Search Results (1,000)

Strigolactones (SLs) have emerged as important regulators of plant adaptation to abiotic stress, functioning not as isolated hormones but as integrative signaling molecules. Beyond stress responses, SLs regulate key biological processes, including shoot branching, root architecture, leaf senescence, nutrient acquisition, rhizosphere communication, flowering-related development, and growth–developmental plasticity. This review synthesizes current knowledge on how SLs modulate plant responses to drought, salinity, heavy metal toxicity, high temperature, and low temperature through crosstalk with abscisic acid, auxin, cytokinin, ethylene, and gibberellin. We examine SL structural diversity, biosynthesis, transport, and signaling together with their roles in growth–stress coordination, hormonal networking, and stress-specific mitigation, while distinguishing endogenous SL functions from responses inferred from exogenous analogs such as GR24. Across stresses, SL-mediated resilience converges on adaptive modules, including water regulation, root–shoot architectural remodeling, redox protection, ion and osmotic homeostasis, photosynthetic maintenance, and rhizosphere-assisted resource acquisition. The mechanistic basis involves transcriptional reprogramming, ROS/RNS-linked redox regulation, metabolic protection, and root–microbe interactions. Translational prospects include SL analogs, genetic manipulation, and breeding for adaptive plasticity, nutrient efficiency, and stress tolerance. However, species specificity, dosage dependence, limited field validation, unclear structure–function relationships, and parasitic-weed stimulation remain major constraints. Full article

Soil salinization severely constrains plant growth, yet the roles of ion composition and rhizosphere microbial communities in shaping plant performance remain poorly resolved. Here, we investigated multiple crop and wild plant species in saline–alkali soils and compared rhizosphere ion composition, microbial communities, and plant growth status. Restricted plant growth was consistently associated with elevated Na⁺ and Cl⁻ concentrations, while fungal diversity was significantly higher in well-growing plants. Ion composition (particularly Na⁺, Cl⁻, SO₄^2–, and Mg²⁺) was strongly correlated with microbial community structure, and a set of microbial taxa, including bacterial phyla such as Deinococcota and Gemmatimonadota and fungal phyla within Ascomycota and Basidiomycota, were repeatedly associated with plant growth status across species. Notably, plant species exhibited distinct apparent, threshold-like responses, and in several cases, plant growth differences were not fully explained by salinity levels alone, suggesting that rhizosphere microbial communities may buffer salt stress. Together, our results reveal that ion composition governs plant growth not only through direct ionic stress but also via microbially mediated pathways, highlighting an ion–microbe–plant interaction framework underlying growth variation in saline–alkali soils. Full article

Sudden death syndrome (SDS) and soybean cyst nematode (SCN) are major yield-limiting diseases in North American soybean production, with limited effective management options. Long-term soybean monoculture has been reported to suppress SDS and SCN, but the mechanisms, onset, and persistence of such suppression remain poorly understood. To study these mechanisms, a six-year field study (2018–2023) was conducted at two Ontario sites with contrasting disease histories: Chatham (conducive) and Essex (suppressive). We evaluated suppression development and resilience across soybean monoculture (SSSSSS) and corn–soybean rotations (SCSCSC/CSCSCS), using eight cultivars differing in SDS and SCN resistance across two maturity groups. In Chatham, disease index (DX) progressively declined under monoculture; the most susceptible cultivar, HS11RY07, declined from a mean DX of 89 to 43 by year six, with corresponding yield increases, and rotational yield advantages diminished. In Essex, introducing corn rotation increased SDS symptoms during soybean phases; monoculture yields became comparable to rotation in later years. Importantly, suppression developed without corresponding reductions in Fusarium virguliforme and SCN populations, which remained variable across years, suggesting that monoculture may disrupt pathogen effectiveness rather than eliminating it. This decoupling of pathogen abundance and disease severity is consistent with soil-mediated biological suppression; the microbial drivers are addressed in subsequent work. Full article

