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Leaf spot and viral diseases are the most frequently occurring leaf problems in Taizishen production. In this study, we examined the controlling role played by the co-application of tetramycin and low dose tebuconazole·azoxystrobin against leaf spot and viral diseases in Taizishen, investigating its resistance, electrophysiological information, growth and quality. Among them, electrophysiological information indicators include electrical signals [intrinsic capacitance (IC), resistance (IR), impedance (IZ), capacitive reactance (IXc), and inductive reactance (IXL)], intracellular water metabolism, nutrient transport, and plant metabolic activity. The results indicate that 0.3% tetramycin 1000-time + 75% tebuconazole·azoxystrobin 2000-time diluent controlled leaf spot and viral diseases the best, with protection effects of 90.03%~90.46% and 71.67%~73.08% at 15~30 days after the last fungicide application, respectively. These values are obviously higher than those treated with high doses of tetramycin or tebuconazole·azoxystrobin alone. Concurrently, their combined application could notably enhance total soluble flavonoids, total soluble phenols, protective enzyme activity, IC, intracellular water metabolism, nutrient transport, and metabolic activity, while reducing its MDA, IR, IZ, IXc, and IXL. Moreover, their co-application also could obviously ameliorate photosynthesis, biomass, agronomic trait, and root growth and quality, as well as actually reduce tebuconazole·azoxystrobin input. Additionally, the control effects of leaf spot and viral diseases in Taizishen treated by their combined application exhibited significant correlations with its disease resistance, electrophysiology, photosynthesis, growth, and quality parameters. This study highlights the combined application of low-dosage tebuconazole·azoxystrobin and tetramycin as a practicable measure for controlling leaf spot and viral diseases in Taizishen, promoting its resistance, growth, and quality, as well as reducing chemical pesticide application. [ABSTRACT FROM AUTHOR]

Background: Abiotic stressors such as heavy metals and nanoparticles pose significant challenges to sustainable agriculture, with copper oxide nanoparticles (CuO NPs) known to inhibit root growth and induce oxidative stress in plants. While silica nanoparticles (SiO2 NPs) have been shown to increase abiotic stress tolerance, their role in mitigating CuO NP-induced stress in crops, especially monocots, remains poorly understood. This study addresses this critical knowledge gap by investigating how SiO2 NP pretreatment modulates CuO NP-induced stress responses, with a particular focus on root growth inhibition and nitro-oxidative stress pathways. Results: Using an in vitro semihydroponic system, seeds were pretreated with varying concentrations of SiO2 NPs (100–800 mg/L) before exposure to CuO NPs at levels known to inhibit root growth by 50%. SiO2 NP pretreatment alleviated CuO NP-induced root growth inhibition in sorghum, wheat, and rye but intensified it in triticale. These responses are associated with species-specific alterations in reactive signaling molecules, including a reduction in nitric oxide levels and an increase in hydrogen sulfide in sorghum, a decrease in superoxide anion levels in rye, and elevated hydrogen peroxide levels in wheat. Protein tyrosine nitration, a marker of nitro-oxidative stress, was reduced in most cases, further indicating the stress-mitigating role of SiO2 NPs. These signaling molecules were selected for their established roles in mediating oxidative and nitrosative stress responses under abiotic stress conditions. Conclusions: SiO2 NP pretreatment modulates CuO NP-induced stress responses through species-specific regulation of reactive oxygen and nitrogen species, demonstrating its potential as a tool for enhancing crop resilience. These findings advance the understanding of nanoparticle‒plant interactions and provide a foundation for future applications of nanotechnology in sustainable agriculture. Clinical trial number: Not applicable. Highlights: SiO2 NP pretreatment counteracts CuO NP-induced stress in sorghum, wheat, and rye roots. Species-specific effects on the ROS and RNS levels under the SiO2 and CuO NP treatments. CuO NP stress increases protein nitration, which is reduced by SiO2 NPs in most cases. NPs impact plant stress pathways, revealing complex mitigation mechanisms. [ABSTRACT FROM AUTHOR]

In Mexico, the center of maize origin (Zea mays ssp. mays), there are landraces from the highlands that develop extensive aerial root systems which secrete a carbohydrate-rich mucilage. This mucilage produces a favorable environment for nitrogenase activity by diazotrophs. This plant-microbial interaction enables the fixation of nitrogen (N) from the atmosphere, reducing the required N that otherwise must come from the soil and/or fertilizers. The objective of this research was to investigate the degree to which other landraces of maize and nutrient management affect aerial root growth and the ability of maize to perform and benefit from N2 fixation. In two replicated field experiments in Columbus, Ohio, USA in 2019 and 2020, we planted 21 maize landraces and three improved varieties with and without fertilizer to measure their growth, production of aerial roots, and rate of atmospheric N2 fixation using the 15N natural abundance method. Maize accessions varied in the growth rate and number of nodes with aerial roots. Up to 36% of plant N was derived from the atmosphere, with values varying by accession, the reference plant used, and the fertilizer level. Moreover, there was a positive relationship between early growth parameters and numbers of nodes with aerial roots, which, in turn, predicted the amount of N derived from the atmosphere. Thus, larger seedlings may experience enhanced root growth and thereby benefit more from N fixation. By phenotyping a diverse set of maize accessions with and without fertilizer, this study explores both environmental and quantitative genetic variation in the traits involved in N fixation capacity, clarifying that N fixation found in the Sierra Mixe landrace is more broadly distributed than previously thought. In sum, farmers stewarding genetic diversity in a crop center of origin have preserved traits essential for biological symbioses that contribute to maize's nutrient requirements. These traits may enable maize crops grown by Mexican farmers, and farmers globally, to benefit from N fixation from the atmosphere. [ABSTRACT FROM AUTHOR]

To elucidate the molecular function of SHORT AND SWOLLEN ROOT1 (SSR1), we screened for suppressors of the ssr1-2 (sus) was performed and identified over a dozen candidates with varying degrees of root growth restoration. Among these, the two most effective suppressors, sus1 and sus2, resulted from G87D and T55M single amino acid substitutions in HSCA2 (At5g09590) and ISU1 (At4g22220), both crucial components of the mitochondrial iron-sulfur (Fe-S) cluster assembly machinery. SSR1 displayed a robust cochaperone-like activity and interacted with HSCA2 and ISU1, facilitating the binding of HSCA2 to ISU1. In comparison to the wild-type plants, ssr1-2 mutants displayed increased iron accumulation in root tips and altered expression of genes responsive to iron deficiency. Additionally, the enzymatic activities of several iron-sulfur proteins and the mitochondrial membrane potential were reduced in ssr1-2 mutants. Interestingly, SSR1 appears to be exclusive to plant lineages and is induced by environmental stresses. Although HSCA2G87D and ISU1T55M can effectively compensate for the phenotypes associated with SSR1 deficiency under favorable conditions, their compensatory effects are significantly diminished under stress. Collectively, SSR1 represents a new and significant component of the mitochondrial Fe-S cluster assembly (ISC) machinery. It may also confer adaptive advantages on plant ISC machinery in response to environmental stress. Author summary: Iron-sulfur (Fe-S) clusters are crucial components found in many proteins that play essential roles in various biological processes. The machinery responsible for making these clusters in mitochondria, known as ISC biosynthesis, has its origins in bacteria and remained largely unchanged through evolution. However, understanding of specific regulators that control Fe-S cluster production in plants is still limited. In this study, we identified a unique protein in plants, SSR1, which acts as a cochaperone. SSR1 facilitates the interaction between the two critical proteins, HSCA2 and ISU1, a necessary process for the release of Fe-S clusters from their scaffold. We also showed that SSR1 has evolved alongside the ISC biosynthetic machinery and that mutations in HSCA2 and ISU1 can compensate for its absence. This highlights the synergistic relationship between SSR1 and other components of the ISC machinery. Overall, this research uncovers a novel component of the ISC biosynthetic system and shows how it varies between plants, animals, and microorganisms. [ABSTRACT FROM AUTHOR]

