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1.
Curr Microbiol ; 80(5): 146, 2023 Mar 23.
Article in English | MEDLINE | ID: mdl-36952131

ABSTRACT

The phosphate-solubilizing microorganism is essential for soil quality and plant development and can serve as an alternative to reduce such Brazilian needs for importing phosphate overseas. Here, we isolated and selected bacteria from Brazilian Cerrado soils capable of solubilize phosphate. We obtained 53 bacteria isolates, of which 23 could solubilize phosphate at a pH of 7.0, 17 could solubilize phosphate at a pH of 6.0, and 8 could solubilize at a pH of 5.5. Using 16S rRNA gene sequences, we identified nine bacteria species clustered in four groups: Bacillus sp., Pseudomonas sp., Priestia sp., and Klebsiella sp. Our results revealed that the UFT01 (P. aeruginosa) and UFT42 (B. cereus) isolates exhibited the best phosphate solubilization performance at all tested pH values. We further recorded higher levels of solubilization and phosphate availability six days after the soil inoculation with P. aeruginosa, and enzymatic analysis of the soil samples revealed that the P. aeruginosa-inoculated samples resulted in four-fold higher enzymatic activities when compared to non-inoculated soils. The B. cereus soil inoculation increased ß-glucosidase activities and resulted in reduced the activities of arylsulfatase. Altogether, our findings demonstrated that P. aeruginosa and B. cereus isolated from Cerrado soils showed high phosphate solubilization potential.


Subject(s)
Phosphates , Pseudomonas aeruginosa , Pseudomonas aeruginosa/genetics , Bacillus cereus/genetics , Soil/chemistry , RNA, Ribosomal, 16S/genetics , Brazil , Soil Microbiology
2.
BMC Infect Dis ; 22(1): 127, 2022 Feb 05.
Article in English | MEDLINE | ID: mdl-35123418

ABSTRACT

BACKGROUND: The city of Manaus, north Brazil, was stricken by a second epidemic wave of SARS-CoV-2 despite high seroprevalence estimates, coinciding with the emergence of the Gamma (P.1) variant. Reinfections were postulated as a partial explanation for the second surge. However, accurate calculation of reinfection rates is difficult when stringent criteria as two time-separated RT-PCR tests and/or genome sequencing are required. To estimate the proportion of reinfections caused by Gamma during the second wave in Manaus and the protection conferred by previous infection, we identified anti-SARS-CoV-2 antibody boosting in repeat blood donors as a mean to infer reinfection. METHODS: We tested serial blood samples from unvaccinated repeat blood donors in Manaus for the presence of anti-SARS-CoV-2 IgG antibodies using two assays that display waning in early convalescence, enabling the detection of reinfection-induced boosting. Donors were required to have three or more donations, being at least one during each epidemic wave. We propose a strict serological definition of reinfection (reactivity boosting following waning like a V-shaped curve in both assays or three spaced boostings), probable (two separate boosting events) and possible (reinfection detected by only one assay) reinfections. The serial samples were used to divide donors into six groups defined based on the inferred sequence of infection and reinfection with non-Gamma and Gamma variants. RESULTS: From 3655 repeat blood donors, 238 met all inclusion criteria, and 223 had enough residual sample volume to perform both serological assays. We found 13.6% (95% CI 7.0-24.5%) of all presumed Gamma infections that were observed in 2021 were reinfections. If we also include cases of probable or possible reinfections, these percentages increase respectively to 22.7% (95% CI 14.3-34.2%) and 39.3% (95% CI 29.5-50.0%). Previous infection conferred a protection against reinfection of 85.3% (95% CI 71.3-92.7%), decreasing to respectively 72.5% (95% CI 54.7-83.6%) and 39.5% (95% CI 14.1-57.8%) if probable and possible reinfections are included. CONCLUSIONS: Reinfection by Gamma is common and may play a significant role in epidemics where Gamma is prevalent, highlighting the continued threat variants of concern pose even to settings previously hit by substantial epidemics.


