RESUMO
The efficient conversion of tissues into reproductive success is a crucial aspect affecting the evolution of life histories. Masting, the interannually variable and synchronous seed production in perennial plants, is a strategy that can enhance reproductive efficiency by mitigating seed predation and pollen limitation. However, evaluating benefits is insufficient to establish whether efficiency has improved, as such assessments neglect the associated costs of masting, particularly during the critical seed-to-seedling stage. We conducted a parentage analysis of seedlings and adults in a population of 209 Sorbus aucuparia trees, monitored over 23 years, providing pioneering documentation of the effects of masting on the fitness of individual trees beyond the seed stage. Our results show high costs of interannual variation that can be mitigated by high synchrony and reveal the existence of phenotypes that appear to reap the benefits of masting while avoiding its costs through regular reproduction.
Assuntos
Plântula , Sorbus , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Sorbus/fisiologia , Reprodução , Sementes/crescimento & desenvolvimento , Sementes/fisiologia , Frutas/crescimento & desenvolvimento , Frutas/fisiologiaRESUMO
Salinity stress represents a major threat to crop production by inhibiting seed germination, growth of seedlings, and final yield and, therefore, to the social and economic prosperity of developing countries. Recently, plant growth-promoting substances have been widely used as a chemical strategy for improving plant resilience towards abiotic stresses. This study aimed to determine whether melatonin (MT) and glycine betaine (GB) alone or in combination could alleviate the salinity-induced impacts on seed germination and growth of maize seedlings. Increasing NaCl concentration from 100 to 200 mM declined seed germination rate (4.6-37.7%), germination potential (24.5-46.7%), radical length (7.7-40.0%), plumule length (2.2-35.6%), seedling fresh (1.7-41.3%) and dry weight (23.0-56.1%) compared to control (CN) plants. However, MT and GB treatments lessened the adverse effects of 100 and 150 mM NaCl and enhanced germination comparable to control plants. In addition, results from the pot experiments show that 200 mM NaCl stress disrupted the osmotic balance and persuaded oxidative stress, presented by higher electrolyte leakage, hydrogen peroxide, superoxide radicals, and malondialdehyde compared to control plants. However, compared to the NaCl treatment, NaCl+MT+GB treatment decreased the accumulation of malondialdehyde (24.2-42.1%), hydrogen peroxide (36.2-44.0%), and superoxide radicals (20.1-50.9%) by up-regulating the activity of superoxide dismutase (28.4-51.2%), catalase (82.2-111.5%), ascorbate peroxidase (40.3-59.2%), and peroxidase (62.2-117.9%), and by enhancing osmolytes accumulation, thereby reducing NaCl-induced oxidative damages. Based on these findings, the application of MT+GB is an efficient chemical strategy for improving seed germination and growth of seedlings by improving the physiological and biochemical attributes of maize under 200 mM NaCl stress.
Assuntos
Betaína , Germinação , Melatonina , Estresse Salino , Plântula , Sementes , Zea mays , Melatonina/farmacologia , Zea mays/efeitos dos fármacos , Zea mays/crescimento & desenvolvimento , Zea mays/fisiologia , Zea mays/metabolismo , Betaína/farmacologia , Betaína/metabolismo , Germinação/efeitos dos fármacos , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Estresse Salino/efeitos dos fármacos , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Sementes/fisiologia , Cloreto de Sódio/farmacologia , Malondialdeído/metabolismo , Salinidade , Antioxidantes/metabolismo , Peróxido de Hidrogênio/metabolismo , Sinergismo Farmacológico , Estresse Oxidativo/efeitos dos fármacosRESUMO
Pathogenesis-related proteins (PR), including osmotins, play a vital role in plant defense, being activated in response to diverse biotic and abiotic stresses. Despite their significance, the mechanistic insights into the role of osmotins in plant defense have not been extensively explored. The present study explores the cloning and characterization of the osmotin gene (WsOsm) from Withania somnifera, aiming to illuminate its role in plant defense mechanisms. Quantitative real-time PCR analysis revealed significant induction of WsOsm in response to various phytohormones e.g. abscisic acid, salicylic acid, methyl jasmonate, brassinosteroids, and ethrel, as well as biotic and abiotic stresses like heat, cold, salt, and drought. To further elucidate WsOsm's functional role, we overexpressed the gene in Nicotiana tabacum, resulting in heightened resistance against the Alternaria solani pathogen. Additionally, we observed enhancements in shoot length, root length, and root biomass in the transgenic tobacco plants compared to wild plants. Notably, the WsOsm- overexpressing seedlings demonstrated improved salt and drought stress tolerance, particularly at the seedling stage. Confocal histological analysis of H2O2 and biochemical studies of antioxidant enzyme activities revealed higher levels in the WsOsm overexpressing lines, indicating enhanced antioxidant defense. Furthermore, a pull-down assay and mass spectrometry analysis revealed a potential interaction between WsOsm and defensin, a known antifungal PR protein (WsDF). This suggests a novel role of WsOsm in mediating plant defense responses by interacting with other PR proteins. Overall, these findings pave the way for potential future applications of WsOsm in developing stress-tolerant crops and improving plant defense strategies against pathogens.
