RESUMO
Perennial grains, which remain productive for multiple years, rather than growing for only one season before harvest, have deep, dense root systems that can support a richness of beneficial microorganisms, which are mostly underexplored. In this work we isolated forty-three bacterial strains associated with the rhizosphere of the OK72 perennial wheat line, developed from a cross between winter common wheat and Thinopyrum ponticum. Identified using 16S rDNA sequencing, these bacteria were assessed for plant growth-promoting traits such as indole-3-acetic acid, siderophores and ACC-deaminase acid production, biofilm formation, and the ability to solubilize phosphate and proteins. Twenty-five strains exhibiting in vitro significant plant growth promoting traits, belong to wheat keystone genera Pseudomonas, Microbacterium, Variovorax, Pedobacter, Dyadobacter, Plantibacter, and Flavobacterium. Seven strains, including Aeromicrobium and Okibacterium genera, were able to promote root growth in a commercial annual wheat cultivar while strains from Pseudomonas genus inhibited the growth of Aspergillus flavus and Fusarium species, using direct antagonism assays. The same strains produced a high amount of 1-undecanol a volatile organic compound, which may aid in suppressing fungal growth. The study highlights the potential of these bacteria to form new commercial consortia, enhancing the health and productivity of annual wheat crops within sustainable agricultural practices.
Assuntos
Raízes de Plantas , Rizosfera , Microbiologia do Solo , Triticum , Triticum/microbiologia , Triticum/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , Bactérias/genética , Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Ácidos Indolacéticos/metabolismo , Desenvolvimento Vegetal , Sideróforos/metabolismo , RNA Ribossômico 16S/genética , FusariumRESUMO
Plant-environment interactions, particularly biotic stress, are increasingly essential for global food security due to crop losses in the dynamic environment. Therefore, understanding plant responses to biotic stress is vital to mitigate damage. Beneficial microorganisms and their association with plants can reduce the damage associated with plant pathogens. One such group is PGPR (Plant growth-promoting rhizobacteria), which influences plant immunity significantly by interacting with biotic stress factors and plant signalling compounds. This review explores the types, metabolism, and mechanisms of action of PGPR, including their enzyme pathways and the signalling compounds secreted by PGPR that modulate gene and protein expression during plant defence. Furthermore, the review will delve into the crosstalk between PGPR and other plant growth regulators and signalling compounds, elucidating the physiological, biochemical, and molecular insights into PGPR's impact on plants under multiple biotic stresses, including interactions with fungi, bacteria, and viruses. Overall, the review comprehensively adds to our knowledge about PGPR's role in plant immunity and its application for agricultural resilience and food security.
Assuntos
Bactérias , Interações entre Hospedeiro e Microrganismos , Desenvolvimento Vegetal , Imunidade Vegetal , Plantas , Bactérias/metabolismo , Interações entre Hospedeiro e Microrganismos/imunologia , Reguladores de Crescimento de Plantas/metabolismo , Plantas/imunologia , Plantas/microbiologia , Plantas/virologia , Transdução de Sinais/imunologia , Estresse Fisiológico , Desenvolvimento Vegetal/imunologiaRESUMO
BACKGROUND: Plant growth-promoting rhizobacteria (PGPR), as a group of environmentally friendly bacteria growing in the rhizosphere of plants, play an important role in plant growth and development and resistance to environmental stresses. However, their limited understanding has led to the fact that their large-scale use in agriculture is still scarce, and the mechanisms by which beneficial bacteria are selected by plants and how they interact with them are still unclear. METHOD: In this study, we investigated the interaction between the auxin-producing strain Bacillus aryabhattai LAD and maize roots, and performed transcriptomic and metabolomic analyses of Bacillus aryabhattai LAD after treatment with maize root secretions(RS). RESULTS: Our results show that there is a feedback effect between the plant immune system and bacterial auxin. Bacteria activate the immune response of plant roots to produce reactive oxygen species(ROS), which in turn stimulates bacteria to synthesize IAA, and the synthesized IAA further promotes plant growth. Under the condition of co-culture with LAD, the main root length, seedling length, root surface area and root volume of maize increased by 197%, 107%, 89% and 75%, respectively. In addition, the results of transcriptome metabolome analysis showed that LAD was significantly enriched in amino acid metabolism, carbohydrate metabolism and lipid metabolism pathways after RS treatment, including 93 differentially expressed genes and 45 differentially accumulated metabolites. CONCLUSION: Our findings not only provide a relevant model for exploring the effects of plant-soil microbial interactions on plant defense functions and thereby promoting plant growth, but also lay a solid foundation for the future large-scale use of PGPR in agriculture for sustainable agricultural development.