Subject(s)
COVID-19 , SARS-CoV-2 , Blood Donors , Brazil/epidemiology , Humans , Reinfection , Seroepidemiologic Studies
3.
Plant Cell Rep ; 41(9): 1907-1929, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35833988

ABSTRACT

KEY MESSAGE: High pigment mutants in tomato (Solanum lycopersicum L.), a loss of function in the control of photomorphogenesis, with greater pigment production, show altered growth, greater photosynthesis, and a metabolic reprogramming. High pigment mutations cause plants to be extremely responsive to light and produce excessive pigmentation as well as fruits with high levels of health-beneficial nutrients. However, the association of these traits with changes in the physiology and metabolism of leaves remains poorly understood. Here, we performed a detailed morphophysiological and metabolic characterization of high pigment 1 (hp1) and high pigment 2 (hp2) mutants in tomato (Solanum lycopersicum L. 'Micro-Tom') plants under different sunlight conditions (natural light, 50% shading, and 80% shading). These mutants occur in the DDB1 (hp1) and DET1 (hp2) genes, which are related to the regulation of photomorphogenesis and chloroplast development. Our results demonstrate that these mutations delay plant growth and height, by affecting physiological and metabolic parameters at all stages of plant development. Although the mutants were characterized by higher net CO2 assimilation, lower stomatal limitation, and higher carboxylation rates, with anatomical changes that favour photosynthesis, we found that carbohydrate levels did not increase, indicating a change in the energy flow. Shading minimized the differences between mutants and the wild type or fully reversed them in the phenotype at the metabolic level. Our results indicate that the high levels of pigments in hp1 and hp2 mutants represent an additional energy cost for these plants and that extensive physiological and metabolic reprogramming occurs to support increased pigment biosynthesis.


Subject(s)
Solanum lycopersicum , Carbon/metabolism , Chromosomal Proteins, Non-Histone/metabolism , Solanum lycopersicum/metabolism , Photosynthesis/genetics , Pigmentation/genetics , Plant Leaves/metabolism , Plant Proteins/genetics , Plants/metabolism
4.
An Acad Bras Cienc ; 94(2): e20211164, 2022.
Article in English | MEDLINE | ID: mdl-35703698

ABSTRACT

The analysis of gait in animals is important for understanding movement disorders in various human pathologies, especially those that develop muscle fibrosis. In the search for treatment alternatives for this problem, essential oils have been studied. Among them, research involving the essential oil of Alpinia zerumbet (EOAz) has been shown to promote relaxation and improve muscle function. Therefore, this study aimed to evaluate the effect of EOAz on gait with muscle fibrosis in immobilized rats. 30 rats (Wistar) were divided into five groups of six animals each: control group (without fibrosis and without treatment), immobilization group (with fibrosis and without treatment), and EOAz treatment groups (with fibrosis and with treatment). The animals were immobilized for 15 days with an ankle plantar flexion orthosis. After this period, they were treated with the oil cutaneously for 30 days. The analysis of behavioral tests before treatment indicated a significant increase in the means of the immobilized groups about to with concerning the control. We conclude that EOAz was effective in improving gait after inducing muscle fibrosis in immobilized rats. Studies are needed to assess the oil's effectiveness in the treatment of muscle fibrosis in human pathologies.


Subject(s)
Alpinia , Oils, Volatile , Animals , Fibrosis , Gait Analysis , Oils, Volatile/pharmacology , Oils, Volatile/therapeutic use , Plant Leaves , Rats , Rats, Wistar
5.
Plant Cell Rep ; 40(8): 1377-1393, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33074436

ABSTRACT

KEY MESSAGE: The tomato mutant Never ripe (Nr), a loss-of-function for the ethylene receptor SlETR3, shows enhanced growth, associated with increased carbon assimilation and a rewiring of the central metabolism. Compelling evidence has demonstrated the importance of ethylene during tomato fruit development, yet its role on leaf central metabolism and plant growth remains elusive. Here, we performed a detailed characterization of Never ripe (Nr) tomato, a loss-of-function mutant for the ethylene receptor SlETR3, known for its fruits which never ripe. However, besides fruits, the Nr gene is also constitutively expressed in vegetative tissues. Nr mutant showed a growth enhancement during both the vegetative and reproductive stage, without an earlier onset of leaf senescence, with Nr plants exhibiting a higher number of leaves and an increased dry weight of leaves, stems, roots, and fruits. At metabolic level, Nr also plays a significant role with the mutant showing changes in carbon assimilation, carbohydrates turnover, and an exquisite reprogramming of a large number of metabolite levels. Notably, the expression of genes related to ethylene signaling and biosynthesis are not altered in Nr. We assess our results in the context of those previously published for tomato fruits and of current models of ethylene signal transduction, and conclude that ethylene insensitivity mediated by Nr impacts the whole central metabolism at vegetative stage, leading to increased growth rates.


