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1.
Bioprocess Biosyst Eng ; 47(8): 1119-1137, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38904717

RESUMEN

Silver nanoparticles (AgNPs) have gained significant attention in various applications due to their unique properties that differ from bulk or macro-sized counterparts. In the advancement of nanotechnology, a reliable, non-toxic, and eco-friendly green synthesis has widely been developed as an alternative method for the production of AgNPs, overcoming limitations associated with the traditional physical and chemical methods. Green synthesis of AgNPs involves the utilization of biological sources including plant extracts with silver salt as the precursor. The potential of phytochemicals in plant extracts serves as a reducing/capping and stabilizing agent to aid in the bio-reduction of Ag+ ions into a stable nanoform, Ag0. This review provides insights into the potentials of various plant parts like root, stem, leaf, flower, fruit, and seed extracts that have been extensively reported for the synthesis of AgNPs.


Asunto(s)
Nanopartículas del Metal , Extractos Vegetales , Plata , Plata/química , Nanopartículas del Metal/química , Extractos Vegetales/química , Semillas/química , Flores/química , Tecnología Química Verde/métodos , Frutas/química , Hojas de la Planta/química , Raíces de Plantas/química
2.
Ecotoxicol Environ Saf ; 207: 111081, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-32927154

RESUMEN

Brassinosteroids and hydrogen peroxide (H2O2) are extensively used to combat several environmental factors, including heavy metal stress in plants, but their cumulative impact on the maintenance of copper (Cu) homeostasis in plants could not be dissected at elevated level. This study was executed to explore the roles of 24-epibrassinolide (EBL; foliar) and H2O2 (root dipping) in resilience of tomato (Solanum lycopersicum L.) plants to Cu stress. The cumulative effect of EBL and H2O2 in tomato plants grown under Cu stress (10 or 100 mg kg-1 soil) were assessed. Roots of 20 d old plants were submerged in 0.1 mM of H2O2 solution for 4 h and subsequently transplanted in the soil-filled earthen pots and at 30 day after transplantation (DAT), the plants were sprinkled with deionized water (control), and/or 10-8 M EBL and plant performances were evaluated at 40 DAT. High Cu (100 mg kg-1 soil) concentration considerably reduced photosynthetic efficacy, cell viability, and plant growth, and deformed chloroplast ultrastructure and root morphology with altered stomatal behavior, but boosted the activity of antioxidant enzymes, proline content and electrolyte leakage in the leaves of tomato. Moreover, EBL and H2O2 implemented through distinct modes improved photosynthetic efficiency, modified chloroplast ultrastructure, stomatal behavior, root structure, cell viability and production of antioxidants and proline (osmolyte) that augmented resilience of tomato plants to Cu stress. This study revealed the potential of EBL and H2O2 applied through distinct mode could serve as an effective strategy to reduce Cu-toxicity in tomato crop.


Asunto(s)
Cobre/toxicidad , Contaminantes del Suelo/toxicidad , Solanum lycopersicum/fisiología , Antioxidantes/farmacología , Brasinoesteroides/farmacología , Supervivencia Celular , Peróxido de Hidrógeno/metabolismo , Solanum lycopersicum/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Fotosíntesis/efectos de los fármacos , Hojas de la Planta/metabolismo , Prolina/metabolismo , Estallido Respiratorio , Suelo , Esteroides Heterocíclicos
3.
Physiol Mol Biol Plants ; 26(1): 25-39, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32158118

RESUMEN

Menthol mint (Mentha arvensis L.) cultivation is significantly affected by the heavy metals like cadmium (Cd) which also imposes severe health hazards. Two menthol mint cultivars namely Kosi and Kushal were evaluated under Cd stress conditions. Impact of plant growth regulators (PGRs) like salicylic acid (SA), gibberellic acid (GA3) and triacontanol (Tria) on Cd stress tolerance was assessed. Reduced growth, photosynthetic parameters, mineral nutrient concentration, and increased oxidative stress biomarkers like electrolyte leakage, malondialdehyde, and hydrogen peroxide contents were observed under Cd stress. Differential upregulation of proline content and antioxidant activities under Cd stress was observed in both the cultivars. Interestingly, low electrolyte leakage, lipid peroxidation, hydrogen peroxide and Cd concentration in leaves were observed in Kushal compared to Kosi. Among all the PGRs tested, SA proved to be the best in improving Cd-stress tolerance in both the cultivars but Kushal responded better than Kosi.

