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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]

Seed-based restoration methods are increasingly recognized as a relevant tool contributing to halt and reverse the loss of seagrass meadows while providing genetic and evolutionary benefit for the conservation of these habitats. Ad-hoc protocols aimed at maximizing the survival of plantlets obtained from seeds in cultivation systems are therefore required. Previous trials of seedling culture of Posidonia oceanica , the dominant seagrass of the Mediterranean Sea, recorded up to 40% loss due to mould development. In this study we aim to (i) identify the putative causal agents of seed decay and (ii) test the efficacy of copper sulphate (0.2 and 2 ppm) and of tannin-based products derived from chestnut, tara and quebracho in reducing seed and seedling decay, while assessing possible phytotoxic effects on plant development. Halophytophthora lusitanica, H. thermoambigua and a putative new Halophytophtora species were identified as possible causal agents of seed loss. The antimicrobial agents (copper and tannins) reduced seed contamination by 20%, although copper sulphate at 2 ppm strongly inhibited the root growth. Among tannins, chestnut and tara reduced seeds germination by up to 75% and decreased shoot and root development, while quebracho showed a less severe phytotoxic effect. The use of copper sulphate at 0.2 ppm is therefore recommended to prevent P. oceanica seedling loss in culture facilities since it reduces seed contamination with no phytotoxic effects. Our results contribute to improving the seedling culture of one the key species of the Mediterranean Sea, increasing propagule availability for restoration purposes. [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]

Nuclear calcium (Ca2+) signaling is crucial for symbiotic interactions between legumes and beneficial microbes, such as rhizobia and arbuscular mycorrhizal fungi. The ion channels DMI1 and CNGC15 are key to generating repetitive nuclear Ca2+ oscillations. Despite more than 20 years of research on symbiotic nuclear Ca2+ spiking, important questions remain, including the exact function of the DMI1 channel. This review highlights recent developments that have filled knowledge gaps regarding the regulation of CNGC15 and its interplay with DMI1. We also explore new insights into the evolutionary conservation of DMI1-induced symbiotic nuclear Ca2+ oscillations and the roles of CNGC15 and DMI1 beyond symbiosis, such as in nitrate signaling, and discuss new questions this raises. As we delve deeper into the regulatory mechanisms and evolutionary history of these ion channels, we move closer to fully understanding the roles of nuclear Ca2+ signaling in plant life. [ABSTRACT FROM AUTHOR]

ABSTRACT Based on the research conducted so far, hydrogen sulphide (H2S) plays a crucial role in the development and stress resilience of plants. H2S, which acts as a signalling molecule, responds to different stresses such as heavy metals, drought, and salinity, and it regulates various aspects of plant growth and development including seed germination, root development, stomatal movement, flowering, and fruit ripening. Additionally, H2S is involved in mediating legume‐Rhizobium symbiosis signalling. It modulates plant responses to external environmental stimuli by interacting with other signalling molecules like phytohormones, nitric oxide, and reactive oxygen species. Furthermore, H2S exerts these regulations since it can modify protein functions through a reversible thiol‐based oxidative posttranslational modification called persulfidation, particularly in stress response and developmental processes. As a result, H2S is recognised as an important emerging signalling molecule with multiple roles in plants. Research in this field holds promise for engineering stress tolerance in crops and may lead to potential biotechnological applications in agriculture and environmental management. [ABSTRACT FROM AUTHOR]

Recalcitrance to root of kiwifruit (Actinidia spp.) stem cuttings (SCs) is a restriction for its commercial production. Exogenous hormone is the key factor to regulate root formation, but the research on exogenous hormone stimulatory effects on Actinidia spp. is still lagging. Kiwifruit plants had been mostly propagated by seeds. However, vegetative propagation offers several advantages over sexual propagation, among them being crop homogeneity, practicability, and simplicity of the technique. A study was therefore conducted to investigate the potential responses of kiwifruit SCs from Actinidia deliciosa rootstock and Actinidia arguta male scion SCs treated with indole-3-butyric acid (IBA) concentrations at low (10, 100 ppm), medium (1,000, 10,000 ppm) and high (100,000 ppm) levels. Parallel experiments for A. deliciosa and A. arguta 's treatments were arranged in a randomized complete block design, with 12 replications. Treatments comprised different IBA concentrations, namely, 0 (control), 10, 100, 1,000, 10,000 and 100,000 ppm. At 103 days, rooting percentage, number of roots, root length, dry root mass, size of callus formation and callus percentage were determined. In A. deliciosa SCs, treatments had high significant (p ≤ 0.05) effects in rooting percentage, number of roots, root length, size of callus formation and callus percentage, except for dry root mass. In A. arguta male SCs, treatments also, showed high significant (p ≤ 0.05) effects in the number of roots, root length and dry root mass, except for the rooting percentage. No callus formation was observed in A. arguta male SCs. Relative to the control, in A. deliciosa SCs, the highest (42%) rooting percentage and lengthy (0.3 cm) roots, both were observed at the medium (10,000 ppm) IBA concentration, whereas the most (0.29) number of roots were produced at the highest (100,000 ppm) IBA concentration. Calli percentage (94%) was highest at low (100 ppm) IBA, while the biggest (2.8) size of callus formation was at the highest IBA concentration of 100,000 ppm, when compared to the control. In A. arguta male SCs, the greatest number of roots (1.08) and root mass (0.07 g) were attained at the medium IBA concentration of 10,000 ppm. The longest (0.94 cm) root length was achieved at the low IBA concentration of 100 ppm. The SCs of A. arguta male scion required low to medium (100 to 10,000 ppm) concentrations of IBA for proper roots stimulation and development, whereas in SCs of A. deliciosa , highest rooting percentage paired with callus formation, was achieved at medium to higher (10,000 to 100,000 ppm) IBA concentrations. Principal component analysis (PCA) revealed that PC1 and PC2 accounted for 99% of the entire variation. While PC1 accounted for 94% of the total variation, PC2 accounted for 5% of the total variation in A. deliciosa. However, in A. arguta PCA revealed that PC1 and PC2 accounted for 93% of the entire variation. While PC1 accounted for 72% of the total variation, PC2 accounted for 21% of the total variation. The use of exogenous application of IBA was effective for adventitious root formation in SCs of A. deliciosa rootstock and A. arguta male scion. IBA showed its effectiveness in stimulating root development at 10000 ppm IBA. [ABSTRACT FROM AUTHOR]

Mikania micrantha ("mile-a-minute" weed) is a global invasive alien weed that can cause severe damage to agroforestry ecosystems and significant agricultural losses worldwide. Although chemical, manual, or mechanical control methods are widely used to control M. micrantha, RNA interference (RNAi)-based biocontrol methods have rarely been reported for this species. The MONOPTEROS (MP) gene, encoding an auxin response factor, plays an essential role in embryonic root initiation in Arabidopsis thaliana. In this study, we identified the MP gene from M. micrantha via orthologous gene analysis. A total of 37 MP orthologous genes was identified in 4 plants, including 9 MP candidate genes in M. micrantha, 13 in Helianthus annuus, 6 in Chrysanthemum nankingense, and 9 in Lactuca sativa. Phylogenetic analysis revealed that an MP candidate gene in M. micrantha (Mm01G000655, named MmMP) was clustered into one clade with the MP gene in A. thaliana (AtMP). In addition, both MmMP and AtMP contain a B3-DNA binding domain that is shared by transcription factors that regulate plant embryogenesis. To study gene function, dsRNA against MmMP (dsMmMP) was applied to the roots of M. micrantha. Compared with those of the controls, the expression of MmMP was reduced by 43.3%, 22.1%, and 26.2% on the first, third, and fifth days after dsMmMP treatment, respectively. The dsMmMP-treated plants presented several morphological defects, mostly in the roots. Compared with water-treated plants, the dsMmMP-treated plants presented reduced developmental parameters, including root length, number of adventitious roots, root fresh and dry weights, plant height, and aboveground biomass. Additionally, safety assessment suggested that this dsMmMP treatment did not silence MP genes from non-target plants, including rice and tomato; nor did it inhibit root growth in those species. Collectively, these results suggest that MmMP plays an important role in root development in M. micrantha and provides a potential target for the development of species-specific RNAi-based herbicides. [ABSTRACT FROM AUTHOR]

