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Microplastics (MP) are recognized as a major pollutant in terrestrial environments, prompting concerns about their effects on plant–soil dynamics. Despite evidence of MP altering soil physicochemical properties, impacts on belowground root traits and arbuscular mycorrhizal (AM) fungi remain poorly explored. Existing research has mainly centred on a few model plant species, emphasizing root biomass, and often employs single polymer types and addition rates that surpass realistic scenarios. To investigate how environmentally relevant mixtures and concentrations of MPs impact plant growth, root trait expression and AM fungal colonization, we conducted a greenhouse experiment using six plant species chosen for their contrasting root life strategies; three species in the Amaryllidaceae family represented resource conservation root traits (Allium fistulosum (onion), Allium tuberosum (chive), Allium porrum (leek)), and three from the Solanaceae family, represented plants with resource acquisitive root traits (Solanum lycopersicum (tomato), Solanum melongena (eggplant), Capsicum annuum (pepper)). MP treatments consisted of control (0% MP), low (0.1% w/w) and high (1% w/w) MP additions, using an environmentally relevant MP mixture of weathered polymer types and shapes. We measured above and belowground biomass, average root trait expression (specific root length (SRL), average root diameter (D) and root tissue density (RTD)), AM fungal colonization, as well as intraspecific variability across MP addition treatments. We found that responses to environmentally relevant additions of MPs were species specific and not determined by root life‐strategy. MPs increased biomass in leek, eggplant and tomato, while decreasing AM fungal colonization in tomato. MP additions had no discernible impact on average root functional trait expression across species. However, the addition of MPs resulted in altered intraspecific variability in root traits and AM fungal colonization, indicating a mechanism for plant tolerance to MPs. To address the impacts of MPs on plant functioning, research needs to focus on environmentally relevant mixtures of MPs, considering various plant species' capacities to tolerate soil contamination and the potential for tipping points under real‐world conditions. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Phosphorus (P) and potassium (K) affect seedling growth, root configuration, and nutrient uptake in hydroponic rice, but there are few studies on all growth stages of rice. The purpose of this experiment was to determine the response characteristics of root morphology, plant physiology, and P and K uptake and utilization efficiency to different supplies of P and K. Two local conventional rice varieties (Shennong 265 and Liaojing 294) were used as experimental materials across four treatments, including HPHK (sufficient P and K supply), HPLK (sufficient P supply under low K levels), LPHK (sufficient K supply under low P levels) and LPLK (low P and K levels) in a hydroponic setting. The results showed that HPHK and HPLK significantly decreased the acid phosphatase activity of leaves and roots from full heading to filling stages when compared to LPHK and LPLK. Sufficient supply of P or K significantly increased the accumulation of P and K (aboveground, leaves, stem sheath, and whole plant) and root morphological parameters (root length, root surface area, total root volume, and tips) during major growth stages when compared to LP or LK levels. HPHK was significantly higher than other treatments in terms of dry weight and the root activity at the main growth stage, P and K uptake rates in nutrient solutions at various stages, related P and K efficiency at the maturity stage, yield, effective panicle number, and grain number per panicle. In addition, the effect of HPHK on the above indexes were significantly greater than those of single sufficient supply of P or K. In conclusion, HPHK can improve plant configuration, increase plant P and K absorption and root activity, and increase rice yield and related P and K utilization efficiency. [ABSTRACT FROM AUTHOR]

A tomato cultivar ('Izmir F1') grafted onto six commercially available rootstocks ('Arnold', 'Dohkko', 'Emperador', 'He-man', 'Kaiser', and 'Suzuka') together with self-grafted plants of the tomato cultivar (Izmir/Izmir) were included in a pot experiment. Growth, root morphology and nutrient uptake parameters were evaluated under different salinity conditions (0 and 50 mM NaCl). Grafting increases root length, specific root length, and root length ratio, which enhances the capabilities of hetero-grafted plants to exploit a larger volume of soil or otherwise increase root density under root restriction conditions. Since the root traits and nutrient concentrations in hetero-grafted variants were less impacted by a change in the salinity level, the use of specific rootstocks ('Arnold,' 'Dohkko,' 'Kaiser') could contribute to a steadier growth and yield of tomato plants under fluctuating salinity levels in the irrigation water. The hetero-grafted tomato plants (Dohkko/Izmir, Suzuka/Izmir) demonstrated higher Na sequestration/compartmentalization capabilities than the self-grafted (Izmir/Izmir) plants which helps to maintain a more appropriate K+/Na+ ratio. By exhibiting lower translocation indexes of some heavy metals (Al, Ni, Zn, and Cd), appropriate rootstock/scion combinations might be a useful tool for reducing the risk of their accumulation in edible plant organs. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) have distributed in agricultural soil. However, the effects of MPs on the growth of tobacco remain unclear. In this study, a pot experiment was conducted to evaluate the effects of linear low-density polyethylene (LLDPE) MPs at four different concentrations (0 mg·kg-1 as control, 10 mg·kg-1, 100 mg·kg-1, and 1000 mg·kg-1) on soil enzyme activity, physiological characteristics, and tobacco growth. The results showed that compared with the control, the treatments of 100 and 1000 mg·kg-1 significantly inhibited the activities of soil catalase (S-CAT) and soil sucrase (S-SC). Compared with the control, the 1000 mg·kg-1 treatment significantly altered root morphology, inhibited tobacco growth, and water content, resulting in a significant decrease in chlorophyll a content, catalase (CAT) and superoxide dismutase (SOD) activities in tobacco leaves, thereby incited a significant increase in malondialdehyde (MDA) content and peroxidase (POD) activity. Interestingly, the 10 mg·kg-1 treatment stimulated the activity of soil urease (S-UE) and root biomass. Overall, this study highlights the significant impact of MPs on soil enzymes, oxidative damage to tobacco, and inhibition of tobacco growth and development. It emphasizes the environmental risks of MPs pollution in soil, particularly for commercial crops like tobacco, and provides insights for controlling MPs abundance in the environment. Further research is needed to investigate the underlying mechanisms of MPs' effects on metabolism and genes in the soil-tobacco-microbial system. [ABSTRACT FROM AUTHOR]

Atmospheric elevated CO2 concentration (e[CO2]) decreases plant nitrogen (N) concentration while increasing water use efficiency (WUE), fertigation increases crop nutrition and WUE in crop; yet the interactive effects of e[CO2] coupled with two N-fertigation levels during deficit irrigation on plant gas exchange, root morphology and WUE remain largely elusive. The objective of this study was to explore the physiological and growth responses of ambient [CO2] (a[CO2], 400 ppm) and e[CO2] (800 ppm) tomato plant exposed to two N-fertigation regimes: (1) full irrigation during N-fertigation (FIN); (2) deficit irrigation during N-fertigation (DIN) under two N fertilizer levels (reduced N (N1, 0.5 g pot−1) and adequate N (N2, 1.0 g pot−1). The results indicated that e[CO2] associated with DIN regime induced the lower N2 plant water use (7.28 L plant−1), maintained leaf water potential (−5.07 MPa) and hydraulic conductivity (0.49 mol m−2 s−1 MPa−1), greater tomato growth in terms of leaf area (7152.75 cm2), specific leaf area (223.61 cm2 g−1), stem and total dry matter (19.54 g and 55.48 g). Specific root length and specific root surface area were increased under N1 fertilization, and root tissue density was promoted in both e[CO2] and DIN environments. Moreover, a smaller and denser leaf stomata (4.96 µm2 and 5.37 mm−2) of N1 plant was obtained at e[CO2] integrated with DIN strategy. Meanwhile, this combination would simultaneously reduce stomatal conductance (0.13 mol m−2 s−1) and transpiration rate (1.91 mmol m−2 s−1), enhance leaf ABA concentration (133.05 ng g−1 FW), contributing to an improvement in WUE from stomatal to whole-plant scale under each N level, especially for applying N1 fertilization (125.95 µmol mol−1, 8.41 µmol mmol−1 and 7.15 g L−1). These findings provide valuable information to optimize water and nitrogen fertilizer management and improve plant water use efficiency, responding to the potential resource-limited and CO2-enriched scenario. [ABSTRACT FROM AUTHOR]

Under the sufficient nitrogen supply, it is of great significance to investigate the law of biomass allocation, root morphological traits, and the salt absorption capacity of euhalophytes to evaluate their biological desalination in saline soil. Although the curvilinear responses of biomass accumulation and root morphology in response to soil salinity have been recognized, these perceptions are still confined to the descriptions of inter-treatment population changes and lack details on biomass allocation in organs at an individual level. In this study, Suaeda salsa was grown in root boxes across a range of soil salt levels. The study showed that their growth and development were significantly affected by soil soluble salts. The law of biomass allocation was described as follows: increased soil soluble salts significantly increased the leaf mass ratio and decreased the stem mass ratio, and slightly increased the root mass ratio among treatments. For individuals at each treatment, leaf mass ratio > stem mass ratio > root mass ratio, except in the control treatment at the flower bud and fruit stages. Biomass responses of the control treatment indicated that salt was not rigorously required for Suaeda salsa in the presence of an adequate nitrogen supply, as verified by the correlation between biomass, nitrogen, and soil soluble salt. Salt could significantly inhibit the growth of Suaeda salsa (P<0.01), whereas nitrogen could significantly promote its growth (P<0.01). Root morphology in response to soil soluble salts showed that salt acquisition by the root was highest at a salt level of 0.70%, which corresponds to light saline soil. Consequently, we conclude that phytodesalination by Suaeda salsa was optimal in the light saline soil, followed by moderate saline soil. [ABSTRACT FROM AUTHOR]

