chlorophyll halotolerant Chlorella with the objective of generating strains with both high chlorophyll concentrations (≥ 5%) and halotolerance (up to 1% NaCl). We used the Chlorella vulgaris K strain in our research institute culture collection and induced mutations with UV irradiation and acriflavine which is known to effect mutations of mitochondrial DNA that are associated with chlorophyll production. Screenings were conducted on seawater-based "For Chlorella spp." (FC) agar medium, and dark-green-colored colonies were visually selected by macroscopic inspection. We obtained a high-chlorophyll halotolerant strain (designated C. vulgaris M-207A7) that had a chlorophyll concentration of 6.7% (d.m.), a level at least three-fold higher than that of K strain. This isolate also exhibited a greater survival rate in seawater that of K strain.


Assuntos
Chlorella vulgaris/crescimento & desenvolvimento , Chlorella vulgaris/metabolismo , Clorofila/biossíntese , Tolerância ao Sal , Acriflavina/farmacologia , Chlorella vulgaris/efeitos dos fármacos , Chlorella vulgaris/genética , Clorofila/análise , DNA Mitocondrial/genética , Mutagênese/efeitos dos fármacos , Mutagênese/efeitos da radiação , Tolerância ao Sal/efeitos dos fármacos , Tolerância ao Sal/genética , Tolerância ao Sal/efeitos da radiação , Água do Mar , Raios Ultravioleta
9.
Planta ; 237(6): 1509-25, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23494613

RESUMO

Plant steroid hormones, brassinosteroids, are essential for growth, development and responses to environmental stresses in plants. Although BR signaling proteins are localized in many organelles, i.e., the plasma membrane, nuclei, endoplasmic reticulum and vacuole, the details regarding the BR signaling pathway from perception at the cellular membrane receptor BRASSINOSTEROID INSENSITIVE 1 (BRI1) to nuclear events include several steps. Brz (Brz220) is a specific inhibitor of BR biosynthesis. In this study, we used Brz-mediated chemical genetics to identify Brz-insensitive-long hypocotyls 2-1D (bil2-1D). The BIL2 gene encodes a mitochondrial-localized DnaJ/Heat shock protein 40 (DnaJ/Hsp40) family, which is involved in protein folding. BIL2-overexpression plants (BIL2-OX) showed cell elongation under Brz treatment, increasing the growth of plant inflorescence and roots, the regulation of BR-responsive gene expression and suppression against the dwarfed BRI1-deficient mutant. BIL2-OX also showed resistance against the mitochondrial ATPase inhibitor oligomycin and higher levels of exogenous ATP compared with wild-type plants. BIL2 participates in resistance against salinity stress and strong light stress. Our results indicate that BIL2 induces cell elongation during BR signaling through the promotion of ATP synthesis in mitochondria.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Mitocôndrias/metabolismo , Desenvolvimento Vegetal , Transdução de Sinais , Trifosfato de Adenosina/biossíntese , Sequência de Aminoácidos , Arabidopsis/efeitos dos fármacos , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Meio Ambiente , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Genes de Plantas/genética , Proteínas de Choque Térmico HSP40/genética , Proteínas de Choque Térmico HSP40/metabolismo , Luz , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/efeitos da radiação , Dados de Sequência Molecular , Mutação/genética , Especificidade de Órgãos/efeitos dos fármacos , Especificidade de Órgãos/genética , Especificidade de Órgãos/efeitos da radiação , Fenótipo , Desenvolvimento Vegetal/efeitos dos fármacos , Desenvolvimento Vegetal/genética , Desenvolvimento Vegetal/efeitos da radiação , Interferência de RNA/efeitos dos fármacos , Interferência de RNA/efeitos da radiação , Tolerância ao Sal/efeitos dos fármacos , Tolerância ao Sal/genética , Tolerância ao Sal/efeitos da radiação , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transdução de Sinais/efeitos da radiação , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Estresse Fisiológico/efeitos da radiação
10.
Photochem Photobiol ; 89(2): 400-5, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22998644