Background: Fe toxicity often inhibits rice growth on acid sulfate soils in tropical coastal lowlands. Previous studies in plant physiology and breeding have focused on high‐Fe stress, but not on growth recovery after stress alleviation. Aims: The objective of this study was to elucidate the morphophysiological characteristics in rice growth recovery from high‐Fe stress. Methods: We evaluated the seedling growths of Taichung65 (T65) (Fe toxicity‐tolerant) and Ciherang (susceptible) in hydroponic culture, during the period of high‐Fe stress (250 mg Fe2+ L−1 for 12 or 18 days) and after stress alleviation. Results: The plant growth rate during recovery was negatively correlated with the leaf bronzing score (damage symptoms due to Fe toxicity) at the end of high‐Fe stress, which in turn was negatively correlated with the shoot Fe concentration. After 18‐day stress, T65 showed greater growth recovery than Ciherang, attributable to its higher net assimilation rate, higher transpiration rate (water uptake/green leaf area), and greater increase in total root length during recovery. In particular, T65 showed vigorous lateral root development in nodal roots that emerged during the stress period and vigorous growth of nodal roots that emerged during recovery. Conclusions: Our results suggest that tolerance to high‐Fe stress confers an advantage in growth recovery. It is likely that tolerance to Fe toxicity contributes not only to the maintenance of green leaf area at the end of stress but also to quick root growth recovery, leading to vigorous water uptake and high photoassimilation capacity after stress alleviation. [ABSTRACT FROM AUTHOR]

Root meristem growth factor (RGF) peptides are essential molecules regulating root growth. As is common with many short signalling peptides, their prepropeptide and mature structure provides insights into function as well as how they interact with receptors. Molecular components of RGF peptide signalling pathways and their closely related orthologues have been implicated in a wide range of developmental processes beyond the root meristem, but few have been linked directly to RGF peptide signalling. Recent studies have provided evidence for their involvement in both beneficial and pathogenic plant–microbe interactions, indicating novel mechanisms with the potential to enhance pathogen resistance. Plant peptide families share distinct characteristics, and many members are in homologous signalling pathways controlling development and responses to external signals. The root meristem growth factor (RGF) peptides/GOLVEN (GLV)/CLAVATA3-ESR-related like (CLEL) are a family of short signalling peptides that are derived from a precursor protein and undergo post-translational modifications. Their role in root meristem development is well established and recent efforts have identified subtilase processing pathways and several downstream signalling components. This discovery has enabled the convergence of previously distinct pathways and enhanced our understanding of plant developmental processes. Here, we review the structure–function relationship of RGF peptides, the post-translational modification pathways, and the downstream signalling mechanisms and highlight components of these pathways that are known in non-RGF-mediated pathways. [ABSTRACT FROM AUTHOR]

• Root development of common bean with humic acid is dose dependent. • The association of HA and Serendipita. indica brings greater benefits to bean photosynthesis. • The joint use of HA and S. indica increased the productivity of common beans. Agriculture increasingly uses sustainable technologies to obtain higher yields and reduce environmental impact. In this context, the use of humic substances and growth-promoting fungi, such as Serendipita indica, has emerged as an alternative for increasing the yield of crops such as beans. This study aimed to assess the effects of using humic acid (HA) isolated from vermicompost on its own or combined with the fungus S. indica on the growth, photosynthesis, and yield of common beans (Phaseolus vulgaris L.). Initially, a dose-response trial was carried out with six treatments (0, 10, 50, 100, 200, and 400 mg L −1 de HA) to identify the best concentration of HA in the initial growth of the bean plant. From the optimal concentration obtained, 200 mg L −1 of HA, a new experiment was developed to investigate the influence of HA and the S. Indica fungus in photosynthesis and plant yield. The treatments were: T1 – control (no humic acid and no fungus); T2 – 200 mg L −1 of HA; T3 – S. indica fungus; T4 – 200 mg L −1 of HA and S. indica fungus. The joint application of HA at a concentration of 200 mg L −1 with the fungus S. indica increased the photosynthetic efficiency and bean grain yield per plot. The associated use of biostimulants can change the production trend of common beans, making them more profitable and attractive for producers. [ABSTRACT FROM AUTHOR]

Drought stress, an inevitable global issue due to climate change, hinders plant growth and yield. Nitric oxide (NO), a tiny gaseous signaling compound is now gaining massive attention from the plant science community due to its unparalleled array of mechanisms for ameliorating various abiotic stresses, including drought. Supplementation of NO has shown its astounding effect in improving drought tolerance by prominently influencing its tendency to modulate stomatal movement and reduce oxidative stress; it can enormously affect the various other physio-biochemical processes such as root structure, photosynthesis, osmolyte cumulation, and seed establishment of plants due to its amalgamation with a wide range of molecules during drought conditions. The production and inhibition of root development majorly depend on NO concentration and/or experimental conditions. As a lipophilic free gasotransmitter, NO readily reacts with free metals and oxygen species and has been shown to enhance or reduce the redox homeostasis of plants, depending on whether acting in a chronic or acute mode. NO can easily alter the enzymes, protein activities, and genomic transcriptional and post-translational modifications that assist functional retrieval from water stress. Although progress is ongoing, much work remains to be done to describe the proper target site and mechanistic approach of this vibrant molecule in plant drought tolerance. This detailed review navigates through the comprehensive and clear picture of the mechanistic potential of NO in drought stress following molecular approaches and suggests effective physiological and biochemical strategies to overcome the negative impacts of drought. We explore its potential to increase crop production, thereby ensuring global food security in drought-prone areas. In an era marked by unrelenting climatic conditions, the implications of NO show a promising approach to sustainable farming, providing a beacon of hope for future crop productivity. [Display omitted] • Drought stress severely hampers plant growth and productivity. • Provides deep insights into the potential significance of NO under drought. • Reviews the novel molecular amendments in NO-drought research. [ABSTRACT FROM AUTHOR]

This case report describes a successful autotransplantation procedure for an impacted mandibular left second premolar with incomplete root formation. Despite caries and root resorption, the patient's mandibular left second primary molar was retained. Furthermore, the severe impaction of the mandibular left second premolar ruled out orthodontic realignment. Due to the young age of the patient, dental implantation was not feasible, leading to the selection of autotransplantation as the preferred method for replacing the retained primary molar. To address the insufficient buccolingual width of the recipient site, a combination of piezosurgery‐assisted alveolar ridge splitting and guided bone regeneration techniques was employed in this autotransplantation procedure. [ABSTRACT FROM AUTHOR]