Lotus pedunculatus (lotus) and Lupinus polyphyllus (Russell lupin) persist in the upland grasslands of New Zealand, where soil acidity and associated aluminium (Al) toxicity impede conventional pasture legumes. This experiment investigated the response of lotus and Russell lupin to soil acidity and Al. The species were sown in 20 cm tall 1.2 L pots of acidic upland soil. A mass of 4.5 or 6.7 g lime (CaCO3)/L was added to either the top or bottom or both soil horizons (0–9 cm and 9–18 cm), resulting in six treatments across six randomised blocks in a glasshouse. The soil pH was 4.4, 4.9, and 5.4; the exchangeable Al concentrations were 24, 2.5, and 1.5 mg/kg for 0, 4.5, and 6.7 g lime/L. At 16 weeks post-sowing, the plants were divided into shoots and roots at 0–9 cm and 9–18 cm. Root morphology, shoot and root dry matter (DM), shoot nitrogen (N), and nodulation were measured. The total plant DM and shoot-to-root DM ratio were higher, and the shoot %N was lower for the lotus plants than the Russell lupin plants for the various lime rates (13.2 vs. 2.9 g plant−1, 5.6 vs. 1.6, and 2.4 vs. 3.3%, p < 0.05). No response to lime in terms of total DM or total root morphology parameters was exhibited in either species (p > 0.05). Root morphology adjustments in response to acidity between soil horizons were not observed. The results indicated that lotus and Russell lupin are tolerant to high soil acidity (pH 4.4–5.4) and exchangeable Al (1.5–24 mg kg−1), highlighting their considerable adaptation to grasslands with acidic soils. [ABSTRACT FROM AUTHOR]

Drought stress is one of the major impediments to plant growth. Plant growth-promoting rhizobacteria (PGPR) can mitigate moisture stress in plants by increasing the ability of plant nutrient uptake and transport. In this study, we investigated the root phenotype, mineral nutrients (in leaves, roots, and soil), soil pH, water saturation deficit (WSD), free water content (FWC), and bound water content (BWC) of leaves of two alfalfa varieties, 'Galalxie Max' (drought-tolerant) and 'Saidi 7' (drought-sensitive), in the presence or absence of Bacillus amyloliquefaciens QST713 under drought stress conditions. The results showed that water stress negatively affected both cultivar root morphology (total root length, average diameter, total surface area, and volume) and the contents of K and Fe in leaves, roots, and soil. It also reduced the Mn and Zn contents in the soil while increasing the content of Na in the leaves and soil. Additionally, alfalfa plants under drought stress exhibited higher levels of soil pH, WSD, and BWC but lower contents of FWC and ratios of BWC/FWC in the leaves of both cultivars. However, QST713 application significantly enhanced the total root length, average root diameter, and the contents of K and Fe in alfalfa leaves, roots, and soil, as well as the BWC/FWC ratio in leaves under drought stress conditions. A significant reduction in the Na content was detected in QST713-treated alfalfa leaves and soil under drought stress. Furthermore, QST713 application noticeably decreased soil pH and WSD. The current findings showed that QST713 enhanced the water stress tolerance of alfalfa plants by ameliorating root morphology, reducing soil pH, and improving the BWC/FWC ratio, consequently promoting the accumulation of mineral nutrients (mainly K and Fe). Overall, Bacillus amyloliquefaciens QST713 can serve as a potential green fertilizer in sustainable agriculture to improve soil nutrients and enhance plant production under increasing drought conditions. [ABSTRACT FROM AUTHOR]

[Objective] The aims of this study are to explore and examine the root morphology and tensile properties of drought resistant and barren slope protection plants, and to provide a basis for the selection and configuration of slope ecological restoration plants. [Methods] Three kinds of plants, Rumex hastatus D., Dodonaea viscosa L. and Ficus tikoua Bur., were selected on the slope of the slag dump in the middle Yunnan diversion project area of Dali City, Yunnan Province. The root samples were obtained by the whole plant excavation method, and the gray scale scanning was carried out under 500 dpi in the Epson12000XL scanner. The root morphological parameters were analyzed by the WinRhizo (Pro. 2019) root analysis system, and the single root tensile test was carried out by the universal testing machine controlled by the microcomputer of Wan Ce brand. [Results] (1) The root morphology of Rumex hastatus D. and Dodonaea viscosa L. was triangular, while that of Ficus tikoua Bur. vine was parabolic. The length of Rumex hastatus [Objective] The aims of this study are to explore and examine the root morphology and tensile properties of drought resistant and barren slope protection plants, and to provide a basis for the selection and configuration of slope ecological restoration plants. [Methods] Three kinds of plants, Rumex hastatus D., Dodonaea viscosa L. and Ficus tikoua Bur., were selected on the slope of the slag dump in the middle Yunnan diversion project area of Dali City, Yunnan Province. The root samples were obtained by the whole plant excavation method, and the gray scale scanning was carried out under 500 dpi in the Epson12000XL scanner. The root morphological parameters were analyzed by the WinRhizo (Pro. 2019) root analysis system, and the single root tensile test was carried out by the universal testing machine controlled by the microcomputer of Wan Ce brand. [Results] (1) The root morphology of Rumex hastatus D. and Dodonaea viscosa L. was triangular, while that of Ficus tikoua Bur. vine was parabolic. The length of Rumex hastatus [ABSTRACT FROM AUTHOR]

Plant nutrient composition is a reliable tool to identify plant ecological strategies and niche differentiation. Here, we aimed to (i) reveal the potential physiological mechanisms governing distinct foliar nutrient compositions among coexisting grassland species and (ii) clarify the role of taxonomy and environmental conditions in these compositions. At the local (grassland) scale, we measured root morphological and physiological traits, photosynthetic parameters and foliar concentrations of six macronutrients (N, P, S, K, Ca and Mg) and four micronutrients (Fe, Mn, Zn and Cu) across 18 coexisting species. At the regional scale, foliar macro‐ and micronutrient concentrations of 76 site‐species combinations of grasses and forbs across temperate meadow, typical, desert and saline grasslands were measured in Inner Mongolia. At the national scale, we collected the data on foliar macronutrient concentrations of 513 site‐species combinations across grasslands in Xinjiang, Qinghai‐Tibet and Inner Mongolia of China. Compared with forbs, grasses had 3.9 times higher root branching intensity, but 58% and 48% lower root carboxylate exudation and leaf transpiration rate. These distinct nutrient acquisition and transport strategies led to lower foliar nutrient (N, P, Ca, Mg and Mn) concentrations in grasses than forbs at the local scale. Most foliar micronutrient concentrations did not differ between grasses and forbs at the regional scale, whereas macronutrient concentrations were higher in forbs than grasses regardless of the grassland type at both the regional and national scales. All macronutrient concentrations exhibited stronger phylogenetic conservatism and less environmental control than micronutrients. The biogeochemical niche segregation (Euclidean distance based on PCA score of foliar macronutrient concentrations) between sympatric grasses and forbs was lower in meadow grassland than in the typical, desert and saline grasslands. Our results suggest that diverse nutrient acquisition and transport strategies can underlie the distinct foliar nutrient compositions between grasses and forbs. The linkage between potential physiological mechanisms and biogeochemical niche differentiation of grasses and forbs will advance our understanding of plant species coexistence and adaptive strategy. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

The application of seaweed extract and microbial biostimulants has been suggested as a promising approach to overcome yield-limiting factors in organic farming. Yet, information regarding their impact on organic strawberry production is limited. This 2-year field study evaluated the effect of seaweed extract and microbial biostimulants and their synergistic effects on strawberry plant growth, nutrient uptake, fruit yield, and quality under organic production. The biostimulant effects were compared on two strawberry cultivars: Sweet SensationVR Florida127 and Florida Brilliance. Over two seasons, the combination of seaweed extract plus microbial biostimulants applied biweekly consistently resulted in a significant increase of whole-season marketable and total strawberry fruit yields by 23% and 20% on average, respectively, compared with the no-biostimulant control. Application of either biostimulant alone did not consistently show positive effects on strawberry productivity. Modified strawberry root system architecture, enhanced N uptake, increased number of crowns, and higher soil respiration were observed in the biostimulant combination treatment in contrast to the no-biostimulant control. The biostimulant impact was not influenced by strawberry cultivar, but genotypic difference in yield performance under organic production was observed. 'Florida Brilliance' produced significantly higher total fruit number and yield than 'Florida127' by 26% and 12%, respectively, in the first season, and by 34% and 11%, respectively, in the second season. Marketable fruit number (by 18%) and yield (by 9%) of 'Florida Brilliance' were also higher in the first season, along with greater marketable fruit number (by 31%) in the second season. In addition, 'Florida Brilliance' showed significantly higher values of SPAD index, photosynthetic rate (early harvest), and fruit mineral contents based on dry weight (late harvest) than 'Florida127' in both seasons. Although the biostimulant treatments exhibited little influence on the fruit quality attributes including soluble solids content (SSC), titratable acidity (TA), SSC/TA, and total anthocyanin content, varietal differences were observed with significantly higher levels of SSC and lower contents of total anthocyanins in 'Florida 127' vs. 'Florida Brilliance' during each season. The benefits of combined application of seaweed extract and microbial biostimulants demonstrated in this study suggest the need to further elucidate their synergistic functions in promoting nutrient uptake and fruit yield in organic strawberry production systems under different soil and environmental conditions. [ABSTRACT FROM AUTHOR]