This work presents an imaging testing system (software and hardware) that can generate repeatable images through a stabilized port in the soil for processes known to change with time. The system includes (i) a stabilized port in the ground made of standard PVC pipe, with sections lined with a borosilicate glass tube, and (ii) a digital imaging instrument to survey the optically transparent portion of the stabilized port. The instrument uses a probe containing a digital camera and two light sources, one using white lights and one using ultraviolet (UV) lights (365 nm). The main instrument controls the probe using a cable within the stabilized port to take overlapping pictures of the soil under the different light sources. Two examples are provided, one to document the distribution of soil and groundwater contaminants known as non-aqueous phase liquids (NAPL, which include petroleum) at variable water saturation levels and a second one to monitor the growth of a plant over a 2-week interval. In both examples, the system successfully identified critical changes in soil processes and showed a resolution of approximately 15 µm (in the order of the thickness of a human hair), demonstrating the potential for repeated imaging of soil processes known to experience temporal changes. Both examples are illustrative, as additional applications might be possible. The novelty of this system lies in its ability to generate repeated measurements at larger depths than the current shallow systems installed by hand. [ABSTRACT FROM AUTHOR]

Wild soybean, which has many desirable traits, such as adaptability to climate change-related stresses, is a valuable resource for expanding the narrow genetic diversity of cultivated soybeans. Plants require roots to adapt to different environments and optimize water and nutrient uptake to support growth and facilitate the storage of metabolites; however, it is challenging and costly to evaluate root traits under field conditions. Previous studies of quantitative trait loci (QTL) have been mainly based on cultivated soybean populations. In this study, an interspecific mapping population from a cross between wild soybean 'PI483463' and cultivar 'Hutcheson' was used to investigate QTLs associated with root traits using image data. Our results showed that 39 putative QTLs were distributed across 10 chromosomes (chr.). Seventeen of these were clustered in regions on chr. 8, 14, 15, 16, and 17, accounting for 19.92% of the phenotypic variation. We identified five significant QTL clusters influencing root-related traits, such as total root length, surface area, lateral total length, and number of tips, across five chr., with favorable alleles from both wild and cultivated soybeans. Furthermore, we identified eight candidate genes controlling these traits based on functional annotation. These genes were highly expressed in root tissues and directly or indirectly affected soybean root growth, development, and stress responses. Our results provide valuable insights for breeders aiming to optimize soybean root traits and leveraging genetic diversity from wild soybean species to develop varieties with improved root morphological traits, ultimately enhancing overall plant growth, productivity, and resilience. [ABSTRACT FROM AUTHOR]

Roots exhibit plasticity in morphology and physiology when exposed to fluctuating nutrient and water availability. However, the dynamics of daily timescale adjustments to changes in water availability are unclear, and experimental evidence of the rates of such adjustments is needed. In this study, we investigated how the root system responds within days to a sudden and localized increase in soil moisture ("hydromatching"). Root systems of maize plants were grown in soil columns divided into four layers by vaseline barriers and continuously monitored using magnetic resonance imaging (MRI) technology. We found that, within 48 h after application of water pulses in a given soil layer, root growth rates in that layer increased, while root growth rates in other layers decreased. Our results indicate local root growth was guided by local changes in soil moisture and potentially even by changes in soil moisture occurring in other parts of the soil profile, which would result in a coordinated response of the entire root system. Hydromatching in maize appears to be a dynamic and reversible phenomenon, for which the investment in biomass is continuously promoted in wet soil volumes and/or halted in drier soil volumes. This sheds new light onto the plasticity of root systems of maize plants and their ability to adjust to local and sudden changes in soil moisture, as would be expected due to patchy infiltration after rainfall or irrigation events. [ABSTRACT FROM AUTHOR]

Feature selection is a pivotal research area within machine learning, tasked with pinpointing the essential subset of features from a broad array that critically influences a model's predictive capabilities. This process enhances model precision and drastically lowers the computational demands associated with training and predicting. Consequently, more advanced optimization techniques are employed to address the challenge of feature selection. This paper introduces an innovative intelligent optimization algorithm, the Plant Root Growth Optimization (PRGO) algorithm, inspired by the structure of plant rhizomes and the way they absorb nutrients.In the algorithm, the plant rhizomes are divided into two categories, the taproot and the fibrous root.the growth process of the taproot plants is associated with the global exploration search, and the growth process of the fibrous root plants relates to the local exploitation search.The global asymptotic convergence of the algorithm is proved by applying Markov's correlation theory, and simulation results using CEC2014 and CEC2017 test sets show that the proposed algorithm has excellent performance.Moreover, a binary variant of this algorithm (BPRGO) has been specifically crafted in this research to tackle the complexities of high-dimensional feature selection issues. The algorithm was compared to eight well-known feature selection methods and its performance was evaluated using a variety of evaluation metrics on 16 high-dimensional datasets from the Arizona State University feature selection library. and the performance of the proposed algorithm was evaluated through feature subset size, classification accuracy, fitness value, and F1-score. The experimental results show that BPRGO achieves the best performance, which has stronger feature reduction ability and achieves better overall performance on most datasets. BPRGO can obtain extremely smaller feature subsets while maintaining much higher classification accuracy, and satisfactory F1-score. [ABSTRACT FROM AUTHOR]

Non-halophytic plants are highly susceptible to salt stress, but numerous studies have shown that halo-tolerant microorganisms can alleviate this stress by producing phytohormones and enhancing nutrient availability. This study aimed to identify and evaluate native microbial communities from salt-affected regions to boost black gram (Vigna mungo) resilience against salinity, while improving plant growth, nitrogen uptake, and nodulation in saline environments. Six soil samples were collected from a salt-affected region in eastern Uttar Pradesh, revealing high electrical conductivity (EC) and pH, along with low nutrient availability. A total of 72 bacterial strains were isolated from soil and 28 from black gram (Vigna mungo) root nodules, with 32 of the soil bacteria tolerating up to 10% NaCl. These bacteria were characterized through taxonomic and biochemical tests. Cross-compatibility analysis showed two rhizobia strains were highly compatible with five salt-tolerant bacteria. These strains exhibited significant plant growth-promoting traits, including phosphate, potassium, and zinc solubilization, as well as ACC deaminase, IAA, siderophore, and EPS production. Strain Paenibacillus sp. SPR11 showed the strongest overall performance. Genetic diversity was assessed using BOX-PCR and ERIC-PCR, and strains were identified through 16S rRNA gene sequencing. In a seed germination study under saline conditions (200 mM and 300 mM), co-inoculation with Bradyrhizobium yuanmingense PR3 and Paenibacillus sp. SPR11 resulted in a significant enhancement in seed germination (40%), root growth (84.45%), and shoot growth (90.15%) compared to single inoculation of B. yuanmingense PR3. Under greenhouse conditions in Leonard jars, co-inoculation with strains PR3 and SPR11 significantly enhanced shoot and root length, fresh and dry biomass, nodule count, and nodule fresh and dry weight. Chlorophyll content, nutrient uptake, and crude protein levels increased, while proline content decreased compared to single inoculation and uninoculated seeds. Our best understanding leads us to believe that this is the very first report of utilizing co-inoculation of salt-tolerant Paenibacillus sp. SPR11 and B. yuanmingense PR3, demonstrating their promising potential to alleviate salt stress and enhance growth, root architecture, nitrogen uptake, and nodule formation in black gram under nitrogen free saline conditions. [ABSTRACT FROM AUTHOR]

