The Deep Learning-Crop Platform (DL-CRoP): For Species-Level Identification and Nutrient Status of Agricultural Crops.

Precise and timely detection of a crop's nutrient requirement will play a crucial role in assuring optimum plant growth and crop yield. The present study introduces a reliable deep learning platform called "Deep Learning-Crop Platform" (DL-CRoP) for the identification of some commercially grown plants and their nutrient requirements using leaf, stem, and root images using a convolutional neural network (CNN). It extracts intrinsic feature patterns through hierarchical mapping and provides remarkable outcomes in identification tasks. The DL-CRoP platform is trained on the plant image dataset, namely, Jammu University-Botany Image Database (JU-BID), available at https://github.com/urfanbutt. The findings demonstrate implementation of DL-CRoP-cases A (uses shoot images) and B (uses leaf images) for species identification for Solanum lycopersicum (tomato), Vigna radiata (Vigna), and Zea mays (maize), and cases C (uses leaf images) and D (uses root images) for diagnosis of nitrogen deficiency in maize. The platform achieved a higher rate of accuracy at 80-20, 70-30, and 60-40 splits for all the case studies, compared with established algorithms such as random forest, K-nearest neighbor, support vector machine, AdaBoost, and naïve Bayes. It provides a higher accuracy rate in classification parameters like recall, precision, and F1 score for cases A (90.45%), B (100%), and C (93.21), while a medium-level accuracy of 68.54% for case D. To further improve the accuracy of the platform in case study C, the CNN was modified including a multi-head attention (MHA) block. It resulted in the enhancement of the accuracy of classifying the nitrogen deficiency above 95%. The platform could play an important role in evaluating the health status of crop plants along with a role in precise identification of species. It may be used as a better module for precision crop cultivation under limited nutrient conditions.

ARR1 and ARR12 modulate arsenite toxicity responses in Arabidopsis roots by transcriptionally controlling the actions of NIP1;1 and NIP6;1.

Cytokinin is central to coordinating plant adaptation to environmental stresses. Here, we first demonstrated the involvement of cytokinin in Arabidopsis responses to arsenite [As(III)] stress. As(III) treatment reduced cytokinin contents, while cytokinin treatment repressed further primary root growth in Arabidopsis plants under As(III) stress. Subsequently, we revealed that the cytokinin signaling members ARR1 and ARR12, the type-B ARABIDOPSIS RESPONSE REGULATORs, participate in cytokinin signaling-mediated As(III) responses in plants as negative regulators. A comprehensive transcriptome analysis of the arr1 and arr12 single and arr1,12 double mutants was then performed to decipher the cytokinin signaling-mediated mechanisms underlying plant As(III) stress adaptation. Results revealed important roles for ARR1 and ARR12 in ion transport, nutrient responses, and secondary metabolite accumulation. Furthermore, using hierarchical clustering and regulatory network analyses, we identified two NODULIN 26-LIKE INTRINSIC PROTEIN (NIP)-encoding genes, NIP1;1 and NIP6;1, potentially involved in ARR1/12-mediated As(III) uptake and transport in Arabidopsis. By analyzing various combinations of arr and nip mutants, including high-order triple and quadruple mutants, we demonstrated that ARR1 and ARR12 redundantly function as negative regulators of As(III) tolerance by acting upstream of NIP1;1 and NIP6;1 to modulate their function in arsenic accumulation. ChIP-qPCR, EMSA, and transient dual-LUC reporter assays revealed that ARR1 and ARR12 transcriptionally activate the expression of NIP1;1 and NIP6;1 by directly binding to their promoters and upregulating their expression, leading to increased arsenic accumulation under As(III) stress. These findings collectively provide insights into cytokinin signaling-mediated plant adaptation to excessive As(III), contributing to the development of crops with low arsenic accumulation.

The bifunctional transcription factor NAC32 modulates nickel toxicity responses through repression of root-nickel compartmentalization and activation of auxin biosynthesis.