Main conclusion: In the angiosperm root apical meristem, the holoploid DNA content is not directly related to cell cycle time. Instead, ploidy, chromosome number, and taxa emerge as key factors that influence this interaction. It is commonly considered that cell cycle time in the angiosperm root apical meristem is directly related to the holoploid DNA content, and this is one of the manifestations of the nucleotypic effect. In this paper, we significantly expanded the previously reported data on cell cycle time using the thymidine method and the rate-of-cell-production method and investigated the nucleotypic effect in different taxonomic groups, in diploids with varying numbers of chromosomes, and in species of different ploidy levels. The nucleotypic effect was most pronounced in diploids with a chromosome number of less than 17, especially in the orders Asparagales and Liliales. In diploids with 17 and a greater number of chromosomes, and in polyploids, the nucleotypic effect was only evident in these two orders and was practically absent in the rest of angiosperms, which have generally lower the holoploid DNA content and average DNA content per chromosome. Overall, our work demonstrates that in angiosperms the relationship between cell cycle time in the root apical meristem and the holoploid DNA content is complex and not homogeneous and it is not directly related to cell cycle time. Instead, ploidy, chromosome number, and taxa emerge as key factors that influence this interaction. [ABSTRACT FROM AUTHOR]

Abscisic acid (ABA) has been well known to strongly improve plant tolerance to heavy metals. However, the comprehensive mechanism of alleviating cadmium (Cd) stress in different plant organ was not been fully elucidated. In this study, foliar spray of 10 μM ABA significantly (p < 0.05) improved the plant height, root length, and the number of lateral roots, and reduced Cd accumulation and effectively restored the mineral contents caused by Cd induced change in leaves, stems, and roots of mung bean seedlings. Transcriptome analysis revealed that a total of 2241 differentially expressed genes (DEGs) (|fold-change|≥ 2.0 and FDR ≤ 0.05) were identified in the ABA + Cd-treated mung bean seedlings compared to the Cd-treated group, with 898, 908, and 859 DEGs identified in leaves, stems, and roots, respectively. Foliar application of ABA predominantly affected the KEGG pathways including phenylpropanoid biosynthesis, alpha-linolenic acid metabolism, starch and sucrose metabolism, and cyanoamino acid metabolism, and regulated the genes related to lipid metabolism, cell wall processes, secondary metabolism, defense and stress responses, hormone signal transduction, photosynthesis, and cell division to mitigate Cd toxicity of the mung bean seedlings. However, ABA exerted distinct effects on the gene profiles of leaves, stems, and roots under Cd stress. Interestingly, although exogenous ABA was applied to the leaves, the genes involved in hormone signaling were found to be regulated primarily in roots on the first day and subsequently in stems and leaves at later stages, indicating that exogenous ABA participates in mitigating Cd toxicity through signal transduction. Notably, significant upregulation of transporter-related genes was observed mainly in leaves and stems, including ABC transporters, NRT1/PTR FAMILY protein encoding genes, and WAT1-related protein encoding genes, which may contribute to the transportation of the ABA, Cd, and nutriments. Furthermore, the expression of genes encoding crucial photosynthetic proteins exhibited significant upregulation or downregulation upon exogenous ABA treatment, implying that exogenous ABA also ameliorated Cd stress by modulating leaf photosynthetic activity. This study may contribute to understanding the molecular mechanism of ABA-alleviated Cd stress in mung bean and identifying a number of highly regulated genes that could potentially be used to improve plant tolerance to heavy metals. [ABSTRACT FROM AUTHOR]

Developmental plasticity is critical for plants to adapt to constantly changing environments. Plant root hairs display dramatic plasticity under different environments and therefore play crucial roles in defense against environmental stressors. Here, we report the isolation of an Arabidopsis mutant, salinityover-sensitivemutant 1–1 (som1-1), also exhibiting root hair developmental defects. Map-based cloning and allelic analyses confirmed that som1-1 is a new mutant allele of SPIRRIG (SPI), which encodes a Beige and Chediak Higashi (BEACH) domain-containing protein. SPI has been reported to facilitate actin dependent root hair development by temporally and spatially regulating the expression of BRICK1 (BRK1), a subunit of the SCAR/WAVE actin nucleating promoting complex. Our living cell imaging examinations revealed that salt stress induces an altered actin organization in root hair that mimics those in the spi mutant, implying SPI may respond to salt stress induced root hair plasticity by modulating actin cytoskeleton organization. Furthermore, we found BRK1 is also involved in root hair developmental change under salt stress, and overexpression of BRK1 resulted in root hairs over-sensitive to salt stress as those in spi mutant. Moreover, based on biochemical analyses, we found BRK1 is unstable and SPI mediates BRK1 stability. Functional loss of SPI results in the accumulation of steady-state of BRK1. [ABSTRACT FROM AUTHOR]

Precise regulation of cell division is essential for proper tissue patterning in multicellular organisms. In Arabidopsis , the ground tissue (GT) comprises cortex and endodermis in the early stages of root development. During GT maturation, additional periclinal cell divisions (PCDs) occasionally occur of the endodermis, generating a middle cortex (MC) layer between the cortex and endodermis. Although several regulatory proteins and phytohormones were identified to mediate GT patterning, such as SHORT-ROOT (SHR), SCARECROW (SCR), CYCLIND6;1 (CYCD6;1), and gibberellins (GAs), the interrelationship among these factors is not elucidated. Here, we report that three closely related receptor-like kinases (RLKs), ARH1, FEI1, and FEI2, play crucial roles in mediating a signal transduction pathway from the SHR-SCR module to GA to regulate GT patterning. Two independent triple mutants of these RLKs (tri-1 and tri-2) exhibit increased MC formation compared with wild type. Genetic analysis indicated that all three RLKs regulate MC formation mainly in a cell-autonomous manner. The transcription levels of these RLKs are negatively controlled by SHR and SCR. The altered GT patterns in shr and scr can be partially complemented by tri-1. GA biosynthesis is significantly reduced in the roots of tri-1. The excessive MC formation in tri-1 can be greatly suppressed by the exogenous application of GA 3 or by the mutation of CYCD6;1. Our results demonstrate a signaling pathway involving SHR/SCR-ARH1/FEI1/FEI2-GA-CYCD6;1 to govern GT patterning in Arabidopsis thaliana. [Display omitted] • Three RLKs, ARH1, FEI1, and FEI2, negatively regulate MC formation • The transcriptions of ARH1 , FEI1 , and FEI2 are negatively controlled by SHR and SCR • ARH1, FEI1, and FEI2 regulate GA biosynthesis to govern ground tissue patterning • CYCD6;1 acts as a downstream target of the SHR/SCR-ARH1/FEI1/FEI2-GAs module Chang et al. reveal that ARH1, FEI1, and FEI2 negatively regulate middle cortex formation via modulating the biosynthesis of GA. They elucidate that SHR and SCR negatively control the expression levels of these RLKs and demonstrate a signaling module, SHR/SCR-ARH1/FEI1/FEI2-GAs-CYCD6;1, in controlling root ground tissue patterning. [ABSTRACT FROM AUTHOR]

Root hairs (RHs) are an innovation of vascular plants whose development is coordinated by endogenous and environmental cues, such as ethylene and light conditions. However, the potential crosstalk between ethylene and light conditions in RH development is unclear. We report that Arabidopsis constitutive photomorphogenic 1 (COP1) integrates ethylene and light signaling to mediate RH development. Darkness suppresses RH development largely through COP1. COP1 inhibits both cell fate determination of trichoblast and tip growth of RHs based on pharmacological, genetic, and physiological analyses. Indeed, COP1 interacts with and catalyzes the ubiquitination of ACS2 and ACS6. COP1- or darkness-promoted proteasome-dependent degradation of ACS2/6 leads to a low ethylene level in underground tissues. The negative role of COP1 in RH development by downregulating ethylene signaling may be coordinated with the positive role of COP1 in hypocotyl elongation by upregulating ethylene signaling, providing an evolutionary advantage for seedling fitness. [Display omitted] • Root hairs respond to light or ethylene by increasing both density and length • Arabidopsis COP1, the light responsive factor, inhibits root hair development • COP1 catalyzes the ubiquitination of type I ACSs to reduce ethylene responses • Dark-induced 26S-proteasome-mediated degradation of type I ACSs largely depends on COP1 Yin et al. report that Arabidopsis constitutive photomorphogenic 1 (COP1), a light response factor, controls root hair development by catalyzing the ubiquitination of type I ACSs and degradation to inhibit ethylene biosynthesis. The negative role of COP1 in root hairs may coordinate with its positive role in hypocotyl elongation to promote seedling fitness. [ABSTRACT FROM AUTHOR]

