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Natural evolution has resulted in reduced cold tolerance in cultivated tomato (Solanum lycopersicum). Herein, we perform a combined analysis of ATAC-Seq and RNA-Seq in cold-sensitive cultivated tomato and cold-tolerant wild tomato (S. habrochaites). We identify that WRKY34 has the most significant association with differential chromatin accessibility and expression patterns under cold stress. We find that a 60 bp InDel in the WRKY34 promoter causes differences in its transcription and cold tolerance among 376 tomato accessions. This 60 bp fragment contains a GATA cis-regulatory element that binds to SWIBs and GATA29, which synergistically suppress WRKY34 expression under cold stress. Moreover, WRKY34 interferes with the CBF cold response pathway through regulating transcription and protein levels. Our findings emphasize the importance of polymorphisms in cis-regulatory regions and their effects on chromatin structure and gene expression during crop evolution.
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Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas , Regiones Promotoras Genéticas , Solanum lycopersicum , Factores de Transcripción , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Regiones Promotoras Genéticas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Frío , Respuesta al Choque por Frío/genética , Cromatina/metabolismo , Cromatina/genética , Evolución MolecularRESUMEN
We analyzed the effects of foliar spraying with amino acids, chitosan (CHS) and nanocomposites (NCs) of chitosan with the amino acids proline, L-cysteine and glycine betaine (CHS-Pro NCs; CHS-Cys NCs, CHS-GB NCs, respectively) on the changes in the physiological and biochemical parameters of iceberg lettuce grown at the control temperature (20 °C) and under chilling conditions (4 °C). The physicochemical parameters of the phospholipid monolayers (PLs) extracted from plants showed the effects of the treatments on the properties of the monolayers, namely, the packing density and flexibility. We observed increased accumulation of proline at 4 °C, and differences in the concentrations of sugars in most of the analyzed variants were a consequence of the lowered temperature and/or the use of organic compounds. A temperature of 4 °C caused a significant increase in the L-ascorbic acid level compared with that at 20 °C. Differences were also found in glutathione (GSH) content depending on the temperature and treatment with the tested organic compounds. CHS NCs loaded with Pro and GB were effective at increasing the amount of phenols under stress temperature conditions. We noted that a significant increase in the antioxidant activity of plants at 4 °C occurred after priming with Cys, CHS-Cys NCs, Pro and CHS-Pro NCs, and the CHS nanocomposites were more effective in this respect. Both low-temperature stress and foliar spraying of lettuce with various organic compounds caused changes in the activity of antioxidant enzymes. Two forms of dismutase (SOD), iron superoxide dismutase (FeSOD) and copper/zinc superoxide dismutase (Cu/ZnSOD), were identified in extracts from the leaves of iceberg lettuce seedlings. The application of the tested organic compounds, alone or in combination with CHS, increased the amount of malondialdehyde (MDA) in plants grown under controlled temperature conditions. Chilling caused an increase in the content of MDA, but some organic compounds mitigated the impact of low temperature. Compared with that of plants subjected to 20 °C, the fresh weight of plants exposed to chilling decreased. However, the tested compounds caused a decrease in fresh weight at 4 °C compared with the corresponding control samples. An interesting exception was the use of Cys, for which the difference in the fresh weight of plants grown at 20 °C and 4 °C was not statistically significant. After Cys application, the dry weight of the chilled plants was greater than that of the chilled control plants but was also greater than that of the other treated plants in this group. To our knowledge, this is the first report demonstrating that engineered chitosan-amino acid nanocomposites could be applied as innovative protective agents to mitigate the effects of chilling stress in crop plants.