4.
Physiol Mol Biol Plants ; 26(10): 1931-1944, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33088040

RESUMEN

Melatonin (MEL) is the potential biostimulator molecule, governing multiple range of growth and developmental processes in plants, particularly under different environmental constrains. Mainly, its role is considered as an antioxidant molecule that copes with oxidative stress through scavenging of reactive oxygen species and modulation of stress related genes. It also enhances the antioxidant enzyme activities and thus helps in regulating the redox hemostasis in plants. Apart from its broad range of antioxidant functions, it is involved in the regulation of various physiological processes such as germination, lateral root growth and senescence in plants. Moreover this multifunctional molecule takes much interest due to its recent identification and characterization of receptorCandidate G-protein-Coupled Receptor 2/Phytomelatonin receptor(CAND2/PMTR1) in Arabidopsis thaliana. In this compiled work, different aspects of melatonin in plants such as melatonin biosynthesis and detection in plants, signaling pathway, modulation of stress related genes and physiological role of melatonin under different environmental stresses have been dissected in detail.

5.
Physiol Mol Biol Plants ; 25(4): 905-919, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31404216

RESUMEN

Brassinosteroids and polyamines are generally used to surpass different abiotic stresses like heavy metal toxicity in plants. The current study was conducted with an aim that 24-epibrassinolide (EBL) and/or spermidine (Spd) could modify root morphology, movement of stomata, cell viability, photosynthetic effectiveness, carbonic anhydrase and antioxidant enzyme activities in Brassica juncea under manganese (Mn) stress (30 or 150 mg kg-1 soil). EBL (10-8 M) and/or Spd, (1.0 mM) were applied to the foliage of B. juncea plants at 35 days after sowing (DAS), grown in the presence of Mn (30 or 150 mg kg-1 soil). High Mn concentration (150 mg kg-1 soil) altered root morphology, affected stomatal movement, reduced the viability of cells and photosynthetic effectiveness and increased the production of reactive oxygen species (O2 ·- and H2O2) in the leaves and antioxidant defense system of B. juncea at 45 DAS. Furthermore, exogenous treatment of EBL and Spd under stress and stress- free conditions improved the aforesaid traits while decreased the O2 ·- and H2O2 production. Therefore, EBL and Spd could be applied to the foliage of B. juncea plants for the better growth under metal stress.

6.
Proc Natl Acad Sci U S A ; 112(46): 14354-9, 2015 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-26578782

RESUMEN

In the past decade, characterization of the host targets of pathogen virulence factors took a center stage in the study of pathogenesis and disease susceptibility in plants and humans. However, the impressive knowledge of host targets has not been broadly exploited to inhibit pathogen infection. Here, we show that host target modification could be a promising new approach to "protect" the disease-vulnerable components of plants. In particular, recent studies have identified the plant hormone jasmonate (JA) receptor as one of the common targets of virulence factors from highly evolved biotrophic/hemibiotrophic pathogens. Strains of the bacterial pathogen Pseudomonas syringae, for example, produce proteinaceous effectors, as well as a JA-mimicking toxin, coronatine (COR), to activate JA signaling as a mechanism to promote disease susceptibility. Guided by the crystal structure of the JA receptor and evolutionary clues, we succeeded in modifying the JA receptor to allow for sufficient endogenous JA signaling but greatly reduced sensitivity to COR. Transgenic Arabidopsis expressing this modified receptor not only are fertile and maintain a high level of insect defense, but also gain the ability to resist COR-producing pathogens Pseudomonas syringae pv. tomato and P. syringae pv. maculicola. Our results provide a proof-of-concept demonstration that host target modification can be a promising new approach to prevent the virulence action of highly evolved pathogens.


