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1.
Photodiagnosis Photodyn Ther ; : 102232, 2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33631380

RESUMO

PURPOSE: The aim of this laboratory study was to investigate the amount of bacterial destruction through riboflavin mediated photodynamic therapy (PDT) around fixed orthodontic devices by using two strains of bacteria including Streptococcus mutans and Streptococcus sanguinis. MATERIALS AND METHODS: A total of 80 metallic brackets were divided into four groups consisting of 20 brackets each. Group-I: riboflavin + LED irradiation; Group-II: riboflavin alone; Group-III: immersion in 0.2% chlorhexidine gluconate solution and Group-IV: not submitted to any treatment. All metallic brackets were immersed in the standard bacterial solutions and incubated at 48 h. All samples were subjected to MTT assay for microbial cell viability testing after treatment. After 24 h of incubation, biofilms adhered on the mesh of metallic brackets after treatment were assessed by confocal laser microscopy. The total CFU/mL was estimated, and the results were log-transformed (log10) and analyzed using one-way analysis of variance and Tukey-Kramer test. P-value was set to <0.05 that indicated statistical significance. RESULTS: The samples from group-IV showed the highest amount of relative biofilm viability compared to any other group while group-I (PDT) showed the least viability of the two bacterial strains studied (p < 0.05). Group-I showed no significant difference when compared with group-III (chlorhexidine) (p > 0.05). The biofilms on the samples from group-II and group-IV were largely viable indicating thick green staining across the mesh of the brackets. Among the group-III samples, there were predominantly dead cells as compared to the live cell staining. A considerable amount of red staining was observed with noticeable less green staining in group-I samples CONCLUSION: This laboratory investigation revealed that riboflavin mediated PDT significantly reduced the amounts of S. mutans and S. sanguinis around the orthodontic brackets.

2.
Sci Rep ; 11(1): 3884, 2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33594138

RESUMO

Synchronization plays a significant role in information transfer and decision-making by neurons and brain neural networks. The development of control strategies for synchronizing a network of chaotic neurons with time delays, different direction-dependent coupling (unidirectional and bidirectional), and noise, particularly under external disturbances, is an essential and very challenging task. Researchers have extensively studied the synchronization mechanism of two coupled time-delayed neurons with bidirectional coupling and without incorporating the effect of noise, but not for time-delayed neural networks. To overcome these limitations, this study investigates the synchronization problem in a network of coupled FitzHugh-Nagumo (FHN) neurons by incorporating time delays, different direction-dependent coupling (unidirectional and bidirectional), noise, and ionic and external disturbances in the mathematical models. More specifically, this study investigates the synchronization of time-delayed unidirectional and bidirectional ring-structured FHN neuronal systems with and without external noise. Different gap junctions and delay parameters are used to incorporate time-delay dynamics in both neuronal networks. We also investigate the influence of the time delays between connected neurons on synchronization conditions. Further, to ensure the synchronization of the time-delayed FHN neuronal networks, different adaptive control laws are proposed for both unidirectional and bidirectional neuronal networks. In addition, necessary and sufficient conditions to achieve synchronization are provided by employing the Lyapunov stability theory. The results of numerical simulations conducted for different-sized multiple networks of time-delayed FHN neurons verify the effectiveness of the proposed adaptive control schemes.

3.
Chemosphere ; 273: 129690, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33524757

RESUMO

Cadmium (Cd) is a primary contaminant in agricultural soils of the world. The ability of Cd uptake, transport, detoxification, and accumulation varies among different plant species and genotypes. Cd is translocated from soil to root by different transporters which are used for essential plant nutrient uptake. A number of strategies have been suggested for decreasing Cd toxicity in Cd contaminated soils. Recently, a lot of research have been carried out on minimizing Cd uptake through selenium (Se) and silicon (Si) applications. Both Se and Si have been reported to mitigate Cd toxicity in different crops. Vacuolar sequestration, formation of phytochelatins, and cell wall adsorption have been reported as effective mechanisms for Cd detoxification. The present review discussed past and current knowledge of literature to better understand Cd toxicity and its mitigation by adopting different feasible and practical approaches.