Assuntos
Bacillus , Ácidos Indolacéticos , Raízes de Plantas , Espécies Reativas de Oxigênio , Zea mays , Zea mays/microbiologia , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo , Bacillus/metabolismo , Bacillus/genética , Raízes de Plantas/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , Espécies Reativas de Oxigênio/metabolismo , Ácidos Indolacéticos/metabolismo , Rizosfera , Microbiologia do Solo , Transcriptoma , Desenvolvimento Vegetal , Reguladores de Crescimento de Plantas/metabolismoRESUMO
The sugars will eventually be exported transporter (SWEET) family is a novel class of sugar transporters that play a crucial role in plant growth, development, and responses to stress. Cranberry (Vaccinium macrocarpon Ait.) is a nutritious berry with economic importance, but little is known about SWEET gene family functions in this small fruit. In this research, 13 VmSWEET genes belonging to four clades were identified in the cranberry genome for the first time. In the conserved domains, we observed seven phosphorylation sites and four amino acid residues that might be crucial for the binding function. The majority of VmSWEET genes in each clade shared similar gene structures and conserved motifs, showing that the VmSWEET genes were highly conserved during evolution. Chromosomal localization and duplication analyses showed that VmSWEET genes were unevenly distributed in eight chromosomes and two pairs of them displayed synteny. A total of 79 cis-acting elements were predicted in the promoter regions of VmSWEETs including elements responsive to plant hormones, light, growth and development and stress responses. qRT-PCR analysis showed that VmSWEET10.1 was highly expressed in flowers, VmSWEET16 was highly expressed in upright and runner stems, and VmSWEET3 was highly expressed in the leaves of both types of stems. In fruit, the expression of VmSWEET14 and VmSWEET16 was highest of all members during the young fruit stage and were downregulated as fruit matured. The expression of VmSWEET4 was higher during later developmental stages than earlier developmental stages. Furthermore, qRT-PCR results revealed a significant up-regulation of VmSWEET10.2, under osmotic, saline, salt-alkali, and aluminum stress conditions, suggesting it has a crucial role in mediating plant responses to various environmental stresses. Overall, these results provide new insights into the characteristics and evolution of VmSWEET genes. Moreover, the candidate VmSWEET genes involved in the growth, development and abiotic stress responses can be used for molecular breeding to improve cranberry fruit quality and abiotic stress resistance.