Subject(s)
Ethylenes/metabolism , Plant Proteins/genetics , Solanum lycopersicum/physiology , Carbon/metabolism , Fruit/genetics , Fruit/metabolism , Gene Expression Regulation, Plant , Solanum lycopersicum/genetics , Solanum lycopersicum/growth & development , Mutation , Photosynthesis , Plant Leaves/anatomy & histology , Plant Leaves/genetics , Plant Leaves/metabolism , Plant Proteins/metabolism , Signal Transduction , Starch/metabolism , Sucrose/metabolism
6.
Curr Microbiol ; 78(10): 3762-3769, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34463817

ABSTRACT

Cowpea (Vigna unguiculata) crops stand out for their efficient adaptation to edaphoclimatic conditions. Insect pests, such as the leaf beetle Cerotoma arcuata, are among the main factors that limit cowpea yield. Chemical control methods are commonly used to control such pests; however, biological methods are an alternative to reduce the indiscriminate use of conventional pesticides. This study aimed to evaluate the effects of Beauveria bassiana inoculation on the growth and physiological parameters of the cowpea plant and assess the influence of the inoculation on the feeding performance and survival of C. arcuata adults. Colonization by B. bassiana was recorded in the stems (63.89%), roots (45.83%), and leaves (25%) of the cowpea plant. It was found that B. bassiana enhanced the plant height, number of leaves, and the dry mass of the inoculated cowpea plants as compared to the control. The treated plants exhibited higher net carbon dioxide (CO2) assimilation rates in the gas exchange evaluation as well as higher stomatal conductance, evapotranspiration rates, and chlorophyll (a + b) content than the control plants. Moreover, the Kaplan-Meier survival analysis showed that the B. bassiana negatively affected the survival of the insect in the leaf disc assays.


Subject(s)
Beauveria , Coleoptera , Vigna , Animals , Insecta , Pest Control, Biological , Plants
7.
Entropy (Basel) ; 23(12)2021 Nov 27.
Article in English | MEDLINE | ID: mdl-34945893

ABSTRACT

Acoustic emission is a non-destructive testing method where sensors monitor an area of a structure to detect and localize passive sources of elastic waves such as expanding cracks. Passive source localization methods based on times of arrival (TOAs) use TOAs estimated from the noisy signals received by the sensors to estimate the source position. In this work, we derive the probability distribution of TOAs assuming they were obtained by the fixed threshold technique-a popular low-complexity TOA estimation technique-and show that, if the sampling rate is high enough, TOAs can be approximated by a random variable distributed according to a mixture of Gaussian distributions, which reduces to a Gaussian in the low noise regime. The optimal source position estimator is derived assuming the parameters of the mixture are known, in which case its MSE matches the Cramér-Rao lower bound, and an algorithm to estimate the mixture parameters from noisy signals is presented. We also show that the fixed threshold technique produces biased time differences of arrival (TDOAs) and propose a modification of this method to remove the bias. The proposed source position estimator is validated in simulation using biased and unbiased TDOAs, performing better than other TOA-based passive source localization methods in most scenarios.

9.
Plant Cell Environ ; 39(10): 2235-46, 2016 10.
Article in English | MEDLINE | ID: mdl-27342381

ABSTRACT

Although Selenium (Se) stress is relatively well known for causing growth inhibition, its effects on primary metabolism remain rather unclear. Here, we characterized both the modulation of the expression of specific genes and the metabolic adjustments in Arabidopsis thaliana in response to changes in Se level in the soil. Se treatment culminated with strong inhibition of both shoot and root growth. Notably, growth inhibition in Se-treated plants was associated with an incomplete mobilization of starch during the night. Minor changes in amino acids levels were observed in shoots and roots of plants treated with Se whereas the pool size of tricarboxylic acid (TCA) cycle intermediates in root was not altered in response to Se. By contrast, decreased levels of organic acids involved in the first part of the TCA cycle were observed in shoots of Se-treated plants. Furthermore, decreased expression levels of expansins and endotransglucosylases/endohydrolases (XHTs) genes were observed after Se treatment, coupled with a significant decrease in the levels of essential elements. Collectively, our results revealed an exquisite interaction between energy metabolism and Se-mediated control of growth in Arabidopsis thaliana to coordinate cell wall extension, starch turnover and the levels of a few essential nutrients.