Mowing significantly influences nutrient cycling and stimulates metabolic adjustments in plants to promote regrowth. Plant growth-promoting rhizobacteria (PGPR) are crucial for enhancing plant growth, nutrient absorption, and stress resilience; however, whether inoculation with PGPR after mowing can enhance plant regrowth capacity further, as well as its specific regulatory mechanisms, remains unexplored. In this study, PGPR Pantoea eucalyptus (B13) was inoculated into mowed Leymus chinensis to evaluate its effects on phenotypic traits, root nutrient contents, and hormone levels during the regrowth process and to further explore its role in the regrowth of L. chinensis after mowing. The results showed that after mowing, root nutrient and sugar contents decreased significantly, while the signal pathways related to stress hormones were activated. This indicates that after mowing, root resources tend to sacrifice a part of growth and prioritize defense. After mowing, B13 inoculation regulated the plant's internal hormone balance by reducing the levels and signal of JA, SA, and ABA and upregulated the signal transduction of growth hormones in the root, thus optimizing growth and defense in a mowing environment. Transcriptomic and metabolomic analyses indicated that B13 promoted nutrient uptake and transport in L. chinensis root, maintained hormone homeostasis, enhanced metabolic pathways related to carbohydrates, energy, and amino acid metabolism to cope with mowing stress, and promoted root growth and regeneration of shoot. This study reveals the regenerative strategy regulated by B13 in perennial forage grasses, helping optimize resource utilization, increase yield, and enhance grassland stability and resilience. [ABSTRACT FROM AUTHOR]

Summary: We investigate the impact of a 20‐yr irrigation on root water uptake (RWU) and drought stress release in a naturally dry Scots pine forest.We use a combination of electrical resistivity tomography to image RWU, drone flights to image the crown stress and sensors to monitor soil water content.Our findings suggest that increased water availability enhances root growth and resource use efficiency, potentially increasing trees' resistance to future drought conditions by enabling water uptake from deeper soil layers.This research highlights the significant role of ecological memory and legacy effects in determining tree responses to environmental changes. [ABSTRACT FROM AUTHOR]

Planting aluminum-tolerant legume green manure is a cost-effective and sustainable method to increase soil fertility as well as decrease Al toxicity in acidic soils. By analyzing the relative root elongation of seven legume green manure species, common vetch (Vicia sativa L.) was identified as an Al-resistant species. Furthermore, cultivars 418 (cv. Sujian No.3) and 426 (cv. Lanjian No.3) were identified as Al-resistant and -sensitive cultivars, respectively, among 12 common vetch germplasms. The root growth of 418 was less inhibited by Al toxicity in both the germination stage and seedling stage than that of 426. Under Al toxicity, 418 accumulated less Al in both roots and shoots. Citrate is more abundant in the roots of common vetch compared to oxalate or malate. The internal citrate contents showed no significant difference between 418 and 426 under either control or Al treatment. However, the citrate efflux increased in response to Al in 418 but not in 426 and was higher in 418 under Al stress than in 426. Consistently, VsMATE1 expression increased faster and to a greater extent in 418 than 426 in response to Al stress. These results indicated that a VsMATE1-mediated citrate efflux might play an important role in Al resistance in common vetch. It is suggested that VsMATE1 is a valuable candidate gene for aluminum resistance breeding. [ABSTRACT FROM AUTHOR]

Intercropping with legume forages is recognized as an effective strategy for enhancing nitrogen levels in agroforestry, while mowing may influence nitrogen fixation capacity and yield. This study investigated the rooting, nitrogen fixation, nutritive value, and yield of alfalfa (Medicago sativa L.) under intercropping and varying mowing frequencies (CK, 2, and 3) from 2021 to 2023, using walnut (Juglans regia L.) and alfalfa as experimental subjects. The results indicated that intercropping suppressed root growth, whereas increased mowing frequency stimulated root development in the topsoil (0–20 cm). Specifically, the average root length density, root surface area, and root volume from the twice- and thrice-mowed treatments increased by 18.26, 17.45, and 4.15%, respectively, in comparison to the control. The δ15N values of the intercropped alfalfa were significantly lower than those of the monocropped alfalfa (p < 0.05), with the δ15N values of the mowing-thrice treatment increasing by an average of 38.61% compared to the control. Intercropping suppressed alfalfa yield but did not affect the total nitrogen content in the leaves or the nutritive value, and all mowing treatments resulted in land equivalent ratios (LERs) greater than 1. Furthermore, increased mowing frequency enhanced both the nutritive value and yield of alfalfa. Our study suggests that intercropping with walnut can improve biological nitrogen fixation in alfalfa, and that adopting a mowing-thrice regime can optimize yield and nutritive value. [ABSTRACT FROM AUTHOR]

Roots play essential roles in the acquisition of water and minerals from soils in higher plants. However, water or nutrient limitation can alter plant root morphology. To clarify the spatial distribution characteristics of essential nutrients in citrus roots and the influence mechanism of micronutrient deficiency on citrus root morphology and architecture, especially the effects on lateral root (LR) growth and development, two commonly used citrus rootstocks, trifoliate orange (Poncirus trifoliata L. Raf., Ptr) and red tangerine (Citrus reticulata Blanco, Cre), were employed here. The analysis of the mineral nutrient distribution characteristics in different root parts showed that, except for the P concentrations in Ptr, the last two LR levels (second and third LRs) had the highest macronutrient concentrations. All micronutrient concentrations in the second and third LRs of Ptr were higher than those of Cre, except for the Zn concentration in the second LR, which indicates that Ptr requires more micronutrients to maintain normal root system growth and development. Principal component analysis (PCA) showed that B and P were very close in terms of spatial distribution and that Mo, Mn, Cu, and Fe contributed significantly to PC1, while B, Cu, Mo, and Zn contributed significantly to PC2 in both rootstocks. These results suggest that micronutrients are major factors in citrus root growth and development. The analysis of root morphology under micronutrient deficiency showed that root growth was more significantly inhibited in Ptr and Cre under Fe deficiency (FeD) than under other micronutrient deficiencies, while Cre roots exhibited better performance than Ptr roots. From the perspective of micronutrient deficiency, FeD and B deficiency (BD) inhibited all root morphological traits in Ptr and Cre except the average root diameter, while Mn deficiency (MnD) and Zn deficiency (ZnD) had lesser impacts, as well as the morphology of the stem. The mineral nutrient concentrations in Ptr and Cre seedlings under micronutrient deficiency revealed that single micronutrient deficiencies affected both their own concentrations and the concentrations of other mineral nutrients, whether in the roots or in stems and leaves. Dynamic analysis of LR development revealed that there were no significant decreases in either the first or second LR number in Ptr seedlings under BD and ZnD stress. Moreover, the growth rates of first and second LRs in Ptr and Cre did not significantly decrease compared with the control under short-term (10 days) BD stress. Altogether, these results indicate that micronutrients play essential roles in citrus root growth and development. Moreover, citrus alters its root morphology and biological traits as a nutrient acquisition strategy to maintain maximal micronutrient acquisition and growth. The present work on the spatial distribution characteristics and micronutrient deficiency of citrus roots provides a theoretical basis for effective micronutrient fertilization and the diagnosis of micronutrient deficiency in citrus. [ABSTRACT FROM AUTHOR]

Heat stress is one of the major concerns for wheat production worldwide. Morphological parameters such as germination, leaf area, shoot, and root growth are affected by heat stress, with affected physiological parameters including photosynthesis, respiration, and water relation. Heat stress also leads to the generation of reactive oxygen species that disrupt the membrane systems of thylakoids, chloroplasts, and the plasma membrane. The deactivation of the photosystems, reduction in photosynthesis, and inactivation of Rubisco affect the production of photo-assimilates and their allocation, consequently resulting in reduced grain yield and quality. The development of thermo-tolerant wheat varieties is the most efficient and fundamental approach for coping with global warming. This review provides a comprehensive overview of various aspects related to heat stress tolerance in wheat, including damages caused by heat stress, mechanisms of heat stress tolerance, genes or QTLs regulating heat stress tolerance, and the methodologies of breeding wheat cultivars with high heat stress tolerance. Such insights are essential for developing thermo-tolerant wheat cultivars with high yield potential in response to an increasingly warmer environment. [ABSTRACT FROM AUTHOR]