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Aminoácidos , Quitosano , Lactuca , Nanocompuestos , Lactuca/efectos de los fármacos , Lactuca/metabolismo , Lactuca/crecimiento & desarrollo , Nanocompuestos/química , Quitosano/química , Aminoácidos/metabolismo , Aminoácidos/química , Estrés Fisiológico/efectos de los fármacos , Hojas de la Planta/química , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/metabolismo , Temperatura , Antioxidantes/metabolismo , Cisteína/metabolismo , Cisteína/química , Prolina/metabolismo , Glutatión/metabolismoRESUMEN
Understanding and optimizing the process of grain filling helps the quest to maximize rice (Oryza sativa L.) seed yield and quality, yet the intricate mechanisms at play remain fragmented. Transcription factors (TFs) are major players in the gene networks underlying the grain filling process. Here, we employed grain incomplete filling (OsGIF1)/cell wall invertase 2, a key gene involved in grain filling, to explore its upstream TFs and identified a bZIP family TF, OsbZIP10, to be a transcriptional activator of OsGIF1. Rice grains of the knockouts of OsbZIP10 showed increased white-core rates but lower amylose content (AC), leading to better eating and cooking qualities in all genetic backgrounds investigated, though the impact of mutations in OsbZIP10 on grain weight depended on genetic background. Multi-omics analyses suggested that, in addition to OsGIF1, multiple genes involved in different biological processes contributing to grain filling were targeted by OsbZIP10, including OsAGPS1, a gene encoding the ADP-Glc pyrophosphorylase (AGPase) small subunit, and genes contributing to homeostasis of reactive oxygen species. Distinct genetic make-up was observed in OsbZIP10 between japonica and indica rice varieties, with the majority varieties of each subspecies belonging to two different haplotypes that were closely associated with AC. Overexpressing the haplotype linked to high-AC in the low-AC genetic background increased AC. Overall, this study sheds crucial light on the significance of the OsbZIP10-OsGIF1 module in the determination of rice grain quality, offering a potential avenue for genetic engineering of rice to produce seeds with tailored attributes.
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Currently, different strategies, including the application of bio-fertilizers, are used to ameliorate the adverse effects posed by salinity stress as the major global problem in plants. Fish waste is suggested as a novel bio-fertilizer to mitigate the effects of biotic and abiotic stresses. In this investigation, an experiment was conducted to investigate the effects by applying different concentrations (0, 5, 10, and 15% (v/v)) of fish waste bio-fertilizer on stevia plants grown under salt stress conditions (0, 20, 40, and 60 mM of NaCl). Results showed that salinity negatively affected growth parameters, the photosynthetic pigments, the relative water content, and the chlorophyll fluorescence parameters while increased the activity of antioxidant enzymes, total phenol, hydrogen peroxide (H2O2), malondialdehyde (MDA), proline, and total carbohydrates compared with control samples. On the other hand, the application of fish waste bio-fertilizer mitigated the effects of salinity stress by enhancing growth and mitigating stress-relative markers, especially at the highest salinity level (60 mM). Overall, fish waste bio-fertilizer could be considered a sustainable, innovative approach for the alleviation of salinity stress effects in plants and, in addition, fish waste bio-fertilizer did not cause more salinity issues, at least with the applied doses and experiment time, which is an imperative aspect.
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Salinity, one of the major abiotic stresses in plants, significantly hampers germination, photosynthesis, biomass production, nutrient balance, and yield of staple crops. To mitigate the impact of such stress without compromising yield and quality, sustainable agronomic practices are required. Among these practices, seaweed extracts (SWEs) and microbial biostimulants (PGRBs) have emerged as important categories of plant biostimulants (PBs). This research aimed at elucidating the effects on growth, yield, quality, and nutrient status of two Greek tomato landraces ('Tomataki' and 'Thessaloniki') following treatments with the Ascophyllum nodosum seaweed extract 'Algastar' and the PGPB 'Nitrostim' formulation. Plants were subjected to bi-weekly applications of biostimulants and supplied with two nutrient solutions: 0.5 mM (control) and 30 mM NaCl. The results revealed that the different mode(s) of action of the two PBs impacted the tolerance of the different landraces, since 'Tomataki' was benefited only from the SWE application while 'Thessaloniki' showed significant increase in fruit numbers and average fruit weight with the application of both PBs at 0.5 and 30 mM NaCl in the root zone. In conclusion, the stress induced by salinity can be mitigated by increasing tomato tolerance through the application of PBs, a sustainable tool for productivity enhancement, which aligns well with the strategy of the European Green Deal.