Summary: Appropriate abiotic stress response is pivotal for plant survival and makes use of multiple signaling molecules and phytohormones to achieve specific and fast molecular adjustments. A multitude of studies has highlighted the role of alternative splicing in response to abiotic stress, including temperature, emphasizing the role of transcriptional regulation for stress response. Here we investigated the role of the core‐splicing factor PORCUPINE (PCP) on temperature‐dependent root development.We used marker lines and transcriptomic analyses to study the expression profiles of meristematic regulators and mitotic markers, and chemical treatments, as well as root hormone profiling to assess the effect of auxin signaling.The loss of PCP significantly alters RAM architecture in a temperature‐dependent manner. Our results indicate that PCP modulates the expression of central meristematic regulators and is required to maintain appropriate levels of auxin in the RAM.We conclude that alternative pre‐mRNA splicing is sensitive to moderate temperature fluctuations and contributes to root meristem maintenance, possibly through the regulation of phytohormone homeostasis and meristematic activity. [ABSTRACT FROM AUTHOR]

SUMMARY: Stylosanthes is an important forage legume in tropical areas with strong resistance to aluminum (Al) toxicity, though knowledge of mechanisms underlying this resistance remains fragmentary. We found that border‐like cells (BLCs) were constitutively produced surrounding the root tips of all 54 examined Stylosanthes guianensis genotypes, but not the Stylosanthes viscose genotype TF0140. In genotypic comparisons under Al conditions, the S. guianensis genotype RY#2 retained significantly more Al in BLCs and thereby showed higher relative root growth than TF0140. Formation of BLCs accompanied changes in cell wall pectin epitopes and differential expression of genes involved in pectin metabolism, including a polygalacturonase (SgPG1). The expression pattern of SgPG1 was consistent with the formation of BLCs in both RY#2 and TF0140. SgPG1 was localized in cell walls and exhibited high activities mediating demethyl‐esterified homogalacturonan degradation. Overexpressing SgPG1 changed cell wall pectin epitopes, enhanced BLCs production, and Al resistance in both Arabidopsis and Stylosanthes hairy roots. Furthermore, combining protein‐DNA binding assays in vitro and in vivo, a bHLH transcription factor SgbHLH19 was demonstrated to be the upstream regulator of SgPG1. Our study demonstrates that S. guianensis Al resistance mainly relies on BLCs, whose formation involves cell wall pectin epitope modification by SgPG1. Significance Statement: The formation of sheath‐like BLCs is a unique and constitutive process for root tip development in Stylosanthes guianensis, contributing more than 50% to Al tolerance. The polygalacturonase SgPG1 regulated by SgbHLH1 modifies cell wall pectin epitope during BLCs detachment. [ABSTRACT FROM AUTHOR]

Determining total organic carbon and its stock and quantifying the chemical fractions of soil organic matter can be used as indicators of the quality of the soil management used in a cropping area. This study aimed to quantify soil organic matter's carbon stock and chemical fractions in different soil management systems used in the western Bahian Cerrado, Brazil, and compare them to a native Cerrado area. Ten microregions (Alto Horizonte, Anel da Soja, Bela Vista, Cascudeiro, Coaceral, Novo Paraná, Panambi, Placas, Roda Velha, Roda Velha de Baixo), three soil management systems [tillage system (TS), no-tillage systems (nTS), native Cerrado (NC)], and two soil layers (0–0.1 and 0.1–0.2 m) were studied. Soil bulk density (Sd), soil organic matter (SOM), total organic carbon (TOC), SOM quantification (qSOM), equivalent carbon stock (EqCs), humin (HF), humic acid (HAF) and fulvic acid (FAF) fractions from SOM were evaluated. The results indicated that Sd in all evaluated microregions was below the critical upper limit that would restrict plant root development. SOM, TOC, EqCs, and qSOM revealed increasing results following the TS, nTS, and NC order. The NC area presented the highest soil organic fraction contents (HF, HAF, and FAF). The microregions with better soil quality for all evaluated parameters were Coaceral and Cascudeiro; the lowest soil quality was observed in Alto Horizonte. The present study indicates that conservation agricultural management, such as the no-tillage system, improves the structure and composition of SOM parameters over time. [ABSTRACT FROM AUTHOR]

Low 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]

Summary Soybean, a staple crop on a global scale, frequently encounters challenges due to lodging under high planting densities, which results in significant yield losses. Despite extensive research, the fundamental genetic mechanisms governing lodging resistance in soybeans remain elusive. In this study, we identify and characterize the Creeping Stem 1 (CS1) gene, which plays a crucial role in conferring lodging resistance in soybeans. The CS1 gene encodes a HEAT‐repeat protein that modulates hypocotyl gravitropism by regulating amyloplast sedimentation. Functional analysis reveals that the loss of CS1 activity disrupts polar auxin transport, vascular bundle development and the biosynthesis of cellulose and lignin, ultimately leading to premature lodging and aberrant root development. Conversely, increasing CS1 expression significantly enhances lodging resistance and improves yield under conditions of high planting density. Our findings shed light on the genetic mechanisms that underlie lodging resistance in soybeans and highlight the potential of CS1 as a valuable target for genetic engineering to improve crop lodging resistance and yield. [ABSTRACT FROM AUTHOR]

Summary Flooding is a widespread natural disaster that causes tremendous yield losses of global food production. Rice is the only cereal capable of growing in aquatic environments. Direct seeding by which seedlings grow underwater is an important cultivation method for reducing rice production cost. Hypoxic germination tolerance and root growth in waterlogged soil are key traits for rice adaptability to flooded environments. Alternative oxidase (AOX) is a non‐ATP‐producing terminal oxidase in the plant mitochondrial electron transport chain, but its role in hypoxia tolerance had been unclear. We have discovered that AOX1a is necessary and sufficient to promote germination/coleoptile elongation and root development in rice under flooding/hypoxia. Hypoxia enhances endogenous H2O2 accumulation, and H2O2 in turn activates an ensemble of regulatory genes including AOX1a to facilitate the conversion of deleterious reactive oxygen species to H2O2 in rice under hypoxia. We show that AOX1a and H2O2 act interdependently to coordinate three key downstream events, that is, glycolysis/fermentation for minimal ATP production, root aerenchyma development and lateral root emergence under hypoxia. Moreover, we reveal that ectopic AOX1a expression promotes vigorous root and plant growth, and increases grain yield under regular irrigation conditions. Our discoveries provide new insights into a unique sensor–second messenger pair in which AOX1a acts as the sensor perceiving low oxygen tension, while H2O2 accumulation serves as the second messenger triggering downstream root development in rice against hypoxia stress. This work also reveals AOX1a genetic manipulation and H2O2 pretreatment as potential targets for improving flooding tolerance in rice and other crops. [ABSTRACT FROM AUTHOR]