Cyclic nucleotide-gated channel 5 (CNGC5), CNGC6, and CNGC9 (CNGC5/6/9 for simplicity) control Arabidopsis root hair (RH) growth by mediating the influx of external Ca2+ to establish and maintain a sharp cytosolic Ca2+ gradient at RH tips. However, the underlying mechanisms for the regulation of CNGCs remain unknown. We report here that calcium dependent protein kinase 1 (CPK1) directly activates CNGC5/6/9 to promote Arabidopsis RH growth. The loss-of-function mutants cpk1-1, cpk1-2, cngc5-1 cngc6-2 cngc9-1 (shrh1/short root hair 1), and cpk1 shrh1 show similar RH phenotypes, including shorter RHs, more RH branching, and dramatically attenuated cytosolic Ca2+ gradients at RH tips. The main CPK1-target sites are identified as Ser20, Ser27, and Ser26 for CNGC5/6/9, respectively, and the corresponding alanine substitution mutants fail to rescue RH growth in shrh1 and cpk1-1, while phospho-mimic versions restore the cytosolic Ca2+ gradient at RH apex and rescue the RH phenotypes in the same Arabidopsis mutants. Thus we discover the CPK1-CNGC modules essential for the Ca2+ signaling regulation and RH growth in Arabidopsis. Cyclic nucleotide-gated channels (CNGCs) contribute to root hair growth through mediating Ca2+ influx at root hair tips. Here calcium dependent protein kinase 1 is found to directly activate CNGCs via phosphorylation and promote root hair growth in Arabidopsis. [ABSTRACT FROM AUTHOR]

Long-termrotary tillage has led to a deterioration in cotton production. It remains unclear whether soil inversion with subsoiling could halt the deterioration. Here, a field experiment was set from 2015 to 2017 with three treatments: CK, 15 cm rotary tillage; T1, replace the top 20 cm soil layer with the 20–40 cm soil layer and loosen the 40–55 cm soil layer; T2, replace the top 20 cm soil layer with the 20–40 cm soil layer and loosen the 40–70 cm soil layer. The results showed that the total nitrogen(N) content, alkaline N content, total phosphorous(P) content, available P content, and available potassium(K) content of T1 and T2 in the 20–40 cm soil layer were significantly higher than those in the top 20 cm soil layer in 2017, and the soil nutrient contents in the top 20 cm soil layer increased with each planting season. Compared with CK, the root dry matter of T1 and T2 increased by 13.1% and 15.2%, respectively, and the boll number and boll weight were also significantly higher, and the seed cotton yield under T1 for the three years increased by 7.7%, 7.6%, and 6.1%, respectively, and the seed cotton yield under T2 for the three years increased by 6.1%, 8.6%, and 8.2%, respectively. The results suggest that soil inversion with subsoiling is a continuously effective tillage practice for increasing the output of cotton in the North China Plain. [ABSTRACT FROM AUTHOR]

Chlormequat chloride (CCC) has been demonstrated to inhibit plant growth and strengthen seedlings. The present study demonstrated that the root growth of Thompson seedless grapevine seedlings was significantly enhanced by the application of CCC treatment. Nevertheless, the precise mechanism by which CCC regulates plant root growth remains to be elucidated. Consequently, an RNA-sequencing (RNA-Seq) analysis was conducted on grapevine roots subjected to CCC treatment and those undergoing natural growth. A total of 819 differentially expressed genes were identified. Subsequently, Gene Ontology (GO) functional enrichment and weighted gene co-expression network analysis (WGCNA) identified the Copper (Cu) homeostasis-associated genes, VvCTr4/5/6/8 and VvFRO4, which play a pivotal role in mediating the effect of CCC. To further elucidate the transcription factor regulating these Cu homeostasis-associated genes, the key transcription factor VvbHLH053 was identified based on the PlantTFDB database, WGCNA results, and expression patterns under CCC treatment. Furthermore, multiple bHLH binding sites were identified on the promoters of VvCTr4/5/6 and VvFRO4. The GUS activity analysis and dual-luciferase assay demonstrated that VvbHLH053 can directly regulate the expression of VvCTr5/6 and VvFRO4. These findings reveal the feedback mechanism of grapevine root growth mediated by CCC and establish a direct functional relationship between CCC, VvbHLH053, and Cu homeostasis-associated genes that regulate root growth. [ABSTRACT FROM AUTHOR]

Background: Paclobutrazol (PBZ) is used in the arboriculture industry to reduce the growth of trees. It works by inhibiting gibberellin biosynthesis, a group of phytohormones associated with cell elongation. A substantial amount of variation exists within the literature as to the impact of PBZ on woody plant root systems. The purpose of this study was to assess the impact of PBZ on belowground growth and biomass allocation among plant species with varying levels of PBZ sensitivity in a controlled setting. Methods: We treated containerized silver maple, white oak, pecan, laurel oak, and stone pine trees with Cambistat® at the full label rate, one category lower, two categories lower, or water-only controls. After a 14-month incubation period, leaf, stem, and root tissue dry mass were quantified, root:shoot ratios were calculated, the length of the longest root quantified, and total root length of a subset of replicates was estimated. Species were statistically analyzed separately and collectively to assess trends. Results: Paclobutrazol application resulted in significantly lower root dry mass and total root length for all species analyzed, and significantly reduced longest root length of all species except for silver maple. Across species and dosage combinations, we saw few dose effects on any response variable and no major trends in root:shoot ratios. Conclusion: The impact of PBZ on trees in the landscape appears to be influenced by a number of factors, but we observed relatively consistent results on belowground biomass when growing conditions were uniform in our controlled experiment. [ABSTRACT FROM AUTHOR]

Background: As long-lived organisms, urban trees often encounter development and redevelopment activities during their lifespans. These activities can damage tree roots, often through methods like root severing during trenching or excavation. Methods: In 2017, we simulated trenching damage on mature Quercus virginiana Mill. trees at 3 different distances from the base (3, 6, or 12 times the stem diameter). After 5 years, we revisited these trees to assess root regrowth based on the cut root's cross-sectional area (CSA) and distance from the base. Results: We observed regrowth in all but 38 (6.7%) of the 557 cut roots revisited. The lack of regrowth in some roots was not associated with our original treatments, the CSA of the roots at the time of trenching, or distance between the cut root end and the trunk (minimum P-value = 0.841). On average, the observed CSA of the regrowth was 22.2% of the original root's CSA. Only our initial trenching treatments (P-value = 0.024) and the distance between the trunk and the cut root end (P-value = 0.002) significantly predicted the level of regrowth observed 5 years after pruning. Conclusions: In summary, our findings indicate that root systems require many years to recover from trenching damage. Increasing the distance between trenching activities and trees may have a minor effect on root regrowth. [ABSTRACT FROM AUTHOR]

Background: Mutualistic mycorrhiza fungi that live in symbiosis with plants facilitates nutrient and water acquisition, improving tree growth and performance. In this study, we evaluated the potential of mutualistic fungal inoculation to improve the growth and disease resistance of Scots pine (Pinus sylvestris L.) against the forest pathogen Heterobasidion annosum. Results: In co-inoculation experiment, Scots pine seedlings were pre-inoculated with mutualistic beneficial fungus (Suillus luteus) prior to H. annosum infection. The result revealed that inoculation with beneficial fungus promoted plant root growth. Transcriptome analyses revealed that co-inoculated plants and plants inoculated with beneficial fungus shared some similarities in defense gene responses. However, pathogen infection alone had unique sets of genes encoding pathogenesis-related (PR) proteins, phenylpropanoid pathway/lignin biosynthesis, flavonoid biosynthesis, chalcone/stilbene biosynthesis, ethylene signaling pathway, JA signaling pathway, cell remodeling and growth, transporters, and fungal recognition. On the other hand, beneficial fungus inoculation repressed the expression of PR proteins, and other defense-related genes such as laccases, chalcone/stilbene synthases, terpene synthases, cytochrome P450s. The co-inoculated plants did not equally enhance the induction of PR genes, chalcone/stilbene biosynthesis, however genes related to cell wall growth, water and nutrient transporters, phenylpropanoid/lignin biosynthesis/flavonoid biosynthesis, and hormone signaling were induced. Conclusion: S. luteus promoted mutualistic interaction by suppressing plant defense responses. Pre-inoculation of Scots pine seedlings with beneficial fungus S. luteus prior to pathogen challenge promoted primary root growth, as well as had a balancing buffering role in plant defense responses and cell growth at transcriptome level. [ABSTRACT FROM AUTHOR]