Assuntos
Frutas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas , Estresse Fisiológico , Vaccinium macrocarpon , Vaccinium macrocarpon/genética , Vaccinium macrocarpon/metabolismo , Vaccinium macrocarpon/química , Estresse Fisiológico/genética , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Família Multigênica , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Transporte de Monossacarídeos/metabolismo , Filogenia , Genoma de Planta , Desenvolvimento Vegetal/genética , Cromossomos de Plantas/genética , Sintenia/genéticaRESUMO
In recent times, increased geogenic and human-centric activities have caused significant heavy metal(loid) (HM) contamination of soil, adversely impacting environmental, plant, and human health. Phytoremediation is an evolving, cost-effective, environment-friendly, in situ technology that employs indigenous/exotic plant species as natural purifiers to remove toxic HM(s) from deteriorated ambient soil. Interestingly, the plant's rhizomicrobiome is pivotal in promoting overall plant nutrition, health, and phytoremediation. Certain secondary metabolites produced by plant growth-promoting rhizobacteria (PGPR) directly participate in HM bioremediation through chelation/mobilization/sequestration/bioadsorption/bioaccumulation, thus altering metal(loid) bioavailability for their uptake, accumulation, and translocation by plants. Moreover, the metallotolerance of the PGPR and the host plant is another critical factor for the successful phytoremediation of metal(loid)-polluted soil. Among the phytotechniques available for HM remediation, phytoextraction/phytoaccumulation (HM mobilization, uptake, and accumulation within the different plant tissues) and phytosequestration/phytostabilization (HM immobilization within the soil) have gained momentum in recent years. Natural metal(loid)-hyperaccumulating plants have the potential to assimilate increased levels of metal(loid)s, and several such species have already been identified as potential candidates for HM phytoremediation. Furthermore, the development of transgenic rhizobacterial and/or plant strains with enhanced environmental adaptability and metal(loid) uptake ability using genetic engineering might open new avenues in PGPR-assisted phytoremediation technologies. With the use of the Geographic Information System (GIS) for identifying metal(loid)-impacted lands and an appropriate combination of normal/transgenic (hyper)accumulator plant(s) and rhizobacterial inoculant(s), it is possible to develop efficient integrated phytobial remediation strategies in boosting the clean-up process over vast regions of HM-contaminated sites and eventually restore ecosystem health.
Assuntos
Biodegradação Ambiental , Metais Pesados , Poluentes do Solo , Metais Pesados/metabolismo , Poluentes do Solo/metabolismo , Desenvolvimento Vegetal , Plantas/metabolismo , Microbiologia do SoloRESUMO
Mountainous regions are vital biodiversity hotspots with high heterogeneity, providing essential refugia for vegetation. However, climate change threatens this diversity with the potential homogenization of the distinct environmental conditions at different elevations. Here, we used a time-series (1985-2023) of Normalized Difference Vegetation Index (NDVI) from Landsat archives (30 m) to quantify vegetation changes across an elevation gradient on Himalaya Mountain. Our analysis revealed that over the past 40 years, the Himalayas have experienced widespread greening, accompanied by homogenization of vegetation across elevations. This homogenization, characterized by a reduction in the differences between high and low elevations, can be attributed to two main factors: (1) increased warming and a higher snowmelt rate at high elevations, facilitating rapid changes in high-elevation vegetation activities; and (2) higher anthropogenic disturbance at low and mid elevations, thus inhibiting low-elevation vegetation. These factors have resulted in a reduction of habitat differentiation along the mountain slopes, homogenizing vegetation and potentially threatening the unique biodiversity adapted to specific elevational zones. Our findings emphasize the urgent need for conservation strategies that prioritize the protection of heterogeneous mountain habitats to preserve their rich biodiversity in the face of climate change.
Assuntos
Altitude , Biodiversidade , Mudança Climática , Ecossistema , Monitoramento Ambiental , Plantas , Conservação dos Recursos Naturais , Desenvolvimento VegetalRESUMO
Although arginine methylation (R-methylation) is one of the most important post-translational modifications (PTMs) conserved in eukaryotes, it has not been studied to the same extent as phosphorylation and ubiquitylation. Technical constraints, which are in the process of being resolved, may partly explain this lack of success. Our knowledge of R-methylation has recently evolved considerably, particularly in metazoans, where misregulation of the enzymes that deposit this PTM is implicated in several diseases and cancers. Indeed, the roles of R-methylation have been highlighted through the analyses of the main actors of this pathway: the PRMT writer enzymes, the TUDOR reader proteins, and potential "eraser" enzymes. In contrast, R-methylation has been much less studied in plants. Even so, it has been shown that R-methylation in plants, as in animals, regulates housekeeping processes such as transcription, RNA silencing, splicing, ribosome biogenesis, and DNA damage. R-methylation has recently been highlighted in the regulation of membrane-free organelles in animals, but this role has not yet been demonstrated in plants. The identified R-met targets modulate key biological processes such as flowering, shoot and root development, and responses to abiotic and biotic stresses. Finally, arginine demethylases activity has mostly been identified in vitro, so further studies are needed to unravel the mechanism of arginine demethylation.