Nickel (Ni) is an important micronutrient, but excess Ni is toxic to many plant species. Currently, relatively little is known about the genetic basis of the plant responses to Ni toxicity. Here, we demonstrate that NAC32 transcription factor functions as a core genetic hub to regulate the Ni toxicity responses in Arabidopsis. NAC32 negatively regulates root-Ni concentration through the IREG2 (IRON REGULATED2) encoding a transporter. NAC32 also induces local auxin biosynthesis in the root-apex transition zone by upregulating YUCCA 7 (YUC7)/8/9 expression, which results in a local enhancement of auxin signaling in root tips, especially under Ni toxicity, thereby impaired primary root growth. By analyses of various combinations of nac32 and ireg2 mutants, as well as nac32 and yuc7/8/9 triple mutants, including high-order quadruple mutant, we demonstrated that NAC32 negatively regulates Ni stress tolerance by acting upstream of IREG2 and YUC7/8/9 to modulate their function in Ni toxicity responses. ChIPqPCR, EMSA (electrophoretic mobility shift assay) and transient dual-LUC reporter assays showed that NAC32 transcriptionally represses IREG2 expression but activates YUC7/8/9 expression by directly binding to their promoters. Our work demonstrates that NAC32 coordinates Ni compartmentation and developmental plasticity in roots, providing a conceptual framework for understanding Ni toxicity responses in plants.

Acetic acid: a cheap but chief metabolic regulator for abiotic stress tolerance in plants.

As sessile organisms, plants constantly face a variety of abiotic stresses, such as drought, salinity, and metal/metalloid toxicity, all of which possess significant threats to plant growth and yield potential. Improving plant resilience to such abiotic stresses bears paramount importance in practicing sustainable agriculture worldwide. Acetic acid/acetate has been recognized as an important metabolite with multifaceted roles in regulating plant adaptation to diverse abiotic stresses. Recent studies have elucidated that acetic acid can potentiate plants' inherent mechanisms to withstand the adverse effects of abiotic stresses through the regulation of lipid metabolism, hormone signaling, epigenetic changes, and physiological defense mechanisms. Numerous studies also underpin the potential use of acetic acid in boosting crop production under unfavorable environmental conditions. This review provides a comprehensive update on the understanding of how acetic acid regulates plant photosynthesis, acts as an antitranspirant, detoxifies reactive oxygen species to alleviate oxidative stress, interacts with phytohormones to regulate physiological processes, and improves soil fertility and microbial diversity, with a specific focus on drought, salinity, and metal toxicity. We also highlight the eco-friendly and economic potential of acetic acid that may attract farmers from developing countries to harness the benefits of acetic acid application for boosting abiotic stress resistance in crops. Given that acetic acid is a widely accessible, inexpensive, and eco-friendly compound, the revelation of acetic acid-mediated regulatory pathways and its crosstalk with other signaling molecules will have significant importance in developing a sustainable strategy for mitigating abiotic stresses in crops.

Link between Plant Phosphate and Drought Stress Responses.

The menace of drought has persistently loomed over global crop production, posing a serious threat to agricultural sustainability. Research on drought stress highlights the important role of the phytohormone abscisic acid (ABA) in orchestrating plant responses to drought conditions. ABA regulates various drought/dehydration-responsive genes, initiates stomatal closure, and influences cellular responses to drought stress. Additionally, plants employ a phosphate starvation response (PSR) mechanism to manage phosphate (Pi) deficiency, with ABA playing a role in its regulation. However, despite intensive research in these fields, the precise connection among PSRs, drought stress, and ABA signaling still needs to be determined. Recently, PSR-related gene induction has been reported to occur before the induction of ABA-responsive genes under progressive mild drought. Mild drought decreases Pi uptake and contents in plants, triggering PSRs, which play an important role in plant growth during mild drought. Both ABA-responsive and PSR-related gene expression could indicate plant perception of external moisture conditions. Thus, integrating the information regarding their associated gene expression with soil moisture contents and thermographic data can enable timely irrigation optimization to mitigate the effect of drought on crop productivity.

Wild grass-derived alleles represent a genetic architecture for the resilience of modern common wheat to stresses.

This review explores the integration of wild grass-derived alleles into modern bread wheat breeding to tackle the challenges of climate change and increasing food demand. With a focus on synthetic hexaploid wheat, this review highlights the potential of genetic variability in wheat wild relatives, particularly Aegilops tauschii, for improving resilience to multifactorial stresses like drought, heat, and salinity. The evolutionary journey of wheat (Triticum spp.) from diploid to hexaploid species is examined, revealing significant genetic contributions from wild grasses. We also emphasize the importance of understanding incomplete lineage sorting in the genomic evolution of wheat. Grasping this information is crucial as it can guide breeders in selecting the appropriate alleles from the gene pool of wild relatives to incorporate into modern wheat varieties. This approach improves the precision of phylogenetic relationships and increases the overall effectiveness of breeding strategies. This review also addresses the challenges in utilizing the wheat wild genetic resources, such as the linkage drag and cross-compatibility issues. Finally, we culminate the review with future perspectives, advocating for a combined approach of high-throughput phenotyping tools and advanced genomic techniques to comprehensively understand the genetic and regulatory architectures of wheat under stress conditions, paving the way for more precise and efficient breeding strategies.