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Plants adapt to the limitation of soil phosphorus (P) induced by nitrogen (N) deposition through a complex interaction of various root and leaf functional traits. In this study, a pot experiment was conducted to explore the effects of different levels of N addition (control, low N [LN]: 25 kg N ha−1 yr−1, high N [HN]: 50 kg N ha−1 yr−1) on tree growth, leaf nutrient content, foliar P fractions and root characteristics of two dominant tree species, the pioneer species Salix rehderiana Schneid and the climax species Abies fabri (Mast.) Craib, in a subalpine forest in southwestern China. The results demonstrated that LN addition had a minimal impact on leaf N and P contents. Conversely, HN addition significantly decreased the leaf P content in both species. Salix rehderiana exhibited more pronounced increases in specific root length and specific root area under P deficiency triggered by HN addition when compared with A. fabri. In contrast, A. fabri showed weaker morphological responses to N addition but had a higher proportion of foliar P to metabolic P, as well as higher root exudates rate and root phosphatase activity in response to HN addition. Abies fabri employs a synergistic approach by allocating a greater amount of leaf P to metabolite P and extracting P from the soil through P-mobilizing exudates and root phosphatase activity, while S. rehderiana exhibits higher flexibility in modifying its root morphology in response to P limitation induced by HN addition. This study provides insights into subalpine tree species adaptation to N-induced P limitation, emphasizing its significance for guiding forest management and conservation in the context of global climate change. [ABSTRACT FROM AUTHOR]

Drought stress severely restricts crop yields. Changes in root morphology and function are critical to rice performance under drought conditions, affecting water uptake efficiency, hormone regulation, and nutrient absorption. This study explores the responses of two rice lines, IZ036 with a small root system and IZ144 with a large root system, to drought stress (soil water potential of – 30 ± 5 kPa). The results showed that drought stress significantly inhibited the growth and yield of both rice lines by 35.6–58.1%. Under drought stress, the root-to-shoot ratio of IZ144 increased by 17.8–68.0%, while IZ036 decreased by 10.2–59.1%. While IZ036 experienced a significant reduction in leaf water potential under drought stress, no such impact was observed in IZ144. Both varieties exhibited altered tissue anatomy under drought stress, including, reduced leaf vascular size, increased proportion of vascular bundles in root cross-section, and changes in root thickness. Notably, IZ036 displayed cell and vessel shrinkage and leaf deformation. In response to drought stress, both rice lines exhibited elevated concentrations of auxin, salicylic acid and abscisic acid (ABA) in leaves and increased ethylene and gibberellin (GA) in roots. Notably, IZ144 had significantly higher ABA, cytokinin (CTK), GA, and auxin levels in leaves and CTK in roots than IZ036. Overall, our findings highlight the superior drought tolerance of IZ144 over IZ036, as evidenced by enhanced physiological and anatomical performances and more effective hormone distribution in leaves and roots, indicating the importance of root size in determining drought stress resilience in rice. [ABSTRACT FROM AUTHOR]

A factorial design consisting of four N treatments (no N fertilization, 0.70, 0.14, and 0.28 mol N·plant−1) combined with two water conditions, drought (D = 25 ± 5% soil moisture content) and well-watered (W = 65 ± 5% soil moisture content), was used. Overall, the gas exchange parameters, chlorophyll, and growth of T. sinensis seedlings were significantly inhibited under drought conditions, while all of them showed improvement with N fertilizer, particularly at 0.14~0.28 mol N·plant−1. Under drought conditions, the root length and root surface area of T. sinensis increased; N application positively influenced the above root morphological changes. The activities of antioxidant enzymes such as superoxide dismutase (SOD; EC1.15.1.1) and peroxidase (POD; EC1.11.1.7) and the contents of osmotic adjustment substances such as soluble sugar and proline increased upon drought stress, but decreased under N application conditions. Overall, T. sinensis responds to drought stress through the synergistic action of drought resistance and drought tolerance mechanisms. N application enhances photosynthesis and improves root morphology, compensating for the need for osmotic regulation and reactive oxygen species scavenging. [ABSTRACT FROM AUTHOR]

AbstractLow soil phosphorus (P) availability is a limiting factor for crop production. Application of livestock manure as organic fertilizer can increase soil P availability, but may cause soil contamination with antibiotics such as sulfadiazine (SD), thus adversely affecting plant growth and nutrient uptake. The effects of P (0 and 50 mg kg−1) and SD (0, 1, 10, and 100 mg kg−1) levels on plant growth, root development, and nitrogen (N) and P uptake of maize and soybean were examined in a pot experiment using a loess soil as the test soil. High levels of SD considerably inhibited plant growth of both crops. Both P fertilization and SD negatively affected root development of both crops, especially at higher SD levels. For both crops, the average root diameter and the proportion of thick roots increased with increasing soil SD level. When soil SD level was ≤10 mg kg−1, the effects of P fertilization and SD on plant N and P concentrations, and N:P, N- and P-utilization efficiency were not significant in most cases. The effects of SD on plant N and P nutrition could not be of a great concern when soil SD level was ≤10 mg kg−1. Overall, soil SD pollution could reduce plant biomass and inhibit root development of soybean and maize, with a stronger effect on root development than on plant biomass at a high soil SD level (≥10 mg kg−1). In agricultural production, attention should be paid to soil SD pollution via manure application. [ABSTRACT FROM AUTHOR]

The present study evaluated the repercussions of magnetopriming on the root system architecture of soybean plants subjected to arsenic toxicity using synchrotron radiation source based micro-computed tomography (SR-µCT). This will be used evey where as abbreviation for the technique for threedimensional imaging. Seeds of soybean were exposed to the static magnetic field (SMF) of strength (200 mT) for 1h prior to sowing. Magnetoprimed and nonprimed seeds were grown for 1 month in a soil-sand mixture containing four different levels of sodium arsenate (0, 5, 10, and 50 mg As kg-1 soil). The results showed that arsenic adversely affects the root growth in non-primed plants by reducing their root length, root biomass, root hair, size and number of root nodules, where the damaging effect of As was observed maximum at higher concentrations (10 and 50 mg As kg-1 soil). However, a significant improvement in root morphology was detected in magnetoprimed plants where SMF pretreatment enhanced the root length, root biomass, pore diameter of cortical cells, root hair formation, lateral roots branching, and size of root nodules and girth of primary roots. Qualitative analysis of x-ray micro-CT images showed that arsenic toxicity damaged the epidermal and cortical layers of the root as well as reduced the pore diameter of the cortical cells. However, the diameter of cortical cells pores in magnetoprimed plants was observed higher as compared to plants emerged from non-primed seeds at all level of As toxicity. Thus, the study suggested that magnetopriming has the potential to attenuate the toxic effect of As and could be employed as a pre-sowing treatment to reduce the phytotoxic effects of metal ions in plants by improving root architecture and root tolerance index. This study is the very first exploration of the potential benefits of magnetopriming in mitigating the toxicity of metals (As) in plant roots utilizing the micro-CT technique. [ABSTRACT FROM AUTHOR]

This study examined how the nutrient flow environment affects lettuce root morphology in hydroponics using multi‐omics analysis. The results indicate that increasing the nutrient flow rate initially increased indicators such as fresh root weight, root length, surface area, volume, and average diameter before declining, which mirrors the trend observed for shoot fresh weight. Furthermore, a high‐flow environment significantly increased root tissue density. Further analysis using Weighted Gene Co‐expression Network Analysis (WGCNA) and Weighted Protein Co‐expression Network Analysis (WPCNA) identified modules that were highly correlated with phenotypes and hormones. The analysis revealed a significant enrichment of hormone signal transduction pathways. Differences in the expression of genes and proteins related to hormone synthesis and transduction pathways were observed among the different flow conditions. These findings suggest that nutrient flow may regulate hormone levels and signal transmission by modulating the genes and proteins associated with hormone biosynthesis and signaling pathways, thereby influencing root morphology. These findings should support the development of effective methods for regulating the flow of nutrients in hydroponic contexts. [ABSTRACT FROM AUTHOR]

Purpose: Selection for root traits has become a target in (pre-)breeding programs aiming at improving crop ability to capture soil resources. However, the benefit of selected traits in heterogeneous target environments will depend on spatial and temporal interactions between root systems, the soil environment (fertility and water supply) and management (fertiliser placement). Methods: We assessed growth and phosphorus acquisition of durum wheat (Triticum durum L.) lines defined by contrasting seminal root angles (41° 'Narrow' vs 82° 'Wide'), in response to different soil phosphorus placements and seasonal water dynamics. Responses were evaluated in clear pots (seedlings), rhizoboxes (late-tillering stage) and a custom lysimeter system (flowering stage). Results: The Narrow genotype increased deep soil exploration (down to 50 cm) during early growth, with a tendency to more rapidly acquire phosphorus placed as a deep fertiliser band (25 cm depth). However, genotypic differences in shoot biomass or phosphorus uptake were not apparent at anthesis, in part due to phosphorus-induced changes in phenological development. Contrastingly, the wide genotype increased root growth in the topsoil (0–10 cm) when phosphorus was stratified in this layer and produced greater biomass at anthesis under these conditions. Shoot and root biomass and phosphorus uptake decreased when the topsoil dried out, with the greatest effect observed for phosphorus stratified in this layer. Conclusion: The benefits of the selected root angle trait strongly depend on nutrient and water distributions and dynamics in the target environment. Ideotype breeding efforts and farmer selection of genotypes should consider the context in which genotypes will be deployed. Highlight: The interaction between root system architecture and heterogeneous distributions of phosphorus and available water determine the relative performance of durum wheat genotypes with contrasting root angles. [ABSTRACT FROM AUTHOR]