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Water stress is a major cause of yield loss in peanut cultivation. Melatonin seed priming has been used to enhance stress tolerance in several crops, but not in peanut. We investigated the impact of seed priming with melatonin on the growth, development, and drought tolerance of two peanut cultivars, TUFRunner™ '511', a drought tolerant cultivar, and New Mexico Valencia A, a drought sensitive cultivar. Peanut seed priming tests using variable rates of melatonin (0-200 µM), indicated that 50 µM of melatonin resulted in more uniform seed germination and improved seedling growth in both cultivars under non stress conditions. Seed priming with melatonin also promoted vegetative growth, as evidenced by higher whole-plant transpiration, net CO2 assimilation, and root water uptake under both well-watered and water stress conditions in both cultivars. Higher antioxidant activity and protective osmolyte accumulation, lower reactive oxygen species accumulation and membrane damage were observed in primed compared with non-primed plants. Seed priming with melatonin induced a growth promoting effect that was more evident under well-watered conditions for TUFRunnner™ '511', whereas for New Mexico Valencia A, major differences in physiological responses were observed under water stress conditions. New Mexico Valencia A primed plants exhibited a more sensitized stress response, with faster down-regulation of photosynthesis and transpiration compared with non-primed plants. The results demonstrate that melatonin seed priming has significant potential to improve early establishment and promote growth of peanut under optimal conditions, while also improve stress tolerance during water stress.
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Arachis , Deshidratación , Melatonina , Semillas , Melatonina/farmacología , Melatonina/metabolismo , Arachis/efectos de los fármacos , Arachis/crecimiento & desarrollo , Arachis/metabolismo , Arachis/fisiología , Semillas/efectos de los fármacos , Semillas/crecimiento & desarrollo , Agua/metabolismo , Germinación/efectos de los fármacos , Antioxidantes/metabolismo , Sequías , Fotosíntesis/efectos de los fármacos , Estrés Fisiológico/efectos de los fármacos , Plantones/efectos de los fármacos , Plantones/crecimiento & desarrolloRESUMEN
Plants are sessile organisms that are often subjected to a multitude of environmental stresses, with the occurrence of these events being further intensified by global climate change. Crop species therefore require specific adaptations to tolerate climatic variability for sustainable food production. Plant stress results in excess accumulation of reactive oxygen species leading to oxidative stress and loss of cellular redox balance in the plant cells. Moreover, enhancement of cellular oxidation as well as oxidative signals has been recently recognized as crucial players in plant growth regulation under stress conditions. Multiple roles of redox regulation in crop production have been well documented, and major emphasis has focused on key redox-regulated proteins and non-protein molecules, such as NAD(P)H, glutathione, peroxiredoxins, glutaredoxins, ascorbate, thioredoxins and reduced ferredoxin. These have been widely implicated in the regulation of (epi)genetic factors modulating growth and health of crop plants, with an agricultural context. In this regard, priming with the employment of chemical and biological agents has emerged as a fascinating approach to improve plant tolerance against various abiotic and biotic stressors. Priming in plants is a physiological process, where prior exposure to specific stressors induces a state of heightened alertness, enabling a more rapid and effective defense response upon subsequent encounters with similar challenges. Priming is reported to play a crucial role in the modulation of cellular redox homeostasis, maximizing crop productivity under stress conditions and thus achieving yield security. By taking this into consideration, the present review is an up-to-date critical evaluation of promising plant priming technologies and their role in the regulation of redox components toward enhanced plant adaptations to extreme unfavorable environmental conditions. The challenges and opportunities of plant priming are discussed, with an aim of encouraging future research in this field toward effective application of priming in stress management in crops including horticultural species.