Assuntos
Arginina , Desenvolvimento Vegetal , Plantas , Processamento de Proteína Pós-Traducional , Metilação , Desenvolvimento Vegetal/genética , Plantas/metabolismo , Plantas/genética , Arginina/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Animais , Estresse Fisiológico , Regulação da Expressão Gênica de PlantasRESUMO
AIMS: This study explores the plant growth-promoting effect (PGPE) and potential mechanisms of the arsenic (As)-resistant bacterium Flavobacterium sp. A9 (A9 hereafter). METHODS AND RESULTS: The influences of A9 on the growth of Arabidopsis thaliana, lettuce, and Brassica napus under As(V) stress were investigated. Additionally, a metabolome analysis was conducted to unravel the underlying mechanisms that facilitate PGPE. Results revealed that A9 significantly enhanced the fresh weight of Arabidopsis seedlings by 62.6%-135.4% under As(V) stress. A9 significantly increased root length (19.4%), phosphorus (25.28%), chlorophyll content (59%), pod number (24.42%), and weight (18.88%), while decreasing As content (48.33%, P ≤ .05) and oxidative stress of Arabidopsis. It also significantly promoted the growth of lettuce and B. napus under As(V) stress. A9 demonstrated the capability to produce ≥31 beneficial substances contributing to plant growth promotion (e.g. gibberellic acid), stress tolerance (e.g. thiamine), and reduced As accumulation (e.g. siderophores). CONCLUSIONS: A9 significantly promoted the plant growth under As stress and decreased As accumulation by decreasing oxidative stress and releasing beneficial compounds.
Assuntos
Arabidopsis , Arsênio , Brassica napus , Flavobacterium , Estresse Oxidativo , Arsênio/metabolismo , Brassica napus/crescimento & desenvolvimento , Brassica napus/microbiologia , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/microbiologia , Arabidopsis/efeitos dos fármacos , Flavobacterium/crescimento & desenvolvimento , Flavobacterium/efeitos dos fármacos , Lactuca/microbiologia , Lactuca/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Clorofila/metabolismo , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Estresse Fisiológico , Microbiologia do Solo , Giberelinas/metabolismo , Giberelinas/farmacologia , Sideróforos/metabolismo , Desenvolvimento Vegetal/efeitos dos fármacos , Farmacorresistência BacterianaRESUMO
Microplastics are heterogeneously distributed in soils. However, it is unknown whether soil microplastic heterogeneity affects plant growth and root foraging responses and whether such effects vary with plant species and microplastic types. We grew each of seven herbaceous species (Platycodon grandiflorus, Trifolium repens, Portulaca oleracea, Medicago sativa, Taraxacum mongolicum, Perilla frutescenst, and Paspalum notatum) in heterogeneous soil (patches without microplastics and patches with 0.2 % microplastics) and homogeneous soil (patches with 0.1 % microplastics). Three microplastic types were tested: polypropylene (PP), polyacrylonitrile (PAN), and polyester (PET). P. frutescens showed no response to soil microplastic heterogeneity. For P. grandiflora, microplastic heterogeneity tended to decrease its biomass (total, shoot and root) when the microplastic was PAN and also shoot biomass when it was PET, but had no effect when it was PP. For T. repens, microplastic heterogeneity promoted biomass when PAN was used, decreased total and root biomass when PET was used, but showed no effect when PP was used. Microplastic heterogeneity increased biomass of P. oleracea and decreased that of M. sativa when PET was used, but had no effect when PP or PAN was used. For T. mongolicum, microplastic heterogeneity reduced biomass when the microplastic was PAN, tended to increase total and root biomass when it was PP, but showed no effect when it was PET. For P. notatum, microplastic heterogeneity increased biomass when the microplastic was PP, decreased it when PET was used, but had no effect when PAN was used. However, biomass of none of the seven species showed root foraging responses at the patch level. Therefore, soil microplastic heterogeneity can influence plant growth, but such effects depend on species and microplastic types and are not associated with root foraging. Our findings highlight the roles of soil microplastic heterogeneity, which may influence species interactions and community structure and productivity.