Climate change models predict increasing precipitation variability in the mid-latitude regions of Earth, generating a need to reduce the negative impacts of these changes on crop production. Despite considerable research on how cover crops support agriculture in a changing climate, understanding is limited of how climate change influences the growth of cover crops. We investigated the early development of two common cover crop species—crimson clover (Trifolium incarnatum) and rye (Secale cereale)—and hypothesized that growing them in the mixture would ameliorate stress from drought or waterlogging. This hypothesis was tested in a 25-day greenhouse experiment, where the two factors (species number and water stress) were fully crossed in randomized blocks, and plant responses were quantified through survival, growth rate, biomass production and root morphology. Water stress negatively influenced the early growth of these two species in contrasting ways: crimson clover was susceptible to drought while rye performed poorly under waterlogging. Per-plant biomass in rye was always greater in mixture than in monoculture, while per-plant biomass of crimson clover was greater in mixture under drought. Both species grew longer roots in mixture than in monoculture under drought, and total biomass of mixtures did not differ significantly from the more-productive monoculture (rye) in any water condition. In the face of increasingly variable precipitation, growing crimson clover and rye together has potential to ameliorate water stress, a possibility that should be further investigated in field experiments. [ABSTRACT FROM AUTHOR]

Biochar is regarded as a soil improvement material possessing superior physical and chemical properties that can effectively enhance plant growth. However, there exists a paucity of research examining the efficacy of biochar in supplanting traditional materials and its subsequent impact on the growth of Ardisia crenata, which is currently domesticated as fruit ornamentals. In this study, the mechanism of biochar's effect on Ardisia crenata was analyzed by controlled experiments. For 180 days, their growth and development were meticulously assessed under different treatments through the measurement of various indices. Compared with the references, the addition of biochar led to an average increase in soil nutrient content, including a 14.1% rise in total nitrogen, a 564.1% increase in total phosphorus, and a 63.2% boost in total potassium. Furthermore, it improved the physical and chemical properties of the soil by reducing soil bulk density by 6.2%, increasing total porosity by 6.33%, and enhancing pore water by 7.35%, while decreasing aeration porosity by 1.11%. The growth and development of Ardisia crenata were better when the appending ratio of biochar was in the range of 30% to 50%, with the root parameters, such as root length, root surface area, and root volume, 48.90%, 62.00%, and 24.04% higher to reference. At the same time, the biomass accumulation of roots in the best group with adding biochar also increased significantly (55.80%). The addition of biochar resulted in a significant improvement in the content of chlorophyll a and chlorophyll b (1.947 mg g−1) and the net photosynthetic rate (5.6003 µmol m−2 s−1). This study's findings underpinned the addition of biochar in soil improvement and plant response. Therefore, biochar can favor the cultivation and industrial application of Ardisia crenata in the future, leading to an efficient and environmentally friendly industrial development. [ABSTRACT FROM AUTHOR]

Combining inorganic and organic soil amendments with mineral fertilizers is promising for soil quality enhancement in modern agronomy systems. In this research, four main organic components were used in fertilizer formulations: coconut coir, biochar, lignite, and leonardite (enriched with microelements, tryptophan, and bacterial metabolic products). The treatments were assigned to the completely randomized design with a control object, without any soil amendments, and with only mineral fertilization. Aboveground biomass and root characteristics of maize (root length density, mean root diameter, root surface area density, specific root length, root volume density, and root dry matter) and water retention and characteristics of soil pores were determined. Compared to the control, all fertilizer formulations applied deteriorated the water retention properties of the soil. The highest plant available water content value was obtained for the control without any fertilizers. The addition of organic fertilizer formulations consisting of coconut coir, biochar, lignite, leonardite, microelements, tryptophan, and metabolic products of Pseudomonas sp. and Bacillus subtilis did not play a significant role in improving soil physical characteristics. The lowest productivity was characterized for maize without any fertilizers and amendments. All soil organic amendments resulted in lower yields than the one with only mineral fertilization. The highest root dry matter was obtained when lignite and leonardite were used as main components. Organic amendments can be recommended for soil bioregeneration, but their main effect on maize productivity is attributed to the mineral component. [ABSTRACT FROM AUTHOR]

Abstract Phosphorus (P) and potassium (K) affect seedling growth, root configuration, and nutrient uptake in hydroponic rice, but there are few studies on all growth stages of rice. The purpose of this experiment was to determine the response characteristics of root morphology, plant physiology, and P and K uptake and utilization efficiency to different supplies of P and K. Two local conventional rice varieties (Shennong 265 and Liaojing 294) were used as experimental materials across four treatments, including HPHK (sufficient P and K supply), HPLK (sufficient P supply under low K levels), LPHK (sufficient K supply under low P levels) and LPLK (low P and K levels) in a hydroponic setting. The results showed that HPHK and HPLK significantly decreased the acid phosphatase activity of leaves and roots from full heading to filling stages when compared to LPHK and LPLK. Sufficient supply of P or K significantly increased the accumulation of P and K (aboveground, leaves, stem sheath, and whole plant) and root morphological parameters (root length, root surface area, total root volume, and tips) during major growth stages when compared to LP or LK levels. HPHK was significantly higher than other treatments in terms of dry weight and the root activity at the main growth stage, P and K uptake rates in nutrient solutions at various stages, related P and K efficiency at the maturity stage, yield, effective panicle number, and grain number per panicle. In addition, the effect of HPHK on the above indexes were significantly greater than those of single sufficient supply of P or K. In conclusion, HPHK can improve plant configuration, increase plant P and K absorption and root activity, and increase rice yield and related P and K utilization efficiency.

The effects of mechanical defoliation and pinching (1 cm tip cutting) on Buxus plant growth, nutrient mobilization, and root architecture were determined. When 100% defoliation was applied, the highest increase rates of 80.3% in shoots and 88% in leaves were observed compared to the control group. In contrast, the overall effects of defoliation and pinching were negative, with 100% defoliation having the most negative effects. The chlorophyll content of the newly formed young leaves was also 50% lower with 100% defoliation. Leaves and root nutrient mobilization changed significantly, depending on the effects of defoliation and pinching. Apart from a very small increase in root length and number of forks, the effects of the treatments were negative, with 100% defoliation having the greatest negative effect on root development. Most affected was the number of crossings, which was 78% lower than in the control. In addition, machine learning (ML) algorithms were used in the study, including multilayer perceptron, J48, PART, and logistic regression. The input variables were evaluated to model and predict the root features. The performance values of the ML algorithms were noted in the following order: Logistic Regression> PART> J48> MultilayerPerceptron. As the severity of defoliation increased, the losses of the plant also increased. However, boxwood has mechanisms to compensate for these losses even when it suffers complete defoliation.

The exogenous application of melatonin by the root drenching method is an effective way to improve crop drought resistance. However, the optimal concentration of melatonin by root drenching and the physiological mechanisms underlying melatonin-induced drought tolerance in cotton (Gossypium hirsutum L.) roots remain elusive. This study determined the optimal concentration of melatonin by root drenching and explored the protective effects of melatonin on cotton roots. The results showed that 50 μmol L−1 melatonin was optimal and significantly mitigated the inhibitory effect of drought on cotton seedling growth. Exogenous melatonin promoted root development in drought-stressed cotton plants by remarkably increasing the root length, projected area, surface area, volume, diameter, and biomass. Melatonin also mitigated the drought-weakened photosynthetic capacity of cotton and regulated the endogenous hormone contents by regulating the relative expression levels of hormone-synthesis genes under drought stress. Melatonin-treated cotton seedlings maintained optimal enzymatic and non-enzymatic antioxidant capacities, and produced relatively lower levels of reactive oxygen species and malondialdehyde, thus reducing the drought stress damage to cotton roots (such as mitochondrial damage). Moreover, melatonin alleviated the yield and fiber length declines caused by drought stress. Taken together, these findings show that root drenching with exogenous melatonin increases the cotton yield by enhancing root development and reducing the root damage induced by drought stress. In summary, these results provide a foundation for the application of melatonin in the field by the root drenching method.

Phosphorus (P) fertilizer is a significant cost in crop production. Understanding the mechanisms behind P fertilizer–soil–crop interactions can enhance phosphorus use efficiency (PUE) and increasing yield. We conducted a rice cultivation bucket experiment in red soil (pH = 5.9) and lime concretion black soil (pH = 7.8) and applied single superphosphate (SSP), calcium magnesium phosphate (CMP), diammonium phosphate (DAP), triple superphosphate (TSP), ammonium polyphosphate (APP), and a control group (CK, no P fertilizer). We analyzed rice P uptake and utilization patterns, evaluated the impact of varying P fertilizer formulations on rice root morphology, yield, and PUE, and investigated changes in soil P pools. In red soil, the APP treatment produced the greatest total root length, rice yield, PUE and increased soil Olsen-P, NaHCO3-Pi at anthesis. In lime concretion black soil, the TSP and APP treatments had the highest rice yields and increased Olsen-P, H2O-P, NaHCO3-Pi at anthesis. Moreover, the TSP treatment had the greatest total root length and root surface area at anthesis and the APP treatment had the largest PUE. Random forest regression analysis revealed that residual-P and Olsen-P significantly impacted rice yield in red soil and lime concretion black soil, respectively. We recommend using APP in red soil and TSP and APP in lime concretion black soil for rice cultivation to optimize soil P pool characteristics and root morphology for nutrient uptake, ultimately leading to the highest yields and PUE.