This study investigated the potential of microbial-assisted phytoremediation using Eichhornia crassipes (water hyacinth) to reduce heavy metal and salinity pollution in produced water collected from Aadi Oil Field in Gujar Khan, Pakistan. Produced water was analyzed for physicochemical parameters and heavy metal content using Inductively Coupled Plasma–Optical Emission Spectrometry (ICP-OES) to establish baseline data. E. crassipes plants augmented with indigenous, contaminant-tolerant microbial isolates were employed in a 15-day laboratory experiment. The results showed a resilient growth response, with plant height increasing to approximately 11–15 cm and root length extending up to 10–13 cm across treatments. Biomass also improved, with wet weights reaching 21–24 g from an initial 20 g. The treatment effectively reduced key physicochemical parameters: pH was stabilized from an initial alkaline value of 9.14 to near-neutral values (7.0–7.5), and total dissolved solids (TDSs) were reduced by approximately 50%. Heavy metal removal rates varied, with the highest efficiency of 79.2% for Silver (Ag) and the lowest (18.5%) for Mercury (Hg) This study demonstrates that E. crassipes actively participated in phytoremediation by absorbing and accumulating heavy metals and reducing salinity. The association with contaminant-tolerant microbes appeared to enhance the plant’s tolerance and overall treatment efficacy, indicating that plant–microbe interactions offer a sustainable strategy for the treatment of produced water. Full article

Salinization of agricultural soils is a global problem causing crop yield declines. This impact is caused by osmotic and oxidative stress, which plants often rely on endophytic bacteria to overcome. A bacterial isolate from the roots of the halophyte Plantago salsa was studied between 2024 and 2026, and its ability to increase barley tolerance to moderate salt stress was determined. Based on 16S rRNA gene sequencing (1410 bp), the isolate PS-50.1 was identified as Providencia sp. It demonstrated key plant growth-promoting properties, including indole-3-acetic acid production (21.4 mg L⁻¹) and phosphate solubilization (69.0 mg L⁻¹). The strain supported barley growth at 7% NaCl. Inoculation of barley seeds with this strain (10⁸ CFU L⁻¹) significantly reduced moderate salt stress in plants both in vitro and in a pot experiment. Inoculated plants under salinity conditions had greater shoot length (+11.6%) compared to non-inoculated; higher pre-flag leaf fresh weight; demonstrated decreased levels of prooxidants (H₂O₂ by 44.8% and malondialdehyde by 31.8%), higher proline accumulation (up to 2.0-fold), and increased antioxidant enzyme activity (catalase by 26.6% and ascorbate peroxidase by 191%). Furthermore, inoculated plants showed 9.4% higher water use efficiency and photosynthetic rate (+5.5%) under salt stress compared to uninoculated plants. These results indicate that the halophytic strain Providencia sp. PS-50.1 is a promising candidate for the development of microbial preparations aimed at increasing crop productivity under saline conditions. Full article

Plants perceive light signals through photoreceptors such as CRY1 to regulate growth and development. It is well-known that Arabidopsis CRY1 is a nucleocytoplasmic protein that mediates light inhibition of hypocotyl elongation in the nucleus, but the mechanisms by which CRY1 regulates root growth and functions in the cytoplasm remain poorly understood. Here, we identified eIF3G1, a subunit of the eukaryotic translation initiation factor 3 (eIF3) complex, as a CRY1-interacting protein associated with light-regulated root development. Under blue light, eif3g1 mutants showed longer primary roots, whereas eIF3G1 overexpression reduced root elongation, accompanied by corresponding changes in root apical meristem size. Differential irradiation experiments indicated that shoot illumination is required for eIF3G1-dependent root phenotypes. Transcriptome analysis revealed changes in translation-related and light-responsive genes in response to eIF3G1 perturbation. Comparison with the cry1 transcriptome revealed overlapping differentially expressed genes, including BIC1 and BIC2, and the bic1 bic2 double mutant showed reduced root elongation. Together, these findings identify eIF3G1 as a CRY1-interacting factor that contributes to the shoot-dependent regulation of root growth under blue light, suggesting that eIF3G1 may be associated with the CRY1-dependent shoot-to-root regulation of root growth. Full article