Assuntos
Defensinas , Regulação da Expressão Gênica de Plantas , Nicotiana , Proteínas de Plantas , Plantas Geneticamente Modificadas , Estresse Fisiológico , Withania , Withania/genética , Withania/fisiologia , Withania/metabolismo , Withania/efeitos dos fármacos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Nicotiana/genética , Nicotiana/fisiologia , Nicotiana/efeitos dos fármacos , Nicotiana/microbiologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Estresse Fisiológico/genética , Defensinas/genética , Defensinas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Alternaria/fisiologia , Secas , Plântula/genética , Plântula/fisiologia , Plântula/efeitos dos fármacos , Ácido Salicílico/metabolismo , Doenças das Plantas/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Peróxido de Hidrogênio/metabolismo , Ácido Abscísico/metabolismo , Ácido Abscísico/farmacologia , Raízes de Plantas/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/fisiologiaRESUMO
Casuarina equisetifolia trees are used as windbreaks in subtropical and tropical coastal zones, while C. equisetifolia windbreak forests can be degraded by seawater atomization (SA) and seawater encroachment (SE). To investigate the mechanisms underlying the response of C. equisetifolia to SA and SE stress, the transcriptome and metabolome of C. equisetifolia seedlings treated with control, SA, and SE treatments were analyzed. We identified 737, 3232, 3138, and 3899 differentially expressed genes (SA and SE for 2 and 24 h), and 46, 66, 62, and 65 differentially accumulated metabolites (SA and SE for 12 and 24 h). The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that SA and SE stress significantly altered the expression of genes related to plant hormone signal transduction, plant-pathogen interaction, and starch and sucrose metabolism pathways. The accumulation of metabolites associated with the biosynthetic pathways of phenylpropanoid and amino acids, as well as starch and sucrose metabolism, and glycolysis/gluconeogenesis were significantly altered in C. equisetifolia subjected to SA and SE stress. In conclusion, C. equisetifolia responds to SA and SE stress by regulating plant hormone signal transduction, plant-pathogen interaction, biosynthesis of phenylpropanoid and amino acids, starch and sucrose metabolism, and glycolysis/gluconeogenesis pathways. Compared with SA stress, C. equisetifolia had a stronger perception and response to SE stress, which required more genes and metabolites to be regulated. This study enhances our understandings of how C. equisetifolia responds to two types of seawater stresses at transcriptional and metabolic levels. It also offers a theoretical framework for effective coastal vegetation management in tropical and subtropical regions.
Assuntos
Água do Mar , Estresse Fisiológico , Estresse Fisiológico/genética , Água do Mar/química , Transcriptoma , Regulação da Expressão Gênica de Plantas , Metaboloma , Plântula/genética , Plântula/fisiologia , Metabolômica , MultiômicaRESUMO
BACKGROUND: The growth and yield of pepper, a typical temperature-loving vegetable, are limited by low-temperature environments. Using low-temperature sensitive 'Hangjiao No. 4' (Capsicum annuum L.) as experimental material, this study analyzed the changes in plant growth and photosynthesis under different treatments: normal control (NT), low-temperature stress alone (LT), low-temperature stress in strigolactone pretreated plants (SL_LT), and low-temperature stress in strigolactone biosynthesis inhibitor pretreated plants (Tis_LT). RESULTS: SL pretreatment increased the net photosynthetic rate (Pn) and PSII actual photochemical efficiency (φPSII), reducing the inhibition of LT on the growth of pepper by 17.44% (dry weight of shoot). Due to promoting the accumulation of carotenoids, such as lutein, and the de-epoxidation of the xanthophyll cycle [(Z + A)/(Z + A + V)] by strigolactone after long-term low-temperature stress (120 h), non-photochemical quenching (NPQ) of pepper was increased to reduce the excess excitation energy [(1-qP)/NPQ] and the photoinhibition degree (Fv/Fm) of pepper seedlings under long-term low-temperature stress was alleviated. Twelve cDNA libraries were constructed from pepper leaves by transcriptome sequencing. There were 8776 differentially expressed genes (DEGs), including 4473 (51.0%) upregulated and 4303 (49.0%) downregulated genes. Gene ontology pathway annotation showed that based on LT, the DEGs of SL_LT and Tis_LT were significantly enriched in the cellular component, which is mainly related to the photosystem and thylakoids. Further analysis of the porphyrin and chlorophyll biosynthesis, carotenoid biosynthesis, photosynthesis-antenna protein, and photosynthetic metabolic pathways and the Calvin cycle under low-temperature stress highlighted 18, 15, 21, 29, and 31 DEGs for further study, which were almost all highly expressed under SL_LT treatment and moderately expressed under LT treatment, whereas Tis_LT showed low expression. CONCLUSION: The positive regulatory effect of SLs on the low-temperature tolerance of pepper seedlings was confirmed. This study provided new insights for the development of temperature-tolerant pepper lines through breeding programs.