Simple Summary: To elucidate the regulatory role of Histone Deacetylase Complex 1 (HDC1) in the primary root growth of Arabidopsis thaliana under potassium (K+) deficiency, we examined primary root growth changes in the hdc1-2 mutant under K+ deficiency stress. The hdc1-2 mutant exhibited significantly inhibited primary root growth compared to the wild-type (WT) plants under low-potassium (LK) conditions, indicating that HDC1 positively regulates root growth under LK conditions. We measured various root zones and found that the inhibition of root growth in hdc1-2 was attributed to reduced apical meristem cell proliferation. The root growth of hdc1-2 showed reduced sensitivity compared to WT after auxin treatment under LK conditions. Moreover, HDC1 negatively regulated the expression of the CBL-CIPK module genes. These findings suggest that HDC1 connects histone deacetylation, auxin signaling, and the CBLs-CIPKs pathway in response to K+ deficiency. Plants frequently encounter relatively low and fluctuating potassium (K+) concentrations in soil, with roots serving as primary responders to this stress. Histone modifications, such as de-/acetylation, can function as epigenetic markers of stress-inducible genes. However, the signaling network between histone modifications and low-K+ (LK) response pathways remains unclear. This study investigated the regulatory role of Histone Deacetylase Complex 1 (HDC1) in primary root growth of Arabidopsis thaliana under K+ deficiency stress. Using a hdc1-2 mutant line, we observed that HDC1 positively regulated root growth under LK conditions. Compared to wild-type (WT) plants, the hdc1-2 mutant exhibited significantly inhibited primary root growth under LK conditions, whereas HDC1-overexpression lines displayed opposite phenotypes. No significant differences were observed under HK conditions. Further analysis revealed that the inhibition of hdc1-2 on root growth was due to reduced apical meristem cell proliferation rather than cell elongation. Notably, the root growth of hdc1-2 showed reduced sensitivity compared to WT after auxin treatment under LK conditions. HDC1 may regulate root growth by affecting auxin polar transport and subsequent auxin signaling, as evidenced by the altered expression of auxin transport genes. Moreover, the organ-specific RT-qPCR analyses unraveled that HDC1 negatively regulates the expression of CBL-CIPK-K+ channel-related genes such as CBL1, CBL2, CBL3, AKT1, and TPK1, thereby establishing a molecular link between histone deacetylation, auxin signaling, and CBLs-CIPKs pathway in response to K+ deficiency. [ABSTRACT FROM AUTHOR]

Simple Summary: This research highlights how proline supplementation can help maize plants survive drought, a period of reduced water availability. Proline improved the growth of shoots and roots under normal conditions and helped to sustain this growth under drought conditions. During drought, proline significantly increased the length and weight of both shoots and roots. It also minimized cell damage, maintained water levels, and preserved the chlorophyll content. Additionally, proline reduced the levels of harmful substances like hydrogen peroxide and malondialdehyde while boosting antioxidant enzyme activities in maize plants. It also enhanced the plants' protein content, nutrient retention, and internal reserves of proline and sugars, supporting osmotic balance. Overall, proline helped maize plants to grow better under drought conditions by alleviating stress, promoting growth, and optimizing water and nutrient management. Drought stress significantly affects maize (Zea mays L.) growth by disrupting vital physiological and biochemical processes. This study investigates the potential of proline supplementation to alleviate drought-induced stress in maize plants. The results show that proline supplementation enhanced shoot and root growth under normal conditions and alleviated drought-induced reductions in growth parameters. Under drought stress, proline increased shoot length by 40%, root length by 36%, shoot fresh weight by 97%, root fresh weight by 247%, shoot dry weight by 77%, and root dry weight by 154% compared to the untreated plants. While drought stress induced electrolyte leakage and reduced the relative water content (RWC) and leaf area, proline treatment mitigated these effects by improving membrane stability, water retention, and chlorophyll content. Moreover, proline supplementation reduced hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels by 38% and 67%, respectively, in the drought-stressed plants compared to the untreated controls. It also enhanced catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activities by 14%, 69%, and 144%, respectively, under drought stress, indicating a strengthened antioxidative defense. Proline also increased the protein content and improved N, P, and K retention by 30%, 40%, and 28%, respectively, in the drought-stressed plants, supporting metabolic and osmotic balance. Additionally, proline improved endogenous proline and sugar levels, facilitating osmotic adjustment and providing energy reserves. These findings suggest that proline supplementation effectively enhances maize resilience under drought stress, improving growth, reducing oxidative stress, and enhancing osmoprotection. [ABSTRACT FROM AUTHOR]

Biostimulants stimulate plant growth and tolerance to salinity stress, which creates unfavorable conditions for plant growth from emergence to harvest; however, little is known about their roles in triggering salt tolerance. Therefore, the study aimed to determine how applying a foliar plant-derived biostimulant (Aminolom Enzimatico® 24%) affects the growth (leaf area, biomass weight, root diameter, root fresh weight, and water-soluble dry matter), physiology (chlorophyll content, electrolyte leakage, cell membrane stability, and relative water content), and stomata of the lower and upper parts of leaves in radish plants (Raphanus sativus L.) under salinity stress. Radish plantlets at 7 d old were irrigated with saline water (i.e., 50, 100, 150, and 200 mM NaCl), and the biostimulant was sprayed twice at 7 d intervals. Under salinity stress, increased water-soluble dry matter content was detected, along with reduced plant biomass weight, root fresh weight, and root diameter. Meanwhile, the foliar biostimulant increased the mean root fresh weight, biomass fresh weight, and leaf area by 12%, 13.6%, and 24% compared to the control, respectively. Increasing NaCl dramatically reduced leaf area and relative water content, whereas chlorophyll content and stomata densities on both sides of the leaves improved. By regulating physiological parameters and thereby promoting root and leaf growth, the biostimulant application improved the radish plants' tolerance to salinity stress up to 100 mM NaCl. Spraying the biostimulant can also boost plant growth, root yield, and radish quality under moderate salinity stress. [ABSTRACT FROM AUTHOR]

The continuous contamination of heavy metals (HMs) in our ecosystem due to industrialization, urbanization and other anthropogenic activities has become a serious environmental constraint to successful crop production. Lead (Pb) toxicity causes ionic, oxidative and osmotic injuries which induce various morphological, physiological, metabolic and molecular abnormalities in plants. Polyethylene glycol (PEG) is widely used to elucidate drought stress induction and alleviation mechanisms in treated plants. Some recent studies have unveiled the potential of PEG in regulating plant growth and developmental procedures including seed germination, root and shoot growth and alleviating the detrimental impacts of abiotic stresses in plants. Therefore, the current study aimed to assess the effects of seed priming with various concentrations (10%, 20%, 30% and 40%) of PEG on the growth and development of radish plants growing under Pb stress (75 mg/kg soil). Lead toxicity reduced root growth (32.89%), shoot growth (32.81%), total chlorophyll (56.25%) and protein content (58.66%) in treated plants. Similarly, plants showed reduced biomass production of root (35.48%) and shoot (31.25%) under Pb stress, while 30% PEG seed priming enhanced biomass production of root (28.57%) and shoot (35.29%) under Pb contaminated regimes. On the other hand, seedlings obtained from 30% PEG priming demonstrated a notable augmentation in the concentrations of photosynthetic pigments, antioxidative activity and biomass accumulation of the plants. PEG-treated plants showed modulations in the enzymatic activities of peroxidase (PO), catalase (CAT) and superoxide dismutase (SOD). These changes collectively played a role in mitigating the adverse effects of Pb on plant physiology. Our data revealed that PEG interceded stress extenuation encompasses numerous regulatory mechanisms including scavenging of ROS through antioxidant and non-antioxidants, improved photosynthetic activity and appropriate nutrition. Hence, it becomes necessary to elucidate the beneficial role of PEG in developing approaches for improving plant growth and stress tolerance. [ABSTRACT FROM AUTHOR]