The accelerating demand for nickel and rare earth elements (REEs) for batteries, renewable energy technologies, and advanced electronics is intensifying pressure on conventional mining, with profound implications for biodiversity, ecosystem integrity, and local communities. Phytomining—cultivating metal-hyperaccumulator plants to recover metals from soils—has emerged as a promising complementary approach that can simultaneously generate metal resources, remediate degraded lands, and deliver conservation co-benefits. Nickel phytomining is now approaching commercial deployment, supported by a diverse flora of more than 500 nickel-hyperaccumulator species and field trials demonstrating economically relevant yields of approximately 22.6–77 kg Ni ha⁻¹ yr⁻¹ on ultramafic and mine-affected soils. In parallel, recent discoveries of REE hyperaccumulator plants and advances in biomass processing, including rapid electrothermal calcination, have revitalized interest in REE phytomining as a sustainable alternative for critical mineral recovery. This review synthesizes current knowledge on the ecology, physiology, and agronomy of nickel and REE hyperaccumulators, with a focus on how their deployment in phytomining systems can contribute to biodiversity conservation, land restoration, and resource recycling. It identifies key research gaps in hyperaccumulator discovery, molecular mechanisms, soil–plant–microbe interactions, agronomic optimization, biomass processing, techno-economic assessment, and social science and governance. In addition, the paper presents a novel techno-economic assessment for Texas as a case study of U.S. deployment, and proposes a phased scouting protocol for discovering and domesticating new hyperaccumulator species. Together, these elements provide a framework for integrating phytomining into conservation planning and critical mineral strategies, particularly in the United States, where ARPA-E programs are beginning to target domestic phytomining supply chains. Full article

Dioecious plant species display sexual dimorphism in terms of their morphological and physiological properties. However, little is known about the differentiation among endophytes within female versus male members of dioecious host plants. Hence, the endophyte diversity and composition of different tissues of male and female Hippophae tibetana were investigated using amplicon sequencing, and key factors driving the differences were determined. The results showed that there were divergences in endophytic diversity, community composition, connectivity and complexity of the co-occurrence network between females and males H. tibetana. The females and males owned their unique phyla of endophytic bacteria (Fusobacteriota and Chloroflexi, respectively). Significant enrichment of species at different levels was found between females and males, suggesting that these species could be potential biomarkers for male and female H. tibetana. Variance partitioning analysis (VPA) and Spearman analysis revealed that the phytostoichiometry and metabolites of H. tibetana explained more differences in community composition of fungal and bacterial endophytes than rhizosphere soil physicochemical properties, and endophytes exhibited a significant positive correlation with the phytostoichiometry and metabolites of H. tibetana. PICRUSt and FUNGuild predictive analyses revealed differences in endophytic fungal function between female and male H. tibetana, while the endophytic bacterial functions were metabolism. These results reveal the sexual differentiation of endophytes in dioecious plants and provide important knowledge for dioecious plant–microbe interactions. Full article

Water stress is a major constraint on peanut (Arachis hypogaea L.) production, as it limits plant growth and biological nitrogen fixation. The development of long-lasting microbial inoculants is a key strategy for mitigating these effects. This study investigated whether the addition of trehalose improves the long-term functionality of Bradyrhizobium sp. SEMIA 6144 when encapsulated in alginate beads, and how this influences peanut yield under water stress conditions. Encapsulated bacteria, with and without trehalose, were stored for 12 months, and their ability to interact with plants at an early stage and promote plant growth was examined. Storage increased bacterial motility and aggregation, while biofilm formation remained stable. Trehalose supplementation significantly enhanced root adhesion, increasing bacterial colonization by approximately 105%. In pot experiments, inoculation with the encapsulated bacteria improved plant growth and nodulation under stress conditions. Plants inoculated with fresh beads exhibited increases in shoot length of up to 24%, maintaining higher biomass than uninoculated controls. Encapsulated formulations also mitigated the effects of drought on nodulation and physiological parameters. Overall, trehalose-enriched alginate encapsulation preserves bacterial functionality during long-term storage and enhances plant–microbe interactions, thereby improving peanut resilience under water stress and offering a promising strategy for the development of sustainable bioinoculants. Full article