Assuntos
Capsicum , Temperatura Baixa , Lactonas , Fotossíntese , Plântula , Capsicum/fisiologia , Capsicum/genética , Capsicum/efeitos dos fármacos , Lactonas/metabolismo , Plântula/efeitos dos fármacos , Plântula/fisiologia , Plântula/genética , Plântula/crescimento & desenvolvimento , Fotossíntese/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Resposta ao Choque Frio/fisiologia , Resposta ao Choque Frio/efeitos dos fármacos , Clorofila/metabolismo , Estresse Fisiológico , Reguladores de Crescimento de Plantas/metabolismo , Reguladores de Crescimento de Plantas/farmacologiaRESUMO
The growth and yield of rapeseed are significantly hampered by salt stress. Indole-3-butyric Acid Potassium Salt (IBA-K) has been found to alleviate the impact of salt stress on plant growth. However, the regulatory effect of IBA-K dipping on salt-stressed rapeseed remains unclear. To explore the implications of IBA-K on the growth and development of rapeseed during the seedling stage, we conducted potting experiments using the Huayouza 62 variety. Five different concentrations of IBA-K for seed soaking (0, 10, 20, 40, 80 mg·L- 1) were tested. The promotional impact of IBA-K on rapeseed demonstrated an initial increase followed by a decline, reaching a peak at 20 mg·L- 1. Therefore, 20 mg·L- 1 was determined as the optimal concentration for subsequent experiments. To further understand the mechanism of IBA-K's action on salt-stressed rapeseed seedlings, we utilized the moderately salt-resistant cabbage rapeseed variety Huayouza 158R and the highly salt-resistant Huayouza 62 as specimens. The investigation focused on their response and repair mechanisms under 150 mmol·L- 1 NaCl stress. The findings demonstrated that compared with the sole NaCl stress, the 20 mg·L- 1 IBA-K seed soaking treatment under salt stress significantly enhanced the plant height, stem diameter, and leaf area of both rapeseed varieties. It also led to greater biomass accumulation, increased chlorophyll content, and improved photosynthetic efficiency in rapeseed. Furthermore, this treatment bolstered the activity of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), while significantly reducing the levels of electrolyte leakage (EL) and malondialdehyde (MDA). Consequently, it alleviated the membrane lipid peroxidation damage induced by NaCl stress, enhanced the accumulation of soluble proteins, maintained cellular osmotic pressure, and effectively mitigated the adverse effects of NaCl stress on rapeseed.
Assuntos
Brassica napus , Indóis , Estresse Salino , Plântula , Sementes , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Brassica napus/efeitos dos fármacos , Brassica napus/crescimento & desenvolvimento , Brassica napus/fisiologia , Indóis/farmacologia , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Estresse Salino/efeitos dos fármacos , Clorofila/metabolismo , Antioxidantes/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Tolerância ao Sal/efeitos dos fármacosRESUMO
Glyphosate (GLY), the most widely used herbicide, has been regarded as an emergent environmental contaminant due to its constant and cumulative use, with potential harm to non-target organisms, such as crops, disrupting cells' redox balance. Therefore, plants need to fine-tune their antioxidant (AOX) mechanisms to thrive under GLY-contaminated environments. Proline overaccumulation is a common response in plants exposed to GLY, yet its role in GLY-induced toxicity remains unclear. Thus, this study explores whether Pro overaccumulation in response to GLY is perceived as a downstream tolerance mechanism or an early-warning stress signal. To investigate this, Arabidopsis thaliana T-DNA mutant lines for Pro biosynthetic (P5CS1) and catabolic genes (ProDH) were used and screened for their GLY susceptibility. Upon seedlings' exposure to GLY (0.75 mg L-1) for 14 days, the herbicide led to reduced biomass in all genotypes, accompanied by Pro overaccumulation. Mutants with heightened Pro levels (prodh) exhibited the greatest biomass reduction, increased lipid peroxidation (LP), and hydrogen peroxide (H2O2) levels, accompanied by a compromised performance of the AOX system. Conversely, p5cs1-4, mutants with lower Pro levels, demonstrated an enhanced AOX system activation, not only with increased levels of glutathione (GSH) and ascorbate (AsA), but also with increased activity of both ascorbate peroxidase (APX) and catalase (CAT). These findings suggest that Pro overaccumulation under GLY exposure is associated with stress sensitivity rather than tolerance, highlighting its potential as an early-warning signal for GLY toxicity in non-target plants and for detecting weed resistance.
Assuntos
Arabidopsis , Glicina , Glifosato , Herbicidas , Prolina , Glicina/análogos & derivados , Glicina/farmacologia , Glicina/toxicidade , Prolina/metabolismo , Arabidopsis/genética , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Herbicidas/toxicidade , Herbicidas/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Antioxidantes/metabolismo , Peróxido de Hidrogênio/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Plântula/efeitos dos fármacos , Plântula/genética , Plântula/fisiologia , Plântula/metabolismoRESUMO
Euphorbia resinifera O. Berg is a prickly, leafless and succulent, Moroccan endemic shrub. Field data indicate that the plant faces many challenges related to its natural regeneration and its gradual decline that can lead to a probability of extinction, at least in some areas. Successful seed germination and survival of E. resinifera seedlings during the dry period is one of the main obstacles encountered in establishing natural seedlings. With this in mind, 3080 seeds of two morphotypes of E. resinifera (M1 and M2) were harvested in the Atlas of Beni Mellal to study their germinative potential and determine suitable conditions for growth and development of the seedlings. In the laboratory, five temperatures (10 °, 15 °C, 18 °C, 25 °C, and 35 °C) and two photoperiods (12 h light/12 h dark and 24 h dark) were tested. Whereas in field research, two factors were considered: the availability of water and the type of substrate (clay, peat, and limestone). Results show a maximum germination rate of around 52% for M2 at 15 °C and 48% for M1 at 18 °C. The Monitoring of plant seedling establishment and growth revealed a high vulnerability to prolonged periods of drought. However, consolidated soil is more conducive to seedling establishment. For this species, it is therefore essential to conserve the habitat within the karst geosystem. Furthermore, the variability of this species' morphotypes and their growth form architecture shows a tendency to favor the dwarf, cushion-shaped morphotype, which is the most widespread in the study area.