Synthetic microbial community (SynCom) application is efficient in promoting crop yield and soil health. However, few studies have been conducted to enhance pepper growth via modulating rhizosphere microbial communities by SynCom application. This study aimed to investigate how SynCom inoculation at the seedling stage impacts pepper growth by modulating the rhizosphere microbiome using high-throughput sequencing technology. SynCom inoculation significantly increased shoot height, stem diameter, fresh weight, dry weight, chlorophyll content, leaf number, root vigor, root tips, total root length, and root-specific surface area of pepper by 20.9%, 36.33%, 68.84%, 64.34%, 29.65%, 27.78%, 117.42%, 35.4%, 21.52%, and 39.76%, respectively, relative to the control. The Chao index of the rhizosphere microbial community and Bray–Curtis dissimilarity of the fungal community significantly increased, while Bray–Curtis dissimilarity of the bacterial community significantly decreased by SynCom inoculation. The abundances of key taxa such as Scedosporium, Sordariomycetes, Pseudarthrobacter, norankSBR1031, and norankA4b significantly increased with SynCom inoculation, and positively correlated with indices of pepper growth. Our findings suggest that SynCom inoculation can effectively enhance pepper growth and regulate root morphology by regulating rhizosphere microbial communities and increasing key taxa abundance like Sordariomycetes and Pseudarthrobacter, thereby benefiting nutrient acquisition, resistance improvement, and pathogen resistance of crops to ensure sustainability. [ABSTRACT FROM AUTHOR]

The mechanisms by which the soil physical structure, nutrient conditions, understory vegetation diversity and forest meteorological factors influence fine root (<2 mm diameter) characteristics mediated by soil moisture content (SMC) and soil heat flux (SHF) remain uncertain under climate change. Therefore, in this research, continuous observations were made of the fine root growth, death and turnover of cypress plantations, as well as the SMC and SHF under the management of four thinning intensities in hilly areas in central Sichuan from 2021 to 2023. The fine root data were obtained using the microroot canals (minirhizotron) in the study, and the soil hydrothermal data were obtained using the ECH2O soil parameter sensor and the PC-2R SHF data logger. In the time series, the fine root growth, death and turnover of the cypress plantations with different thinning intensities first increased and then decreased throughout the year; the vertical center of the gravity of the fine roots of cypress was concentrated in the 30–50 cm range. This research also revealed that the variability in the SMC decreased with increasing soil depth. Additionally, the SHF was transmitted from greater soil depths to the surface in unthinned cypress plantation at a rate of 0.036 per year, which decreased the heat in the fine root region. However, SHF was transmitted from the soil surface to greater depths at rates of 0.012 per year, 0.08 per year and 0.002 per year, which increased the heat in the fine root area. The redundancy analysis (RDA) and structural equation model (SEM) results indicated that the SMC and soil heat energy distribution pattern obviously affected fine root growth, death and turnover in the cypress plantation. However, the climate conditions in the forest, the characteristics of vegetation in the understory and the physical and chemical characteristics of the soil directly or indirectly affect the characteristics of the fine roots of cypress plantations with changes in thinning intensity. This research provides a basis for understanding ecosystem structure, nutrient cycling and carbon balance and may guide artificial plantation development and management. [ABSTRACT FROM AUTHOR]

This experiment examined the effects of blending bottom ash produced after combusting dry livestock manure (BACL, 2–4 mm particle) as a soil amendment on the physicochemical properties of the root zone and growth response of creeping bentgrass in sandy soil. The treatments were designed as follows: control [100% sand], 3% BACL (3% BACL + 97% sand), 5% BACL (5% BACL + 95% sand), 7% BACL (7% BACL + 93% sand), and 10% BACL (10% BACL + 90% sand). Although BACL improved the soil physical properties, such as the capillary porosity, total porosity, and hydraulic conductivity, it reduced the cation exchangeable capacity. The BACL treatments increased the pH, EC, Av-P2O5, and Ex-K compared to the control. The turf color index, chlorophyll content, shoot length, clipping yield, and shoot dry weight after the BACL treatments were similar to the control. The growth and nutrient uptake of the roots in the BACL treatment were higher than those of the control. The BACL application amount was positively correlated with the capillary porosity and total porosity of the root zone (p ≤ 0.01) and with the growth and nutrient levels of the roots (p ≤ 0.05). These results suggest that applying BACL as a soil amendment enhanced the uptake of phosphorus and potassium in the roots of creeping bentgrass by improving the soil porosity in the root zone and by supplying phosphate and potassium. [ABSTRACT FROM AUTHOR]

Brace roots are the primary organs for water and nutrient absorption, and play an important role in lodging resistance. Dissecting the genetic basis of brace root traits will facilitate breeding new varieties with lodging resistance and high yield. In present study, genome-wide association study (GWAS) and genomic selection (GS) for brace root penetrometer resistance (PR), root number (RN), and tier number (TN) were conducted in a multi-parent doubled haploid (DH) population. Although the three brace root traits were significantly influenced by genotype-by-environment interactions, relatively high heritabilities were observed for RN (79.25%), TN (81.00%), and PR (74.28%). At the threshold of P-value < 7.42 × 10− 6, 22 SNPs distributed on all 10 chromosomes, except for chromosome 7, and 50 candidate genes were identified using the FarmCPU model. Zm00001d028733, Zm00001d002350, Zm00001d002349, and Zm00001d043694 may be involved in brace root growth. The prediction accuracies of RN, TN, and PR estimated by five-fold cross-validation method with genome-wide SNPs were 0.39, 0.36, and 0.51, respectively, which can be greatly improved by using 100–300 significant SNPs. This study provides new insights into the genetic architecture of brace root traits and genomic selection for breeding lodging resistance maize varieties. [ABSTRACT FROM AUTHOR]

In our previous study, three TaPSK genes highly expressed in the roots of wheat were screened. To explore the effects of adverse stresses on the wheat root phenotype and the expression of TaPSK3 , TaPSK9 and TaPSK10 , we measured the phenotypic parameters of the JM22 root system at the seedling stage after treatment with different concentrations of NaCl and PEG6000. Additionally, the relative expression levels of TaPSK3, TaPSK9, and TaPSK10 were analyzed via RT-qPCR within 72 h of treatment with 150 mM NaCl and 30% PEG6000. The results revealed that drought and salt stress significantly inhibited phenotypic parameters such as total root length, root surface area, root biomass distribution estimation and root tip number in wheat. Notably, salt stress causes wheat roots to germinate more root hairs. The expression of TaPSK3 did not change significantly during salt stress but was upregulated approximately five-fold at 12 h of drought stress. The gene expression levels of TaPSK9 and TaPSK10 were upregulated to varying degrees but gradually returned to normal at 72 h. These results show that when wheat encounters stresses, the expression of TaPSK genes is upregulated to promote root growth and ensure the normal growth and development of plants. This study provides data and theoretical support for further study of TaPSK gene function and cultivation of high-quality wheat plants with strong stress resistance. [ABSTRACT FROM AUTHOR]