Cannabis sativa L. is a multipurpose crop of increasing agricultural and medical relevance, whose productivity and phytocannabinoid profile are influenced not only by genotype and environmental factors but also by the composition of its microbiota. This review synthesizes current knowledge (2020–2026) on the rhizosphere and endophytic microbiota of hemp, with particular emphasis on plant growth-promoting bacteria (PGPB) and their mechanisms of action. Molecular studies indicate that hemp-associated bacterial communities are dominated by Proteobacteria, Actinobacteriota, Firmicutes and Bacteroidota, with genotype-, tissue- and developmental-stage-dependent variation. PGPB influence plant performance through direct mechanisms, including biological nitrogen fixation, phosphate solubilization, siderophore production and phytohormone synthesis (indole-3-acetic acid (IAA), gibberellins, cytokinins, and 1-aminocyclopropane-1-carboxylate (ACC) deaminase), as well as indirect mechanisms such as antibiosis, enzyme-mediated pathogen inhibition and induction of systemic tolerance to abiotic stress. Experimental studies demonstrate that inoculation with selected strains or consortia can enhance biomass accumulation, improve germination and root architecture, increase resistance to Fusarium oxysporum and modulate cannabinoid and terpene profiles. Importantly, plant responses are cultivar-specific, highlighting the need for genotype-tailored microbial formulations. Full article

The genus Burkholderia encompasses both plant pathogenic and beneficial species, yet the genomic determinants underlying this lifestyle divergence remain poorly understood. Using 16S rRNA sequencing of 100 rice cultivars, our companion study demonstrated that resistant varieties are enriched in beneficial Burkholderiaceae, leading to the isolation of three phenotypically contrasting strains. Here, we present comparative genomic analyses of non-pathogenic biocontrol strain Burkholderia vietnamiensis J14EpLeaf2 and pathogenic strains Burkholderia gladioli A1EpSeed5 and Burkholderia cepacia J14Eple. Pathogenic strains possess significantly larger genomes (8.36–8.46 Mb) enriched in mobile genetic elements compared to the streamlined 6.95 Mb genome of B. vietnamiensis. CAZyme analysis revealed broader repertoires of glycoside hydrolases and polysaccharide lyases in pathogens, consistent with enhanced plant cell wall degradation. B. gladioli possesses a complete T3SS and expanded T6SS with 301 predicted effectors, while B. cepacia lacks structural T3SS genes but harbors 271 candidate effectors predicted to be secreted via alternative secretion pathways, compared to 180 in B. vietnamiensis. Notably, B. cepacia harbors cystic fibrosis-associated markers (cable pili, ZmpA/ZmpB), raising significant biosafety concerns that preclude its agricultural application. LC-MS validated IAA, ornibactin, and AHL production in B. vietnamiensis, supporting its plant growth-promoting and biocontrol functions. Computational PPI networks predicted distinct interaction landscapes requiring experimental validation. This study provides a genomic framework for distinguishing pathogenic from beneficial Burkholderia and supports B. vietnamiensis as a safe biocontrol agent while cautioning against B. cepacia J14Eple. Full article

Cadmium (Cd) and lead (Pb) co-contamination in construction and demolition waste landfill soils presents a significant challenge to ecosystem health, necessitating effective remediation strategies. This study investigated a synergistic approach combining a composite amendment (compost, superphosphate, desulfurized gypsum) with seven plant species to elucidate the interactions driving metal immobilization and phytoextraction. The amendment significantly altered soil properties: it reduced total Cd while increasing its bioavailability, and enhanced soil fertility (e.g., elevated organic matter and total nitrogen). Plant responses varied: Solanum americanum Mill. and Tagetes patula L. exhibited high Cd phytoextraction capacity, whereas Lolium perenne L. sequestered Cd/Pb primarily in roots. The bacterial community shifted from an oligotrophic, stress-tolerant state (e.g., Sphingomonas-dominated) in contaminated soil to a copiotrophic, functionally active state (e.g., Streptomyces-enriched) in amended soil. Community structure was strongly correlated with available Cd, pH, and nutrient levels. Key microbial biomarkers were specifically enriched in different plant rhizospheres. In contrast, the fungal community exhibited minimal responsiveness. These findings demonstrate that remediation efficiency is governed by an integrated “amendment–plant–microbe” framework: amendments regulate metal bioavailability, plants execute extraction or stabilization, and the restructured microbiome supports nutrient cycling and plant health. This integrated remediation strategy directly supports the Sustainable Development Goals of the 2030 Agenda, especially on environmentally sound management of chemicals and wastes and land degradation neutrality. This mechanistic understanding underscores the necessity of combined biological and chemical strategies for sustainable remediation of co-contaminated soils, ultimately enabling ecological reclamation and safe recycling of such urban marginal lands into productive uses. Full article