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Productos Agrícolas , Oxidación-Reducción , Productos Agrícolas/metabolismo , Agricultura/métodos , Estrés Fisiológico , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Currently, salinization is impacting more than 50% of arable land, posing a significant challenge to agriculture globally. Salt causes osmotic and ionic stress, determining cell dehydration, ion homeostasis, and metabolic process alteration, thus negatively influencing plant development. A promising sustainable approach to improve plant tolerance to salinity is the use of plant growth-promoting bacteria (PGPB). This work aimed to characterize two bacterial strains, that have been isolated from pea root nodules, initially called PG1 and PG2, and assess their impact on growth, physiological, biochemical, and molecular parameters in three pea genotypes (Merveille de Kelvedon, Lincoln, Meraviglia d'Italia) under salinity. Bacterial strains were molecularly identified, and characterized by in vitro assays to evaluate the plant growth promoting abilities. Both strains were identified as Erwinia sp., demonstrating in vitro biosynthesis of IAA, ACC deaminase activity, as well as the capacity to grow in presence of NaCl and PEG. Considering the inoculation of plants, pea biometric parameters were unaffected by the presence of the bacteria, independently by the considered genotype. Conversely, the three pea genotypes differed in the regulation of antioxidant genes coding for catalase (PsCAT) and superoxide dismutase (PsSOD). The highest proline levels (212.88 µmol g-1) were detected in salt-stressed Lincoln plants inoculated with PG1, along with the up-regulation of PsSOD and PsCAT. Conversely, PG2 inoculation resulted in the lowest proline levels that were observed in Lincoln and Meraviglia d'Italia (35.39 and 23.67 µmol g-1, respectively). Overall, this study highlights the potential of these two strains as beneficial plant growth-promoting bacteria in saline environments, showing that their inoculation modulates responses in pea plants, affecting antioxidant gene expression and proline accumulation. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-024-01419-8.
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Major depressive disorder (MDD) is a prevalent psychological mood disorder that can disrupt one's functioning and result in decreased engagement in daily activities. Psychotherapy, in different approaches, is a common approach for individuals experiencing MDD. Nevertheless, a literature review of the research supporting the effectiveness of psychotherapeutic interventions in patients with MDD-impacted areas of their daily occupations, such as back to work, cognitive deficits, and well-being, has not been conducted. A literature review was carried out to evaluate the effectiveness of psychotherapy on daily occupations for individuals diagnosed with MDD. Due to variations in study design and outcome measures, a best evidence synthesis was carried out instead of a meta-analysis. Forty-one identified articles were fully assessed in total. These studies were conducted in various countries so that a global approach could be considered comprehensive. The findings showed strong evidence supporting the effectiveness of psychotherapy on return-to-work interventions in improving depressive symptoms. There was limited evidence for the effectiveness of psychotherapy on lifestyle interventions in reducing anxiety and suicidal ideation, as well as limited evidence for enhancing work participation. Notably, there were no studies evaluating individualized client-centered psychotherapy interactions with occupations, revealing a research gap. Challenges such as incomplete reporting within studies and study heterogeneity prevented a meta-analysis. While the overall evidence base for the effectiveness of psychotherapy for MDD in treating functionality is limited, the findings provide strong support for the efficacy of occupational therapy return-to-work interventions. This is particularly important given the economic costs associated with mental health issues and work-related absences. Further research is required to strengthen the existing evidence base.
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This review explores different methods of sustainably introducing nutrients from agro-industrial waste into the soil. The focus is on sustainable agriculture and how the soil system can be modified by introducing secondary raw materials and beneficial microorganisms. Soil is a nexus between plants and microorganisms that must be balanced. The article emphasizes the importance of maintaining the microbiological balance when supplying nutrients. This review is focused on the possible techniques involved in the production of biofertilizers and their mode of application into the soil system and on plants. We addressed several advantages concerning the use of beneficial microorganisms in waste management by microbial formulation techniques. Not only the advantages but several limitations and challenges were also discussed in regard to the large scale production of microbial products. Therefore, the proper treatment of industrial waste is essential so that we can preserve the environment and human safety and also achieve sustainable agriculture.