4.
Environ Sci Pollut Res Int ; 28(8): 9002-9019, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33464530

RESUMO

Plant diseases significantly impact the global economy, and plant pathogenic microorganisms such as nematodes, viruses, bacteria, fungi, and viroids may be the etiology for most infectious diseases. In agriculture, the development of disease-free plants is an important strategy for the determination of the survival and productivity of plants in the field. This article reviews biosensor methods of disease detection that have been used effectively in other fields, and these methods could possibly transform the production methods of the agricultural industry. The precise identification of plant pathogens assists in the assessment of effective management steps for minimization of production loss. The new plant pathogen detection methods include evaluation of signs of disease, detection of cultured organisms, or direct examination of contaminated tissues through molecular and serological techniques. Laboratory-based approaches are costly and time-consuming and require specialized skills. The conclusions of this review also indicate that there is an urgent need for the establishment of a reliable, fast, accurate, responsive, and cost-effective testing method for the detection of field plants at early stages of growth. We also summarized new emerging biosensor technologies, including isothermal amplification, detection of nanomaterials, paper-based techniques, robotics, and lab-on-a-chip analytical devices. However, these constitute novelty in the research and development of approaches for the early diagnosis of pathogens in sustainable agriculture.


Assuntos
Técnicas Biossensoriais , Plantas , Agricultura , Animais , Fungos , Dispositivos Lab-On-A-Chip , Tecnologia
5.
Ecotoxicol Environ Saf ; 208: 111758, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396081

RESUMO

The cultivation of leafy vegetables on metal contaminated soil embodies a serious threat to yield and quality. In the present study, the potential role of exogenous jasmonic acid (JA; 0, 5, 10, and 20 µM) on mitigating chromium toxicity (Cr; 0, 150, and 300 µM) was investigated in choysum (Brassica parachinensis L.). With exposure to increasing Cr stress levels, a dose-dependent decline in growth, photosynthesis, and physio-biochemical attributes of choysum plants was observed. An increase in Cr levels also resulted in oxidative stress closely associated with higher lipoxygenase activity (LOX), hydrogen peroxide (H2O2) generation, lipid peroxidation (MDA), and methylglyoxal (MG) levels. Exogenous application of JA alleviated the Cr-induced phytotoxic effects on photosynthetic pigments, gas exchange parameters, and restored growth of choysum plants. While exposed to Cr stress, JA supplementation induced plant defense system via enhanced regulation of antioxidant enzymes, ascorbate and glutathione pool, and the glyoxalase system enzymes. The coordinated regulation of antioxidant and glyoxalase systems expressively suppressed the oxidative and carbonyl stress at both Cr stress levels. More importantly, JA restored the mineral nutrient contents, restricted Cr uptake, and accumulation in roots and shoots of choysum plants when compared to the only Cr-stressed plants. Overall, the application of JA2 treatment (10 µM JA) was more effective and counteracted the detrimental effects of 150 µM Cr stress by restoring the growth and physio-biochemical attributes to the level of control plants, while partially mitigated the detrimental effects of 300 µM Cr stress. Hence, JA application might be considered as an effective approach for minimizing Cr uptake and its detrimental effects in choysum plants grown on contaminated soils.


