- The constitutive expression of alfalfa MsMYB2L enhances salinity and drought tolerance of Arabidopsis thaliana. [Journal Article]
- PPPlant Physiol Biochem 2019 Jun 08; 141:300-305
- MYB-type transcription factors are known to participate in the response of plants to a number of stress agents. MsMYB2L is an alfalfa member of this large gene family. Its transcription in alfalfa se…
MYB-type transcription factors are known to participate in the response of plants to a number of stress agents. MsMYB2L is an alfalfa member of this large gene family. Its transcription in alfalfa seedlings was found to be rapidly and strongly induced by salinity, moisture deficiency and exogenously supplied abscisic acid. An analysis based on a yeast one hybrid assay indicated that its product is able to activate transcription, consistent with its function as a transcription factor. When the gene was constitutively expressed in Arabidopsis thaliana, both germination and seedling growth were more sensitive to ABA treatment than wild type, and growth was less strongly compromised by salinity and moisture deficiency stress, presumably as a result of the induction of certain stress-related genes active in ABA-dependent pathways. The transgenic seedlings' enhanced the synthesis of many osmotic regulatory substances such as proline and soluble sugar, and decreased the lipid peroxidation. In all, MsMYB2L represents a potential candidate gene for manipulating the salinity and drought tolerance of alfalfa.
- Activation of fulvic acid-like in paper mill effluents using H2O2/TiO2 catalytic oxidation: Characterization and salt stress bioassays. [Journal Article]
- JHJ Hazard Mater 2019 May 29; 378:120702
- Increasing environmental concerns about organic waste in paper mill effluents demand alternative wastewater management technology. We reported novel activation of fulvic acid-like in paper mill efflu…
Increasing environmental concerns about organic waste in paper mill effluents demand alternative wastewater management technology. We reported novel activation of fulvic acid-like in paper mill effluents using hydrogen peroxide (H2O2) as oxidizer and titanium oxide (TiO2) as catalyst. Spectroscopic characteristics of fulvic acid-like in paper mill effluents before and after activation (PFA and PFA-Os, respectively) were compared with a benchmark fulvic acid extracted from leonardite (LFA). Results indicated that PFA-Os exhibited less lignin structures, more functional groups and lower molecular weight than PFA, sharing much similarity with LFA. Among PFA-Os with varying degrees of oxidation, PFA-O-3 activated with 1:2 vol ratio of paper mill effluent and 30% H2O2 for 20 min digestion at 90 °C stands out to be the optimal for further examination of its biological activity. Bioassays with rice seed/seedling indicated that applications of LFA at 2-5 mg-C/L and PFA-O-3 at 60-100 mg-C/L significantly increased rice seed germination rate and seedling growth under salt stress imposed with 100 mM NaCl. The mechanism was mainly through reduced oxidative damage via activation of antioxidative enzymes and lipid peroxidation. This study provides the needed technical basis of safer and cleaner technologies for innovative management of paper mill effluents.
- Impact of mesophilic co-composting conditions on the quality of substrates produced from winery waste activated sludge and grape stalks: Lab-scale and pilot-scale studies. [Journal Article]
- BTBioresour Technol 2019 Jun 08; 289:121622
- In this study, different amounts of a mixture of winery waste activated sludge and grape stalks were co-composted for 8 weeks, at lab-scale under different temperatures and aeration rates, and at pil…
In this study, different amounts of a mixture of winery waste activated sludge and grape stalks were co-composted for 8 weeks, at lab-scale under different temperatures and aeration rates, and at pilot-scale. None of the experiments showed the occurrence of a thermophilic stage, even when the composting temperature was kept at 34 °C, which might suggest biological suppression by the acclimated mesophilic microorganisms ubiquitous to the winery waste activated sludge. The composted substrates were fully characterized by physicochemical analysis, plant growth tests and germination indexes using parsley (Petroselinum crispum) seedlings and seeds. Surprisingly, despite the higher volume reduction at lab-scale, it was the initial mixture and the mixture composted outdoors which presented the best horticultural qualities, with seedling survival rates of 88.9% and 87.0% and modified germination indexes of 54% and 161%, respectively. These findings shed some light on previous contradictory results and allow the development of new recycling strategies.