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The mechanical properties of CuTi alloys have been characterized extensively through experimental studies. However, a detailed understanding of why the strength of Cu increases after a small fraction of Ti atoms are added to the alloy is still missing. In this work, we address this question using density functional theory (DFT) and molecular dynamics (MD) simulations with the modified embedded atom method (MEAM) interatomic potentials. First, we performed calculations of the uniaxial tension deformations of small bicrystalline Cu cells using DFT static simulations. We then carried out uniaxial tension deformations on much larger bicrystalline and polycrystalline Cu cells by using MEAM MD simulations. In bicrystalline Cu, the inclusion of Ti increases the grain boundary separation energy and the maximum tensile stress. The DFT calculations demonstrate that the increase in the tensile stress can be attributed to an increase in the local charge density arising from Ti. MEAM simulations in larger bicrystalline systems have shown that increasing the Ti concentration decreases the density of the stacking faults. This observation is enhanced in polycrystalline Cu, where the addition of Ti atoms, even at concentrations as low as 1.5 atomic (at.) %, increases the yield strength and elastic modulus of the material compared to pure Cu. Under uniaxial tensile loading, the addition of small amounts of Ti hinders the formation of partial Shockley dislocations in the grain boundaries of Cu, leading to a reduced level of local deformation. These results shed light on the role of Ti in determining the mechanical properties of polycrystalline Cu and enable the engineering of grain boundaries and the inclusion of Ti to improve degradation resistance.
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Plants are exposed to multiple threats linked to climate change which can cause critical yield losses. Therefore, designing novel crop management tools is crucial. Chemical priming has recently emerged as an effective technology for improving tolerance to stress factors. Several compounds such as phytohormones, reactive species, and synthetic chimeras have been identified as promising priming agents. Following remarkable developments in nanotechnology, several unique nanocarriers (NCs) have been engineered that can act as smart delivery systems. These provide an eco-friendly, next-generation method for chemical priming, leading to increased efficiency and reduced overall chemical usage. We review novel engineered NCs (NENCs) as vehicles for chemical agents in advanced priming strategies, and address challenges and opportunities to be met towards achieving sustainable agriculture.
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Amigos , Estrés Fisiológico , Humanos , Plantas , AgriculturaRESUMEN
Soil salinity is one of the increasing problems in agricultural fields in many parts of the world, adversely affecting the performance and health of the plants. As a pleiotropic signal and antioxidant molecule in both animals and plants, melatonin has been reported to possess significant roles in combating with stress factors, in general and salt stress, in particular. In this study, the interactive effects of melatonin (0, 75, and 150 µM) and salt stress (0, 50 and 100 mM NaCl) were investigated by assaying the some agronomic, physlogical and biochemical attributes and essential oil compounds of bitter melon (Momordica charantia). The results showed that exogenous melatonin could promote net photosynthetic rate (Pn) and PSII efficiency (Fv/Fm), increase K+ content and activity of antioxidant enzymes and decrease reactive oxygen species, malondialdehyde and Na+ content in stress-submitted seedlings, in comparison to the non-stressed seedlings (p < 0.05). Melatonin increased content of essential oils. Concerning the major compounds of fruits of bitter melon, charantin, momordicin and cucurbitacin were increased with the melatonin treatments, whereas they were critically decreased with the salt stress. In addition, melatonin increased the antioxidant capacity in fruits under non-saline and salinity conditions. Amid the concentrations of melatonin, plants treated with 150 µM of melatonin under either non-saline or saline conditions showed better performance and productivity. Therefore, application of 150 µM melatonin resulted in a significant improvement of salinity tolerance and essential oil compounds in bitter melon plant, suggesting this as an efficient 'green' strategy for sustainable crop production under salt stress conditions.