Assuntos
Antioxidantes/farmacologia , Brassica/fisiologia , Cromo/toxicidade , Ciclopentanos/farmacologia , Oxilipinas/farmacologia , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Brassica/efeitos dos fármacos , Brassica/metabolismo , Glutationa/metabolismo , Peróxido de Hidrogênio/metabolismo , Oxirredução , Estresse Oxidativo/fisiologia , Fotossíntese/efeitos dos fármacos , Folhas de Planta/metabolismo
6.
Exp Appl Acarol ; 83(2): 211-227, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33387143

RESUMO

The webbing life type of three spider mite species of the genus Oligonychus was studied based on web-associated behavioral characteristics. All tested Oligonychus species-viz., avocado brown mite, Oligonychus punicae (Hirst), date palm mite, Oligonychus afrasiaticus (McGregor), and banks grass mite, Oligonychus pratensis (Banks)-exhibited a complicated-web (CW) life type on various host plants. A new life type, 'CW-c,' was documented for O. punicae on the adaxial leaf side of Conocarpus erectus L. (Combretaceae). The weaving pattern with guy ropes is spun by the O. punicae female and is associated with stalked eggs; it appeared as a unique character in the CW-life type. Oligonychus afrasiaticus, also showed a new life type, 'CW-d,' when reared on the abaxial side of leaves of four host plants, viz., desert fan palm, maize, sorghum, and sugarcane. Oligonychus afrasiaticus showed a site for quiescence and a site for oviposition as variables, whereas the site for defecation (SD) was a persistent characteristic on all four tested host plants. Oligonychus pratensis showed the characteristics of the sub-type 'CW-u' on the abaxial leaf side of Washingtonia filifera (Lindl.) H. Wendl. (Arecaceae). The SD was a distinguishing behavioral characteristic used to separate O. afrasiaticus from O. pratensis when inhabiting the same host plant, W. filifera.


Assuntos
Ácaros , Persea , Phoeniceae , Tetranychidae , Animais , Feminino , Masculino , Oviposição
7.
J Hazard Mater ; 402: 123919, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33254825

RESUMO

The heavy metal pollution is a worldwide problem and has received a serious concern for the ecosystem and human health. In the last decade, remediation of the agricultural polluted soil has attracted great attention. Phytoremediation is one of the technologies that effectively alleviate heavy metal toxicity, however, this technique is limited to many factors contributing to low plant growth rate and nature of metal toxicities. Arbuscular mycorrhizal fungi (AMF) assisted alleviation of heavy metal phytotoxicity is a cost-effective and environment-friendly strategy. AMF have a symbiotic relationship with the host plant. The bidirectional exchange of resources is a hallmark and also a functional necessity in mycorrhizal symbiosis. During the last few years, a significant progress in both physiological and molecular mechanisms regarding roles of AMF in the alleviation of heavy metals (HMs) toxicities in plants, acquisition of nutrients, and improving plant performance under toxic conditions of HMs has been well studied. This review summarized the current knowledge regarding AMF assisted remediation of heavy metals and some of the strategies used by mycorrhizal fungi to cope with stressful environments. Moreover, this review provides the information of both molecular and physiological responses of mycorrhizal plants as well as AMF to heavy metal stress which could be helpful for exploring new insight into the mechanisms of HMs remediation by utilizing AMF.

8.
Chemosphere ; 263: 128169, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297138

RESUMO

A hydroponic study was conducted to determine the effects of single and/or combined application of different doses (0, 5 and 10 µM L-1) of abscisic acid (ABA) and 6-benzylaminopurine (BAP) on cobalt (Co) accumulation, morpho-physiological and antioxidative defense attributes of tomato (Solanum lycopersicum L.) exposed to severe Co stress (400 µM L-1). The single Co treatment (T1), prominently decreased tomato growth, relative water contents, photosynthetic pigments (chlorophyll a and chlorophyll b), whereas enhanced oxidative stress and Co accumulation in shoot and root tissues. Nonetheless, the supplementation of ABA and 6-BAP via nutrient media significantly (P < 0.05) enhanced plant biomass, root morphology and chlorophyll contents of tomato, compared to only Co treatment (T1). Moreover, the oxidative stress indicators such as malondialdehyde, proline and H2O2 contents were ameliorated through activation of enzymatic antioxidant activities i.e. ascorbate peroxidase, superoxide dismutase, catalase, and peroxidase, in growth modulator treatments in comparison to T1. The Co uptake, translocation (TF) and bioaccumulation factor (BAF) by shoot and root tissues of tomato were significantly reduced under all the treatments than that of T1. The supply of 6-BAP alone or in combination with ABA at 10 µM L-1 application (T7) rate was found the most effective to reduce Co accumulation in the roots and shoots by 48.4% and 70.2% respectively than T1 treatment. It can be concluded that two plant growth modulators could improve the stress tolerance by inhibition of Co uptake in tomato plants.