Purpose: Given the growing interest in the topic of knowledge management (KM) in family firms (FFs) and the subsequent increasing number of papers published, this study aims to review the field to identify and analyze the main themes and trends. Design/methodology/approach: This study applies bibliometric techniques to a sample of 146 papers published from 2007 to 2023 and their 8,126 unique cited references. Bibliometric coupling is performed on the sample papers to explore the current intellectual structure of the field of KM in FFs, whereas cocitations analysis is performed to investigate the different literature streams that served as roots for the development of such a field. Findings: Bibliographic coupling reveals that sample papers can be grouped into four clusters, and, through papers content analysis, the author identifies their core themes as knowledge sharing, innovation, knowledge-based dynamic capabilities and intellectual capital. Cocitation analysis of the cited references revealed four main clusters that can be considered the literature streams that served as roots for the development of the field, i.e. knowledge-based view, socioemotional wealth, strategic management and social capital (as a theory and as a resource). Originality/value: This study contributes to the literature on KM in FFs by extending prior systematic review efforts with bibliometric analyses and combining these results to highlight connections between the main research themes around which scholars have debated (i.e. the clusters identified through bibliometric coupling) and their theoretical foundations (i.e. the clusters identified through cocitation analysis). This study also has practical implications by synthesizing and informing managers about FFs' advantages and weaknesses in the KM process. [ABSTRACT FROM AUTHOR]

Paddy fields are important anthropogenic emission sources of methane (CH4). However, it is not clear how rice root development and rhizosphere soil properties affect CH4 emissions. Therefore, we selected rice varieties with similar growth periods but different root traits in the local area. We measured CH4 emission fluxes, cumulative CH4 emissions, root dry weight, root length, and the dissolved organic carbon (DOC), microbial biomass carbon (MBC), redox potential (Eh), ammonium nitrogen ( N H 4 + –N), and nitrate nitrogen ( N O 3 − –N) contents in rhizosphere soil. Methanogens and methanotrophs are crucial factors influencing CH4 emissions; thus, their abundance and community composition were also assessed. The result showed that CH4 fluxes of each rice variety reached the peak at tillering stage and jointing-booting stage. The CH4 emissions in tillering stage were the largest in each growth period. CH4 emissions had negative correlations with root length, root dry weight, Eh N O 3 − –N, methanotroph abundance, and the pmoA/mcrA ratio, and positive correlations with N H 4 + –N, MBC, DOC, and methanogen abundance. Path analysis confirmed methanogens and methanotrophs as direct influences on CH4 emissions. Root development and rhizosphere soil properties affect CH4 emissions indirectly through these microbes. This study suggests that choosing rice varieties with good root systems and managing the rhizosphere soil can effectively reduce CH4 emissions. [ABSTRACT FROM AUTHOR]

Paeonia ostii, a plant of substantial economic significance, continues to face constraints in achieving large-scale propagation. In vitro propagation offers a promising avenue for the production of disease-free plants and the genetic transformation of peonies to instill novel traits. However, significant challenges persist in tissue culture, particularly with regards to the reproduction coefficient of shoots and the rooting process. This study reports an efficacious protocol for P. ostii micropropagation, focusing on in vitro root development facilitated through the application of phloroglucinol (PG). Furthermore, the study unveils the molecular signature of P. ostii during in vitro root development. The results indicate that the modified Y3 medium (Y3M), supplemented with 1 mg/L 6-benzyladenine (BA) and 0.1 mg/L α-naphthaleneacetic acid (NAA), is optimal for adventitious bud induction, achieving a 96.67% induction rate and an average of 16.03 adventitious shoots per sample. The highest elongation percentage (92.15%) and the longest average shoot length (3.87 cm) were obtained with Y3M containing 0.3 mg/L BA and 0.03 mg/L NAA. Additionally, the optimal medium for inducing root formation in P. ostii was identified as WPM supplemented with 3 mg/L indole-3-butyric acid (IBA) and 100 mg/L phloroglucinol (PG). Lignin content detection, microscope inspection, and molecular signature results demonstrated that PG enhanced lignin biosynthesis, thereby promoting in vitro rooting of P. ostii. [ABSTRACT FROM AUTHOR]

Casparian strip membrane domain proteins like (CASPL), exhibit profound associations with root development, stress responsiveness and mineral element uptake in plants. Nonetheless, a comprehensive bioinformatics analysis of the ZmCASPL gene family in maize remains unreported. In the study, we have identified 47 ZmCASPL members at the whole-genome level, systematically classifying them into six distinct groups. Furthermore, our analysis revealed that the same group of ZmCASPL contains similar gene structures and conserved motifs. Duplication events showed whole genome duplication (WGD) and tandem duplication (TD) contribute to the generation of the ZmCASPL gene family together in maize, but the former plays a more prominent role. Furthermore, we observed that most ZmCASPL genes contain MYB-binding sites (CAACCA), which are associated with the Casparian strip. Utilizing RNA-seq data, we found that ZmCASPL21 and ZmCASPL47 are specifically highly expressed only in the roots. This finding implies that ZmCASPL21 and ZmCASPL47 may be involved in the Casparian strip development. Additionally, RNA-seq analysis illuminated that drought, salt, heat, cold stresses, low nitrogen and phosphorus conditions, as well as pathogen infection, significantly impact the expression patterns of ZmCASPL genes. RT-qPCR revealed that ZmCASPL 5/13/25/44 genes showed different expression patterns under PEG and NaCl treatments. Collectively, these findings provide a robust theoretical foundation for further investigations into the functional roles of the ZmCASPL gene family in maize. [ABSTRACT FROM AUTHOR]

Introduction: Single-cell RNA-seq (scRNA-seq) technologies have been widely used to reveal the diversity and complexity of cells, and pioneering studies on scRNA-seq in plants began to emerge since 2019. However, existing studies on plants utilized scRNA-seq focused only on the gene expression regulation. As an essential post-transcriptional mechanism for regulating gene expression, alternative polyadenylation (APA) generates diverse mRNA isoforms with distinct 3' ends through the selective use of different polyadenylation sites in a gene. APA plays important roles in regulating multiple developmental processes in plants, such as flowering time and stress response. Methods: In this study, we developed a pipeline to identify and integrate APA sites from different scRNA-seq data and analyze APA dynamics in single cells. First, high-confidence poly(A) sites in single root cells were identified and quantified. Second, three kinds of APA markers were identified for exploring APA dynamics in single cells, including differentially expressed poly(A) sites based on APA site expression, APA markers based on APA usages, and APA switching genes based on 3′ UTR (untranslated region) length change. Moreover, cell type annotations of single root cells were refined by integrating both the APA information and the gene expression profile. Results: We comprehensively compiled a single-cell APA atlas from five scRNA-seq studies, covering over 150,000 cells spanning four major tissue branches, twelve cell types, and three developmental stages. Moreover, we quantified the dynamic APA usages in single cells and identified APA markers across tissues and cell types. Further, we integrated complementary information of gene expression and APA profiles to annotate cell types and reveal subtle differences between cell types. Discussion: This study reveals that APA provides an additional layer of information for determining cell identity and provides a landscape of APA dynamics during Arabidopsis root development. [ABSTRACT FROM AUTHOR]