Subject(s)
Arabidopsis/drug effects , Selenium/pharmacology , Stress, Physiological , Arabidopsis/growth & development , Arabidopsis/metabolism , Carbon/metabolism , Cell Wall/metabolism , Citric Acid Cycle , Gene Expression Regulation, Plant/drug effects , Photosynthesis/drug effects , Plant Roots/drug effects , Plant Roots/growth & development , Plant Roots/metabolism , Plant Shoots/drug effects , Plant Shoots/growth & development , Plant Shoots/metabolism
10.
J Exp Bot ; 67(10): 2989-3001, 2016 05.
Article in English | MEDLINE | ID: mdl-27012286

ABSTRACT

The rates of increase in yield of the main commercial crops have been steadily falling in many areas worldwide. This generates concerns because there is a growing demand for plant biomass due to the increasing population. Plant yield should thus be improved in the context of climate change and decreasing natural resources. It is a major challenge which could be tackled by improving and/or altering light-use efficiency, CO2 uptake and fixation, primary metabolism, plant architecture and leaf morphology, and developmental plant processes. In this review, we discuss some of the traits which could lead to yield increase, with a focus on how natural genetic variation could be harnessed. Moreover, we provide insights for advancing our understanding of the molecular aspects governing plant growth and yield, and propose future avenues for improvement of crop yield. We also suggest that knowledge accumulated over the last decade in the field of molecular physiology should be integrated into new ideotypes.


Subject(s)
Crop Production , Genetic Variation/physiology , Plant Development/genetics , Plant Leaves/anatomy & histology , Genetic Variation/genetics , Photosynthesis/genetics , Photosynthesis/physiology , Plant Development/physiology , Plant Leaves/physiology , Plant Transpiration/genetics
11.
BMJ Open ; 14(1): e076354, 2024 01 17.
Article in English | MEDLINE | ID: mdl-38233051

ABSTRACT

OBJECTIVE: Dose shortages delayed access to COVID-19 vaccination. We aim to characterise inequality in two-dose vaccination by sociodemographic group across Brazil. DESIGN: This is a cross-sectional study. SETTING: We used data retrieved from the Brazilian Ministry of Health databases published between 17 January 2021 and 6 September 2021. METHODS: We assessed geographical inequalities in full vaccination coverage and dose by age, sex, race and socioeconomic status. We developed a Campaign Optimality Index to characterise inequality in vaccination access due to premature vaccination towards younger populations before older and vulnerable populations were fully vaccinated. Generalised linear regression was used to investigate the risk of death and hospitalisation by age group, socioeconomic status and vaccination coverage. RESULTS: Vaccination coverage is higher in the wealthier South and Southeast. Men, people of colour and low-income groups were more likely to be only partially vaccinated due to missing or delaying a second dose. Vaccination started prematurely for age groups under 50 years which may have hindered uptake in older age groups. Vaccination coverage was associated with a lower risk of death, especially in older age groups (ORs 9.7 to 29.0, 95% CI 9. 4 to 29.9). Risk of hospitalisation was greater in areas with higher vaccination rates due to higher access to care and reporting. CONCLUSIONS: Vaccination inequality persists between states, age and demographic groups despite increasing uptake. The association between hospitalisation rates and vaccination is attributed to preferential delivery to areas of greater transmission and access to healthcare.


Subject(s)
COVID-19 Vaccines , COVID-19 , Male , Female , Humans , Aged , Middle Aged , Socioeconomic Factors , Brazil/epidemiology , Cross-Sectional Studies , Sociodemographic Factors , COVID-19/epidemiology , COVID-19/prevention & control , Vaccination , Immunization Programs
12.
J Plant Physiol ; 293: 154170, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38271894

ABSTRACT

Although significant efforts to produce carotenoid-enriched foods either by biotechnology or traditional breeding strategies have been carried out, our understanding of how changes in the carotenoid biosynthesis might affect overall plant performance remains limited. Here, we investigate how the metabolic machinery of well characterized tomato carotenoid mutant plants [namely crimson (old gold-og), Delta carotene (Del) and tangerine (t)] adjusts itself to varying carotenoid biosynthesis and whether these adjustments are supported by a reprogramming of photosynthetic and central metabolism in the source organs (leaves). We observed that mutations og, Del and t did not greatly affect vegetative growth, leaf anatomy and gas exchange parameters. However, an exquisite metabolic reprogramming was recorded on the leaves, with an increase in levels of amino acids and reduction of organic acids. Taken together, our results show that despite minor impacts on growth and gas exchange, carbon flux is extensively affected, leading to adjustments in tomato leaves metabolism to support changes in carotenoid biosynthesis on fruits (sinks). We discuss these data in the context of our current understanding of metabolic adjustments and carotenoid biosynthesis as well as regarding to improving human nutrition.