Assuntos
Euphorbia , Germinação , Plântula , Germinação/fisiologia , Euphorbia/fisiologia , Euphorbia/crescimento & desenvolvimento , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Conservação dos Recursos Naturais , Temperatura , Sementes/crescimento & desenvolvimento , Sementes/fisiologiaRESUMO
In breeding programs, stress memory in plants can develop drought stress tolerance. Memory stress, as an approach, can keep stress data by activating tolerance mechanisms. This research was conducted to evaluate some physiologically effective mechanisms in inducing memory drought stress in the seeds that were exposed to water stress three times in four treatments including rainfed, 33%, 66%, and 100% of field capacity (FC). After the production of the seeds, the third-generation seeds were placed under different irrigation treatments, seed and seedling traits, starch to carbohydrate ratio in seed, protein concentration and glutathione reductase were investigatied in a factorial format based on a randomized complete block design with three replications. Results showed that percentage of changes from the lowest to the highest value for traits including seed vigor, seed endosperm weight, seed coat weight, accelerated aging, cold test, seedling biomass and seedling length were 25, 37, 65, 65, 55, 77, 55, 65 and 79, respectively and germination uniformity was 3.9 times higher than the lowest amount. According to the deterioration percentage, seed vigor and the percentage of seed germination in cold test data, it can be reported that seed production by 100% FC was not appropriate for rainfed plots. However, considering the the appropriate results in the percentage of germination for a cold test, germination uniformity percentage, and the lowest accelerated aging seeds, seed production under the rainfed conditions with 33% FC watering can be recommended. In-silico analysis was coducted on Glutathione reductase (GR) enzymes in Gossypium hirsutum. It is clear that GR has a Redox-active site and NADPH binding, and it interacts with Glutathione S transferase (GST). So, memory drought stress through inducing physiological drought tolerance mechanisms such as starch-to-carbohydrate ratio and GR can determine the suitable pattern for seed production for rainfed and low rainfall regions in a breeding program. Our study thus illustrated that seed reprduction under 33% FC equipped cotton with the tolerance against under draught stress from the seedling stage. This process is done through activating glutathione reductase and balancing the ratio of starch to carbohydrates concentration.
Assuntos
Secas , Glutationa Redutase , Gossypium , Plântula , Gossypium/fisiologia , Gossypium/enzimologia , Gossypium/crescimento & desenvolvimento , Glutationa Redutase/metabolismo , Plântula/fisiologia , Plântula/crescimento & desenvolvimento , Simulação por Computador , Estresse Fisiológico , Sementes/fisiologia , Sementes/crescimento & desenvolvimento , Proteínas de Plantas/metabolismoRESUMO
Reserves of non-structural carbohydrates (NSC) stored in living cells are essential for drought tolerance of trees. However, little is known about the phenotypic plasticity of living storage compartments (SC) and their interactions with NSC reserves under changing water availability. Here, we examined adjustments of SC and NSC reserves in stems and roots of seedlings of two temperate tree species, Acer negundo L. and Betula pendula Roth., cultivated under different substrate water availability. We found that relative contents of soluble NSC, starch and total NSC increased with decreasing water availability in stems of both species, and similar tendencies were also observed in roots of A. negundo. In the roots of B. pendula, soluble NSC contents decreased along with the decreasing water availability, possibly due to phloem decoupling or NSC translocation to shoots. Despite the contrast in organ responses, NSC contents (namely starch) positively correlated with proportions of total organ SC. Individual types of SC showed markedly distinct plasticity upon decreasing water availability, suggesting that water availability changes the partitioning of organ storage capacity. We found an increasing contribution of parenchyma-rich bark to the total organ NSC storage capacity under decreasing water availability. However, xylem SC showed substantially greater plasticity than those in bark. Axial storage cells, namely living fibers in A. negundo, responded more sensitively to decreasing water availability than radial parenchyma. Our results demonstrate that drought-induced changes in carbon balance affect the organ storage capacity provided by living cells, whose proportions are sensitively coordinated along with changing NSC reserves.