Assuntos
Antioxidantes , Lycopersicon esculentum , Ácido Abscísico , Compostos de Benzil , Clorofila , Clorofila A , Cobalto/toxicidade , Peróxido de Hidrogênio , Folhas de Planta , Purinas
9.
Int J Biol Macromol ; 168: 383-394, 2021 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-33321134

RESUMO

Different films comprising pure chitosan (CS) and chitosan coated sodium zeolites composites films designated as CSZ1, CSZ2, CSZ3 and CSZ4 respectively are presented here for the sequestration of MO dye. The as-synthesized films were characterized by using FSESM, XPS XRD, and TGA analysis. The sequestration of methyl orange dye (MO) was studied under various adsorption parameters i.e. pH effect, reaction temperature, catalytic dosage, interaction period, and original dye concentration in batch experiments. The adsorption power of MO dye sequestration in the presence of CSZ3 was 287 mg g-1 higher than the fine CS (201 mg g-1), and lowest for CSZ4 (173 mg g-1). The experimental data is fitted in the pseudo-second order of chemical kinetics. The Freundlich and Langmuir adsorption models were used on behalf of the analysis of experimental data that revealed multilayered adsorption of MO dye. Kinetics, equilibrium and thermodynamic process were discussed in detailed, suggesting the endothermic and spontaneous process of the adsorption of MO dye on the exterior of films. The present work is general for the MO adsorption, however, it can be applied on large scale applications and can be easily adjustable in the water purification assemblies.

10.
Artigo em Inglês | MEDLINE | ID: mdl-33281032

RESUMO

Silicon (Si), a major contributing constituent for plant resistance against abiotic stresses. In spite of this, the detailed mechanisms underlying the potential of Si in mitigating salt toxicity in maize (Zea mays L.) are still poorly understood. The present study deals with the response of Si application on growth, gaseous exchange, ion homeostasis and antioxidant enzyme activities in two maize cultivars (P1574 and Hycorn 11) grown under saline conditions. Salt stress remarkably reduced the plant tissue (roots and shoots) biomass, relative water contents (RWC), membrane stability index (MSI), gaseous exchange characteristics, and antioxidant enzymatic activities i.e., superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX) and catalase (CAT). However, salt-induced phytotoxicity increased the plant tissue concentration of malondialdehyde (MDA), hydrogen peroxide (H2O2), Na+/K+ ionic ratio, Na+ translocation (root to shoot), and its uptake. The detrimental effects were more prominent in Hycorn 11 cultivar than the P1574 cultivar at higher salinity level (S2; 160 mM NaCl). The addition of Si alleviated salt toxicity, which was more obvious in P1574 relative to Hycorn 11 as demonstrated by an increasing trend in RWC, MSI, and activities of SOD, POD, APX and CAT. Besides, Si-induced mitigation of salt stress was due to the depreciation in Na+/K+ ratio, Na+ ion uptake at the surface of maize roots, translocation in plant tissues and thereby significantly reduced Na+ ion accumulation. The findings showed a new dimension regarding the beneficial role of Si in maize plants grown under salt toxicity.

11.
Physiol Plant ; 2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-33159319

RESUMO

Recently, melatonin has gained significant importance in plant research. The presence of melatonin in the plant kingdom has been known since 1995. It is a molecule that is conserved in a wide array of evolutionary distant organisms. Its functions and characteristics have been found to be similar in both plants and animals. The review focuses on the role of melatonin pertaining to physiological functions in higher plants. Melatonin regulates physiological functions regarding auxin activity, root, shoot, and explant growth, activates germination of seeds, promotes rhizogenesis (growth of adventitious and lateral roots), and holds up impelled leaf senescence. Melatonin is a natural bio-stimulant that creates resistance in field crops against various abiotic stress, including heat, chemical pollutants, cold, drought, salinity, and harmful ultra-violet radiation. The full potential of melatonin in regulating physiological functions in higher plants still needs to be explored by further research.