Abstract Background On tropical regions, phosphorus (P) fixation onto aluminum and iron oxides in soil clays restricts P diffusion from the soil to the root surface, limiting crop yields. While increased root surface area favors P uptake under low-P availability, the relationship between the three-dimensional arrangement of the root system and P efficiency remains elusive. Here, we simultaneously assessed allelic effects of loci associated with a variety of root and P efficiency traits, in addition to grain yield under low-P availability, using multi-trait genome-wide association. We also set out to establish the relationship between root architectural traits assessed in hydroponics and in a low-P soil. Our goal was to better understand the influence of root morphology and architecture in sorghum performance under low-P availability. Result In general, the same alleles of associated SNPs increased root and P efficiency traits including grain yield in a low-P soil. We found that sorghum P efficiency relies on pleiotropic loci affecting root traits, which enhance grain yield under low-P availability. Root systems with enhanced surface area stemming from lateral root proliferation mostly up to 40 cm soil depth are important for sorghum adaptation to low-P soils, indicating that differences in root morphology leading to enhanced P uptake occur exactly in the soil layer where P is found at the highest concentration. Conclusion Integrated QTLs detected in different mapping populations now provide a comprehensive molecular genetic framework for P efficiency studies in sorghum. This indicated extensive conservation of P efficiency QTL across populations and emphasized the terminal portion of chromosome 3 as an important region for P efficiency in sorghum. Increases in root surface area via enhancement of lateral root development is a relevant trait for sorghum low-P soil adaptation, impacting the overall architecture of the sorghum root system. In turn, particularly concerning the critical trait for water and nutrient uptake, root surface area, root system development in deeper soil layers does not occur at the expense of shallow rooting, which may be a key reason leading to the distinctive sorghum adaptation to tropical soils with multiple abiotic stresses including low P availability and drought.

Abstract Introduction The efficacy of root canal treatment is greatly impacted by a thorough understanding of root canal anatomy. This systematic review and meta-analysis aim to thoroughly investigate the root morphology and canal configuration (RMCC) of permanent premolars (PMs). Methodology A comprehensive analysis was conducted following the PRISMA guidelines. Literature exploration was carried out across four electronic databases (PubMed, Embase, Cochrane, and Web of Science). The risk of bias assessment was conducted for the included studies utilizing the Anatomical Quality Assessment (AQUA) tool. Data analysis was performed utilizing SPSS and RevMAN5.3.3. The meta-analysis was applied with a 95% confidence interval to calculate odds ratios (OR). Results Among the 82 selected studies, 59 studies exhibited potential bias in domain one (objective(s) and subject characteristics), followed by domain three (methodology characterization). The majority of maxillary PM1s had either single root (46.7%) or double roots (51.9%), while three-rooted variants were uncommon (1.4%). Conversely, most other PMs exhibited a single root. In terms of canal configuration, maxillary PM1s predominantly featured double distinct canals (87.2%), with the majority of maxillary PM2s displaying either a single canal (51.4%) or double canals (48.3%). Mandibular PMs were primarily characterized by single canals, accounting for 78.3% of mandibular PM1s and 90.3% of mandibular PM2s. Subgroup analyses revealed higher incidences of single-rooted and single-canalled PMs among Asians compared to Caucasians. Additionally, women exhibited a higher incidence of single-rooted PMs, while men showed a greater frequency of double-rooted PMs. Conclusions The comprehensive analysis indicated that maxillary PM1s predominantly possess double roots and double canals, whereas maxillary PM2s and mandibular PMs were primarily characterized by single-rooted with a single canal. Notably, single root and single canal were more prevalent among women and Asian samples.

Background and ObjectiveClinicians must possess a comprehensive understanding of variations in canal morphology and configuration during endodontic procedures to enhance treatment success. This study aims to assess and analyze the canal configurations of maxillary first premolars using Cone-Beam Computed Tomography within the sub-population of Western Saudi Arabia. Materials and MethodsIn this cross-sectional study, following the acquisition of ethical clearance from Batterjee Medical College in Jeddah, Saudi Arabia, a retrospective examination of Cone-Beam Computed Tomography (CBCT) scans of maxillary first premolars in adult patients was conducted. The study focused on quantifying the number of canals and characterizing their configurations, with classification based on Vertucci’s categorization. ResultsThe study examined 399 CBCT images of maxillary first premolars, revealing that type IV canal configurations were the predominant morphology (56.9%), followed by type V (24.6%). Significant gender-related disparities were observed, with females displaying a higher incidence of types I and V canals. At the same time, males exhibited a greater prevalence of types IV and VI canals. Notably, no substantial associations were discerned between canal types and age groups. ConclusionWithin the context of maxillary first premolars, type IV canal configuration emerged as the most prevalent. Gender-based distinctions were evident, with females predominantly presenting types I and V canal configurations, whereas males displayed a higher occurrence of types IV and VI canal configurations.

Human activities have increased nitrogen (N) and phosphorus (P) inputs to the Yellow River Delta and the supply level of N and P affects plant growth as well as ecosystem structure and function directly. However, the root growth, stoichiometry, and antioxidant system of plants in response to N and P additions, especially for herbaceous halophyte in the Yellow River Delta (YRD), remain unknown. A field experiment with N addition (0, 5, 15, and 45 g Nm-2 yr-1, respectively) as the main plot, and P addition (0 and 1 g Nm-2 yr-1, respectively) as the subplot, was carried out with a split-plot design to investigate the effects on the root morphology, stoichiometry, and antioxidant system of Suaeda salsa. The results showed that N addition significantly increased the above-ground and root biomass as well as shoot-root ratio of S. salsa, which had a significant interaction with P addition. The highest biomass was found in the treatment with 45 g N m-2 yr-1 combined with P addition. N addition significantly increased TN content and decreased C:N ratio of root, while P addition significantly increased TP content and decreased C:P ratio. The main root length (MRL), total root length (TRL), specific root length (SRL), and root tissue density (RTD) of S. salsa root were significantly affected by N addition and P addition, as well as their interaction. The treatments with or without P addition at the 45 g N m-2 yr-1 of N addition significantly increased the superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) activities and soluble protein content of roots, decreased malondialdehyde (MDA) content. And there was a significant interaction between the N and P addition on SOD activity. Therefore, N and P additions could improve the growth of S. salsa by altering the root morphology, increasing the root nutrient content, and stimulating antioxidant system. [ABSTRACT FROM AUTHOR]

Background: On tropical regions, phosphorus (P) fixation onto aluminum and iron oxides in soil clays restricts P diffusion from the soil to the root surface, limiting crop yields. While increased root surface area favors P uptake under low-P availability, the relationship between the three-dimensional arrangement of the root system and P efficiency remains elusive. Here, we simultaneously assessed allelic effects of loci associated with a variety of root and P efficiency traits, in addition to grain yield under low-P availability, using multi-trait genome-wide association. We also set out to establish the relationship between root architectural traits assessed in hydroponics and in a low-P soil. Our goal was to better understand the influence of root morphology and architecture in sorghum performance under low-P availability. Result: In general, the same alleles of associated SNPs increased root and P efficiency traits including grain yield in a low-P soil. We found that sorghum P efficiency relies on pleiotropic loci affecting root traits, which enhance grain yield under low-P availability. Root systems with enhanced surface area stemming from lateral root proliferation mostly up to 40 cm soil depth are important for sorghum adaptation to low-P soils, indicating that differences in root morphology leading to enhanced P uptake occur exactly in the soil layer where P is found at the highest concentration. Conclusion: Integrated QTLs detected in different mapping populations now provide a comprehensive molecular genetic framework for P efficiency studies in sorghum. This indicated extensive conservation of P efficiency QTL across populations and emphasized the terminal portion of chromosome 3 as an important region for P efficiency in sorghum. Increases in root surface area via enhancement of lateral root development is a relevant trait for sorghum low-P soil adaptation, impacting the overall architecture of the sorghum root system. In turn, particularly concerning the critical trait for water and nutrient uptake, root surface area, root system development in deeper soil layers does not occur at the expense of shallow rooting, which may be a key reason leading to the distinctive sorghum adaptation to tropical soils with multiple abiotic stresses including low P availability and drought. [ABSTRACT FROM AUTHOR]