Assuntos
Microplásticos , Poluentes do Solo , Solo , Poluentes do Solo/análise , Microplásticos/toxicidade , Solo/química , Desenvolvimento Vegetal/efeitos dos fármacosRESUMO
Restoring submerged plants naturally has been a significant challenge in water ecology restoration programs. Some silicate-based mineral materials have shown promise in improving the substrate properties for plant growth. While it is well-established that silicate mineral materials enhance submerged plant growth by improving salt release and reducing salt stress, the influence of rhizosphere microorganisms on phytohormone synthesis and key enzyme activities has been underestimated. This study focused on two typical silicate mineral materials, bentonite and maifanite, to investigate their effects on Myriophyllum oguraense from both plant physiology and microbiome perspectives. The results demonstrated that both bentonite and maifanite regulated the synthesis of phytohormones such as gibberellin (GA) and methyl salicylate (MESA), leading to inhibition of cellular senescence and promotion of cell division. Moreover, these silicate mineral materials enhanced the activity of antioxidant enzymes, thereby reducing intracellular reactive oxygen species levels. They also optimized the structure of rhizosphere microbial communities, increasing the proportion of functional microorganisms like Nitrospirota and Sva0485, which indirectly influenced plant metabolism. Analysis of sediment physicochemical properties revealed increased rare earth elements, macronutrients, and oxygen content in pore water in the presence of silicate materials, creating favorable conditions for root growth. Overall, these findings shed light on the multifaceted mechanisms by which natural silicate mineral materials promote the growth of aquatic plants, offering a promising solution for restoring aquatic vegetation in eutrophic lake sediments.
Assuntos
Microbiota , Minerais , Silicatos , Microbiota/efeitos dos fármacos , Reguladores de Crescimento de Plantas , Rizosfera , Desenvolvimento Vegetal/efeitos dos fármacos , Fenômenos Fisiológicos VegetaisRESUMO
The hormonal system plays a decisive role in controlling plant growth and development [...].
Assuntos
Reguladores de Crescimento de Plantas , Reguladores de Crescimento de Plantas/metabolismo , Desenvolvimento Vegetal , Plantas/metabolismoRESUMO
Plant wearable sensors have shown exceptional promise in continuously monitoring plant health. However, the potential adverse effects of these sensors on plant growth remain unclear. This study systematically quantifies wearable sensors' interference with plant growth using two ornamental species, Peperomia tetraphylla and Epipremnum aureum. We evaluated the impacts of four common disturbances-mechanical pressure, hindrance of gas exchange, hindrance of light acquisition, and mechanical constraint-on leaf growth. Our results indicated that the combination of light hindrance and mechanical constraint demonstrated the most significant interference. When the sensor weight was no greater than 0.6 g and the coverage was no greater than 5% of the leaf area, these four disturbances resulted in slight impacts on leaf growth. Additionally, we fabricated a minimally interfering wearable sensor capable of measuring the air temperature of the microclimate of the plant while maintaining plant growth. This research provides valuable insights into optimizing plant wearable sensors, balancing functionality with minimal plant interference.