An insight into the antioxidant activities and the exploration of record high quantities of quercetin and luteolin in the plant parts of Myxopyrum smilacifolium (wall.) Blume.

This study attempts to reveal antioxidants in the plant parts of Myxopyrum smilacifolium (Wall.) Blume using antioxidant assays and LC-MS/MS analysis. Methanol is the most effective solvent for collecting antioxidants. The roots-derived methanol extract demonstrates the greatest antioxidant activity, corresponding to the extremely low IC50 values of 16.39 µg/mL and 19.80 µg/mL for DPPH and ABTS radicals, respectively. The high phenolic and flavonoid contents are the primary reason for outstanding total antioxidant capacity (TAC; i.e. 247.73 ± 1.62 mg GA/g or 163.93 ± 0.83 mg AS/g) of the root extract. LC-MS/MS quantification of five phenolic compounds reveals exceptionally high amounts of quercetin and luteolin in the root extract, ranging from 238.86 ± 5.74 to 310.99 ± 1.44 µg/g and from 201.49 ± 7.84 to 234.10 ± 2.54 µg/g, respectively, in the root-derived methanol extract. The achievement highlights M. smilacifolium as a promising source of natural antioxidants for large-scale medical applications.

Positive roles of the Ca2+ sensors GbCML45 and GbCML50 in improving cotton Verticillium wilt resistance.

As a universal second messenger, cytosolic calcium (Ca2+) functions in multifaceted intracellular processes, including growth, development and responses to biotic/abiotic stresses in plant. The plant-specific Ca2+ sensors, calmodulin and calmodulin-like (CML) proteins, function as members of the second-messenger system to transfer Ca2+ signal into downstream responses. However, the functions of CMLs in the responses of cotton (Gossypium spp.) after Verticillium dahliae infection, which causes the serious vascular disease Verticillium wilt, remain elusive. Here, we discovered that the expression level of GbCML45 was promoted after V. dahliae infection in roots of cotton, suggesting its potential role in Verticillium wilt resistance. We found that knockdown of GbCML45 in cotton plants decreased resistance while overexpression of GbCML45 in Arabidopsis thaliana plants enhanced resistance to V. dahliae infection. Furthermore, there was physiological interaction between GbCML45 and its close homologue GbCML50 by using yeast two-hybrid and bimolecular fluorescence assays, and both proteins enhanced cotton resistance to V. dahliae infection in a Ca2+-dependent way in a knockdown study. Detailed investigations indicated that several defence-related pathways, including salicylic acid, ethylene, reactive oxygen species and nitric oxide signalling pathways, as well as accumulations of lignin and callose, are responsible for GbCML45- and GbCML50-modulated V. dahliae resistance in cotton. These results collectively indicated that GbCML45 and GbCML50 act as positive regulators to improve cotton Verticillium wilt resistance, providing potential targets for exploitation of improved Verticillium wilt-tolerant cotton cultivars by genetic engineering and molecular breeding.

The era of panomics-driven gene discovery in plants.

Panomics is an approach to integrate multiple 'omics' datasets, generated using different individuals or natural variations. Considering their diverse phenotypic spectrum, the phenome is inherently associated with panomics-based science, which is further combined with genomics, transcriptomics, metabolomics, and other omics techniques, either independently or collectively. Panomics has been accelerated through recent technological advancements in the field of genomics that enable the detection of population-wide structural variations (SVs) and hence offer unprecedented insights into the genetic variations contributing to important agronomic traits. The present review provides the recent trends of panomics-driven gene discovery toward various traits related to plant development, stress tolerance, accumulation of specialized metabolites, and domestication/dedomestication. In addition, the success stories are highlighted in the broader context of enhancing crop productivity.

Small peptides: novel targets for modulating plant-rhizosphere microbe interactions.

The crucial role of rhizosphere microbes in plant growth and their resilience to environmental stresses underscores the intricate communication between microbes and plants. Plants are equipped with a diverse set of signaling molecules that facilitate communication across different biological kingdoms, although our comprehension of these mechanisms is still evolving. Small peptides produced by plants (SPPs) and microbes (SPMs) play a pivotal role in intracellular signaling and are essential in orchestrating various plant development stages. In this review, we posit that SPPs and SPMs serve as crucial signaling agents for the bidirectional cross-kingdom communication between plants and rhizosphere microbes. We explore several potential mechanistic pathways through which this communication occurs. Additionally, we propose that leveraging small peptides, inspired by plant-rhizosphere microbe interactions, represents an innovative approach in the field of holobiont engineering.