Asunto(s)
Aminoácidos/metabolismo , Arabidopsis , Toxinas Bacterianas/metabolismo , Interacciones Huésped-Patógeno , Indenos/metabolismo , Pseudomonas syringae , Aminoácidos/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/microbiología , Toxinas Bacterianas/genética , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Pseudomonas syringae/patogenicidad , Pseudomonas syringae/fisiología
7.
Ecotoxicol Environ Saf ; 129: 25-34, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26974871

RESUMEN

24-Epibrassinolide (EBL) and Selenium (Se) individually confer tolerance to various abiotic stresses, but their interactive effect in the regulation of copper (Cu) homeostasis in plants exposed to toxic levels of Cu is poorly investigated. This study provides an insight into the effects of EBL (foliar) and/or Se (through sand) on Brassica juncea plants exposed to toxic levels of Cu. The combined effect of EBL and Se on compartmentalization of Cu, oxidative stress markers, photosynthetic machinery and biochemical traits in B. juncea were analyzed. Application of EBL and Se through different mode modulated the compartmentalization of Cu in different parts of plants, enhanced the photosynthetic traits, and activities of various antioxidant enzymes and proline accumulation in B. juncea under excess copper levels. These enhanced levels of antioxidant enzymes, proline (osmolyte) accumulation triggered by combination of EBL and Se could have conferred tolerance to the B. juncea plants under toxic level of copper and also maintained Cu homeostasis in various parts of plants. This study indicates that combination of EBL and Se through different mode is an operative approach for Cu detoxification in plants and could be exploited for removal of excess copper from polluted soil.


Asunto(s)
Brasinoesteroides/farmacología , Cobre/metabolismo , Planta de la Mostaza/efectos de los fármacos , Prolina/metabolismo , Selenio/farmacología , Esteroides Heterocíclicos/farmacología , Planta de la Mostaza/metabolismo , Estrés Oxidativo/efectos de los fármacos , Fotosíntesis/efectos de los fármacos
8.
Physiol Mol Biol Plants ; 20(4): 449-60, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25320468

RESUMEN

The role of 28-homobrassinolide (HBL) in countering nickel-induced oxidative damage through overexpression of antioxidant enzymes and proline in Vigna radiata has been investigated. Two varieties of V. radiata, one sensitive to Ni (PDM-139) and the other tolerant to Ni (T-44), were sown in the soil fed with different levels (0, 50, 100 or 150 mg kg(-1)) of Ni, and at 29-day stage, foliage of plants was applied with deionized water (control), 10(-8) or 10(-6) M of HBL. The plants were sampled at 45-day stage of growth to assess various physiological as well as biochemical characteristics. The remaining plants were allowed to grow up to maturity to study the yield characteristics. The growth traits, leghemoglobin, nitrogen and carbohydrate content in the nodules, leaf chlorophyll content, photosynthesis efficiency, leaf water potential, activities of nitrate reductase, carbonic anhydrase and nitrogenase decreased proportionately with the increasing concentrations of nickel, whereas electrolyte leakage, various antioxidant enzymes viz. catalase, peroxidase and superoxide dismutase and accumulation of proline increased at 45-day stage. However, the exogenously applied HBL to the nickel-stressed or non-stressed plants improved growth, nodulation and photosynthesis and further enhanced the various antioxidant enzymes viz. catalase, peroxidase and superoxide dismutase and accumulation of proline. The deleterious impact of Ni on the plants was concentration dependent where HBL applied to the foliage induced overexpression of antioxidant enzyme and accumulation of proline (osmolyte) which could have conferred tolerance to Ni up to 100 mg kg(-1), resulting in improved growth, nodulation, photosynthesis and yield attributes.