Oral diseases affect nearly half of the global population throughout their lifetime causing pain, as estimated by the World Health Organization. Preservation of vital pulp is the therapeutic core as well as a challenge to protect natural teeth. Current bottleneck lies in that the regenerative capacity of injured pulp is undetermined. In this study, we identified a lifelong lineage that is labelled by cathepsin K (Ctsk) contributing to the physiological, reactionary and reparative odontogenesis of mouse molars. Ctsk+ cell‐mediated dentin formation is regulated by nociceptive nerve‐derived Sonic Hedgehog (Shh), especially rapidly responsive to acute injury. Notably, exogenous Shh protein to the injury pulp can preserve Ctsk+ cell capacity of odontogenesis for the nearby crown pulp and even remote root apex growth, alleviating conventionally developmental arrest in youth pulpitis. Exposed to chronical attrition, aged pulp Ctsk+ cells still hold the capacity to respond to acute stimuli and promote reparative odontogenesis, also enhanced by exogenous Shh capping. Therefore, Ctsk+ cells may be one of the lineages for accelerating precision medicine for efficient pulp treatment across ages. Shh application can be a candidate for vital pulp preservation and pulp injury repair by promoting regenerative odontogenesis to a certain extent from young adults to older individuals. [ABSTRACT FROM AUTHOR]

Introduction: Drought stress severely hampers seedling growth and root architecture, resulting in yield penalties. Seed priming is a promising approach to tolerate drought stress for stand establishment and root development. Methods: Here, various seed priming treatments, viz., hydro priming, ascorbic acid priming (AsA), and spermidine priming (Spd), were adopted concerning root morphological, physiological, microstructural, and molecular studies under drought stress on rice variety Hanyou 73. Results and discussion: Results demonstrated that drought severely suppressed seedling establishment, while AsA or Spd priming effectively alleviated the inhibitory effects of drought stress, and significantly increased shoot length (24.5-27.9%), root length (34.6-38.8%), shoot dry weight (56.1-97.1%), root dry weight (39.6-40.6%), total root length (47.0-57.8%), surface area (77.0-84.9%), root volume (106.5-109.8%), average diameter (16.4-19.7%), and root tips (46.8-61.1%); meanwhile, priming with AsA or Spd alleviated microscopic and ultrastructural damage from root cell, and improved root activity (183.8-192.0%). The mitigating effects of AsA or Spd priming on drought stress were primarily responsible for decreasing the accumulation of reactive oxygen species by increasing antioxidants activities and osmoprotectants contents, which reduced oxidative stress and osmotic cell potential and facilitated improved water and nutrients absorption in roots. Additionally, seed priming with AsA or Spd substantially improved auxin synthesis by upregulating of OsYUC7 , OsYUC11 and, OsCOW1 expression. However, there were certain differences in the defense responses of plants and mechanisms of reducing the damage of drought stress after seed treatment with AsA or Spd. Under stress conditions, AsA had a greater impact on improving the fresh and dry weight of aboveground parts, while Spd affected the concentration of total sugar and total protein in plants. Likewise, the degree of oxidative damage was lowered, and POD and CAT activities were elevated due to Spd priming under water-deficient conditions. [ABSTRACT FROM AUTHOR]

Aluminum (Al) toxicity in acidic soils poses significant challenges to crop growth and development. However, the response mechanism of Shatian pomelo (Citrus maxima 'Shatian Yu') roots to Al toxicity remains poorly understood. This study employed root phenotype analysis, physiological response index measurement, root transcriptome analysis, and quantitative PCR (qPCR) validation to investigate the effects of Al toxicity on Shatian pomelo roots. The findings revealed that Al toxicity inhibited root growth and development, resulting in reduced root biomass, total root length, total root surface area, root volume, average root diameter, and root tip count. Antioxidant enzyme activities (peroxidase, superoxide dismutase, ascorbate peroxidase, and catalase activity) and soluble protein content increased with rising Al toxicity, whereas malondialdehyde content initially increased and then declined. Additionally, Al toxicity stress increased Al (1439.25%) content and decreased boron (B, 50.64%), magnesium (Mg, 42.04%), calcium (Ca, 46.02%), manganese (Mn, 86.75%), and iron (Fe, 69.92%) levels in the roots. RNA sequencing (RNA-seq) analysis identified 3855 differentially expressed genes (DEGs) between 0 mmol/L Al (control) and 4 mmol/L Al (Al toxicity) concentrations, with 1457 genes up-regulated and 2398 down-regulated, indicating a complex molecular regulatory response. The qPCR results further validated these findings. This study elucidates the response mechanisms of Shatian pomelo roots to Al toxicity stress, providing insights into the regulatory pathways involved. The findings offer valuable reference points for breeding Al-resistant Shatian pomelo varieties. The results of this study provide important genetic tools and technical support for the screening and breeding of highly resistant varieties of Shatian pomelo. On the one hand, by detecting the key indexes (such as antioxidant enzyme activity and nutrient absorption capacity) of Shatian pomelo, varieties with excellent anti-Al toxicity characteristics can be selected. On the other hand, the Al-resistant genes identified in this study, such as TFM1 and ALERTFA0, can be used to develop molecular markers, assisted marker breeding, or transgenic breeding to accelerate the breeding process of Al-resistant strains. [ABSTRACT FROM AUTHOR]

Background: Root growth is most commonly determined with the destructive soil core method, which is very labor-intensive and destroys the plants at the sampling spots. The alternative minirhizotron technique allows for root growth observation throughout the growing season at the same spot but necessitates a high-throughput image analysis for being labor- and cost-efficient. In this study, wheat root development in agronomically varied situations was monitored with minirhizotrons over the growing period in two years, paralleled by destructive samplings at two dates. The aims of this study were to (i) adapt an existing CNN-based segmentation method for wheat minirhizotron images, (ii) verify the results of minirhizotron measurements with root growth data obtained by the destructive soil core method, and (iii) investigate the effect of the presence of the minirhizotron tubes on root growth. Results: The previously existing CNN could successfully be adapted for wheat root images. The minirhizotron technique seems to be more suitable for root growth observation in the subsoil, where a good agreement with destructively gathered data was found, while root length results in the topsoil were dissatisfactory in comparison to the soil core method in both years. The tube presence was found to affect root growth only if not installed with a good soil-tube contact which can be achieved by slurrying, i.e. filling gaps with a soil/water suspension. Conclusions: Overall, the minirhizotron technique in combination with high-throughput image analysis seems to be an alternative and valuable technique for suitable research questions in root research targeting the subsoil. [ABSTRACT FROM AUTHOR]

Summary: Phosphate (Pi) availability is well known to regulate plant root growth. However, it remains largely unknown how flavonoid synthesis participates in affecting plant root growth in response to Pi starvation.In the study, the crystal structure of a plant protein phosphatase, GmHAD1‐2, was dissected using X‐ray crystallography for the first time. It was revealed that GmHAD1‐2 contained a modified Rossmannoid class of α/β folds with three layered α/β sandwich.Transcripts of GmHAD1‐2 were increased by Pi starvation in soybean roots, especially in lateral root tips. GmHAD1‐2 suppression or overexpression significantly influenced soybean lateral root length and number, as well as phosphorus (P) content. Furthermore, GmHAD1‐2 was found to interact with a chalcone reductase, GmCHR1. Suppression of GmHAD1‐2 significantly changed the flavonoid biosynthesis pathway in soybean roots.Taken together, the results highlight that GmHAD1‐2 can regulate soybean root growth by influencing flavonoid metabolism. [ABSTRACT FROM AUTHOR]