Polythiophene-wrapped Chitosan Nanofibrils with a Bouligand Structure toward Electrochemical Macroscopic Membranes.

Exploring structural biomimicry is a great opportunity to replicate hierarchical frameworks inspired by nature in advanced functional materials for boosting new applications. In this work, we present the biomimetic integration of polythiophene into chitosan nanofibrils in a twisted Bouligand structure to afford free-standing macroscopic composite membranes with electrochemical functionality. By considering the integrity of the Bouligand structure in crab shells, we can produce large, free-standing chitosan nanofibril membranes with iridescent colors and flexible toughness. These unique structured features lead the chitosan membranes to host functional additives to mimic hierarchically layered composites. We used the iridescent chitosan nanofibrils as a photonic platform to investigate the host-guest combination between thiophene and chitosan through oxidative polymerization to fabricate homogeneous polythiophene-wrapped chitosan composites. This biomimetic incorporation fully retains the twisted Bouligand organization of nanofibrils in the polymerized assemblies, thus giving rise to free-standing macroscopic electrochemical membranes. Our further experiments are the modification of the biomimetic polythiophene-wrapped chitosan composites on a glassy carbon electrode to design a three-electrode system for simultaneous electrochemical detection of uric acid, xanthine, hypoxanthine, and caffeine at trace concentrations.

Identification of bZIP Transcription Factors That Regulate the Development of Leaf Epidermal Cells in Arabidopsis thaliana by Single-Cell RNA Sequencing.

Epidermal cells are the main avenue for signal and material exchange between plants and the environment. Leaf epidermal cells primarily include pavement cells, guard cells, and trichome cells. The development and distribution of different epidermal cells are tightly regulated by a complex transcriptional regulatory network mediated by phytohormones, including jasmonic acid, and transcription factors. How the fate of leaf epidermal cells is determined, however, is still largely unknown due to the diversity of cell types and the complexity of their regulation. Here, we characterized the transcriptional profiles of epidermal cells in 3-day-old true leaves of Arabidopsis thaliana using single-cell RNA sequencing. We identified two genes encoding BASIC LEUCINE-ZIPPER (bZIP) transcription factors, namely bZIP25 and bZIP53, which are highly expressed in pavement cells and early-stage meristemoid cells. Densities of pavement cells and trichome cells were found to increase and decrease, respectively, in bzip25 and bzip53 mutants, compared with wild-type plants. This trend was more pronounced in the presence of jasmonic acid, suggesting that these transcription factors regulate the development of trichome cells and pavement cells in response to jasmonic acid.

Multi-objective ecological restoration priority in China: Cost-benefit optimization in different ecological performance regimes based on planetary boundaries.

In the context of the "United Nations Decade on Ecosystem Restoration", optimizing spatiotemporal arrangements for ecological restoration is an important approach to enhancing overall socioecological benefits for sustainable development. However, against the background of ecological degradation caused by the human use of most natural resources at levels that have approached or exceeded the safe and sustainable boundaries of ecosystems, it is key to explain how to optimize ecological restoration by classified management and optimal total benefits. In response to these issues, we combined spatial heterogeneity and temporal dynamics at the national scale in China to construct five ecological performance regimes defined by indicators that use planetary boundaries and ecological pressures which served as the basis for prioritizing ecological restoration areas and implementing zoning control. By integrating habitat conservation, biodiversity, water supply, and restoration cost constraints, seven ecological restoration scenarios were simulated to optimize the spatial layout of ecological restoration projects (ERPs). The results indicated that the provinces with unsustainable freshwater use, climate change, and land use accounted for more than 25%, 66.7%, and 25%, respectively, of the total area. Only 30% of the provinces experienced a decrease in environmental pressure. Based on the ecological performance regimes, ERP sites spanning the past 20 years were identified, and more than 50% of the priority areas were clustered in regime areas with increased ecological stress. As the restoration area targets doubled (40%) from the baseline (20%), a multi-objective scenario presents a trade-off between expanded ERPs in areas with highly beneficial effects and minimal restoration costs. In conclusion, a reasonable classification and management regime is the basis for targeted restoration. Coordinating multiple objectives and costs in ecological restoration is the key to maximizing socio-ecological benefits. Our study offered new perspectives on systematic and sustainable planning for ecological restoration.