9.
Plant Physiol Biochem ; 208: 108502, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38492486

RESUMEN

Gamma-aminobutyric acid (GABA) is an amino acid with a four-carbon structure, widely distributed in various organisms. It exists as a zwitterion, possessing both positive and negative charges, enabling it to interact with other molecules and participate in numerous physiological processes. GABA is widely distributed in various plant cell compartments such as cytoplasm mitochondria, vacuoles, peroxisomes, and plastids. GABA is primarily synthesized from glutamate using glutamate decarboxylase and participates in the GABA shunt within mitochondria, regulating carbon and nitrogen metabolism in plants The transport of GABA is regulated by several intracellular and intercellular transporters such as aluminium-activated malate transporters (ALMTs), GABA transporters (GATs), bidirectional amino acid transporters (BATs), and cationic amino acid transporters (CATs). GABA plays a vital role in cellular transformations, gene expression, cell wall modifications, and signal transduction in plants. Recent research has unveiled the role of GABA as a signaling molecule in plants, regulating stomatal movement and pollen tube growth. This review provides insights into multifaceted impact of GABA on physiological and biochemical traits in plants, including cellular communication, pH regulation, Krebs cycle circumvention, and carbon and nitrogen equilibrium. The review highlights involvement of GABA in improving the antioxidant defense system of plants, mitigating levels of reactive oxygen species under normal and stressed conditions. Moreover, the interplay of GABA with other plant growth regulators (PGRs) have also been explored.


Asunto(s)
Plantas , Ácido gamma-Aminobutírico , Ácido gamma-Aminobutírico/metabolismo , Plantas/metabolismo , Carbono/metabolismo , Estrés Fisiológico/genética , Transducción de Señal , Nitrógeno/metabolismo
10.
Plant Physiol Biochem ; 211: 108674, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38705044

RESUMEN

Plants produce a diverse range of secondary metabolites that serve as defense compounds against a wide range of biotic and abiotic stresses. In addition, their potential curative attributes in addressing various human diseases render them valuable in the development of pharmaceutical drugs. Different secondary metabolites including phenolics, terpenes, and alkaloids have been investigated for their antioxidant and therapeutic potential. A vast number of studies evaluated the specific compounds that possess crucial medicinal properties (such as antioxidative, anti-inflammatory, anticancerous, and antibacterial), their mechanisms of action, and potential applications in pharmacology and medicine. Therefore, an attempt has been made to characterize the secondary metabolites studied in medicinal plants, a brief overview of their biosynthetic pathways and mechanisms of action along with their signaling pathways by which they regulate various oxidative stress-related diseases in humans. Additionally, the biotechnological approaches employed to enhance their production have also been discussed. The outcome of the present review will lead to the development of novel and effective phytomedicines in the treatment of various ailments.


Asunto(s)
Fitoquímicos , Plantas Medicinales , Metabolismo Secundario , Humanos , Alcaloides/metabolismo , Antioxidantes/metabolismo , Fenoles/metabolismo , Plantas/metabolismo , Plantas Medicinales/química , Plantas Medicinales/metabolismo , Terpenos/metabolismo , Fitoquímicos/uso terapéutico
11.
Plant Physiol Biochem ; 196: 1065-1083, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36921557

RESUMEN

Adverse environmental constraints such as drought, heat, cold, salinity, and heavy metal toxicity are the primary concerns of the agricultural industry across the globe, as these stresses negatively affect yield and quality of crop production and therefore can be a major threat to world food security. Recently, it has been demonstrated that hydrogen sulfide (H2S), which is well-known as a gasotransmitter in animals, also plays a potent role in various growth and developmental processes in plants. H2S, as a potent signaling molecule, is involved in several plant processes such as in the regulation of stomatal pore movements, seed germination, photosynthesis and plant adaptation to environmental stress through gene regulation, post-translation modification of proteins and redox homeostasis. Moreover, a number of experimental studies have revealed that H2S could improve the adaptation capabilities of plants against diverse environmental constraints by mitigating the toxic and damaging effects triggered by stressful environments. An attempt has been made to uncover recent development in the biosynthetic and metabolic pathways of H2S and various physiological functions modulated in plants, H2S donors, their functional mechanism, and application in plants. Specifically, our focus has been on how H2S is involved in combating the destructive effects of abiotic stresses and its role in persulfidation. Furthermore, we have comprehensively elucidated the crosstalk of H2S with plant growth regulators.