Background: Phosphorus in the soil is mostly too insoluble for plants to utilize, resulting in inhibited aboveground biomass, while Carex can maintain their aboveground biomass through the presence of dauciform roots. However, dauciform roots lead to both morphological and physiological changes in the root system, making their primary mechanism unclear. Methods: A greenhouse experiment was conducted on three Carex species, in which Al-P, Ca-P, Fe-P, and K-P were employed as sole phosphorus sources. The plants were harvested and assessed after 30, 60 and 90 days. Results: (1) The density of dauciform roots was positively correlated with root length and specific root length, positively influencing aboveground biomass at all three stages. (2) The aboveground phosphorus concentration showed a negative correlation with both dauciform root density and aboveground biomass in the first two stages, which became positive in the third stage. (3) Aboveground biomass correlated negatively with the aboveground Al concentration, and positively with Ca and Fe concentration (except Al-P). (4) Root morphological traits emerged as critical factors in dauciform roots' promotion of aboveground biomass accumulation. Conclusion: Despite the difference among insoluble phosphorus, dauciform roots have a contributing effect on aboveground growth status over time, mainly by regulating root morphological traits. This study contributes to our understanding of short-term variation in dauciform roots and their regulatory mechanisms that enhance Carex aboveground biomass under low available phosphorus conditions. [ABSTRACT FROM AUTHOR]

No-tillage of summer maize after the harvest of winter wheat is the primary agricultural practice on the North China Plain. However, prolonged no-tillage without deep tillage practices negatively impacts soil properties, which is detrimental to the growth and yield of summer maize. In this study, Xianyu 688 and Jifeng 2 were used as test maize materials, no-tillage and surface fertilizing with normal nitrogen (N) (BC240), no-tillage and surface fertilizing with N reduction (BC180), subsoiling layered fertilization with normal N (FC240) and subsoiling layered fertilization with N reduction (FC180)were designed, in order to assess root distribution, N utilization and grain yield of summer maize. In the two maize cultivars, the FC240 and FC180 treatments significantly reduced soil bulk density in the 10–50 cm depth soil layer compared to the other two treatments, and also increased total N content in the 20–50 cm depth soil layer. Compare BC 240 treatment, the FC240 treatment significantly increased root length in the 20–40 cm soil layer and root rap bleeding. Additionally, the FC240 and FC180 treatments enhanced dry matter and N accumulation, grain yield, N uptake efficiency and N fertilizer partial factor productivity. In various treatment, Xianyu 688 exhibited increased grain yield, N uptake efficiency and N fertilizer partial factor productivity compare with Jifeng 2. When employing a total N application level of 180–240 kg N/hm2, the synergistic improvement of summer maize grain yield and N efficiency can be achieved by incorporating subsoiling combined with layered nitrogen application. [ABSTRACT FROM AUTHOR]

Background and aims: Shoot traits related to soybean yield improvement are well characterized, but little is known about changes in root traits and their contribution to yield improvements under different P levels. Methods: Field experiments conducted in 2018 and 2019 (two sites each year under 0 (P0) and 35 (P35) kg P ha–1) compared root morphology, P and N accumulation and uptake efficiencies, and seed yield of 12 soybean cultivars released from 1995 to 2016. A supplementary pot experiment with the same soybean cultivars compared root exudates and arbuscular mycorrhizal (AM) colonization rates under 0 and 60 mg kg–1 P supply. Results: The four site × year field combinations revealed significant genetic gain from soybean breeding for seed yield under P35 (2.1–2.3%) and P0 (1.8–2.0%), respectively. Soybean breeding significantly increased P and N accumulation, which positively correlated with seed yield under P35 and P0. Root length, specific root length, and carboxylate exudation were associated with P and N accumulation and uptake efficiencies, but only root exudates significantly improved with year of cultivar release. The AM colonization rate increased under low soil availability but did not change with year of release. Conclusions: Our results suggest that indirect selection of root traits, such as root exudates, during soybean breeding could improve P and N accumulation and uptake efficiencies to improve seed yield. [ABSTRACT FROM AUTHOR]

Phosphorus (P) fertilizer is a significant cost in crop production. Understanding the mechanisms behind P fertilizer–soil–crop interactions can enhance phosphorus use efficiency (PUE) and increasing yield. We conducted a rice cultivation bucket experiment in red soil (pH = 5.9) and lime concretion black soil (pH = 7.8) and applied single superphosphate (SSP), calcium magnesium phosphate (CMP), diammonium phosphate (DAP), triple superphosphate (TSP), ammonium polyphosphate (APP), and a control group (CK, no P fertilizer). We analyzed rice P uptake and utilization patterns, evaluated the impact of varying P fertilizer formulations on rice root morphology, yield, and PUE, and investigated changes in soil P pools. In red soil, the APP treatment produced the greatest total root length, rice yield, PUE and increased soil Olsen-P, NaHCO 3 -Pi at anthesis. In lime concretion black soil, the TSP and APP treatments had the highest rice yields and increased Olsen-P, H 2 O-P, NaHCO 3 -Pi at anthesis. Moreover, the TSP treatment had the greatest total root length and root surface area at anthesis and the APP treatment had the largest PUE. Random forest regression analysis revealed that residual-P and Olsen-P significantly impacted rice yield in red soil and lime concretion black soil, respectively. We recommend using APP in red soil and TSP and APP in lime concretion black soil for rice cultivation to optimize soil P pool characteristics and root morphology for nutrient uptake, ultimately leading to the highest yields and PUE. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore the changes of root morphology, configuration, and nitrogen use efficiency of rice under mulched drip irrigation and their relationship with fractal dimension. From 2021 to 2022, a pot experiment was conducted with two irrigation methods of drip irrigation (DI) and flooding irrigation (FI) and four nitrogen (N) application levels (0, 150, 300 and 450 kg hm-2) using high nitrogen efficient (high-NUE) cultivar (T-43) and low-NUE cultivar (Ken-26) as the experimental materials. Based on the box-counting method combined with the root image fractal analysis program, the fractal dimension and fractal abundance of root morphology were calculated, and the effects of drip irrigation and nitrogen application on rice yield, nitrogen use efficiency, root morphology, configuration, fractal dimension, and fractal abundance were studied. The results showed as follows: (1) under the same N application level, compared with FI, the fine root percentage, root length density (RLD) β-value, and N agronomic efficiency (NAE) of the two varieties under DI were significantly increased (6.8%-14.5% and 9.9%-17.2%, 0.65%-5.45% and 0.32%-3.43%, 12.1%-22.4% and 12.2%-20.5%); >0.5 mm RLD, surface area density (SAD) and root bulk density (RLD), fractal dimension (FD), fractal abundance (FA) were significantly lower in the 0-40 cm soil layer, resulting in lower yields (3.8%-37.4% and 7.6%-48.3%). (2) Under DI, nitrogen application significantly increased FD and FA of rice roots. T-43 had the highest FD and FA when the nitrogen application rate was 300 kg hm-2 (1.55 and 14.07), and Ken-26 had the highest FD and FA when the nitrogen application rate was 450 kg hm-2 (1.62 and 14.78). (3) Correlation analysis showed that FD and FA were significantly or extremely significantly positively correlated with RLD of 0.1-0.3 mm in diameter, root length, and root mass density, yield and N grain production efficiency in 0-10 cm soil layer, and significantly negatively correlated with the surface area density in 30-40 cm soil layer. Therefore, under drip irrigation, the high-NUE cultivar "T-43" with N fertilizer of 300 kg hm-2 can increase the proportion of fine root length density, optimize the distribution of surface root morphology, and increase the fractal dimension and abundance of the root system, thus achieving a synergistic increase in the yield of drip-irrigated rice and the efficiency of nitrogen fertilizer utilization. [ABSTRACT FROM AUTHOR]

Sufficient soil moisture is required to ensure the successful transplantation of sweet potato seedlings. Thus, reasonable water management is essential for achieving high quality and yield in sweet potato production. We conducted field experiments in northern China, planted on 18 May and harvested on 18 October 2021, at the Nancun Experimental Base of Qingdao Agricultural University. Three water management treatments were tested for sweet potato seedlings after transplanting: hole irrigation (W1), optimized drip irrigation (W2), and traditional drip irrigation (W3). The variation characteristics of soil volumetric water content, soil temperature, and soil CO2 concentration in the root zone were monitored in situ for 0–50 days. The agronomy, root morphology, photosynthetic parameters, 13C accumulation, yield, and yield components of sweet potato were determined. The results showed that soil VWC was maintained at 22–25% and 27–32% in the hole irrigation and combined drip irrigation treatments, respectively, from 0 to 30 days after transplanting. However, there was no significant difference between the traditional (W3) and optimized (W2) drip irrigation systems. From 30 to 50 days after transplanting, the VWC decreased significantly in all treatments, with significant differences among all treatments. Soil CO2 concentrations were positively correlated with VWC from 0 to 30 days after transplanting but gradually increased from 30 to 50 days, with significant differences among treatments. Soil temperature varied with fluctuations in air temperature, with no significant differences among treatments. Sweet potato survival rates were significantly lower in the hole irrigation treatments than in the drip irrigation treatments, with no significant difference between W2 and W3. The aboveground biomass, photosynthetic parameters, and leaf area index were significantly higher under drip irrigation than under hole irrigation, and values were higher in W3 than in W2. However, the total root length, root volume, and 13C partitioning rate were higher in W2 than in W3. These findings suggest that excessive drip irrigation can lead to an imbalance in sweet potato reservoir sources. Compared with W1, the W2 and W3 treatments exhibited significant yield increases of 42.98% and 36.49%, respectively. The W2 treatment had the lowest sweet potato deformity rate. [ABSTRACT FROM AUTHOR]