Assuntos
Acer , Amido , Água , Água/metabolismo , Acer/metabolismo , Acer/fisiologia , Amido/metabolismo , Betula/metabolismo , Betula/fisiologia , Raízes de Plantas/metabolismo , Raízes de Plantas/fisiologia , Caules de Planta/metabolismo , Caules de Planta/fisiologia , Árvores/metabolismo , Árvores/fisiologia , Secas , Metabolismo dos Carboidratos , Xilema/metabolismo , Madeira/metabolismo , Plântula/metabolismo , Plântula/fisiologiaRESUMO
Although there is evidence to suggest that the endophytic fungus Serendipita indica plays a crucial role in enhancing plant tolerance against biotic/abiotic stressors, less is known about the impacts of this symbiosis association on root mucilage chemical composition and its physical functions. The mucilage of inoculated and non-inoculated seedlings of four wheat cultivars (i.e., Roshan, Ghods, Kavir and Pishtaz) were extracted using an aeroponic method. Total solute concentration (TCm), carbon content (Cmucilage), electrical conductivity (EC), pH, fatty acids, surface tension (σm), and viscosity (ηm) of mucilage were measured. Ghods and Kavir had the highest and lowest root colonization percents, respectively. Saturated fatty acids, including palmitic and stearic acids, were dominant over unsaturated fatty acids in wheat root mucilage. However, their compositions were significantly different among wheat cultivars. S. indica colonization, especially for Ghods, increased the TCm, Cmucilage, and palmitic acid. Moreover, root mucilage of S. indica-inoculated Ghods had lower σm and greater ηm. An increased amount of powerful surfactants like palmitic acid in the mucilage of S. indica inoculated treatments led to lower σm and greater ηm. Such studies provide further support for the idea that plant-released mucilage plays a major role in modifying the physical environment of the rhizosphere. This knowledge toward truly understanding the rhizosphere can be potentially used for improving the rhizosphere soil quality and increasing crop growth and yield.
Assuntos
Basidiomycota , Mucilagem Vegetal , Raízes de Plantas , Simbiose , Triticum , Triticum/fisiologia , Triticum/microbiologia , Triticum/metabolismo , Raízes de Plantas/microbiologia , Raízes de Plantas/fisiologia , Raízes de Plantas/metabolismo , Mucilagem Vegetal/metabolismo , Simbiose/fisiologia , Basidiomycota/fisiologia , Ácidos Graxos/metabolismo , Plântula/fisiologiaRESUMO
To address salinity stress in plants in an eco-friendly manner, this study investigated the potential effects of salinity-resistant bacteria isolated from saline agricultural soils on the growth of cucumber (Cucumis sativus, cv. Royal) seedlings. A greenhouse factorial experiment was conducted based on a completely randomized design (CRD) with two factors, salinity at four levels and five bacterial treatments, with three replications (n = 3). Initially, fifty bacterial isolates were screened for their salinity and drought tolerance, phosphate solubilization activity, along with production of auxin, siderophore and hydrogen cyanide. Isolates K4, K14, K15, and C8 exhibited the highest resistance to salinity and drought stresses in vitro. Isolates C8 and K15 demonstrated the highest auxin production capacity, generating 2.95 and 2.87 µg mL- 1, respectively, and also exhibited significant siderophore production capacities (by 14% and 11%). Additionally, isolates C8 and K14 displayed greater phosphate solubilization activities, by 184.64 and 122.11 µg mL- 1, respectively. The statistical analysis revealed that the selected four potent isolates significantly enhanced all growth parameters of cucumber plants grown under salinity stress conditions for six weeks. Plant height increased by 41%, fresh and dry weights by 35% and 7%, respectively, and the leaf area index by 85%. The most effective isolate, C8, was identified as Bacillus subtilis based on the 16 S rDNA amplicon sequencing. This study demonstrated that inoculating cucumber seedlings with halotolerant bacterial isolates, such as C8 (Bacillus subtilis), possessing substantial plant growth-promoting properties significantly alleviated salinity stress by enhancing plant growth parameters. These findings suggest a promising eco-friendly strategy for improving crop productivity in saline agricultural environments.
Assuntos
Cucumis sativus , Tolerância ao Sal , Plântula , Cucumis sativus/microbiologia , Cucumis sativus/crescimento & desenvolvimento , Cucumis sativus/fisiologia , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Plântula/fisiologia , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Bactérias/classificação , Microbiologia do Solo , Fosfatos/metabolismo , Sideróforos/metabolismo , Ácidos Indolacéticos/metabolismo , Salinidade , SecasRESUMO
Here, we elucidate the interaction between IAA and melatonin (MT) in response to chilling in cucumber. The results showed that chilling stress induced the increase of endogenous MT and IAA, and the application of MT promoted the synthesis of IAA, while IAA could not affect endogenous MT content under chilling stress. Moreover, MT and IAA application both remarkably increased the chilling tolerance of cucumber seedlings in terms of lower contents of MDA and ROS, higher mRNA abundance of cold response genes, net photosynthetic rate (Pn), maximum regeneration rate of ribulose-1,5-diphosphate (Jmax), Rubisco maximum carboxylation efficiency (Vcmax), the activities and gene expression of RCA and Rubisco, as well as the content of active P700 (I/I0) and photosynthetic electron transport, compared with the plants in H2O treatment. Further analysis revealed that the inhibition of IAA transportation significantly reduced the chilling tolerance induced by MT, whereas the inhibition of endogenous MT did not affect the chilling tolerance induced by IAA. Meanwhile, we found that overexpression of the MT biosynthesis gene CsASMT increased the chilling tolerance, which was blocked by inhibition of endogenous IAA, and the silence of IAA biosynthesis gene CsYUCCA10 decreased the chilling tolerance of cucumber, which could not be alleviated by MT. These data implied IAA acted as a downstream signal to participate in the MT-induced chilling tolerance of cucumber seedlings. The study has implications for the production of greenhouse cucumber in winter seasons.