Assuntos
Desenvolvimento Vegetal , Folhas de Planta , Dispositivos Eletrônicos Vestíveis , Técnicas BiossensoriaisRESUMO
Globally, numerous ecosystems have been co-invaded by multiple exotic plant species that can have competitive or facilitative interactions with each other and with native plants. Invaded ecosystems often exhibit spatial heterogeneity in soil moisture and nutrient levels, with some habitats having more nutrient-rich and moist soils than others. The stress-gradient hypothesis predicts that plants are likely to engage in facilitative interactions when growing in stressful environments, such as nutrient-deficient or water-deficient soils. In contrast, when resources are abundant, competitive interactions between plants should prevail. The invasional meltdown hypothesis proposes that facilitative interactions between invasive species can enhance their establishment and amplify their ecological impact. Considering both hypotheses can offer insights into the complex interactions among invasive and native plants across environmental gradients. However, experimental tests of the effects of soil moisture and nutrient co-limitation on interactions between invasive and native plants at both interspecific and intraspecific levels in light of these hypotheses are lacking. We performed a greenhouse pot experiment in which we cultivated individual focal plants from five congeneric pairs of invasive and native species. Each focal plant was subjected to one of three levels of plant-plant interactions: (1) intraspecific, in which the focal plant was grown with another individual of the same species; (2) interspecific, involving a native and an invasive plant; and (3) interspecific, involving two native or invasive individuals. These plant-plant interaction treatments were fully crossed with two levels of water availability (drought vs. well-watered) and two levels of nutrient supply (low vs. high). Consistent with the stress-gradient and invasional meltdown hypotheses, our findings show that under low-nutrient conditions, the biomass production of invasive focal plants was facilitated by invasive interspecific neighbors. However, under high-nutrient conditions, the biomass production of invasive focal plants was suppressed by invasive interspecific neighbors. When competing with native interspecific neighbors, high-nutrient conditions similarly enhanced the biomass production of both invasive and native focal plants. Invasive and native focal plants were neither competitively suppressed nor facilitated by conspecific neighbors. Taken together, these results suggest that co-occurring invasive exotic plant species may facilitate each other in low-nutrient habitats but compete in high-nutrient habitats.
Assuntos
Espécies Introduzidas , Solo , Solo/química , Ecossistema , Plantas/classificação , Plantas/metabolismo , Especificidade da Espécie , Nutrientes , Água , Desenvolvimento Vegetal/fisiologiaRESUMO
This review article explores the fascinating world of chitosan coating applied to seeds and its profound impacts on enhancing the germination process and growth performance of plants. Chitosan, a biodegradable and non-toxic polysaccharide derived from chitin, has shown remarkable potential in seed treatment due to its bioactive properties. The review discusses the mechanisms of chitosan's effect on plant germination including promoting water uptake, enhancing nutrient absorption, and protecting seeds from biotic and abiotic stresses. Moreover, it evaluates the effects of chitosan on plant growth parameters such as root development, shoot growth, chlorophyll content, and overall yield. The review also discusses the sustainable aspects of chitosan coatings in agriculture, emphasizing their eco-friendly nature and potential for reducing reliance on synthetic chemicals. Overall, the findings underscore the significant benefits of chitosan-coated seeds in improving the overall performance of plants, paving the way for a greener and more productive agricultural future. Finally, the article will conclude with a SWOT analysis discussing the strengths, weaknesses, opportunities, and threats of this technology.
Assuntos
Quitosana , Germinação , Sementes , Quitosana/farmacologia , Quitosana/química , Germinação/efeitos dos fármacos , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Desenvolvimento Vegetal/efeitos dos fármacosRESUMO
BACKGROUND: Pseudomonas eucalypticola, a new species of the P. fluorescens group that generates most Pseudomonas-based biocontrol agents, has not been found in any plants other than Eucalyptus dunnii leaves. Except for antagonism to the growth of a few fungi, its features in plant growth promotion and disease control have not been evaluated. Here, we identified a similar species of P. eucalypticola, 1021Bp, from endophyte cultures of healthy leaves of English boxwood (Buxus sempervirens 'Suffruticosa') and investigated its antifungal activity, plant growth promotion traits, and potential for boxwood blight control. RESULTS: Colorimetric or plate assays showed the properties of 1021Bp in nitrogen fixation, phosphate solubilization, and production of indole-3-acetic acid (IAA) and siderophores, as well as the growth suppression of all five plant fungal pathogens, including causal agents of widespread plant diseases, gray mold, and anthracnose. Boxwood plant leaves received 87.4% and 65.8% protection from infection when sprayed with cell-free cultural supernatant (CFS) but not the resuspended bacterial cells at 108-9/mL of 1021Bp at one and seven days before inoculation (dbi) with boxwood blight pathogen, Calonectria pseudonaviculata, at 5 × 104 spores/mL. They also received similarly high protection with the 1021Bp cell culture without separation of cells and CFS at 14 dbi (67.5%), suggesting a key role of 1021Bp metabolites in disease control. CONCLUSIONS: Given the features of plant growth and health and its similarity to P. eucalypticola with the P. fluorescens lineage, 1021Bp has great potential to be developed as a safe and environmentally friendly biofungicide and biofertilizer. However, its metabolites are the major contributors to 1021Bp activity for plant growth and health. Application with the bacterial cells alone, especially with nonionic surfactants, may result in poor performance unless survival conditions are present.