Oligosaccharides, as a wide type of polysaccharide, have a broad antimicrobial spectrum and promote development as plant growth stimulants. To investigate the regulation effects of different oligosaccharides on the dynamic changes of chlorophyll content, leaf fluorescence, root activity and morphology, and chloroplast ultrastructure, as well as the yields and yield components of strawberry and cucumber, typical greenhouse experiments were conducted over two years (2021–2022). The experimental plants were foliar sprayed with tap water (CK), chitosan oligosaccharide (CSOS), and mixed oligosaccharides (MixOS) five times before flowering. The conventional management (CM) was conducted as a conventional control. The findings of the present study suggest that the application of MixOS has the greatest regulation effects on delayed leaf senescence, well-developed roots, and higher fruit productions of strawberry and cucumber. Exogenous MixOS resulted in significant increases in SPAD values, maximum photochemical efficiency (Fv/Fm), and photochemical quenching coefficiency (qP); they were increased by 1.94–28.96%, 5.41–33.89%, and 9.93–62.07%, compared to the CSOS, CM, and CK treatments, respectively. The orderly and steady structure of thylakoids in the chloroplast, and the randomly distributed starch grains, could be clearly observed in the MixOS treatment, while the non-photochemical quenching (NPQ) was correspondingly reduced by 19.04–45.92%. Meanwhile, the remarkable promotion of root activity and root surface morphology indicators (i.e., root length, surface area, average diameter, and volume) could be observed when exposed to the MixOS treatments, and the total yields of strawberry and cucumber were all increased by 12.40–25.57%. These findings suggest that the mixed oligosaccharides mainly promote the coordinated growth of root and shoot, which leads to the improved yields of strawberry and cucumber. [ABSTRACT FROM AUTHOR]

The cultivated Echinochloa frumentacea (Roxb.) Link and Echinochloa crusgalli (L.) Beauv. var. mitis (Pursh) Peter are two valuable grass species that are widely used in improving saline-alkali soil. Here we conducted a pot experiment combined with roots morphological analysis to investigate the adaptability of grass roots to saline stress environments, with cultivated E. frumentacea and E. crusgalli being subjected to salt treatments of 0 (CK), 100, 220, and 340 mmoL·L-. Results indicated that E. frumentacea had longer primary roots with fewer root hairs and lower local branching density than E. crusgalli, with the root volume of E. frumentacea being 1.43 times greater than that of E. crusgalli. The aboveground biomass of both grasses decreased significantly (p < 0.05) with increasing salt concentrations, whereas the root-to-shoot ratio exhibited the opposite trend, suggesting the preferential allocation of photosynthetic products to the roots under salt stress. The total length, surface area, and tip number of fine roots and the growth of coarse roots (d > 2.00 mm) showed significant differences (p < 0.05) between the two grass species. Different concentrations of salt stress had inconsistent effects on the biomass and radial growth of roots for grasses. The cultivated E. frumentacea seems to adopt an adapt strategy of gradually increasing its root thickness, root hairs, and root density under increasing salt stress. E. crusgalli, on the other hand, employed a strategy of increasing root length, maintaining uniform thickness, and developing root hairs. [ABSTRACT FROM AUTHOR]

To examine the effect of microplastics on terrestrial plants, the germination, growth, and oxidative stress of rice exposed to polystyrene microspheres(PS, PSC, PSN)with different surface modifications(original, carboxylated, and aminated)were investigated. The exposure concentrations were 0.2, 1, 5 mg·L-1, and 30 mg·L-1 . Inhibition of the three microplastics on germination rate and seedling root mass were in the order of PSN>PSC>PS, and the suppression of root morphology(root length, root surface area, and root projection area) was generally stronger for the two modified microspheres compared with the original one. Original PS at lower concentrations(0.2 mg·L-1 and 1 mg · L-1 )stimulated rice roots to increase defensive activity of the antioxidative system, thereby avoiding oxidative stress. With increasing concentration, the antioxidative ability of roots gradually weakened, which resulted in lipid peroxidation at 30 mg·L-1 . However, two surface-modified microplastics led to the inhibition of root antioxidative system at lower concentrations(0.2, 1 mg·L-1 ). PSC induced root oxidative stress at the highest concentration(30 mg·L-1 )alone, whereas PSN induced oxidative stress at 1 mg·L-1 . With increasing PSN concentration, oxidative stress was further intensified. Eluted substances from the rice root surface increased significantly with increasing microplastic concentration, which may be associated with the antioxidative reaction in the roots. Microplastics of PSC and PSN were observed in root surface eluates at the highest concentration(30 mg·L-1 ), and the root adsorption may result in oxidative stress and retardation in growth and development. Rice sprout was less sensitive to microplastics than roots, and the sprout weight and chlorophyll content were inhibited to a certain extent. All microplastics led to oxidative stress in sprouts at the highest concentration(30 mg ·L-1 ), whereas the differences between various treatments were not significant. The surface-modified microplastics(particularly PSN)exerted stronger negative impacts on rice seed germination, root growth, and antioxidant system compared with the original PS. [ABSTRACT FROM AUTHOR]

Background and Aims: Root exudations play a crucial role in plant nutrient uptake; however, studies on their response to different forms of nitrogen (N) are lacking. To bridge these gaps, we examined the effect of different N forms on the root exudation rates among tree species. Methods: NO3−-N, NH4+-N, and organic N were added to the soil at identical concentrations for three months. Root exudate, fine root, and soil samples were collected from the seedlings of four temperate tree species to determine the root exudation rate, aboveground biomass, root characteristics (morphological, physiological, and nutrient traits), and soil characteristics (soil physicochemical properties and enzymatic activity). The differences in all variables among different N forms and tree species were investigated to explore the causative factors for the variations in root exudation. Results: All three forms of N addition reduced the root exudation rate (up to 43.8%), which was consistent across all species and was positively correlated with root morphological traits and negatively correlated with soil total N concentration. The effect of N addition on root exudation was not affected by N form. Conclusion: For four temperate tree species, inorganic and organic N additions increased soil N availability and reduced root exudation rates, and the effects were not varied with N form. The results indicated that, in the short-term, temperate tree species do not show a preference in utilizing different N resources. These findings provide new insights into the effect of different N form additions on belowground C dynamics and root-soil interactions. [ABSTRACT FROM AUTHOR]

BACKGROUND: Soil is a key foundation of crop root growth. There are interactions between root system and soil in multiple ways. The present study aimed to further explore the response of root distribution and morphology to soil physical and chemical environment under maize (Zea mays L.) soybean (Glycine Max L. Merr.) relay strip intercropping (MS) An experiment was carried out aiming to examine the effects of nitrogen (N) applications and interspecific distances on root system and soil environment in MS. The two N application levels, referred to as no N application (NN) and conventional N application (CN), were paired with different interspecific distances: 30, 45 and 60 cm (MS30, MS45 and MS60) and 100 cm of monoculture maize and soybean (MM/SS100). RESULTS: The results demonstrated that MS45 increased the distribution of soil aggregates (> 2 mm) near the crop roots and maize soil nutrients status, which increased by 20.3% and 15.6%. Meanwhile, MS reduced soil bulk density, increased soil porosity and improved soil oxygen content. Optimization of the soil environment facilitated root growth. The MS45 achieved a better result on root distribution and morphology than the other configuration and also increased land productivity. CONCLUSION: Relay intercropped soybean with maize in interspecific row spacing of 45 cm, improved soil physicochemical environment, reshaped root architecture and optimized root spatial distribution of crops to achieve greater land productivity. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Roots are the hidden and most important part of plants. They serve as stabilizers and channels for uptaking water and nutrients and play a crucial role in the growth and development of plants. Here, two-dimensional image data were used to identify quantitative trait loci (QTL) controlling root traits in an interspecific mapping population derived from a cross between wild soybean 'PI366121' and cultivar 'Williams 82'. A total of 2830 single-nucleotide polymorphisms were used for genotyping, constructing genetic linkage maps, and analyzing QTLs. Forty-two QTLs were identified on twelve chromosomes, twelve of which were identified as major QTLs, with a phenotypic variation range of 36.12% to 39.11% and a logarithm of odds value range of 12.01 to 17.35. Two significant QTL regions for the average diameter, root volume, and link average diameter root traits were detected on chromosomes 3 and 13, and both wild and cultivated soybeans contributed positive alleles. Six candidate genes, Glyma.03G027500 (transketolase/glycoaldehyde transferase), Glyma.03G014500 (dehydrogenases), Glyma.13G341500 (leucine-rich repeat receptor-like protein kinase), Glyma.13G341400 (AGC kinase family protein), Glyma.13G331900 (60S ribosomal protein), and Glyma.13G333100 (aquaporin transporter) showed higher expression in root tissues based on publicly available transcriptome data. These results will help breeders improve soybean genetic components and enhance soybean root morphological traits using desirable alleles from wild soybeans. [ABSTRACT FROM AUTHOR]