12.
Chemosphere ; : 128938, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33199108

RESUMO

Cadmium (Cd) pollution is a key concern globally that affects plant growth and productivity. Boron (B) is a micronutrient that helps in the formation of the primary cell wall (CW) and alleviates negative effects of toxic elements on plant growth. Nonetheless, knowledge about how B can reduce Cd toxicity in rice seedlings is not enough, particularly regarding CW-Cd adsorption. Therefore, the current experiment investigated the alleviative role of B on Cd toxicity in rice seedling. The experiment was carried out with 0 µM and 30 µM H3BO3 under 50 µM Cd toxicity in hydroponics. The results showed that Cd exposure alone inhibited plant growth parameters and caused lipid peroxidation. Moreover, Cd toxicity led to obvious visible toxicity symptoms on the leaves. However, increasing the availability of B alleviated Cd toxicity by reducing Cd concentration in plant tissues and improving antioxidative system. Moreover, cell wall pectin and hemicellulose adsorbed a significant amount of Cd. Fourier-Transform Infrared spectroscopy (FTIR) spectra exhibited that cell wall functional groups were increased by B application. Scanning electron microscopy (SEM) equipped with energy-dispersive X-ray (EDX) microanalysis confirmed the higher Cd binding onto CW. The findings of this investigation showed that B could mitigate Cd stress by decreasing Cd uptake and encouraging Cd adsorption on CW, and activation of the protective mechanisms. The present results might help to increase rice productivity on Cd polluted soils.

13.
Physiol Plant ; 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33206390

RESUMO

The unpredictable precipitation and water deficit conditions in semiarid regions significantly reduce the yield of summer maize. The exogenous application of plant growth regulators can be used as a strategy to enhance plant stress tolerance and improve the growth and yield of maize under semiarid conditions. Here, we studied the protective role of melatonin application on maize yield using grain filling rate and hormonal crosstalk in maize grains. In the first field experiment, seeds were soaked with melatonin at a concentration of 0 (SM0 ), 25 (SM1 ), 50 (SM2 ), and 75 µM (SM3 ) µM. In contrast, in the second experiment, melatonin was applied on the foliage at the ninth leaf stage at a concentration of 0 (FM0 ), 25 (FM1 ), 50 (FM2 ), and 75 (FM3 ) µM. Our findings showed that melatonin treatments as seed soaking significantly increased single seed weight, seed filling rate in superior, medium and inferior seeds by regulating the hormone levels compared to foliar application. Application of melatonin significantly increased the zeatin + zeatin riboside (Z + ZR), indole-3-acetic acid (IAA), gibberellic acid (GA) contents. However, it significantly inhibited the contents of abscisic acid (ABA) during the seed filling period. The content of Z + ZR, IAA, and GA was positively correlated with the maximum seed filling rate, seed weight, and mean filling rate in middle, superior and lower seeds, while the ABA was negatively correlated. The ABA content in inferior seeds was positively correlated with the maximum and mean seed filling rate. In semiarid regions, melatonin treatment of SM2 and FM2 significantly increased the dry matter per plant, hundred grain weight, seed filling rate, IAA, Z + ZR, GA contents, ear characteristics, and maize yield.