- Evaluation of the effectiveness of a bioremediation process in experimental soils polluted with chromium and lindane. [Journal Article]
- EEEcotoxicol Environ Saf 2019 Jun 11; 181:255-263
- Bioremediation using actinobacterium consortia proved to be a promising alternative for the purification of co-contaminated environments. In this sense, the quadruple consortium composed of Streptomy…
Bioremediation using actinobacterium consortia proved to be a promising alternative for the purification of co-contaminated environments. In this sense, the quadruple consortium composed of Streptomyces sp. M7, MC1, A5, and Amycolatopsis tucumanensis AB0 has been able to remove significant levels of Cr(VI) and lindane from anthropogenically contaminated soils. However, the effectiveness of the bioremediation process could not be evaluated only by analytical monitoring, which is complex mainly due to the characteristics of the matrix, producing non-quantitative analyte recoveries, or interferences in the detection stage and quantification. However, the effectiveness of the bioremediation process cannot be evaluated only through analytical monitoring, which is complex due mainly to the characteristics of the matrix, to the recoveries of non-quantitative analytes or to interferences in the detection and quantification stage. For this reason, it is essential to have tools of ecological relevance to assess the biological impact of pollutants on the environment. In this context, the objective of this work was to establish the appropriate bioassays to evaluate the effectiveness of a bioremediation process of co-contaminated soils. For this, five model species were studied: four plant species (Lactuca sativa, Raphanus sativus, Lycopersicon esculentum, and Zea mays) and one animal species (Eisenia fetida). On plant species, the biomarkers evaluated were inhibition of germination (IG) and the length of hypocotyls/steam and radicles/roots of the seedling. While on E. fetida, mortality (M), weight lost, coelomocyte concentration and cell viability were tested. These bioindicators and the battery of biomarkers quantified in them showed a different level of sensitivity, from maximum to minimum: E. fetida > L. esculentum > L. sativa > R. sativus ≫>Z. mays. Therefore, E. fetida and L. esculentum and their respective biomarkers were selected to evaluate the effectiveness of the bioremediation process due to the capability of assessing the effect on the flora and the fauna of the soil, respectively. The joint application of these bioindicators in a field scale bioremediation process is a feasible tool to demonstrate the recovery of the quality and health of the soil.
- Removal of triazines, triazoles and organophophates in biomixtures and application of a biopurification system for the treatment of laboratory wastewaters. [Journal Article]
- CChemosphere 2019 Jun 03; 233:733-743
- Biopurification systems (BPS) have been barely explored for removing complex mixtures of pesticides. In this study, the potential of a biomixture to remove simultaneously a mixture of herbicides (tri…
Biopurification systems (BPS) have been barely explored for removing complex mixtures of pesticides. In this study, the potential of a biomixture to remove simultaneously a mixture of herbicides (triazines), fungicides (triazoles) and insecticides (organophosphates) is presented. Also, a BPS using the same biomixture was used for treating a pesticide testing laboratory wastewater containing a mixture of 38 compounds. Ecotoxicological assays were conducted on the BPS elutriates to investigate the mixture detoxification. A mixture (concentrations of 4-8 mg kg-1) run in small-scale biomixture systems (SSB) for 128 d showed 59.3% removal of triazines, 68.5% of organophosphates and no elimination of triazoles. The treatment of the laboratory wastewater (individual concentrations range: 0.0036-0.25 mg kg-1) in the pilot-scale BPS for 281 d resulted in the elimination pattern of organophosphates (90.0%) > triazoles (73.4%) > carbamates (71.3%) > triazines (54.3%). Complete detoxification towards Daphnia magna and partial detoxification in Lactuca sativa seeds germination occurred in the BPS. Although the pesticide mixture complexity is higher in the BPS, the lower concentrations found in this matrix, could explain removal differences between SSB and BPS and the apparent inhibition in the elimination of carbamates and some triazines observed in the latter. These findings suggest that disposal of pesticide-containing laboratory-wastewater should be done in separate containers, according to chemical groups before their treatment in separate BPS, in order to reduce treatment periods. Monitoring the treatment process in the BPS with a battery of ecotoxicological tests is strongly recommended.
- Overexpression of a trypanothione synthetase gene from Trypanosoma cruzi, TcTrys, confers enhanced tolerance to multiple abiotic stresses in rice. [Journal Article]
- GENEGene 2019 Jun 11
- Plants are frequently exposed to variable environmental stresses that adversely affect plant growth, development and agricultural production. In this study, a trypanothione synthetase gene from Trypa…
Plants are frequently exposed to variable environmental stresses that adversely affect plant growth, development and agricultural production. In this study, a trypanothione synthetase gene from Trypanosoma cruzi, TcTryS, was chemically synthesized and its roles in tolerance to multiple abiotic stresses were functionally characterized by generating transgenic rice overexpressing TcTryS. Overexpression of TcTryS in rice endows transgenic plants with hypersensitivity to ABA, hyposensitivity to NaCl- and mannitol-induced osmotic stress at the seed germination stage. TcTryS overexpression results in enhanced tolerance to drought, salt, cadmium, and 2,4,6-trichlorophenol stresses in transgenic rice, simultaneously supported by improved physiological traits. The TcTryS-overexpression plants also accumulated greater amounts of proline, less malondialdehyde and more transcripts of stress-related genes than wild-type plants under drought and salt stress conditions. In addition, TcTryS might play a positive role in maintaining chlorophyll content under 2,4,6-trichlorophenol stress. Histochemical staining assay showed that TcTryS renders transgenic plants better ROS-scavenging capability. All of these results suggest that TcTryS could function as a key regulator in modulation of abiotic stress tolerance in plant, and may have applications in the engineering of economically important crops.