Subject(s)
Solanum lycopersicum , Humans , Solanum lycopersicum/genetics , Fruit/metabolism , Metabolic Reprogramming , Carotenoids/metabolism , Plants/metabolism , Plant Leaves/metabolism , Gene Expression Regulation, Plant
13.
Sci Rep ; 14(1): 22546, 2024 09 29.
Article in English | MEDLINE | ID: mdl-39343801

ABSTRACT

The production of açaí seed waste from the commercial and extractive exploitation of the Euterpe oleraceae palm tree is a serious problem that contributes to environmental contamination and production of greenhouse gases, a fact that suggests the need for an environmentally correct destination for this waste produced on a large scale. To this end, this study was conducted to evaluate the potential of acaí seed biochar (BCA) in mitigating the toxic effects of copper in Brazilian mahogany plants, analyzing biometrics and gas exchange. The experimental design was in randomized blocks, with five blocks, in a 4 × 3 factorial scheme, corresponding to the control (without Cu) and three concentration of Cu (200, 400, and 600 mg Cu kg-1) and three levels of BCA (0%, 5% and 10%) proportional to the amount of soil in the pots, totaling sixty experimental units. The use of 5% BCA in soils contaminated with up to 200 mg kg-1 Cu promoted biometric increase (height, diameter, number of leaves), maintaining gas exchange (photosynthesis, stomatal conductance, transpiration, internal carbon and internal/external carbon), and consequently, maintaining water use efficiency in plants under abiotic stress, resulting in plant growth. The findings of this study allow us to indicate the use of biochar in remediating and improving the growth of plants grown in copper-contaminated soils. The production of biochar from açaí seeds is an ecologically sustainable alternative, because it reduces its accumulation on public roads and contributes to reducing soil pollution. In the context of public policies, biochar production could be a source of income in the context of the bioeconomy and circular economy practiced in the Amazon, because it is produced in large quantities.


Subject(s)
Charcoal , Copper , Soil Pollutants , Soil Pollutants/toxicity , Soil/chemistry , Seeds/growth & development , Seeds/drug effects , Photosynthesis/drug effects
14.
Sports (Basel) ; 11(12)2023 Dec 11.
Article in English | MEDLINE | ID: mdl-38133109

ABSTRACT

The current study verified the acute responses of participants to a football match in terms of blood markers. Sixteen elite U-18 male football players were divided into two groups: experimental (EG, n = 10), who played a friendly football match; and control (CG), who were not exposed to any physical exertion. Intravenous blood samples were collected from both groups at baseline, pre-match, half-time, and post-match. The blood analysis consisted of four groups: immunological (leukocytes, platelets, and cortisol), muscle damage (creatine kinase and lactate dehydrogenase), metabolic (lactate, glucose, erythrocytes, hematocrit, hemoglobin, and urea), and electrolytic (sodium, calcium, and potassium). Edwards' training impulse demonstrated that the first half was more demanding than the second half (p = 0.020). Significant changes between time points and groups were observed for leukocytes (pre-match: 6920 ± 1949; post-match: 13,890 ± 3292; p ≤ 0.05) and cortisol (pre-match: 10.78 ± 3.63; post-match: 19.15 ± 7.40; p ≤ 0.05). CK (pre-match: 516.50 ± 248.38; post-match: 713.70 ± 308.20; p ≤ 0.05) and LDH (pre-match: 348.80 ± 36.49; post-match: 414.80 ± 26.55; p ≤ 0.05) increased significantly across the time points for the EG, with no difference between the groups, however. Raised lactate (pre-match: 1.05 ± 0.32; post-match: 3.24 ± 1.60; p ≤ 0.05) and glucose (pre-match: 72.54 ± 9.76; post-match: 101.42 ± 19.87; p ≤ 0.05) differences between the groups at half-time were also observed. These current findings provide helpful information to better understand football match demands regarding physiological effects.