14.
Nanoscale ; 12(41): 21409-21419, 2020 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-33079113

RESUMO

The Himalayan monal is a bird in the pheasant family, and it is the national bird of Nepal. The bird possesses spectacular iridescent plumage with a range of different metallic colours. Here, we have studied the internal structure of its feathers from different parts of the bird's body and showed that its beautiful colours and iridescence are due to photonic structures present in the internal structure of the feathers. Sharp changes in the reflected brilliance were observed from the feathers upon changing the illumination conditions, such as horizontal and azimuthal angles. The feathers exhibited interesting hydrophobic properties, with the dull-coloured proximal end showing lower hydrophobicity with a contact angle between 90° and 110° compared with the iridescent distal end of a feather exhibiting a contact angle between 115° and 120°, attributed to the change in the internal structure and/or density of the feathers. A quick reversible change in colours of these feathers was observed when they were soaked in water and other liquids, which reversed upon drying. The shift in colour was suggested to be due to the swelling of the keratin layer of barbules that absorbed liquids and as a result modified the refractive index and periodicity of the internal photonic structures. The colour shift response of feathers was different in the case of alcohols and other water-based solutions, suggesting different swelling behaviour of keratin against different liquids; the water-based solution had the more pronounced effect. Such photonic modulation can be utilized in colour selective filters and sensing devices.

16.
Artigo em Inglês | MEDLINE | ID: mdl-33006098

RESUMO

Air pollution has become a major global problem. Thus, the goal of this study was to find out the economic impacts (treatment cost) of air pollution on households as well as the principal factors inducing an individual's willingness to pay for better air quality. District Faisalabad was purposively selected for sampling, as it is a major industrial hub in Pakistan. The required information was collected from 120 sampled respondents through a structured questionnaire. The ordinary least squares method was used for assessing the impact of various factors on the treatment cost of the most recent episode of ailment related to air pollution. The ordered logit model was used to assess the impacts of factors affecting the willingness to pay for programs aimed at the provision of better environmental services. The results revealed that high air pollution in the urban area resulted in more lost workdays and higher health costs. The findings also showed that people were willing to pay for better air quality in urban areas than in rural areas. Based on the findings, it is suggested that the incentive schemes may be designed for the promotion of cleaner services in rural and urban areas.

17.
J Chromatogr A ; 1631: 461559, 2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-33007581

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are generated primarily during the incomplete combustion of organic matter and are ubiquitous environmental pollutants. For the first time, in this study, a mesoporous carbon derived from asphalt with high surface area (2300 m²g-1 with an average of 1.2 cm³ g-1) was utilized as a sorbent for the solid-phase extraction (SPE) of several PAHs in tap water samples. The factors influencing the extraction capability of the new material were investigated and the optimum conditions were determined to be as follows: Sample volume - 200 mL, no adjustment of sample pH, and sorbent amount - 50 mg. Under the most favorable SPE conditions, with gas chromatography-mass spectrometric analysis, the method exhibited a linear range of 0.5-50 µgL-1 with limits of detection between 0.004 and 0.026 µgL-1. The recoveries obtained from spiked tap water samples spiked at 1 µgL-1 and 5 µgL-1, were in the range 86.7-98.2% with relative standard deviations of <9%. The method was also applied to tap water samples collected from the local environment. The concentrations of PAHs detected ranged between 0.13 and 48 µgL-1. The reusability of the sorbent was tested with five consecutive SPE extraction, and no carryover of analytes was observed.

18.
Sci Total Environ ; 755(Pt 2): 142582, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-33065502

RESUMO

The application of biochar to soils contaminated with potentially toxic elements (PTEs) has received particular attention due to its ability to reduce PTE uptake by the plants. Therefore, we conducted a meta-analysis to identify Cd and Pb concentrations in plant shoots and roots in response to biochar application and soil properties. We collected data from 65 peer-reviewed journal articles published from 2009 to 2020 in which 66% of manuscripts were published from 2015 to 2020. The data were processed using OpenMEE software. The results pinpointed that addition of biochar to soil caused a significant decrease in shoot and root Cd and Pb concentrations as compared to untreated soils with biochar (control), and the reduction rate was affected by plant types and both biochar and soil properties. The biochar size less than 2 mm, biochar pH higher than 10, pyrolysis temperature of 401-600 °C, and the application rate higher than 2% appeared to be effective in reducing shoot and root Cd and Pb concentration. Soil properties such as pH, SOC, and texture influenced the efficiency of biochar for reducing plant Cd and Pb uptake. Biochar application increased SOC (54.3%), CEC (48.0%), pH (0.08), and EC (59.4%), and reduced soil extractable Cd (42.1%) and Pb (47.1%) concentration in comparison to control. A detailed study on the rhizosphere chemistry and uptake mechanism will help to underpin the biochar application rates and their efficiency reducing PTE mobility and plant uptake.