Asunto(s)
Gasotransmisores , Sulfuro de Hidrógeno , Reguladores del Crecimiento de las Plantas/metabolismo , Sulfuro de Hidrógeno/metabolismo , Estrés Fisiológico , Plantas/metabolismo , Gasotransmisores/metabolismo
12.
Plants (Basel) ; 12(19)2023 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-37836091

RESUMEN

This study aimed to assess the effects of low-temperature stress on two tomato cultivars (S-22 and PKM-1) treated with 24-epibrassinolide (EBL) and selenium (Se) by determining the changes in the proteomics profiles, growth biomarkers, biochemical parameters, and physiological functions. The growth parameters, photosynthetic traits, and activity of nitrate reductase in the S-22 and PKM-1 plants were markedly reduced by exposure to low temperatures. However, the combined application of EBL and Se under different modes significantly enhanced the aforementioned parameters under stress and non-stress conditions. Exposure to low temperatures increased the activities of the antioxidant enzymes (catalase, peroxidase, and superoxide dismutase) and the proline content of leaves, which were further enhanced by treatment with Se and EBL in both varieties. This research sheds light on the potential for employing exogenous EBL and Se as crucial biochemical tactics to assist tomato plants in surviving low-temperature stress. Moreover, the differentially expressed proteins that were involved in plant metabolism following the combined application of EBL and Se under low-temperature stress were additionally identified. Functional analysis revealed that the Q54YH4 protein plays an active role against plant stressors. The conserved regions in the protein sequences were analyzed for assessing the reliability of plant responses against the external application of EBL and Se under low temperatures.

13.
J Hazard Mater ; 434: 128830, 2022 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-35429754

RESUMEN

Selenium (Se) is a well-known beneficial element in plants. The window of Se between toxic and optimal concentration is narrow and uneven which fluctuates with plants species. This experiment was aimed to investigate the morpho-physiological, microscopic and histochemical responses of two different varieties of tomato (S-22 and PKM-1), exposed to different concentrations of Se (0, 10, 40 or 80 µM), applied to soil at 30 days after transplantation (DAT). At 40 DAT, it was observed that high concentrations (40 or 80 µM) of Se radically increased oxidative stress examined by elevated reactive oxygen species (ROS), malondialdehyde (MDA) content, cell death, electrolyte leakage and decreased chlorophyll content leading phenotypic symptoms of Se-induced toxicity like stunted growth and chlorosis. Furthermore, high doses of Se altered the chloroplast and stomatal organisation, and adversely affected the photosynthetic performance of plants. But low concentration of Se improved the plant dry mass, photosynthesis, Rubisco activity, protein content and maintained the steady-state equilibrium among ROS generation and antioxidant enzymes like catalase, peroxidase and superoxide dismutase. Our outcomes proposed that high concentration of Se generated toxicity (phyto-selenosis), whereas lower concentration of Se-triggered positive impact by improving growth, photosynthetic traits and maintaining steady-state equilibrium between scavenging-system and ROS generation.