- Identification of L-Valine-initiated-germination-active genes in Bacillus subtilis using Tn-seq. [Journal Article]
- PlosPLoS One 2019; 14(6):e0218220
- Bacterial endospores can survive harsh environmental conditions and long-term dormancy in the absence of nutrients, but can rapidly germinate under favorable conditions. In the present study, we empl…
Bacterial endospores can survive harsh environmental conditions and long-term dormancy in the absence of nutrients, but can rapidly germinate under favorable conditions. In the present study, we employed transposon sequencing (Tn-seq) to identify genes with previously uncharacterized roles in spore germination. Identified genes that encoded spore inner membrane proteins were chosen for study of defined mutants, which exhibited delayed germination in several assays in response to varying germinants. Significantly slowed release of DPA indicated that mutants were affected in Stage I of germination. Several mutants exhibited phenotypic traits consistent with failure of a GerA germinant receptor-mediated response, while others appeared to have a more general loss of response to varied germinants. Use of a gerA-lacZ transcriptional fusion and quantitative western blotting of GerAC allowed mutants to be classified based upon normal or decreased gerA transcription and normal or reduced GerA accumulation. Fourteen genes were identified to have newly described roles within Bacillus spore germination. A more complete understanding of this process can contribute to the development of better spore decontamination procedures.
- Protein S-acyl Transferase 15 is Involved in Seed Triacylglycerol Catabolism during Early Seedling Growth in Arabidopsis. [Journal Article]
- JEJ Exp Bot 2019 Jun 13
- Seeds of Arabidopsis contain ~40% of triacylglycerol. It is converted to sugar to support post germination growth. We identified an Arabidopsis T-DNA knockout mutant that was sugar dependent during e…
Seeds of Arabidopsis contain ~40% of triacylglycerol. It is converted to sugar to support post germination growth. We identified an Arabidopsis T-DNA knockout mutant that was sugar dependent during early seedling establishment. Our study showed that the β-oxidation process involved in catabolising the free fatty acids released from the seed triacylglycerol was impaired in this mutant. This mutant was confirmed to be transcriptional null for the Protein Acyl Transferase 15, AtPAT15 (At5g04270), one of the 24 protein acyl transferases in Arabidopsis. Although it is the shortest AtPAT15 contains the signature 'Asp-His-His-Cys cysteine rich domain' which is essential for the enzyme activity of this family of proteins. The function of AtPAT15 was validated because it rescued the growth defect of the yeast protein acyl transferase mutant akr1 and it was also auto-acylated in vitro. Transient expression of AtPAT15 in Arabidopsis and tobacco localized AtPAT15 in the Golgi apparatus. Taken together, our data clearly demonstrated that AtPAT15 is involved in β-oxidation of triacylglycerol, revealing the importance of protein S-acylation in seed storage lipid breakdown during early seedling growth of Arabidopsis.
- Increasing access to microfluidics for studying fungi and other branched biological structures. [Journal Article]
- FBFungal Biol Biotechnol 2019; 6:1
- CONCLUSIONS: This pre-packaging approach provides a simple, one step process to initiate microfluidics in any setting for fungal studies, bacteria-fungal interactions, and other biological inquiries. This process improves access to microfluidics for controlling biological microenvironments, and further enabling visual and quantitative analysis of fungal cultures.
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- Achene heteromorphism in Bidens pilosa (Asteraceae): differences in germination and possible adaptive significance. [Journal Article]
- APAoB Plants 2019; 11(3):plz026
- Bidens pilosa (Asteraceae), a noxious weed in many ecosystems worldwide, produces large amounts of heteromorphic (central and peripheral) achenes. The primary aims of the present study were to compar…
Bidens pilosa (Asteraceae), a noxious weed in many ecosystems worldwide, produces large amounts of heteromorphic (central and peripheral) achenes. The primary aims of the present study were to compare the morphological, dormancy/germination characteristics of dimorphic achenes. Temperatures simulating those in the natural habitat of B. pilosa were used to test for primary dormancy and germination behaviour of fresh central and peripheral achenes. The effects of cold stratification, gibberellic acid (GA3) and dry storage on breaking dormancy were tested and the germination percentage of dimorphic achenes in response to osmotic stress was measured. Cold stratification, GA3 and dry storage significantly increased the germination percentage, suggesting both types of achenes had non-deep physiological dormancy. Variously pretreated central achenes had significantly higher germination percentages than peripheral achenes. Central achenes were more osmotically tolerant than peripheral achenes with a high germination percentage in high polyethylene glycol concentrations. These above differences among dimorphic achenes of B. pilosa increased the species' fitness to adapt to heterogeneous habitats creating an ecological adaptive strategy that may allow B. pilosa to successfully thrive in stressful habitats.