RESUMO

We investigated the effects of salinity and artificial UV radiation on the accumulation of mycosporine-like amino acids (MAAs) in sexual and parthenogenetic Artemia from Lake Urmia. The nauplii hatched from the cysts were cultured until adulthood under two salinities (150 and 250 g L(-1) ) and two light treatments (PAR and PAR+UVR) in the laboratory. Finally, the Artemia were analyzed for their concentration of MAAs. In most of the cases, the higher salinity level applied was found to increase the MAA concentrations in both Artemia populations significantly. The acquisition efficiency of MAAs in both Artemia populations increased under exposure to UVR-supplemented photosynthetically active radiation (PAR) compared to those raised under PAR, except for Porphyra-334. It was observed that combination of UV radiation and elevated salinity significantly increased the bioaccumulation of MAAs. Thus, the presence of these compounds in these populations of Artemia may increase their adaptability for living in high-UV and high-salinity conditions prevailing in Lake Urmia. Higher concentrations of MAAs in the parthenogenetic population of Artemia could be probably attributed to its mono sex nature and higher adaptation capacities to extreme environmental conditions.


Assuntos
Aminoácidos/biossíntese , Artemia/fisiologia , Cicloexanóis/metabolismo , Estágios do Ciclo de Vida/fisiologia , Partenogênese/fisiologia , Tolerância ao Sal/efeitos da radiação , Animais , Artemia/efeitos dos fármacos , Artemia/efeitos da radiação , Irã (Geográfico) , Lagos , Estágios do Ciclo de Vida/efeitos dos fármacos , Estágios do Ciclo de Vida/efeitos da radiação , Partenogênese/efeitos dos fármacos , Partenogênese/efeitos da radiação , Salinidade , Tolerância ao Sal/fisiologia , Cloreto de Sódio/farmacologia , Raios Ultravioleta
11.
J Integr Plant Biol ; 51(7): 675-88, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19566646

RESUMO

Impacts of salinity become severe when the soil is deficient in oxygen. Oxygation (using aerated water for subsurface drip irrigation of crop) could minimize the impact of salinity on plants under oxygen-limiting soil environments. Pot experiments were conducted to evaluate the effects of oxygation (12% air volume/volume of water) on vegetable soybean (moderately salt tolerant) and cotton (salt tolerant) in a salinized vertisol at 2, 8, 14, 20 dS/m EC(e). In vegetable soybean, oxygation increased above ground biomass yield and water use efficiency (WUE) by 13% and 22%, respectively, compared with the control. Higher yield with oxygation was accompanied by greater plant height and stem diameter and reduced specific leaf area and leaf Na+ and Cl- concentrations. In cotton, oxygation increased lint yield and WUE by 18% and 16%, respectively, compared with the control, and was accompanied by greater canopy light interception, plant height and stem diameter. Oxygation also led to a greater rate of photosynthesis, higher relative water content in the leaf, reduced crop water stress index and lower leaf water potential. It did not, however, affect leaf Na+ or Cl- concentration. Oxygation invariably increased, whereas salinity reduced the K+ : Na+ ratio in the leaves of both species. Oxygation improved yield and WUE performance of salt tolerant and moderately tolerant crops under saline soil environments, and this may have a significant impact for irrigated agriculture where saline soils pose constraints to crop production.


Assuntos
Agricultura/métodos , Gases/metabolismo , Gossypium/crescimento & desenvolvimento , Salinidade , Tolerância ao Sal/fisiologia , Soja/crescimento & desenvolvimento , Biomassa , Eletrólitos/metabolismo , Gossypium/fisiologia , Gossypium/efeitos da radiação , Luz , Exsudatos de Plantas/fisiologia , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Raízes de Plantas/metabolismo , Raízes de Plantas/efeitos da radiação , Caules de Planta/metabolismo , Caules de Planta/efeitos da radiação , Tolerância ao Sal/efeitos da radiação , Estações do Ano , Solo , Soja/fisiologia , Soja/efeitos da radiação , Água
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