Asunto(s)
Selenio , Solanum lycopersicum , Antioxidantes/metabolismo , Catalasa/metabolismo , Clorofila/metabolismo , Solanum lycopersicum/metabolismo , Estrés Oxidativo , Fotosíntesis , Especies Reactivas de Oxígeno/metabolismo , Selenio/metabolismo , Superóxido Dismutasa/metabolismo
14.
Plant Physiol Biochem ; 188: 97-107, 2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-35995025

RESUMEN

Salinity stress is one of the major abiotic constraints that limit plant growth and yield, which thereby is a serious concern to world food security. It adversely affects crop production by inducing hyperosmotic stress and ionic toxicity as well as secondary stresses such as oxidative stress, all of which disturb optimum physiology and metabolism. Nonetheless, various strategies have been employed to improve salt tolerance in crop plants, among which the application of Melatonin (Mel) could also be used as it has demonstrated promising results. The ongoing experimental evidence revealed that Mel is a pleiotropic signaling molecule, which besides being involved in various growth and developmental processes also mediates environmental stress responses. The current review systematically discusses and summarizes how Mel mediates the response of plants under salt stress and could optimize the balance between plant growth performances and stress responses. Specifically, it covers the latest advances of Mel in fine-tuning the signaling in plants. Furthermore, it highlights plant-built tolerance of salt stress by manifesting the biosynthesis of Mel, its cross talks with nitric oxide (NO), and Mel as a multifaceted antioxidant molecule.


Asunto(s)
Melatonina , Antioxidantes/metabolismo , Melatonina/farmacología , Plantas/metabolismo , Estrés Salino , Tolerancia a la Sal , Estrés Fisiológico
15.
Arch Environ Contam Toxicol ; 60(1): 68-76, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20464550

RESUMEN

Seeds of five wheat (Triticum aestivum) cultivars (PBW-373, UP-2338, DL-LOK-01, DL-373, and HD-2338) were sown in earthen pots and 10-day-old seedlings were exposed to 0, 50, and 100 µM of nickel (Ni) in the form of nickel chloride. At the 20-day stage, seedlings were sprayed with 0.01 µM of 28-homobrassinolide (HBL). The results of the experiment at the 30-day stage revealed a decline in the dry mass per plant, leaf area, leaf water potential, and net photosynthetic rate with concomitant decline in the activities of various enzymes (viz. carbonic anhydrase and nitrate reductase) with an increasing concentration of Ni. However, an increase in proline content and the activities of catalase, peroxidase, and superoxide dismutase was observed as a result of an increase in Ni concentration. Moreover, the treatment of these stressed plants with HBL enhanced the activities of carbonic anhydrase and nitrate reductase, catalase, peroxidase, and superoxide dismutase. The proline content in the leaves also increased, which is known to act as an osmolyte and reactive oxygen species scavenger. The toxic effects generated by Ni were ameliorated by HBL through an improved antioxidant system and osmolyte. Moreover, improvement of photosynthetic parameters and growth characteristics further strengthen our belief that HBL acted as a potent stress alleviator.


Asunto(s)
Colestanonas/metabolismo , Níquel/toxicidad , Hojas de la Planta/efectos de los fármacos , Triticum/efectos de los fármacos , Antioxidantes/metabolismo , Enzimas/metabolismo , Fotosíntesis , Hojas de la Planta/enzimología , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Prolina/análisis , Prolina/metabolismo , Triticum/enzimología , Triticum/crecimiento & desarrollo , Triticum/metabolismo
16.
Plant Physiol Biochem ; 168: 381-397, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34715564

RESUMEN

In plants, the reactive oxygen species (ROS) formed during normal conditions are essential in regulating several processes, like stomatal physiology, pathogen immunity and developmental signaling. However, biotic and abiotic stresses can cause ROS over-accumulation leading to oxidative stress. Therefore, a suitable equilibrium is vital for redox homeostasis in plants, and there have been major advances in this research arena. Salicylic acid (SA) is known as a chief regulator of ROS; however, the underlying mechanisms remain largely unexplored. SA plays an important role in establishing the hypersensitive response (HR) and systemic acquired resistance (SAR). This is underpinned by a robust and complex network of SA with Non-Expressor of Pathogenesis Related protein-1 (NPR1), ROS, calcium ions (Ca2+), nitric oxide (NO) and mitogen-activated protein kinase (MAPK) cascades. In this review, we summarize the recent advances in the regulation of ROS and antioxidant defense system signalling by SA at the physiological and molecular levels. Understanding the molecular mechanisms of how SA controls redox homeostasis would provide a fundamental framework to develop approaches that will improve plant growth and fitness, in order to meet the increasing global demand for food and bioenergy.