Carrageenans as biostimulants and bio-elicitors: plant growth and defense responses.

In the context of climate change, the need to ensure food security and safety has taken center stage. Chemical fertilizers and pesticides are traditionally used to achieve higher plant productivity and improved plant protection from biotic stresses. However, the widespread use of fertilizers and pesticides has led to significant risks to human health and the environment, which are further compounded by the emissions of greenhouse gases during fertilizer and pesticide production and application, contributing to global warming and climate change. The naturally occurring sulfated linear polysaccharides obtained from edible red seaweeds (Rhodophyta), carrageenans, could offer climate-friendly substitutes for these inputs due to their bi-functional activities. Carrageenans and their derivatives, known as oligo-carrageenans, facilitate plant growth through a multitude of metabolic courses, including chlorophyll metabolism, carbon fixation, photosynthesis, protein synthesis, secondary metabolite generation, and detoxification of reactive oxygen species. In parallel, these compounds suppress pathogens by their direct antimicrobial activities and/or improve plant resilience against pathogens by modulating biochemical changes via salicylate (SA) and/or jasmonate (JA) and ethylene (ET) signaling pathways, resulting in increased production of secondary metabolites, defense-related proteins, and antioxidants. The present review summarizes the usage of carrageenans for increasing plant development and defense responses to pathogenic challenges under climate change. In addition, the current state of knowledge regarding molecular mechanisms and metabolic alterations in plants during carrageenan-stimulated plant growth and plant disease defense responses has been discussed. This evaluation will highlight the potential use of these new biostimulants in increasing agricultural productivity under climate change.

γ-Aminobutyric acid (GABA) in N2-fixing-legume symbiosis: Metabolic flux and carbon/nitrogen homeostasis in responses to abiotic constraints.

Nodule symbiosis is an energetic process that demands a tremendous carbon (C) cost, which massively increases in responses to environmental stresses. Notably, most common respiratory pathways (e.g., glycolysis and Krebs cycle) that sustain nitrogenase activity and subsequent nitrogen (N) assimilation (amino acid formation) display a noncyclic mode of C flux. In such circumstances, the nodule's energy charge could markedly decrease, leading to a lower symbiotic activity under stresses. The host plant then attempts to induce alternative robust metabolic pathways to minimize the C expenditure and compensate for the loss in respiratory substrates. GABA (γ-aminobutyric acid) shunt appears to be among the highly conserved metabolic bypass induced in responses to stresses. Thus, it can be suggested that GABA, via its primary biosynthetic pathway (GABA shunt), is simultaneously induced to circumvent stress-susceptible decarboxylating portion of the Krebs cycle and to replenish symbiosome with energy and C skeletons for enhancing nitrogenase activity and N assimilation besides the additional C costs expended in the metabolic stress acclimations (e.g., biosynthesis of secondary metabolites and excretion of anions). The GABA-mediated C/N balance is strongly associated with interrelated processes, including pH regulation, oxygen (O2) protection, osmoregulation, cellular redox control, and N storage. Furthermore, it has been anticipated that GABA could be implicated in other functions beyond its metabolic role (i.e., signaling and transport). GABA helps plants possess remarkable metabolic plasticity, which might thus assist nodules in attenuating stressful events.

Jasmonic acid priming augments antioxidant defense and photosynthesis in soybean to alleviate combined heat and drought stress effects.

In the aftermaths of global warming, plants are more frequently exposed to the combination of heat stress and drought in natural conditions. Jasmonic acid (JA) has been known to modulate numerous plant adaptive responses to diverse environmental stresses. However, the function of JA in regulating plant responses to the combined effects of heat and drought remains underexplored. In this study, we elucidated the functions of JA in enhancing the combined heat and drought tolerance of soybean (Glycine max). Our results showed that priming with JA improved plant biomass, photosynthetic efficiency and leaf relative water content, which all together contributed to the improved performance of soybean plants under single and combined heat and drought conditions. Exposure to single and combined heat and drought conditions caused oxidative damage in soybean leaves. Priming soybean plants, which were exposed to single and combined heat and drought conditions, with JA, on the other hand, substantially quenched the reactive oxygen species-induced oxidative burden possibly by bolstering their antioxidant defense system. Together, our findings provide direct evidence of the JA-mediated protective mechanisms in maintaining the optimal photosynthetic rate and plant performance under combined heat and drought conditions.