Bioenergy sorghum's large and deep nodal root system and associated microbiome enables uptake of water and nutrients from and deposition of soil organic carbon into soil profiles, key contributors to the crop's resilience and sustainability. The goal of this study was to increase our understanding of bioenergy sorghum nodal root bud development. Sorghum nodal root bud initiation was first observed on the stem node of the 7th phytomer below the shoot apex. Buds were initiated near the upper end of the stem node pulvinus on the side of the stem opposite the tiller bud, then additional buds were added over the next 6-8 days forming a ring of 10-15 nascent nodal root buds around the stem. Later in plant development, a second ring of nodal root buds began forming on the 17th stem node immediately above the first ring of buds. Overall, nodal root bud development can take ~40 days from initiation to onset of nodal root outgrowth. Nodal root buds were initiated in close association with vascular bundles in the rind of the pulvinus. Stem tissue forming nascent nodal root buds expressed sorghum homologs of genes associated with root initiation (WOX4), auxin transport (LAX2, PIN4), meristem activation (NGAL2), and genes involved in cell proliferation. Expression of WOX11 and WOX5 , genes involved in root stem niche formation, increased early in nodal root bud development followed by genes encoding PLTs, LBDs (LBD29), LRP1, SMB, RGF1 and root cap LEAs later in development. A nodal root bud gene regulatory network module expressed during nodal root bud initiation predicted connections linking PFA5 , SPL9 and WOX4 to genes involved in hormone signaling, meristem activation, and cell proliferation. A network module expressed later in development predicted connections among SOMBRERO , a gene involved in root cap formation, and GATA19 , BBM , LBD29 and RITF1 /RGF1 signaling. Overall, this study provides a detailed description of bioenergy sorghum nodal root bud development and transcriptome information useful for understanding the regulation of sorghum nodal root bud formation and development. [ABSTRACT FROM AUTHOR]

In Arabidopsis , RNA editing alters more than 500 cytidines (C) to uridines (U) in mitochondrial transcripts, a process involving the family of pentatricopeptide repeat (PPR) proteins. Here, we report a previously uncharacterized mitochondrial PLS-type PPR protein, GEND2, which functions in the mitochondrial RNA editing. The T-DNA insertion in the 5′-untranslated region of GEND2 , referred to as gend2-1 , results in defective root development compared to wild-type (WT) plants. A comprehensive examination of mitochondrial RNA-editing sites revealed a significant reduction in the gend2-1 mutant compared to WT plants, affecting six specific mitochondrial RNA editing sites, notably within the mitochondrial genes CcmFn-1, RPSL2 and ORFX. These genes encode critical components of cytochrome protein maturation pathway, mitochondrial ribosomal subunit and twin arginine translocation subunits, respectively. Further analysis of the transcriptional profile of the gend2-1 mutant and WT revealed a striking induction of expression in a cluster of genes associated with mitochondrial dysfunction and regulated by ANAC017, a key regulator coordinating organelle functions and stress responses. Intriguingly, the gend2-1 mutation activated an ANAC017-dependent signaling aimed at countering cell wall damage induced by cellulose synthase inhibitors, as well as an ANAC017-independent pathway that retarded root growth under normal condition. Collectively, our findings identify a novel mitochondrial PLS-type PPR protein GEND2, which participates in the editing of six specific mitochondrial RNA editing sites. Furthermore, the gend2-1 mutation triggers two distinct pathways in plants: an ANAC017-dependent pathway and ANAC017-independent pathway. [ABSTRACT FROM AUTHOR]

Planting density is a crucial factor in sweet potato output. However, the relationship among photosynthetic performance, yield, and storage root commercial features that respond to planting density is not well understood. We conducted a three-year field experiment with four planting densities (83,280 plants hm−2, plant spacing 15 cm, D15; 62,520 plants hm−2, plant spacing 20 cm, D20; 50,025 plants hm−2, panting spacing 25 cm, D25; and 41,640 plants hm−2, 30 cm, D30; 80 cm row space for all) to investigate the dynamic of photosynthetic performance, dry matter, yield, carbohydrate metabolism, and commercial features of storage root. The result showed that the highest yield was observed in the D20 treatment, and the yield increment was by 8.47–24.92% when compared to the D25 control treatment during the three growth periods. The observation can be attributed to the fact that appropriate planting density D20 can shape a good canopy structure to improve photosynthetic performance by significantly increasing IPAR, TPAR, light transmission, and extinction coefficient through different canopy levels. Hence, the Pn, Tr, Ci, Gs and WUE, and the chlorophyll fluorescence parameters were significantly improved. Eventually, promoting root sink development by up-regulating starch, fructose, glucose, and sucrose in storage roots, resulting in vigorous carbon flux from the source toward the root sink. Therefore, the optimal planting density D20 treatment increased individual plant yield and commercial features by increasing the number of storage roots, particularly medium-sized ones. Herein, we claim that optimizing the plant population density of sweet potatoes can be a good way to increase the yield and commercial features, and our results are great and important for improving the market value and profits of sweet potatoes. [ABSTRACT FROM AUTHOR]

To increase biodiversity in tomato cultivation, two herbal aromatic plants, thyme (Thymus vulgaris) and basil (Ocimum basilicum L.), were introduced as companion plants. Their role was to improve crop plant growth and stress resistance. Moreover, the effect of the soil application of Trichoderma microbial preparations on tomato growth parameters and yield, in combination with companion plants, was studied. Ligno-cellulose multi-layer microcapsules with Trichoderma atroviride TRS14 spores (MIC14) and the commercial preparation Trianum G (TG) were used as microbial preparations. This experiment was carried out in a certified organic field. Tomato plants were intercropped with thyme or basil in the arrangement of two tomato rows alternating with one herbal row. In all intercropping arrangements and in the control (tomato plants grown without herbs), subplots were sectioned. The soil in the subplots was amended with the MIC14 and TG preparations used at a concentration of 104 spores g−1 of the soil and planted with tomato transplants. No control measures were applied during tomato growing, and the plants were naturally infected with late blight. Tomato plant growth parameters and yield were assessed, and late blight severity was monitored. The degree of soil colonization by Trichoderma fungi and the effect of these applications on soil microbial activity and biodiversity (dehydrogenases activity, EcoPlates AWCD, and Shannon index) were evaluated. The results clearly showed a significant influence of thyme and basil on tomato growth and yield in organic production. The cultivation of thyme adjacent to tomatoes had a beneficial effect on the development of the root system and the number of flowers and fruits on the crop plants. Basil, on the other hand, clearly decreased tomato yield and adversely affected the effect of Trichoderma applications by reducing root system development. Moreover, basil as a companion plant increased late blight symptoms. Both Trichoderma strains colonized soil, but they had no significant effect on the microbial activity or metabolic potential measured on the EcoPlates with the use of the BIOLOG system. However, a decrease in dehydrogenases activity was noted. In organic cultivation, the Trichoderma preparations used had no significant effect on tomato yield, opposite to its increase in integrated tomato production. [ABSTRACT FROM AUTHOR]

Excessive application of phosphorus (P) fertilizers does not alleviate P deficiency in soils and may cause water eutrophication. The available P in acidic soils is bound to minerals, such as iron and aluminum, in forms that are difficult to utilize by plants. The low availability of P is detrimental to soil health and crop growth. To address the P imbalance in the soil, different bioremediation techniques, such as phosphate-solubilizing bacteria (PSB) application, have been employed. However, the systematic analysis of the effects of composite inoculation of PSB on crops remains elusive. In this study, the effects of composite-inoculated PSB on plant growth were systematically evaluated by two scales: plate experiment and soil test. This study employed six different strains of PSB including Lelliottia amnigena 1-1 (A), Kluyvera intermedia 1-2 (B), Pseudomonas tolaasii 1-6 (C), Burkholderia cepacia 2-5 (D), Pseudomonas frederiksbergensis 2-11 (E), and Pseudomonas rhodesiae 2-47 (F). Among the 57 different combinations of these strains, four combinations (AE, AF, ADF, and AEF) indicated higher phosphate-solubilizing abilities than the single strains. These combinations were used for subsequent experiments. The plate experiment revealed that composite strains were more effective than single strains in promoting the growth and development of seedlings and roots of oilseed rape. Furthermore, AE, AF, and AEF combinations indicated excellent growth-promoting effects. Moreover, the soil test revealed that the composite inoculation of AE and AEF significantly enhanced biomass accumulation and root development in oilseed rape. The increased growth-promoting effects of the composite strains were observed to be associated with to their phosphate-solubilizing capacities. Both scales confirmed that compared to single inoculation, composite inoculation of PSB is more beneficial for plant growth. This study provides composite inoculation materials and foundational data to support the bioremediation of P imbalance in soil. [ABSTRACT FROM AUTHOR]