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Melatonina , Momordica charantia , Aceites Volátiles , Melatonina/farmacología , Antioxidantes/farmacología , Frutas/química , Tolerancia a la Sal , Aceites Volátiles/farmacología , SalinidadRESUMEN
BACKGROUND: Cadmium (Cd) stress displays critical damage to the plant growth and health. Uptake and accumulation of Cd in plant tissues cause detrimental effects on crop productivity and ultimately impose threats to human beings. For this reason, a quite number of attempts have been made to buffer the adverse effects or to reduce the uptake of Cd. Of those strategies, the application of functionalized nanoparticles has lately attracted increasing attention. Former reports clearly noted that putrescine (Put) displayed promising effects on alleviating different stress conditions like Cd and similarly chitosan (CTS), as well as its nano form, demonstrated parallel properties in this regard besides acting as a carrier for many loads with different applications in the agriculture industry. Herein, we, for the first time, assayed the potential effects of nano-conjugate form of Put and CTS (CTS-Put NP) on grapevine (Vitis vinifera L.) cv. Sultana suffering from Cd stress. We hypothesized that their nano conjugate combination (CTS-Put NPs) could potentially enhance Put proficiency, above all at lower doses under stress conditions via CTS as a carrier for Put. In this regard, Put (50 mg L- 1), CTS (0.5%), Put 50 mg L- 1 + CTS 0.5%" and CTS-Put NPs (0.1 and 0.5%) were applied on grapevines under Cd-stress conditions (0 and 10 mg kg- 1). The interactive effects of CTS-Put NP were investigated through a series of physiological and biochemical assays. RESULTS: The findings of present study clearly revealed that CTS-Put NPs as optimal treatments alleviated adverse effects of Cd-stress condition by enhancing chlorophyll (chl) a, b, carotenoids, Fv/Fm, Y(II), proline, total phenolic compounds, anthocyanins, antioxidant enzymatic activities and decreasing Y (NO), leaf and root Cd content, EL, MDA and H2O2. CONCLUSIONS: In conclusion, CTS-Put NPs could be applied as a stress protection treatment on plants under diverse heavy metal toxicity conditions to promote plant health, potentially highlighting new avenues for sustainable crop production in the agricultural sector under the threat of climate change.
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Quitosano , Vitis , Humanos , Cadmio/toxicidad , Antioxidantes , Quitosano/farmacología , Putrescina/farmacología , Antocianinas , Peróxido de Hidrógeno , Clorofila ARESUMEN
Voids in face-centered cubic (fcc) metals are commonly assumed to form via the aggregation of vacancies; however, the mechanisms of vacancy clustering and diffusion are not fully understood. In this study, we use computational modeling to provide a detailed insight into the structures and formation energies of primary vacancy clusters, mechanisms and barriers for their migration in bulk copper, and how these properties are affected at simple grain boundaries. The calculations were carried out using embedded atom method (EAM) potentials and density functional theory (DFT) and employed the site-occupation disorder code (SOD), the activation relaxation technique nouveau (ARTn) and the knowledge led master code (KLMC). We investigate stable structures and migration paths and barriers for clusters of up to six vacancies. The migration of vacancy clusters occurs via hops of individual constituent vacancies with di-vacancies having a significantly smaller migration barrier than mono-vacancies and other clusters. This barrier is further reduced when di-vacancies interact with grain boundaries. This interaction leads to the formation of self-interstitial atoms and introduces significant changes into the boundary structure. Tetra-, penta-, and hexa-vacancy clusters exhibit increasingly complex migration paths and higher barriers than smaller clusters. Finally, a direct comparison with the DFT results shows that EAM can accurately describe the vacancy-induced relaxation effects in the Cu bulk and in grain boundaries. Significant discrepancies between the two methods were found in structures with a higher number of low-coordinated atoms, such as penta-vacancies and di-vacancy absortion by grain boundary. These results will be useful for modeling the mechanisms of diffusion of complex defect structures and provide further insights into the structural evolution of metal films under thermal and mechanical stress.