Introducing single cell stereo-sequencing technology to transform the plant transcriptome landscape.

Single cell RNA-sequencing (scRNA-seq) advancements have helped detect transcriptional heterogeneities in biological samples. However, scRNA-seq cannot currently provide high-resolution spatial transcriptome information or identify subcellular organs in biological samples. These limitations have led to the development of spatially enhanced-resolution omics-sequencing (Stereo-seq), which combines spatial information with single cell transcriptomics to address the challenges of scRNA-seq alone. In this review, we discuss the advantages of Stereo-seq technology. We anticipate that the application of such an integrated approach in plant research will advance our understanding of biological process in the plant transcriptomics era. We conclude with an outlook of how such integration will enhance crop improvement.

Improvement of qualitative and quantitative traits in cotton under normal and stressed environments using genomics and biotechnological tools: A review.

Due to the increasing demand for high-quality and high fiber-yielding cotton (Gossypium spp.), research into the development of stress-resilient cotton cultivars has acquired greater significance. Various biotic and abiotic stressors greatly affect cotton production and productivity, posing challenges to the future of the textile industry. Moreover, the content and quality of cottonseed oil can also potentially be influenced by future environmental conditions. Apart from conventional methods, genetic engineering has emerged as a potential tool to improve cotton fiber quality and productivity. Identification and modification of genome sequences and the expression levels of yield-related genes using genetic engineering approaches have enabled to increase both the quality and yields of cotton fiber and cottonseed oil. Herein, we evaluate the significance and molecular mechanisms associated with the regulation of cotton agronomic traits under both normal and stressful environmental conditions. In addition, the importance of gossypol, a toxic phenolic compound in cottonseed that can limit consumption by animals and humans, is reviewed and discussed.

Unraveling the genetic enigma of rice submergence tolerance: Shedding light on the role of ethylene response factor-encoding gene SUB1A-1.

The world's low-lying rice (Oryza sativa) cultivation areas are under threat of submergence or flash flooding due to global warming. Rice plants manifest a variety of physiological and morphological changes to cope with submergence and hypoxia, including lowering carbohydrate consumption, inhibiting shoot elongation, and forming a thicker leaf gas film during submergence. Functional studies have revealed that submergence tolerance in rice is mainly determined by an ethylene response factor (ERF) transcription factor-encoding gene, namely SUBMERGENCE 1A-1 (SUB1A-1) located in the SUB1 quantitative trait locus. The SUB1A-1-dependent submergence tolerance is manifested through hormonal signaling involving ethylene, gibberellic acid, brassinosteroid, auxin and jasmonic acid. Considerable progress has been made toward the introduction of SUB1A-1 into rice varieties through a conventional marker-assisted backcrossing approach. Here, we review the recent advances in the physiological, biochemical and molecular dynamics of rice submergence tolerance mediated by the 'quiescence strategy'. Thus, the present review aims to provide researchers with insights into the genetics of rice submergence tolerance and future perspectives for designing submergence-resilient plants for sustainable agriculture under the uncertainties of climate change.

Granular bacterial inoculant alters the rhizosphere microbiome and soil aggregate fractionation to affect phosphorus fractions and maize growth.

The constraint of phosphorus (P) fixation on crop production in alkaline calcareous soils can be alleviated by applying bioinoculants. However, the impact of bacterial inoculants on this process remains inadequately understood. Here, a field study was conducted to investigate the effect of a high-concentration, cost-effective, and slow-release granular bacterial inoculant (GBI) on maize (Zea mays L.) plant growth. Additionally, we explored the effects of GBI on rhizosphere soil aggregate physicochemical properties, rhizosphere soil P fraction, and microbial communities within aggregates. The outcomes showed a considerable improvement in plant growth and P uptake upon application of the GBI. The application of GBI significantly enhanced the AP, phoD gene abundance, alkaline phosphatase activity, inorganic P fractions, and organic P fractions in large macroaggregates. Furthermore, GBI impacted soil aggregate fractionation, leading to substantial alterations in the composition of fungal and bacterial communities. Notably, key microbial taxa involved in P-cycling, such as Saccharimonadales and Mortierella, exhibited enrichment in the rhizosphere soil of plants treated with GBI. Overall, our study provides valuable insight into the impact of GBI application on microbial distributions and P fractions within aggregates of alkaline calcareous soils, crucial for fostering healthy root development and optimal crop growth potential. Subsequent research endeavors should delve into exploring the effects of diverse GBIs and specific aggregate types on P fraction and community composition across various soil profiles.