Assuntos
Doenças das Plantas , Folhas de Planta , Pseudomonas , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Pseudomonas/genética , Pseudomonas/crescimento & desenvolvimento , Pseudomonas/metabolismo , Folhas de Planta/microbiologia , Antibiose , Ácidos Indolacéticos/metabolismo , Fungos/crescimento & desenvolvimento , Fungos/genética , Fungos/classificação , Fungos/efeitos dos fármacos , Sideróforos/metabolismo , Endófitos/metabolismo , Endófitos/genética , Desenvolvimento Vegetal , Agentes de Controle Biológico , Antifúngicos/farmacologia , Antifúngicos/metabolismoRESUMO
Due to the burgeoning global population and the advancement of economies, coupled with human activities leading to the degradation of soil ecosystems and the depletion of non-renewable resources, concerns have arisen regarding food security and human survival. In order to address these adverse impacts, the spotlight has been cast upon plant growth-promoting rhizobacteria (PGPR), driven by a strong environmental consciousness. PGPR possesses the capability to foster plant growth and amplify crop yield through both direct and indirect mechanisms. By expediting plant growth, augmenting nutrient assimilation, heightening crop yield and caliber, and fortifying stress resilience, the application of PGPR can mitigate reliance on chemical fertilizers and pesticides while diminishing ecological perils. This exposition delves into the function of PGPR in modulating plant hormones, fostering nutrient solubilization, and fortifying plant resistance against biotic and abiotic stressors. This review offers valuable insights into the intricate interplay between PGPR and plants, elucidating uncertainties ripe for further investigation. Profound comprehension and judicious utilization of PGPR are indispensable for attaining sustainable agricultural progression, making substantial contributions to resolving the conundrums of global food security and environmental conservation.
Assuntos
Agricultura , Produtos Agrícolas , Microbiologia do Solo , Produtos Agrícolas/microbiologia , Produtos Agrícolas/crescimento & desenvolvimento , Agricultura/métodos , Desenvolvimento Vegetal , Produção Agrícola , Desenvolvimento Sustentável , Solo/químicaRESUMO
The unique geographical and climatic conditions in the Three-River Headwaters Region gave birth to distinctive plant species and vegetation types. To reveal the spatial distribution of plant communities and soil habitats along the riparian zone of the Sanjiangyuan Region and their influencing mechanisms, 14 survey plots were set up ï¼ten from the Yangtze River source, two from the Lancang River source, and two from the Yellow River sourceï¼, and the effects of soil nutrient characteristics ï¼especially soil phosphorus morphologyï¼, climate factors, and river topography on plant community characteristics were quantitatively analyzed. The results showed that the plant community composition in the riparian zone of the source of the three rivers was dominated by perennial herbs ï¼72.2%ï¼, followed by annual herbs ï¼20.4%ï¼ and shrubs ï¼7.4%ï¼. The dominant plants were Stipa purpurea, Polygonum orbiculatum, Carex parvula, Potentilla anserina, and Gentiana straminea. The average plant coverage, Shannon-Wiener index, and Pielou index were ï¼64.4% ±23.6%ï¼, ï¼1.31 ±0.42ï¼, and ï¼0.84 ±0.08ï¼, respectively. The plant community diversity index was the highest in the Yangtze River source, followed by that in the Lancang River source, and the lowest in the Yellow River source. The soil pH of the riparian zone of the Yangtze River source was significantly higher than that of the Lancang River source, whereas the mean contents of organic matter, total nitrogen, and Fe-Al combined phosphorus were significantly lower than those of the Lancang River source. The calcium and magnesium-combined phosphorus was the main form of phosphorus in riparian soil ï¼63.89%ï¼. Temperature, soil organic phosphorus content, and pH had significant effects on plant composition in the riparian zone of the Three-River Headwaters Region, whereas soil calcium and magnesium-combined phosphorus content had significant effects on plant community diversities. These results may deepen the scientific understanding of the evolution trend and genetic mechanism of plant communities in the riparian zone of the Three-River Headwaters Region.