Asunto(s)
Inmunidad de la Planta , Ácido Salicílico , Oxidación-Reducción , Especies Reactivas de Oxígeno , Transducción de Señal
17.
Chemosphere ; 252: 126486, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32234629

RESUMEN

Hydrogen peroxide (H2O2) acts as a significant regulatory component interrelated with signal transduction in plants. The positive role of H2O2 in plants subjected to myriad of abiotic factors has led us to comprehend that it is not only a free radical, generated as a product of oxidative stress, but also helpful in the maintenance of cellular homeostasis in crop plants. Studies over the last two centuries has indicated that H2O2 is a key molecule which regulate photosynthesis, stomatal movement, pollen growth, fruit and flower development and leaf senescence. Exogenously-sourced H2O2 at nanomolar levels functions as a signalling molecule, facilitates seed germination, chlorophyll content, stomatal opening, and delays senescence, while at elevated levels, it triggers oxidative burst to organic molecules, which could lead to cell death. Furthermore, H2O2 is also known to interplay synergistically or antagonistically with other plant growth regulators such as auxins, gibberellins, cytokinins, abscisic acid, jasmonic acid, ethylene and salicylic acid, nitric oxide and Ca2+ (as signalling molecules), and brassinosteroids (steroidal PGRs) under myriad of environmental stresses and thus, mediate plant growth and development and reactions to abiotic factors. The purpose of this review is to specify accessible knowledge on the role and dynamic mechanisms of H2O2 in mediating growth responses and plant resilience to HM stresses, and its crosstalk with other significant PGRs in controlling various processes. More recently, signal transduction by mitogen activated protein kinases and other transcription factors which attenuate HM stresses in plants have also been dissected.


Asunto(s)
Metales Pesados/toxicidad , Desarrollo de la Planta/efectos de los fármacos , Estrés Fisiológico/fisiología , Ácido Abscísico/metabolismo , Muerte Celular , Clorofila/metabolismo , Citocininas/metabolismo , Homeostasis , Peróxido de Hidrógeno/metabolismo , Ácidos Indolacéticos/metabolismo , Metales Pesados/metabolismo , Óxido Nítrico/metabolismo , Fotosíntesis , Reguladores del Crecimiento de las Plantas/metabolismo , Plantas/metabolismo , Transducción de Señal
18.
Chemosphere ; 230: 544-558, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31125883

RESUMEN

Plant growth and development could be modulated by minute concentrations of hydrogen peroxide (H2O2) which serves as a signaling molecule for various processes. The present work was conducted with an aim that H2O2 could also modify root morphology, morphology and movement of stomata, photosynthetic responses, activity of carbonic anhydrase, and antioxidant systems in tomato (Solanum lycopersicum L.) plants under copper stress (Cu; 10 or 100 mg kg-1 soil). Roots of 20 d old plants were dipped in 0.1 or 0.5 mM of H2O2 solution for 4 h and then transplanted to the soil filled in earthen pots. High Cu stress (100 mg kg-1 soil) altered root morphology, reduced chlorophyll content and photosynthetic capacity and also affected movement of stomata and generation of antioxidant species at 40 d after transplantation. Further, root dipping treatment of H2O2 to plants under stress and stress-free conditions enhanced accumulation of proline and activity of catalase, peroxidase, and superoxide dismutase, whereas production of superoxide radical (O2•¯) and H2O2 were decreased. Overall, H2O2 treatment improved growth, photosynthesis, metabolic state of the plants which provided tolerance and helped the plants to cope well under Cu stress.