15.
J Vis Exp ; (199)2023 09 22.
Article in English | MEDLINE | ID: mdl-37811948

ABSTRACT

Reestablishing balance after a trip is challenging for lower-limb amputees and often results in a fall. The effectiveness of reestablishing balance following a trip depends on factors such as amputation level (transtibial or transfemoral) or which limb is tripped (prosthetic or sound/lead or trailing). Understanding the recovery responses can help identify strategies to avoid a trip becoming a fall and what trip-response functionality could be designed into a prosthesis. This study presents an experimental approach for inducing unexpected trips in individuals with amputation. Tripping was manually triggered by activating an electromagnetic device to raisea polypropylene wire to obstruct (bring to a near halt) theswinging limb during its mid-swing phase. A safety harness attached to a ceiling rail ensured participants did not hit the ground if they failed to reestablish balance following the trip (i.e., it prevented a fall from occurring). One transtibial amputee completed repeated walking trials in which a trip was induced around 1 out of 15 times to avoid it being anticipated. 3D kinematics were determined via two smartphones (60Hz) using the OpenCap software, highlighting that the experimental approach induced meaningful tripping/recovery responses dependent on which limb was tripped (prosthetic or sound). The presented methodology avoids using a rigid obstacle, potentially reducing the risk of injuries, and is inexpensive and easy to set up. Importantly it permits a trip to be unexpectedly introduced during the mid-swing phase of the gait and hence provides an approach for identifying real-world trip recovery responses. When tripping the sound limb, participants could 'disentangle' from the trip-wire (post-trip) by plantarflexing the ankle, but such action was not possible when tripping the prosthetic limb.


Subject(s)
Amputees , Artificial Limbs , Humans , Lower Extremity/surgery , Lower Extremity/physiology , Gait/physiology , Walking/physiology , Biomechanical Phenomena
16.
Braz J Microbiol ; 54(4): 3113-3125, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37661212

ABSTRACT

The study aimed to evaluate the effectiveness of endophytic colonization via leaf and root inoculation of five Trichoderma species in a Eucalyptus hybrid, as well as the effects of inoculation on plant growth. The experimental design was completely randomized in a 6 × 2 factorial scheme. Plant growth was evaluated during the experimental period at three different times: 20 days after inoculation (d.a.i), 40 d.a.i., and 60 d.a.i. A statistical difference was observed between the inoculation methods during each period and between the Trichoderma species. Plants inoculated with T. asperellum showed the greatest growth among the treatments. Root-inoculated plants produced the greatest growth response. This showed that the presence of Trichoderma in the roots assisted in nutrient assimilation, promoted greater plant growth, when compared with leaf-inoculated plants. Evaluation of the effectiveness of endophytic colonization was performed at each sampling period by collecting leaf samples, and at 60 d.a.i., by collecting leaf, stem, and root samples. T. longibrachiatum and T. harzianum were isolated from leaves at 20 d.a.i., with an increase in the number of colonized plants throughout the evaluation of leaf-inoculated plants. In root-inoculated plants, treatment with T. longibrachiatum, T. harzianum, and T. asperellum presented the highest endophytic colonization in the stem and root samples (at 60 d.a.i.).


Subject(s)
Eucalyptus , Trichoderma , Trichoderma/physiology , Plant Roots/microbiology
17.
Plant Physiol Biochem ; 202: 107994, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37660605

ABSTRACT

Boron (B) is an essential nutrient for the plant, and its stress (both deficiency and toxicity) are major problems that affect crop production. Ethylene metabolism (both signaling and production) is important to plants' differently responding to nutrient availability. To better understand the connections between B and ethylene, here we investigate the function of ethylene in the responses of tomato (Solanum lycopersicum) plants to B stress (deficiency, 0 µM and toxicity, 640 µM), using ethylene related mutants, namely nonripening (nor), ripening-inhibitor (rin), never ripe (Nr), and epinastic (Epi). Our results show that B stress does not necessarily inhibit plant growth, but both B stress and ethylene signaling severely affected physiological parameters, such as photosynthesis, stomatal conductance, and chlorophyll a fluorescence. Under B toxicity, visible symptoms of toxicity appeared in the roots and margins of the older leaves through necrosis, caused by the accumulation of B which stimulated ethylene biosynthesis in the shoots. Both nor and rin (ethylene signaling) mutants presented similar responses, being these genotypes more sensitive and displaying several morphophysiological alterations, including fruit productivity reductions, in response to the B toxicity conditions. Therefore, our results suggest that physiological and metabolic changes in response to B fluctuations are likely mediated by ethylene signaling.