Anchorene, identified as an endogenous bioactive carotenoid‐derived dialdehyde and diapocarotenoid, affects root development by modulating auxin homeostasis. However, the precise interaction between anchorene and auxin, as well as the mechanisms by which anchorene modulates auxin levels, remain largely elusive. In this study, we conducted a comparative analysis of anchorene's bioactivities alongside auxin and observed that anchorene induces multifaceted auxin‐like effects. Through genetic and pharmacological examinations, we revealed that anchorene's auxin‐like activities depend on the indole‐3‐pyruvate‐dependent auxin biosynthesis pathway, as well as the auxin inactivation pathway mediated by Group II Gretchen Hagen 3 (GH3) proteins that mainly facilitate the conjugation of indole‐3‐acetic acid (IAA) to amino acids, leading to the formation of inactivated storage forms. Our measurements indicated that anchorene treatment elevates IAA levels while reducing the quantities of inactivated IAA–amino acid conjugates and oxIAA. RNA sequencing further revealed that anchorene triggers the expression of numerous auxin‐responsive genes in a manner reliant on Group II GH3s. Additionally, our in vitro enzymatic assays and biolayer interferometry (BLI) assay demonstrated anchorene's robust suppression of GH3.17‐mediated IAA conjugation with glutamate. Collectively, our findings highlight the significant role of carotenoid‐derived metabolite anchorene in modulating auxin homeostasis, primarily through the repression of GH3‐mediated IAA conjugation and inactivation pathways, offering novel insights into the regulatory mechanisms of plant bioactive apocarotenoids. [ABSTRACT FROM AUTHOR]

Hertwig's epithelial root sheath (HERS) interacts with dental apical mesenchyme and guides development of the tooth root, which is integral to the function of the whole tooth. However, the key genes in HERS essential for root development are understudied. Here, we show that Axin1, a scaffold protein that negatively regulates canonical Wnt signaling, is strongly expressed in the HERS. Axin1 ablation in the HERS of mice leads to defective root development, but in a manner independent of canonical Wnt signaling. Further studies reveal that Axin1 in the HERS negatively regulates the AKT1-mTORC1 pathway through binding to AKT1, leading to inhibition of ribosomal biogenesis and mRNA translation. Sonic hedgehog (Shh) protein, a morphogen essential for root development, is over-synthesized by upregulated mTORC1 activity upon Axin1 inactivation. Importantly, either haploinsufficiency of the mTORC1 subunit Rptor or pharmacological inhibition of Shh signaling can rescue the root defects in Axin1 mutant mice. Collectively, our data suggest that, independently of canonical Wnt signaling, Axin1 controls ribosomal biogenesis and selective mRNA translation programs via AKT1-mTORC1 signaling during tooth root development. [ABSTRACT FROM AUTHOR]

Quercus variabilis (Q. variabilis), a significant broadleaf species used in afforestation across high, sandy, and mountainous regions, presents unique challenges for transplantation. This species is characterized by its slow above-ground growth and rapid taproot development, which suppresses the proliferation of lateral and fibrous roots, negatively impacting post-transplant survival. Research indicates that targeted root pruning—specifically, the removal of one-third of the roots—promotes the development of lateral roots in these seedlings. This study involved pruning the root systems of Q. variabilis and assessing the subsequent root development in comparison to an unpruned control group. Our analysis, which included transcriptome sequencing and plant hormone metabolism assays conducted at 2, 12, and 25 days post-pruning, yielded 126.02 Gb of clean data and identified 7662 differentially expressed genes (DEGs). These genes were primarily enriched in the plant hormone signal transduction pathway. Further investigation of this pathway, along with hormone content measurements, elucidated the mechanisms that contribute to enhanced root growth following pruning. Additionally, through a weighted correlation network analysis (WGCNA), we identified 20 key genes that are instrumental in promoting root development in Q. variabilis saplings. This research advances the theoretical framework for forestry seedling production and afforestation, laying the groundwork for scientifically informed vegetation restoration techniques. [ABSTRACT FROM AUTHOR]

Germin-like proteins (GLPs) play important roles in the regulation of various plant development processes, such as seed vigor, root and leaf development and disease resistance, while the roles of GLPs on agronomic traits are rarely studied in Brassica napus. Here, we identified GLPs family genes in rapeseed and analyzed their potential functions. There are 77 GLPs family genes (BnGLPs) in the Zhongshuang11 rapeseed reference genome, divided into a, b, c, d, e, f six subfamilies. Tissue expression profile analysis of BnGLPs revealed the following: e subfamily genes were highly expressed in early stages of silique, cotyledon, vegetative rosette and leaf development; f subfamily genes were highly expressed in seed development; genes of a subfamily were mainly expressed in the root; and genes of b, c, d subfamily exhibited low-level or no expression in above mentioned tissues. RT-qPCR analysis confirmed that the transcripts of two f subfamily members decreased dramatically during seed germination, suggesting that f subfamily proteins may play vital roles in the early stage of seed germination. Transcriptome analysis of axillary buds in sequential developing stages revealed that the transcripts of eight e subfamily genes showed a rapid increase at the beginning of shoot branching, implying that the e subfamily members played vital roles in branch development. These results demonstrate that rapeseed BnGLPs likely play essential roles in seedling development, root development and plant architecture, indicating that harnessing certain BnGLPs may contribute to the improvement of rapeseed yield. [ABSTRACT FROM AUTHOR]

Seagrass seed‐based restoration has been developed in several places worldwide, but disturbance at the vulnerable initial stages of seedling recruitment has proved to be a major bottleneck to successful restoration. A detailed investigation of seagrass seedling survival and growth at the earliest stages of seedling development is an important contribution to developing techniques to improve seedling establishment and survival. Here, we investigated the early seedling development of Posidonia australis and P. sinuosa as well as quantifying the variation in seedling survival and development under different seed‐based restoration methods. Early seedling development was documented in indoor aquaria during the first month after fruit dehiscence. In the second ex situ experiment, we determined the effects of three different restoration methods (surface sowing, seedling planting, and planting inside a hessian bag) on seedling survival and development over the first 2 months of life. In the first experiment, a primary root with the first root hairs developed after 7 days. After 1 month, roots were 20–60 mm in length, firmly establishing the seedling into the sediment. Compared to surface sowing, seedling planting and hessian bag restoration treatments did not significantly affect survival for P. australis but increased seedling mortality in P. sinuosa, although growth was greater (shoot and root lengths were approximately 50 and 40% longer, respectively). These aquarium‐scale experiments suggest that planting methods would enhance seedling establishment at larger scales in some species, promoting restoration of damaged seagrass habitats. [ABSTRACT FROM AUTHOR]