Assuntos
Ecossistema , Fósforo , Rios , Solo , China , Solo/química , Fósforo/análise , Plantas/classificação , Desenvolvimento Vegetal , Monitoramento Ambiental , Dinâmica Populacional , Biodiversidade , Poaceae/crescimento & desenvolvimento , Análise EspacialRESUMO
Established as a plant macronutrient, potassium (K) substantially bestows plant growth and thus, global food production. It is absorbed by plants as potassium cation (K+) from soil solution, which is enriched through slow-release from soil minerals or addition of soluble fertilizers. Contribution of bioavailable K+ from soil is usually insignificant (< 2â¯%), although the earth's crust is rich in K-bearing minerals. However, K is fixed largely in interlayer spaces of K-bearing minerals, which can be released by K-solubilizing bacteria (KSB) such as Bacillus, Pseudomonas, Enterobacter, and Acidithiobacillus. The underlying mechanisms of K dissolution by KSB include acidolysis, ion exchange reactions, chelation, complexolysis, and release of various organic and inorganic acids such as citric, oxalic, acetic, gluconic, and tartaric acids. These acids cause disintegration of K-bearing minerals and bring K+ into soil solution that becomes available to the plants. Current literature review updates the scientific information about microbial species, factors, and mechanisms governing the bio-intrusion of K-bearing minerals. Moreover, it explores the potential of KSB not only for K-solubilization but also to enhance bioavailability of phosphorus, nitrogen, and micronutrients, as well as its other beneficial impact on plant growth. Thus, in the context of sustainable agricultural production and global food security, utilization of KSB may facilitate plant nutrient availability, conserve natural resources, and reduce environmental impacts caused by chemical fertilizers.
Assuntos
Agricultura , Bactérias , Disponibilidade Biológica , Potássio , Microbiologia do Solo , Solo , Potássio/metabolismo , Solo/química , Bactérias/metabolismo , Fertilizantes , Desenvolvimento Vegetal , Nitrogênio/metabolismo , Fósforo/metabolismo , Minerais/metabolismoRESUMO
Clarifying vegetation changes and the driving factors can provide references for ecological restoration and sustainable social development. We analyzed vegetation distribution and trend changes in Henan Province and its basin zoning (Haihe River basin zoning, Yellow River basin zoning, Huaihe River basin zoning, Yangtze River basin zoning), with fractional vegetation cover data from 2000 to 2020 based on the Google Earth Engine platform, and by combining Theil-Sen Median trend analysis, Mann-Kendall test, and Hurst index. We also utilized factor detection and factor interaction to explore the individual and mutual influences of natural and anthropogenic factors on vegetation at different scales. The results showed that the fractional vegetation cover (FVC) in Henan Province exhibited a distribution pattern of higher coverage in the south and lower in the north during the study period, predominantly characterized by moderate to high vegetation coverage. The Yangtze River basin zoning had the highest coverage. FVC in Henan Province and its zoning exhibited a consistent pattern of fluctuating upward trends, with all areas showing significant improvement. Particularly, the Yangtze River basin zoning had the largest area of improvement. According to the Hurst index, apart from the possibility of continued improvement in the Huaihe River basin zoning, other zoning would be likely to shift from improvement to degradation in the future. Vegetation changes in Henan Province and its zoning were the result of combined effects of anthropogenic and natural factors, with the influence of these factors changing over time and the dominant factors varying by region. Anthropogenic factors such as land use/cover type and nighttime lighting had a stronger impact on vegetation than natural factors like elevation, slope, and annual mean low temperature. The interaction between factors, particularly between anthropogenic and natural factors, exhibited a nonlinear enhancing pattern.