Subject(s)
Boron , Ethylenes , Solanum lycopersicum , Solanum lycopersicum/drug effects , Solanum lycopersicum/genetics , Solanum lycopersicum/growth & development , Solanum lycopersicum/metabolism , Fruit , Boron/toxicity , Signal Transduction , Mutation , Ethylenes/metabolism , Photosynthesis , Nitrates/metabolism , Sugars/analysis , Amino Acids/analysis
18.
Plants (Basel) ; 12(13)2023 Jul 05.
Article in English | MEDLINE | ID: mdl-37447116

ABSTRACT

Water deficit inhibits plant growth by affecting several physiological processes, which leads to the overproduction of reactive oxygen species (ROS) that may cause oxidative stress. In this regard, iodine (I) is already known to possibly enhance the antioxidant defense system of plants and promote photosynthetic improvements under adverse conditions. However, its direct effect on water deficit responses has not yet been demonstrated. To verify the efficiency of I concerning plant tolerance to water deficit, we exposed soybean plants to different concentrations of potassium iodide (KI) fed to pots with a nutrient solution and subsequently submitted them to water deficit. A decline in biomass accumulation was observed in plants under water deficit, while exposure to KI (10 and 20 µmol L-1) increased plant biomass by an average of 40%. Furthermore, exposure to KI concentrations of up to 20 µM improved gas exchange (~71%) and reduced lipid peroxidation. This is related to the higher enzymatic antioxidant activities found at 10 and 20 µM KI concentrations. However, when soybean plants were properly irrigated, KI concentrations greater than 10 µM promoted negative changes in photosynthetic efficiency, as well as in biomass accumulation and partition. In sum, exposure of soybean plants to 10 µM KI improved tolerance to water deficit, and up to this concentration, there is no evidence of phytotoxicity in plants grown under adequate irrigation.

19.
Plants (Basel) ; 12(23)2023 Nov 29.
Article in English | MEDLINE | ID: mdl-38068658

ABSTRACT

A water deficit can negatively impact fruit yield and quality, affecting critical physiological processes. Strategies to mitigate water deficits are crucial to global food security. Iodine (I) may increase the efficiency of the antioxidant system of plants, but its role against water deficits is poorly understood. This study aimed to evaluate the effectiveness of I in attenuating water deficits and improving fruit quality, investigating whether metabolic responses are derived from a "priming effect" or stress relief during water deficits. Tomato plants were exposed to different concentrations of potassium iodide (KI) via a nutrient solution and subjected to a water deficit. A water deficit in tomatoes without KI reduced their yield by 98%. However, a concentration of 100 µM of KI increased the yield under a water deficit by 28%. This condition is correlated with increased antioxidant activity, photosynthetic efficiency improvement, and malondialdehyde reduction. In addition, the concentration of 100 µM of KI promoted better fruit quality through antioxidant capacity and a decline in the maturation index. Therefore, KI can be an alternative for attenuating water deficits in tomatoes, inducing positive responses during the water deficit period while at the same time improving fruit quality.

20.
J Mot Behav ; 54(3): 382-390, 2022.
Article in English | MEDLINE | ID: mdl-34569440

ABSTRACT

In elite-level soccer, the ability to take shots with both limbs from different positions in the pitch may be key to success. This research aimed to: 1) analyze footedness of elite-football players in European leagues during shooting by computing frequency of right- and left-foot use and accuracy; and 2) investigate whether an athlete's distance from the target (goal, penalty, and outside penalty area) and pitch zone (center, left, or right from the goal) can constrain foot selection during shooting. We analyzed 1826 games from the 2017/18 season, divided between: Spanish LaLiga (380 matches); Italian Serie A (380 matches); English Premier League (380 matches); German Bundesliga (306 matches); and French Ligue 1 (380 matches). Results revealed asymmetrical proportions of foot selection, favoring the preferred foot for right- and left-footed athletes. Frequency of preferred foot selection increased as a function of distance from the target (i.e., the farther the athlete, higher the percentage of preferred foot selection). Shots taken from the left side were more often performed with the right foot and vice-versa, for both left- and right-footed athletes. Interestingly, asymmetries were observed only in foot selection, but not in performance, as success rate did not vary between limbs in any position.


Subject(s)
Athletic Performance , Soccer , Humans , Athletes , Europe , Foot
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