Assuntos
Temperatura Baixa , Cucumis sativus , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos , Melatonina , Cucumis sativus/genética , Cucumis sativus/fisiologia , Cucumis sativus/metabolismo , Melatonina/metabolismo , Ácidos Indolacéticos/metabolismo , Plântula/fisiologia , Plântula/genética , Transdução de Sinais , Fotossíntese/fisiologia , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genéticaRESUMO
Lead (Pb) exposure can induce molecular changes in plants, disrupt metabolites, and impact plant growth. Therefore, it is essential to comprehend the molecular mechanisms involved in Pb tolerance in plants to evaluate the long-term environmental consequences of Pb exposure. This research focused on maize as the test subject to study variations in biomass, root traits, genes, and metabolites under hydroponic conditions under Pb conditions. The findings indicate that high Pb stress significantly disrupts plant growth and development, leading to a reduction in catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) activities by 17.12, 5.78, and 19.38%, respectively. Conversely, Pb stress led to increase malondialdehyde (MDA) contents, ultimately impacting the growth of maize. The non-targeted metabolomics analysis identified 393 metabolites categorized into 12 groups, primarily consisting of organic acids and derivatives, organ heterocyclic compounds, lipids and lipid-like molecules and benzenoids. Further analysis indicated that Pb stress induced an accumulation of 174 metabolites mainly enriched in seven metabolic pathways, for example phenylpropanoid biosynthesis and flavonoid biosynthesis. Transcriptome analysis revealed 1933 shared differentially expressed genes (DEGs), with 1356 upregulated and 577 downregulated genes across all Pb treatments. Additionally, an integrated analysis identified several DEGs and differentially accumulated metabolites (DAMs), including peroxidase, alpha-trehalose, and D-glucose 6-phosphate, which were linked to cell wall biosynthesis. These findings imply the significance of this pathway in Pb detoxification. This comprehensive investigation, employing multiple methodologies, provides a detailed molecular-level insight into maize's response to Pb stress.
Assuntos
Regulação da Expressão Gênica de Plantas , Chumbo , Metabolômica , Plântula , Zea mays , Zea mays/genética , Zea mays/efeitos dos fármacos , Zea mays/metabolismo , Zea mays/fisiologia , Chumbo/toxicidade , Chumbo/metabolismo , Plântula/efeitos dos fármacos , Plântula/genética , Plântula/fisiologia , Plântula/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Transcriptoma/genética , Perfilação da Expressão Gênica , Malondialdeído/metabolismo , Superóxido Dismutase/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Estresse Fisiológico/genética , Catalase/metabolismo , Catalase/genética , Peroxidase/metabolismo , Peroxidase/genéticaRESUMO
KEY MESSAGE: Overexpression of rice A20/AN1 zinc-finger protein, OsSAP10, improves water-deficit stress tolerance in Arabidopsis via interaction with multiple proteins. Stress-associated proteins (SAPs) constitute a class of A20/AN1 zinc-finger domain containing proteins and their genes are induced in response to multiple abiotic stresses. The role of certain SAP genes in conferring abiotic stress tolerance is well established, but their mechanism of action is poorly understood. To improve our understanding of SAP gene functions, OsSAP10, a stress-inducible rice gene, was chosen for the functional and molecular characterization. To elucidate its role in water-deficit stress (WDS) response, we aimed to functionally characterize its roles in transgenic Arabidopsis, overexpressing OsSAP10. OsSAP10 transgenics showed improved tolerance to water-deficit stress at seed germination, seedling and mature plant stages. At physiological and biochemical levels, OsSAP10 transgenics exhibited a higher survival rate, increased relative water content, high osmolyte accumulation (proline and soluble sugar), reduced water loss, low ROS production, low MDA content and protected yield loss under WDS relative to wild type (WT). Moreover, transgenics were hypersensitive to ABA treatment with enhanced ABA signaling and stress-responsive genes expression. The protein-protein interaction studies revealed that OsSAP10 interacts with proteins involved in proteasomal pathway, such as OsRAD23, polyubiquitin and with negative and positive regulators of stress signaling, i.e., OsMBP1.2, OsDRIP2, OsSCP and OsAMTR1. The A20 domain was found to be crucial for most interactions but insufficient for all interactions tested. Overall, our investigations suggest that OsSAP10 is an important candidate for improving water-deficit stress tolerance in plants, and positively regulates ABA and WDS signaling via protein-protein interactions and modulation of endogenous genes expression in ABA-dependent manner.