Summary: Phosphate (Pi) plays a key role in plant growth and development. Hence, plants display a range of adaptations to acquire it, including changes in root system architecture (RSA). Whether Pi triggers directional root growth is unknown.We investigated whether Arabidopsis roots sense Pi and grow towards it, that is whether they exhibit phosphotropism. While roots did exhibit a clear Pi‐specific directional growth response, it was, however, always to the left, independent of the direction of the Pi gradient.We discovered that increasing concentrations of KH2PO4, trigger a dose‐dependent skewing response, in both primary and lateral roots. This phenomenon is Pi‐specific – other nutrients do not trigger this – and involves the reorganisation of the microtubule cytoskeleton in epidermal cells of the root elongation zone. Higher Pi levels promote left‐handed cell file rotation that results in right‐handed, clockwise, root growth and leftward skewing as a result of the helical movement of roots (circumnutation).Our results shed new light on the role of Pi in root growth, and may provide novel insights for crop breeding to optimise RSA and P‐use efficiency. [ABSTRACT FROM AUTHOR]

Excessive copper (Cu) has become a common physiological disorder restricting the sustainable production of citrus. Coumarin (COU) is a hydroxycinnamic acid that can protect plants from heavy metal toxicity. No data to date are available on the ameliorative effect of COU on plant Cu toxicity. 'Xuegan' (Citrus sinensis (L.) Osbeck) seedlings were treated for 24 weeks with nutrient solution containing two Cu levels (0.5 (Cu0.5) and 400 (Cu400) μM CuCl2) × four COU levels (0 (COU0), 10 (COU10), 50 (COU50), and 100 (COU100) μM COU). There were eight treatments in total. COU supply alleviated Cu400-induced increase in Cu absorption and oxidative injury in roots and leaves, decrease in growth, nutrient uptake, and leaf pigment concentrations and CO2 assimilation (ACO2), and photo-inhibitory impairment to the whole photosynthetic electron transport chain (PETC) in leaves, as revealed by chlorophyll a fluorescence (OJIP) transient. Further analysis suggested that the COU-mediated improvement of nutrient status (decreased competition of Cu2+ with Mg2+ and Fe2+, increased uptake of nutrients, and elevated ability to maintain nutrient balance) and mitigation of oxidative damage (decreased formation of reactive oxygen species and efficient detoxification system in leaves and roots) might lower the damage of Cu400 to roots and leaves (chloroplast ultrastructure and PETC), thereby improving the leaf pigment levels, ACO2, and growth of Cu400-treated seedlings. [ABSTRACT FROM AUTHOR]

In this research study, we investigated four strains of Enterobacter ludwigii that showed promising properties for plant growth. These strains were tested for their ability to mobilize phosphorus and produce ammonium, siderophores, and phytohormones. The strains exhibited different values of PGP traits; however, the analysis of the complete genomes failed to reveal any significant differences in known genes associated with the expression of beneficial plant traits. One of the strains, GMG_278, demonstrated the best potential for promoting wheat growth in pot experiments. All morphological parameters of wheat were improved, both when GMG_278 was applied alone and when combined with mineral fertilizer. The combined effect we observed may suggest various mechanisms through which these treatments influence plants. The amount of pigments and proline suggests that bacterial introduction operates through pathways likely related to stress resilience. A study on the genetic mechanisms behind plant resilience to stress has revealed a significant upregulation of genes related to reactive oxygen species (ROS) defense after bacterial exposure. It is important to note that, in the initial experiments, the strain showed a significant production of salicylic acid, which is a potent inducer of oxidative stress. In addition, the synthesis of some phytohormones has been restructured, which may affect root growth and the architecture of root hairs. When combined with additional mineral fertilizers, these changes result in a significant increase in plant biomass. [ABSTRACT FROM AUTHOR]

Soil compaction poses a significant challenge in modern agriculture, as it constrains root development and hinders crop growth. The increasing evidence indicated that various phytohormones collaborate in distinct root zones to regulate root growth in compacted soils. However, the study of root development in maize under such conditions has been relatively limited. Here, we identified that the ZmSPL12 gene, belonging to the SPL transcription factor family, plays a crucial and positive role in regulating root development in the compacted soil. Specifically, the overexpression of ZmSPL12 resulted in significantly less inhibition of root growth than the wild-type plants when subjected to soil compaction. Histological analysis revealed that the capacity for root growth in compacted soil is closely associated with the development of the root cap. Further exploration demonstrated that ZmSPL12 modulates root growth through regulating ethylene signaling. Our findings underscored that ZmSPL12 expression level is induced by soil compaction and then enhances root penetration by regulating root cap and development, thereby enabling roots to thrive better in the compacted soil environment. [ABSTRACT FROM AUTHOR]

The physiological and morphological characteristics of rice (Oryza sativa L.) vary with environmental conditions. Homogeneous plant growth is assumed among rice fields within a local rice farming community when managed with the same cultural practices owing to little variation in climatic conditions. However, heterogeneity in the belowground environment is also found within communities. In this study, we hypothesized that rice plants stabilize shoot growth and, hence, grain yield by changing rice root traits in response to belowground environmental heterogeneity. On-farm trials were conducted in the Kaya and Ishikawa villages (4 km apart) in Yosano town, Kyoto, Japan. The rice cultivar Koshirikari was grown organically with or without zeolite or dolomite to alter the soil conditions further. Increased root weight due to many thick nodal roots deeper into the soil layers was detected in Ishikawa. In contrast, reduced root weight due to many thin lateral roots, eventually forming root mats in shallow soil layers under continuous flooding conditions, was detected in Kaya. Physiological root activity, as evaluated by the bleeding rate per root weight, was significantly higher in Kaya than in Ishikawa. The application of material had little effect on root responses. While shoot dry weight and grain yield responded to the location and material application, the effect of belowground environmental heterogeneity was much more pronounced on root growth than shoot growth. These results suggest that rice plants maintain relatively stable aboveground growth despite dynamic belowground changes within the local rice farming community. Although the results support the hypothesis, these preliminary data must be reinforced by more evidence from replicate trials over time and detailed analyses on plant and soil features. [ABSTRACT FROM AUTHOR]

ABSTRACT Besides playing a crucial role in plant immunity via the nonexpressor of pathogenesis‐related (NPR) proteins, increasing evidence shows that salicylic acid (SA) can also regulate plant root growth. However, the transcriptional regulatory network controlling this SA response in plant roots is still unclear. Here, we found that NPR1 and WRKY45, the central regulators of SA response in rice leaves, control only a reduced sector of the root SA signaling network. We demonstrated that SA attenuates root growth via a novel NPR1/WRKY45‐independent pathway. Furthermore, using regulatory network analysis and mutant characterization, we identified a set of new NPR1/WRKY45‐independent regulators that conservedly modulate the root development and root‐associated microbiota composition in both Oryza sativa (monocot) and Arabidopsis thaliana (dicot) in response to SA. Our results established the SA signaling as a central element regulating plant root functions under ecologically relevant conditions. These results provide new insights to understand how regulatory networks control plant responses to abiotic and biotic stresses. [ABSTRACT FROM AUTHOR]

The plant peptide-containing sulfated tyrosine (PSY) family plays critical roles in plant cell proliferation and stress responses. However, the functional characterization of the PSY peptide family in wheat remains unclear. This study systematically identified a total of 29 TaPSY genes at the genome-wide level, classifying them into six subgroups based on PSY-like motifs. These peptides contain a highly conserved active peptide domain, closely resembling the Arabidopsis AtPSY1 motif. All TaPSY homologs are predicted to have a sulfated tyrosine catalyzed by plant tyrosylprotein sulfotransferase (TPST). The TaPSY genes displayed distinct expression patterns across various tissues, with most genes showing higher expression levels in roots and stems. Synthetic sulfated TaPSY peptides enhanced root growth in both wild-type Arabidopsis and the tpst-1 mutant plants. In wheat, exogenous application of TaPSY peptides also promoted root growth, with the synthetic TaPSY5 peptide affecting reactive oxygen species levels in wheat taproots to stimulate primary root growth. Furthermore, transgenic Arabidopsis plants overexpressing TaPSY10 exhibited longer primary roots and increased lateral root numbers. These findings provide insights into the physiological roles of TaPSY peptides in regulating wheat root growth. [ABSTRACT FROM AUTHOR]