Asunto(s)
Antioxidantes/metabolismo , Cobre/toxicidad , Peróxido de Hidrógeno/farmacología , Estrés Oxidativo/efectos de los fármacos , Fotosíntesis/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Solanum lycopersicum/crecimiento & desarrollo , Solanum lycopersicum/enzimología , Solanum lycopersicum/metabolismo , Raíces de Plantas/enzimología , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo
19.
Chemosphere ; 236: 124830, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31549671

RESUMEN

Polyamines (PAs) are recognized as plant growth regulators that are involved in the stress management in various crops. In the current study, mitigative roles of spermidine (Spd) and putrescine (Put) were assessed in manganese (Mn) stressed Brassica juncea plants. Spd or Put (1.0 mM) were applied to the foliage of Brassica juncea at 35 days after sowing (DAS) grown in the presence of Mn (30 or 150 mg kg-1 soil). The higher level of Mn (150 mg kg-1) diminished photosynthetic attributes and growth, enhanced the production of reactive oxygen species (ROS) like hydrogen peroxide (H2O2) and superoxide anion ( [Formula: see text] ) content, affected stomatal movement and increased the Mn concentration in roots and shoots of the plant at 45 DAS, whereas it enhanced the activities of various antioxidant enzymes and proline content in the foliage of Brassica juncea plants. On the other hand, treatment of PAs (Spd or Put) to Mn stressed as well as non-stressed plants resulted in a remarkable improvement in the stomatal behaviour, photosynthetic attributes, growth and biochemical traits, decreased the production of ROS (H2O2 and [Formula: see text] ) and concentration of Mn in different parts of plant. It is concluded that out of the two polyamines (Spd or Put), Spd proved more efficient and enhanced growth, photosynthesis, and metabolic state of the plants which bestowed tolerance and helped the plants to cope efficiently under Mn stress.


Asunto(s)
Antioxidantes/farmacología , Manganeso/toxicidad , Planta de la Mostaza/química , Fotosíntesis , Poliaminas/farmacología , Antioxidantes/metabolismo , Peróxido de Hidrógeno/metabolismo , Manganeso/farmacología , Planta de la Mostaza/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Poliaminas/metabolismo , Putrescina/farmacología , Especies Reactivas de Oxígeno/metabolismo , Espermidina/farmacología
20.
Environ Sci Pollut Res Int ; 26(17): 17163-17172, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31001773

RESUMEN

High temperature poses a severe extortion to productivity of many crops like wheat. Therefore, well documented roles of brassinosteroid (BR) and silicon (Si) in terms of abiotic stress tolerance, the current study was designed to evaluate the response of wheat (Triticum aestivum L. Var. PBW-343) to 24-epibrassinolide (EBL) mediated by silicon grown under high temperature stress. At 10- and 12-day stage after sowing, the seedlings were administered Si (0.8 mM) through the sand, and the plants at 20, 22, or 24 days after sowing (DAS) were given EBL (0.01µM) through foliage. Plants were treated to high-temperature stress (35/28 or 40/35 °C), for 24 h with 12-h photoperiod in plant growth chamber at 25- and 26-day stage of growth. High temperatures cause significant reduction in growth performance and photosynthesis-related attributes at 35 days after sowing. However, antioxidant enzymes and proline content also augmented substantially with increasing temperature. BR and Si enhanced antioxidant activity and proline content, which was earlier increased by the high temperature. It is established that interaction of EBL and Si considerably improved the growth features, photosynthetic efficacy, and several biochemical traits under high-temperature stress through elevated antioxidant system and osmoprotectant.


Asunto(s)
Brasinoesteroides/metabolismo , Silicio/metabolismo , Esteroides Heterocíclicos/metabolismo , Temperatura , Triticum/fisiología , Antioxidantes , Fotosíntesis , Prolina/metabolismo , Plantones/metabolismo , Silicio/química , Estrés Fisiológico/fisiología , Superóxido Dismutasa/metabolismo , Triticum/crecimiento & desarrollo
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