Assuntos
Ácido Abscísico , Arabidopsis , Regulação da Expressão Gênica de Plantas , Oryza , Proteínas de Plantas , Plantas Geneticamente Modificadas , Complexo de Endopeptidases do Proteassoma , Transdução de Sinais , Arabidopsis/genética , Arabidopsis/fisiologia , Oryza/genética , Oryza/fisiologia , Oryza/metabolismo , Ácido Abscísico/metabolismo , Ácido Abscísico/farmacologia , Transdução de Sinais/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Complexo de Endopeptidases do Proteassoma/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Germinação/genética , Germinação/efeitos dos fármacos , Secas , Água/metabolismo , Desidratação , Plântula/genética , Plântula/fisiologiaRESUMO
High temperature stress is one of the most severe forms of abiotic stress in alfalfa. With the intensification of climate change, the frequency of high temperature stress will further increase in the future, which will bring challenges to the growth and development of alfalfa. Therefore, untargeted metabolomic and RNA-Seq profiling were implemented to unravel the possible alteration in alfalfa seedlings subjected to different temperature stress (25 â, 30 â, 35 â, 40 â) in this study. Results revealed that High temperature stress significantly altered some pivotal transcripts and metabolites. The number of differentially expressed genes (DEGs) markedly up and down-regulated was 1876 and 1524 in T30_vs_CK, 2, 815 and 2667 in T35_vs_CK, and 2115 and 2, 226 in T40_vs_CK, respectively. The number for significantly up-regulated and down-regulated differential metabolites was 173 and 73 in T30_vs_CK, 188 and 57 in T35_vs_CK, and 220 and 66 in T40_vs_CK, respectively. It is worth noting that metabolomics and transcriptomics co-analysis characterized enriched in plant hormone signal transduction (ko04705), glyoxylate and dicarboxylate metabolism (ko00630), from which some differentially expressed genes and differential metabolites participated. In particular, the content of hormone changed significantly under T40 stress, suggesting that maintaining normal hormone synthesis and metabolism may be an important way to improve the HTS tolerance of alfalfa. The qRT-PCR further showed that the expression pattern was similar to the expression abundance in the transcriptome. This study provides a practical and in-depth perspective from transcriptomics and metabolomics in investigating the effects conferred by temperature on plant growth and development, which provided the theoretical basis for breeding heat-resistant alfalfa.
Assuntos
Medicago sativa , Metabolômica , Transcriptoma , Medicago sativa/genética , Medicago sativa/metabolismo , Medicago sativa/fisiologia , Perfilação da Expressão Gênica , Metaboloma , Regulação da Expressão Gênica de Plantas , Temperatura Alta , Estresse Fisiológico/genética , Plântula/genética , Plântula/metabolismo , Plântula/fisiologia , Plântula/crescimento & desenvolvimento , Resposta ao Choque Térmico/genéticaRESUMO
Elymus nutans Griseb. (E. nutans), a pioneer plant for the restoration of high quality pasture and vegetation, is widely used to establish artificial grasslands and ecologically restore arid and salinized soils. To investigate the effects of drought stress and salt stress on the physiology and endogenous hormones of E. nutans seedlings, this experiment configured the same environmental water potential (0 (CK), - 0.04, - 0.14, - 0.29, - 0.49, - 0.73, and - 1.02 MPa) of PEG-6000 and NaCl stress to investigate the effects of drought stress and salt stress, respectively, on E. nutans seedlings under the same environmental water potential. The results showed that although the physiological indices and endogenous hormones of the E. nutans seedlings responded differently to drought stress and salt stress under the same environmental water potential, the physiological indices of E. nutans shoots and roots were comprehensively evaluated using the genus function method, and the physiological indices of the E. nutans seedlings under the same environmental water potential exhibited better salt tolerance than drought tolerance. The changes in endogenous hormones of the E. nutans seedlings under drought stress were analyzed to find that treatment with gibberellic acid (GA3), gibberellin A7 (GA7), 6-benzyladenine (6-BA), 6-(y,y-dimethylallylaminopurine) (2.IP), trans-zeatin (TZ), kinetin (KT), dihydrozeatin (DHZ), indole acetic acid (IAA), and 2,6-dichloroisonicotininc acid (INA) was more effective than those under drought stress. By analyzing the amplitude of changes in the endogenous hormones in E. nutans seedlings, the amplitude of changes in the contents of GA3, GA7, 6-BA, 2.IP, TZ, KT, DHZ, IAA, isopentenyl adenosine (IPA), indole-3-butyric acid (IBA), naphthalene acetic acid (NAA), and abscisic acid was larger in drought stress compared with salt stress, which could be because the endogenous hormones are important for the drought tolerance of E. nutans itself. The amplitude of the changes in the contents of DHZ, TZR, salicylic acid, and jasmonic acid was larger in salt stress compared with drought stress. Changes in the content of melatonin were larger in salt stress compared with drought stress, which could indicate that endogenous hormones and substances are important for the salt tolerance of E. nutans itself.
Assuntos
Secas , Reguladores de Crescimento de Plantas , Estresse Salino , Plântula , Plântula/fisiologia , Plântula/efeitos dos fármacos , Plântula/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Estresse Fisiológico , Raízes de Plantas/fisiologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Tolerância ao Sal , Ácidos Indolacéticos/metabolismo , Poaceae/fisiologia , Poaceae/efeitos dos fármacos , Poaceae/metabolismoRESUMO
Drought is a significant global issue affecting agricultural production, and the utilization of beneficial rhizosphere microorganisms is one of the effective ways to increase the productivity of crops and forest under drought. In this study, we characterized a novel growth-promoting dark septate endophytes (DSE) fungus R16 (Dothideomycetes sp.) derived from blueberry roots. Hyphae or microsclerotia were visible within the epidermal or cortical cells of R16-colonized blueberry roots, which was consistent with the typical characteristics of DSE fungi. Inoculation with R16 promoted the growth of blueberry seedlings, and the advantage over the control group was more significant under PEG-induced drought. Comparison of physiological indicators related to drought resistance between the inoculated and control groups was performed on the potted blueberry plants, including the chlorophyll content, net photosynthetic rate, root activities, malondialdehyde and H2O2 content, which indicated that R16 colonization mitigated drought injury in blueberry plants. We further analyzed the effects of R16 on phytohormones and non-structural carbohydrates (NSCs) to explore the mechanism of increased drought tolerance by R16 in blueberry seedlings. The results showed that except for the gibberellin content, indole-3-acetic acid, zeatin and abscisic acid varied significantly between the inoculated and control groups. Sucrose phosphate synthase and sorbitol-6-phosphate dehydrogenase activities in mature leaves, the key enzymes responsible for sucrose and sorbitol synthesis, respectively, as well as sorbitol dehydrogenase, sucrose synthase, cell wall invertase, hexokinase and fructokinase in roots, the key enzymes involved in the NSCs metabolism, showed significant differences between the inoculated and control groups before and after drought treatment. These results suggested that the positive effects of R16 colonization on the drought tolerance of blueberry seedlings are partially attributable to the regulation of phytohormone and sugar metabolism. This study provided valuable information for the research on the interaction between DSE fungi and host plants as well as the application of DSE preparations in agriculture.