19.
Protoplasma ; 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-32968872

RESUMO

Phytohormones are important for the growth and development of plants. The objective of the experiment was to investigate the effect of foliar application of uniconazole (UCZ) at the four-leaf stage on hormone crosstalk and production of winter wheat. An experiment was carried out during 2015-2016 and 2016-2017 growth season in a semi-arid region, where UCZ at a concentration of 0 (CK, distilled water), 15 (FU15), 30 (FU30), and 45 (FU45) mg L-1 were sprayed on wheat crop at the four-leaf stage at a rate of 138.8 mL m-2. UCZ alters the endogenous hormone contents in flag leaves and in grains. UCZ inhibited gibberellic acid (GA) in flag leaves and in grains where the lower GA with UCZ improved the zeatin + zeatin riboside (Z + ZR) and abscisic acid (ABA) contents. The lower GA and higher Z + ZR and ABA contents with UCZ-treated plants improved the chlorophyll content and canopy apparent photosynthesis (CAP) as well as the grain-filling characteristics. The Z + ZR and ABA in flag leaves were positively correlated with chlorophyll content and CAP value while negatively with GA. Moreover, the Z + ZR and ABA were positively correlated with maximum grain weight, mean grain-filling rate, and maximum grain-filling rate, while negatively with GA level. Treatment FU30 significantly improved the chlorophyll content, CAP value, spike weight, grain-filling characteristics, and hormone contents of Z + ZR and ABA while it decreased the GA level. The hormone crosstalk with UCZ significantly increased the yield of wheat crop, where FU30 treatment performs better.

20.
Cureus ; 12(8): e9751, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32944466

RESUMO

Introduction The prognosis of breast cancer depends on the histological type, size of the tumor, tumor necrosis, skin, nipple and chest wall invasion, lymphovascular invasion, grade, stage, the status of estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor 2 (HER2), cell proliferation marker (ki-67), and type of therapy. Estrogen receptor and progesterone receptor expression in breast cancer is, so far, the most useful predictive marker. We have undertaken this study to find the expression of ER and PgR in breast carcinoma and its association with other prognostically important clinicopathological variables. Materials and methods In this cross-sectional study, a total of 130 cases of modified radical mastectomy that have been diagnosed as malignant on histopathology were collected from the pathology department of Allama Iqbal Medical College, Lahore, from January 2016 to May 2018. The demographic data and gross and microscopic findings were recorded. Immunohistochemistry (ER, PgR) was applied to suitable tumor sections and their status was evaluated semi-quantitatively by histopathologists using College American Pathologist (CAP) guidelines. Result Most of the breast cancer patients (69; 53.1%) were below 50 years of age. Fifty-nine (45.4%) and 48 (36.9%) cases were positive for ER and PgR, respectively, showing lower hormonal receptor positivity than that reported in the western population where ER expression has been found in 50%-80% of cases and PR expression is found in 60%-70% of cases of invasive ductal carcinoma. The association of the expression of hormone receptors with a clinicopathological variable was demonstrated. ER-/PgR- tumors showed a higher histologic grade, greater tumor size, and more lymph node involvement by metastasis. Conclusion Low hormone receptor positivity is associated with young patients, advanced stage at presentation, and higher grade in our population. The tumor characteristics are different as compared to the western population. This suggests more consideration to the screening, early diagnosis, and molecular or immunohistochemical typing of this cancer in our population.

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