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Advances in the nanotechnology fields provided crucial applications in plant sciences, contributing to the plant performance and health under stress and stress-free conditions. Amid the applications, selenium (Se), chitosan and their conjugated forms as nanoparticles (Se-CS NPs) have been revealed to have potential of alleviating the harmful effects of the stress on several crops and subsequently enhancing the growth and productivity. The present study was addressed to assay the potential effects of Se-CS NPs in reversing or buffering the harmful effects of salt stress on growth, photosynthesis, nutrient concentration, antioxidant system and defence transcript levels in bitter melon )Momordica charantia(. In addition, some secondary metabolite-related genes were explicitly examined. In this regard, the transcriptional levels of WRKY1, SOS1, PM H+-ATPase, SKOR, Mc5PTase7, SOAR1, MAP30, α-MMC, polypeptide-P and PAL were quantified. Our results demonstrated that Se-CS NPs increased growth parameters, photosynthesis parameters (SPAD, Fv/Fm, Y(II)), antioxidant enzymatic activity (POD, SOD, CAT) and nutrient homeostasis (Na+/K+, Ca2+, and Cl-) and induced the expression of genes in bitter melon plants under salt stress (p ≤ 0.05). Therefore, applying Se-CS NPs might be a simple and effective way of improving crop plants' overall health and yield under salt stress conditions.
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Quitosano , Momordica charantia , Nanopartículas , Selenio , Selenio/farmacología , Antioxidantes/farmacología , Plantones , Quitosano/farmacología , Estrés SalinoRESUMEN
Due to their sessile nature, plant cannot escape from stress factors in their growing environment, in either biotic or abiotic nature. Amid the abiotic stress factors; high levels of soil cadmium (Cd) impose heavy metal stress on plants, resulting in critical injuries and reduced agronomic performance. In order to buffer the adverse effects of Cd stress, novel nanoparticles (NP) have been applied and notable improvements have been reported. According to the literature, the protective roles of polyamines (e.g., Putrescine; Put) and carbon quantum dots (CQD) have been reported with respect to the plant productivity under either stress or non-stress conditions. Those reports led us to hypothesize that the conjugation of Put and CQD (Put-CQD NPs) might lead to further augmented performance of plants under stress and non-stress conditions. In this regard, we successfully synthesized a novel nanomaterial Put-CQD NPs. In this respect, Put (50 mg L-1), CQD (50 mg L-1) and Put-CQD NPs (25 and 50 mg L-1) were sprayed in 'Sultana' grapevines under Cd stress (10 mg kg-1). As expected, upon stress, Cd content in leaf and root tissues increased by 103.40% and 65.15%, respectively (p < 0.05). The high uptake and accumulation of Cd in plant tissues were manifested in significant alterations of physiological and biochemical attributes of the plant. Concerning stress markers, Cd stress caused increases in content of induced MDA, H2O2, and proline as well as electrolyte leakage rate. As expected, Cd stress caused critical reductions in fresh and dry leaf weight by 21.31% and 42.34%, respectively (p < 0.05). On the other hand, both Put-CQD NPs increased fresh and dry leaf weigh up to approximately 30%. The Cd-mediated disturbances in photosynthetic pigments and chlorophyll fluorescence were buffered with Put-CQD NPs. Of the defence system, enzymatic (SOD, APX, GP) as well as anthocyanin and phenolics were induced by both Cd stress and Put-CQD NPs (p < 0.05). On the other hand, Cd stress reduced content of polyamines (putrescine (Put), spermine (Spm) and spermidine (Spd) by 39.28%, 53.36%, and 39.26%, respectively (p < 0.05). However, the reduction levels were buffered by the treatments. Considering the effectiveness of both NP concentrations, the lower dose (25 mg L-1) could be considered as an optimal concentration. To our knowledge, this is the first report of its kind as a potential agent to reduce the adverse effects of Cd stress in grapevines.