Assuntos
Mirtilos Azuis (Planta) , Endófitos , Reguladores de Crescimento de Plantas , Mirtilos Azuis (Planta)/microbiologia , Mirtilos Azuis (Planta)/fisiologia , Mirtilos Azuis (Planta)/crescimento & desenvolvimento , Reguladores de Crescimento de Plantas/metabolismo , Endófitos/fisiologia , Secas , Raízes de Plantas/microbiologia , Raízes de Plantas/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Ascomicetos/fisiologia , Metabolismo dos Carboidratos , Plântula/fisiologia , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Resistência à SecaRESUMO
Abiotic stresses significantly impact agricultural productivity and food security. Innovative strategies, including the use of plant-derived compounds and plant growth-promoting rhizobacteria (PGPR), are necessary to enhance plant resilience. This study delved into how Bacillus zanthoxyli HS1 (BzaHS1) and BzaHS1-derived volatile organic compounds (VOC) conferred systemic tolerance against salt and heat stresses in cabbage and cucumber plants. Direct application of a BzaHS1 strain or exposure of BzaHS1-derived VOC to cabbage and cucumber plants promoted seedling growth under stressed conditions. This induced systemic tolerance was associated with increased mRNA expression and enzymatic activities of superoxide dismutase (EC 1.15.1.1), catalase (EC 1.11.1.6), or ascorbate peroxidase (EC 1.11.1.1), leading to a reduction in oxidative stress in cabbage and cucumber plants. Plants co-cultured with BzaHS1 and exposed to BzaHS1-derived VOC triggered the accumulation of callose and minimized stomatal opening in response to high salt and temperature stresses, respectively. In contrast, exogenous treatment of azelaic acid, a well-characterized plant defense primer, had no significant impact on the seedling growth of cabbage and cucumber plants grown under abiotic stress conditions. Taken together, BzaHS1 and its VOC show potential for enhancing plant tolerance responses to salt and heat stresses through modulation of osmotic stress-regulatory networks.
Assuntos
Bacillus , Cucumis sativus , Estresse Fisiológico , Cucumis sativus/fisiologia , Cucumis sativus/microbiologia , Cucumis sativus/genética , Bacillus/fisiologia , Brassica/fisiologia , Brassica/genética , Brassica/microbiologia , Plântula/fisiologia , Plântula/crescimento & desenvolvimento , Compostos Orgânicos Voláteis/metabolismo , Superóxido Dismutase/metabolismo , Catalase/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Estresse OxidativoRESUMO
The increasing prevalence of drought events poses a major challenge for upcoming crop production. Melatonin is a tiny indolic tonic substance with fascinating regulatory functions in plants. While plants can respond in several ways to alleviate drought stress, the processes underpinning stress sensing and signaling are poorly understood. Hereafter, the objectives of this investigation were to explore the putative functions of melatonin in the regulation of sugar metabolism and abscisic acid biosynthesis in drought-stressed tomato seedlings. Melatonin (100 µM) and/or water were foliar sprayed, followed by the plants being imposed to drought stress for 14 days. Drought stress significantly decreased biomass accumulation, inhibited photosynthetic activity, and stimulated senescence-associated gene 12 (SAG12) expression. Melatonin treatment effectively reversed drought-induced growth retardation as evidenced by increased leaf pigment and water balance and restricted abscisic acid (ABA) accumulation. Sugar accumulation, particularly sucrose content, was higher in drought-imposed seedlings, possibly owing to higher transcription levels of sucrose non-fermenting 1-related protein kinase 2 (SnKR2.2) and ABA-responsive element binding factors 2 (AREB2). Melatonin addition further uplifted the sucrose content, which coincided with increased activity of sucrose synthase (SS, 130%), sucrose phosphate synthase (SPS, 137%), starch degradation encoding enzyme ß-amylase (BAM, 40%) and α-amylase (AMY, 59%) activity and upregulated their encoding BAM1(10.3 folds) and AMY3 (8.1 folds) genes expression at day 14 relative to the control. Under water deficit conditions, melatonin supplementation decreased the ABA content (24%) and its biosynthesis gene expressions. Additionally, sugar transporter subfamily genes SUT1 and SUT4 expression were upregulated by the addition of melatonin. Collectively, our findings illustrate that melatonin enhances drought tolerance in tomato seedlings by stimulating sugar metabolism and negatively regulating ABA synthesis.