Silicon (Si) has been widely used in recent years to improve crop salt tolerance. However, few studies concentrated on the effects of Si on salt tolerance and quality of medicinal plants. In this study, the long-term effects of spraying of Si (K2SiO3) on Glycyrrhiza uralensis Fisch. and Glycyrrhiza inflata Bat., grown in Xinjiang under different salt concentrations (medium and high-salt), on the plant growth, photosynthetic pigment content, gas exchange parameters, osmotic adjustment ability, total flavonoids and glycyrrhizic acid contents were investigated. The results showed that the plant height, leaf area, leaf number, relative water content (RWC), photosynthetic pigment content, and gas exchange parameters decreased on different salt treatments in both licorice species; their biomass accumulation both above- and below-ground was inhibited, leading to a significant decrease in total flavonoids and glycyrrhizic acid levels in the roots. On the contrary, foliar Si application increased the number and area of leaves; improved the RWC, net photosynthetic rate, and stomatal conductance; and reduced the degradation rate of photosynthetic pigments subjected to salt stress. Additionally, the length, number, and absorptive area of the root systems increased on Si application, alleviating the inhibition of salt on root growth, increasing the accumulation of total flavonoids and glycyrrhizic in roots, and promoting the medicinal quality of licorice. Si application also alleviated the damage caused by salt stress-induced lipid peroxidation and maintained the integrity of the plasma membrane by promoting the synthesis of soluble sugars, soluble proteins, and proline, thereby enhanced the salt tolerance of licorice. [ABSTRACT FROM AUTHOR]

Phosphorus is one of the essential nutrients for crop growth and development, and plays an important role in the life process of crops. Crops have formed a series of low phosphorus adaptation mechanisms in the long-term evolution process, mainly involving the activation, absorption, transport of soil phosphorus and the recycling and reuse of phosphorus in crop tissues. In this paper, the latest research progress on the mechanism of low phosphorus tolerance of crops was reviewed from four aspects: root morphology, root exudates, symbiotic system with microorganisms, and molecular mechanism under low phosphorus stress, in order to provide reference for crop cultivation regulation and improvement and breeding of low phosphorus tolerant crop varieties. [ABSTRACT FROM AUTHOR]

Background and Objective: Clinicians must possess a comprehensive understanding of variations in canal morphology and configuration during endodontic procedures to enhance treatment success. This study aims to assess and analyze the canal configurations of maxillary first premolars using Cone-Beam Computed Tomography within the sub-population of Western Saudi Arabia. Materials and Methods: In this cross-sectional study, following the acquisition of ethical clearance from Batterjee Medical College in Jeddah, Saudi Arabia, a retrospective examination of Cone-Beam Computed Tomography (CBCT) scans of maxillary first premolars in adult patients was conducted. The study focused on quantifying the number of canals and characterizing their configurations, with classification based on Vertucci's categorization. Results: The study examined 399 CBCT images of maxillary first premolars, revealing that type IV canal configurations were the predominant morphology (56.9%), followed by type V (24.6%). Significant gender-related disparities were observed, with females displaying a higher incidence of types I and V canals. At the same time, males exhibited a greater prevalence of types IV and VI canals. Notably, no substantial associations were discerned between canal types and age groups. Conclusion: Within the context of maxillary first premolars, type IV canal configuration emerged as the most prevalent. Gender-based distinctions were evident, with females predominantly presenting types I and V canal configurations, whereas males displayed a higher occurrence of types IV and VI canal configurations. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is one of the main nutrients for all plants, including grasses. However, sources of P fertilizer are not renewable, are not evenly distributed and overfertilization can lead to serious environmental degradation. Smart combinations of grasses may be able to more efficiently take up P from soils through complementarity. In a two-year field mesocosm experiment, we compared the performance of Lolium perenne L. and Festuca arundinacea Schreb. in monocultures and in combination, as well as a mixture of both species with a tetraploid variety of Lolium perenne L and Phleum pratense L. Plants were grown in an unfertilized low P soil and in P fertilized soil for two growing seasons. We measured biomass production, root traits, nutrient uptake, microbial biomass and enzymatic activities. In the unfertilized plots the combination of Lolium perenne and Festuca arundinacea generated the highest cumulative yields (25,951 ± 4059 kg ha−1), relative total yield (> 1) and P nutrition index (0.79). We related this to the complementarity found in root traits and lower intraspecific competition of Festuca arundinacea and Lolium perenne diploid. Festuca arundinacea produced higher root biomass than Lolium perenne diploid at deeper soil layers (98 vs. 44 g m−2; p < 0.05). On the other hand, Lolium perenne diploid had significantly finer roots than Festuca arundinacea both at topsoil and bottom layers (0.19 vs. 0.22 mm and 0.19 vs. 0.23 mm at top and bottom layers respectively). The 4 species combination did not result in higher yields. Our results show that, in low P soils, combinations of grass species with contrasting root traits could lead to significantly higher yields than monocultures. [ABSTRACT FROM AUTHOR]

Industrial hemp (Cannabis sativa L.) is receiving increasing attention for its multiple end-uses; therefore, an improvement in its production is needed to meet the increased demand. In the present study, the effect of seed inoculation with two Trichoderma afroharzianum strains, T-AA and T-22, on plant growth and root morphology of hemp plants at sixth-leaf (S6) and tenth-leaf (S10) stages was assessed for two consecutive years (2020 and 2021). In addition, the ability of the two strains to enhance the accumulation of phenolic compounds in hemp leaves was also evaluated. The results obtained revealed the ability of T-22 to improve the growth and root morphology of hemp plants both in 2020 and 2021, although with different impact, probably ascribable to the different weather conditions in the two years. In 2020, the positive effects of T-22 were detected at S10 stage with significant increases in the shoot and root length (38% and 17%, respectively) and dried biomass (35% and 30%, respectively) compared to untreated plants. The total root surface area and the number of tips, forks, and crossings also increased significantly (24–36%) at this stage. In 2021, significant increases in the shoot length and dried biomass (40% and 30%, respectively) were observed at S6 stage, whereas root length and dried biomass increased significantly at S6 (55% and 47%, respectively) and S10 stage (121% and 40%, respectively). Significant increases in the total surface area and volume, as well as in the number of tips, forks, and crossings were also observed at both S6 and S10 stage (50–63% and 105–187%, respectively). Interestingly, in both years and at both stages, the two strains induced significant increases in the leaf accumulation of phenolic compounds and the antioxidant activity, which were greater in T-22- compared to T-AA-treated plants (18–102% and 13–34%, respectively). The results are discussed in light of the potential practical applications of T-22 as a biostimulant of hemp plant growth under favorable and unfavorable environmental conditions, and of both strains as promising tools for the improvement of the leaves' economic value as a source of health-promoting compounds. [ABSTRACT FROM AUTHOR]

The stability of riverbank slopes is crucial in watershed ecology. The morphology and tensile strength properties of plant roots play a significant role in slope stability, which is of great importance for the ecological stability of riverbanks. The Jinsha and Yalong River basins are the largest hydropower bases in China and are in the ecologically fragile areas of the dry and hot river valleys, yet fewer studies are available on these basins. Further studies on the growth morphology and root mechanical properties of plant roots in the riparian zone at different elevations have not been reported. Therefore, we selected the dominant species of Cynodon dactylon root as the research subject, analyzed the root morphology, and conducted indoor single-root tensile tests to study its root structure and mechanical properties at various elevations. The results showed that the root morphology of Cynodon dactylon was positively correlated with elevation. Compared to low elevations (L and M), the root length increased by 57.3% and 21.47%, the root diameter increased by 24.85% and 13.92%, the root surface area increased by 93.5% and 67.37%, and the total root volume increased by 119.91% and 107.36%. As the elevation gradient increased, the flooding time decreased, leading to more developed plant roots for Cynodon dactylon. The Young's modulus ranged from 148.43 to 454.18 MPa for Ertan Cynodon dactylon roots and 131.31 to 355.53 MPa for Guanyingyan Cynodon dactylon roots. The maximum tensile strength, ultimate tensile strength, ultimate elongation, and Young's modulus of the plant root of the Cynodon dactylon showed a power function relationship with the diameter. The maximum tensile strength increased as the diameter increased, while the remaining properties decreased following a power function relationship. The maximum tensile strength, ultimate tensile strength, and Young's modulus of Cynodon dactylon were positively correlated with elevation, while the ultimate elongation was negatively correlated with elevation. The results elucidate the influence of elevation on the root morphology and mechanical properties of dominant riparian species. This provides a theoretical basis for managing and protecting riparian slopes in ecologically fragile areas. [ABSTRACT FROM AUTHOR]

Water stress is the most important factor limiting crop production in arid and semiarid regions. Cultivating crops using a plastic film mulch can significantly increase crop yields by optimizing soil hydrothermal conditions in semiarid agroecosystems. Therefore, clarifying root adaptability to plastic film mulch cultivation is crucial when attempting to produce stable and high maize yields. A two-year experiment was conducted to investigate the effects of two treatments, no mulching (NM) and plastic film mulching (FM), on the yield, water productivity (WP), and root morphology of spring maize on the Loess Plateau. The results showed that the FM yield (14.31–15.02 t ha–1) significantly increased by 18.6–29.7 % compared to NM (11.03–12.66 t ha–1). The FM treatment also significantly increased dry matter (51.0–61.6 %), leaf area (19.7–25.7 %), and WP (28.8–46.3 %), but decreased ET (8.6–12.8 %). In addition, soil water storage in the FM surface soil layer significantly increased compared to that of NM. Film mulching also produced more robust roots and promoted the convergence of roots towards the surface of the soil, whereas NM roots tended to grow downwards to obtain water from the lower soil layers. The regression analyses indicated that root length (R2 = 0.725, P < 0.01) and biomass (R2 = 0.736, P < 0.01) were positively correlated with grain yield. The results suggested that maize adapts to changes in root morphological behavior under FM. These changes contribute to soil water and nutrient capture and shoot development, which subsequently support the high yields produced under plastic film mulching. Therefore, film mulching is a promising strategy for improving yield and WP and for optimizing root morphology in dryland agriculture.