As a non-pathogenic oomycete, Pythium oligandrum possesses unique advantages, particularly in the context of being a biological control agent. With the increasing awareness of consumer consciousness, people are paying more attention to the use of environmentally friendly strategies in plant disease prevention and control. Pythium oligandrum is a type of biocontrol oomycete that can be developed as a biological control agent, and it does not have adverse effects on humans in the prevention and control of plant diseases. Consequently, there is increasing scientific interest in the beneficial plant–microbe interactions mediated by P. oligandrum. Currently, the main points of focus regarding the beneficial role of P. oligandrum in plant interactions are as follows: (i) P. oligandrum can activate plant defense responses and cause plants to produce resistance, thus protecting them from disease attacks; (ii) it is a strong mycoparasite that can coil around various oomycetes and fungi, directly killing pathogenic microorganisms; (iii) in addition, it can also promote plant growth. In this paper, we will discuss the aforementioned three main features in detail. Full article

Understanding the interaction between plants and rhizosphere microorganisms is critical for the development of biofertilizers. Fluorescent labeling of rhizosphere microorganisms serves as a key strategy to track their behavior during plant–microbe coculture. However, most newly isolated strains are novel and lack available molecular tools for such studies. In this research, Planococcus dechangensis NEAU-ST10-9^T (P. dechangensis NEAU-ST10-9^T), a salt-tolerant strain, was obtained from the China General Microbiological Culture Collection Center (CGMCC). It significantly increased maize root length by approximately 1.56-fold. To investigate the underlying mechanism, a donor strain (Ec102) and a shuttle plasmid (pAS104) were engineered to mediate conjugation with P. dechangensis NEAU-ST10-9^T and drive GFP overexpression in the bacterium, generating the genetically labeled strain Pd103. The fluorescence intensity (expressed as GFP/OD₆₀₀, arbitrary units) of Pd103 increased with bacterial growth and was approximately tenfold higher than that of the wild-type strain after 16 h of culture. Following inoculation onto maize seeds, confocal microscopy analysis revealed that Pd103 colonized the epidermis and endodermis of maize roots. These results indicated that P. dechangensis NEAU-ST10-9^T could invade maize roots and promote maize seedling growth. In summary, we have successfully established a robust fluorescence labeling and tracking system tailored for P. dechangensis NEAU-ST10-9^T, which constitutes a valuable tool for elucidating the cellular and molecular mechanisms governing its plant–microbe interaction. Full article

Rhizosphere microbiome engineering is a promising approach that can enhance crop resilience and input use efficiency by redirecting plant–microbe–soil interactions toward predictable functions. Here, we review the mechanistic bases underlying rhizosphere assembly and stability, including root exudate-mediated selection, priority effects, keystone taxa, and metabolite-driven signaling, and connect these principles to proposed design rules for microbial inoculants. We present a generalizable Design–Build–Test–Learn (DBTL) framework for engineering synthetic microbial consortia, covering trait-to-module mapping (nutrient acquisition, phytohormone modulation, ACC deaminase activity, stress-protective metabolites, and biocontrol), compatibility screening, minimal yet robust community architectures, and iterative optimization driven by multi-omics and high-throughput phenotyping. Translation to field settings is framed as an engineering challenge defined by formulation and administration limitations, including carrier type, seed coating and encapsulation methods, shelf life, strain invasiveness, and permanence of colonization amid environmental diversity. We also summarize how integrative measurement pipelines (amplicon and shotgun sequencing, transcriptomics, metabolomics, and network or causal analyses) can advance microbiome studies from correlation to actionability. We describe how precision agriculture (sensors, remote sensing, and variable-rate inputs) and AI/ML (split-sample comparisons, transfer learning, and active learning) approaches can accelerate strain discovery, mixture optimization, and adaptive experimentation, driven by the need for stringent controls, metadata-rich reporting, and cross-site comparability. Use cases focus on stress conditions (drought, salinity, thermal extremes, and biotic stress) to demonstrate how microbial functions translate to agronomic outcomes and to highlight critical bottlenecks for reproducible, scalable microbiome products. Full article