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Puntos Cuánticos , Vitis , Putrescina/farmacología , Cadmio/toxicidad , Cadmio/química , Peróxido de Hidrógeno , Poliaminas , Antioxidantes/farmacologíaRESUMEN
Using grand canonical thermodynamic analysis with inputs from DFT calculations we calculated equilibrium molar fractions of copper vacancies (VCu), H interstitials (Hi) and their complexes in bulk Cu in a wide range of temperature and hydrogen pressure values. The results show that the equilibrium molar fractions of both VCu and Hi are low in most conditions of interest, in good agreement with available experimental data. Although Hi-VCu complexes have significantly lower formation energies than the isolated defects, the low molar fraction of H is predicted to have little impact on the rise in vacancy molar fraction for external hydrogen pressures below 100 bar. Only at relatively high hydrogen pressures exceeding 10 kbar in the presence of Cu vacancies, the H molar fraction was found to reach the same order of magnitude as the molar fraction of vacancies. These results put thermodynamic limits on the hydrogen-induced vacancy clustering and void formation in bulk Cu.
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Salt stress is of the most detrimental abiotic stress factors on either crop or non-crop species. Of the strategies employed to boost the performance of the plants against harmful impacts of salt stress; application of novel nano-engineered particles have recently gained great attention as a promising tool. Octa-aminopropyl polyhedral oligomeric silsesquioxanes nanoparticles (OA-POSS NPs) were synthesized and then a foliar-application of OA-POSS NPs were carried out on sweet basil plants subjected to the salt stress. In that context, interactive effects of OA-POSS NPs (25, 50 and 100 mg L-1) and salinity stress (50 and 100 mM NaCl) were assayed by estimating a series of agronomic, physiological, biochemical and analytical parameters. OA-POSS NPs decreased the harmful effects of salinity by increasing photosynthetic pigment content, adjusting chlorophyll fluorescence, and triggering non-enzymatic (phenolic content) and enzymatic antioxidant components. The findings suggested that 25 mg L-1 OA-POSS NPs is the optimum concentration for sweet basil grown under salt stress. Considering the essential oil profile, estragole was the predominant compound with a percentage higher than 50% depending on the treatment. In comparison to the control group, 50 mM NaCl did not significantly affect estragole content, whilst 100 mM NaCl caused a substantial increase in estragole content. Regarding OA-POSS NPs treatments, increments by 16.8%, 11.8% and 17.5% were observed following application with 25, 50 and 100 mg L-1, respectively. Taken together, the current study provides evidence that POSS NPs can be employed as novel, 'green' growth promoting agents in combating salt stress in sweet basil.
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Nanopartículas , Ocimum basilicum , Cloruro de Sodio/farmacología , Estrés SalinoRESUMEN
In this study, we describe the results obtained in a study of the transgenerational phenotypic effects of chromium (Cr) stress on the model plant species Arabidopsis thaliana. The F1 generation derived from parents grown under chronic and medium chronic stress showed significantly higher levels of the maximal effective concentration (EC50) compared with F1 plants generated from unstressed parents. Moreover, F1 plants from Cr-stressed parents showed a higher germination rate when grown in the presence of Cr. F1 plants derived from parents cultivated under chronic Cr stress displayed reduced hydrogen peroxide levels under Cr stress compared to controls. At lower Cr stress levels, F1 plants were observed to activate promptly more genes involved in Cr stress responses than F0 plants, implying a memory effect linked to transgenerational priming. At higher Cr levels, and at later stages, F1 plants modulated significantly fewer genes than F0 plants, implying a memory effect leading to Cr stress adaptation. Several bHLH transcription factors were induced by Cr stress in F1 but not in F0 plants, including bHLH100, ORG2 and ORG3. F1 plants optimized gene expression towards pathways linked to iron starvation response. A model of the transcriptional regulation of transgenerational memory to Cr stress is presented here, and could be applied for other heavy metal stresses.