This study determined the allelopathic potential of Rhododendron arboreum Sm. on the germination and growth of 4-crops (Eleusine coracana (L.) Gaertn., Echinochloa frumentacea Link, Glycine max (L.) Merr. and Vigna umbellata (Thunb.) Ohwi & H. Ohashi) of Garhwal Himalaya. Both in-vitro and pot culture bioassays were conducted to evaluate the impact of leaf and bark aqueous extracts (2 %, 5 % and 10 %) on germination (%), mean germination time (MGT), germination index (GI), and root and shoot growth of test crops. The crop species had significant and variable impacts on germination and growth parameters in both in-vitro and pot-culture bioassays. In contrast, extract types greatly influenced these parameters under in-vitro conditions than in pot culture. Under in-vitro conditions, leaf extracts significantly inhibited the germination and seedling development of Eleusine coracana and Glycine max, with reductions in radicle and plumule length. Bark extracts exhibited both inhibitory as well as stimulatory effect on germination and growth. In pot culture, both extract types elicited variable germination responses in all crops. Stimulatory effects on root and shoot growth were observed in V. umbellata and E. frumentacea. E. coracana showed inhibition in shoot growth but stimulation in root growth, while in G. max root and shoot development was inhibited. The allelopathic effects of R. arboreum extracts both inhibited and stimulated crop growth depending on extract concentration and crop type. R. arboreum longer-term interactions enhanced the growth of V. umbellata and E. frumentacea. Further research is needed to identify the specific allelochemicals involved and their mechanisms of action and to explore the broader ecological and agricultural implications of these interactions. [ABSTRACT FROM AUTHOR]

SUMMARY: The formation and development of storage roots is the most important physiological process in sweetpotato production. Sucrose transporters (SUTs) regulate sucrose transport from source to sink organs and play important roles in growth and development of plants. However, whether SUTs involved in sweetpotato storage roots formation is so far unknown. In this study, we show that IbSUT1, a SUT, is localized to the plasma membrane. Overexpression of IbSUT1 in sweetpotato promotes the sucrose efflux rate from leaves, leading to increased sucrose levels in roots, thus induces lignin deposition in the stele, which inhibits the storage roots formation and compromises the yield. Heterologous expression of IbSUT1 in Arabidopsis significantly increases the sucrose accumulation and promotes lignification in the inflorescence stems. RNA‐seq and biochemical analysis further demonstrated that IbMYB1 negatively regulates the expression of IbSUT1. Overexpression of IbMYB1 in Arabidopsis reduces the sucrose accumulation and lignification degree in the inflorescence stems. Moreover, co‐overexpression of IbMYB1 and IbSUT1 restores the phenotype of lignin over‐deposition in Arabidopsis. Collectively, our results reveal that IbSUT1 regulates source‐sink sucrose transport and participates in the formation of sweetpotato storage roots and highlight the potential application of IbSUT1 in improving sweetpotato yield in the future. Significance Statement: The formation and development of storage roots is the most important physiological process in sweetpotato production. IbSUT1 plays a crucial role in the formation of storage roots by regulating sucrose transport to affect lignin biosynthesis in roots, which provides valuable information for understanding the mechanisms underlying sweetpotato root development and may have implications for the improvement of sweetpotato yields. [ABSTRACT FROM AUTHOR]

ABSTRACT Introduction Methods Results Conclusion The aim of this study was to evaluate root development in autotransplanted teeth using cone‐beam computed tomography (CBCT) images.Twelve premolars with incomplete root formation, which were selected to replace prematurely lost upper central incisors, were analyzed by CBCT on two different occasions. The first CBCT examination (T1) was conducted before tooth autotransplantation. The second CBCT examination (T2) was performed over a follow‐up period of at least 12 months and < 5 years. Three previously calibrated evaluators assessed root development. The positions of the tomographic planes were standardized. The mean root length in sagittal and coronal tomographic sections was used to validate the root length at T1 and T2. Longitudinal root development of the transplanted tooth was determined by calculating the difference in root length between T2 and T1. The intraclass correlation coefficient (ICC), paired t‐test, and Pearson test were applied, with significance set at 5%.The mean time elapsed between T1 and T2 was 962 days/2.6 years. The ICC was > 0.75. The measurements obtained at T2 were significantly greater than at T1 (p = 0.001). The mean increase in root length was 2.83 mm. There was no significant correlation (p = 0.413; r = 0.261) between root length increase and the time elapsed between T1 and T2.Premolar teeth with incompletely formed roots transplanted to the upper central incisor region showed continued root development during postoperative follow‐up. [ABSTRACT FROM AUTHOR]

Poplar is one of the fastest-growing temperate trees in the world and is widely used in ornamental horticulture for shade. The root is essential for tree growth and development and its utilization potential is huge. Calcium (Ca), as a signaling molecule, is involved in the regulation of plant root development. However, the detailed underlying regulatory mechanism is elusive. In this study, we analyzed the morphological and transcriptomic variations of 84K poplar (Populus alba x P. glandulosa) in response to different calcium concentrations and found that low Ca2+ (1 mmol • L-1) promoted lateral root development, while deficiency (0.1 mmol • L-1 Ca2+) inhibited lateral root development. Co-expression analysis showed that Ca2+ channel glutamate receptors (GLRs) were present in various modules with significance for root development. Two GLR paralogous genes, PagGLR3.3a and PagGLR3.3b, were mainly expressed in roots and up-regulated under Ca2+ deficiency. The CRISPR/Cas9-mediated signal gene (crispr-PagGLR3.3a, PagGLR3.3b) and double gene (crispr-PagGLR3.3ab) mutants presented more and longer lateral roots. Anatomical analysis showed that crispr-PagGLR3.3ab plants had more xylem cells and promoted the development of secondary vascular tissues. Further transcriptomic analysis suggested that knockout of PagGLR3.3a and PagGLR3.3b led to the up-regulation of several genes related to protein phosphorylation, auxin efflux, lignin and hemicellulose biosynthesis as well as transcriptional regulation, which might contribute to lateral root growth. This study not only provides novel insight into how the Ca2+ channels mediated root growth and development in trees, but also provides a directive breeding of new poplar species for biofuel and bioenergy production. [ABSTRACT FROM AUTHOR]

Inducing adventitious root (AR) formation in mature walnut species (Juglans L.) is challenging. However, the AR formation of mature trees can be improved by rejuvenation. In rejuvenated cuttings, exogenous indole-3-butyric acid (IBA) is essential for AR formation, and the underlying mechanism is still not well understood. Therefore, we utilized transcriptome sequencing to investigate the mechanism of IBA-induced AR formation. Our results revealed that, in comparison to the control group, IBA treatment (9 mmol • L-1) significantly increased the endogenous indole-3-acetic acid (IAA) content, leading to an enhanced rooting rate. We performed RNA sequencing to identify differentially expressed genes (DEGs) between the IBA-treated and control (CK) groups at 1, 2, 3, and 5 days after cutting (DAC). The results showed that, compared to the control cuttings, there were 1 539, 889, 785, and 984 up-regulated genes and 2 791, 2 936, 3 017, and 1 752 down-regulated genes, at 1, 2, 3, and 5 DAC, respectively. Analysis of RNA-seq data revealed that G-type ATP-binding cassette 36/37 (ABCG36/37) and ATP-binding cassette subfamily D 1 (ABCD1), associated with IBA transport, were down-regulated in the rejuvenation cuttings. In contrast, PIN-FORMED (PIN) and PINOID (PID), associated with auxin efflux, were up-regulated. We identified 49 auxin/indole-3-acetic acid (AUX/IAA)-encoding genes, including IAA1, IAA3, IAA5, IAA6, IAA8, IAA11, IAA12, IAA19, and IAA20, which were up-regulated at 1e5 DAC in the rejuvenated cuttings. This study highlights that the overexpression of JrWOX5/11 in poplar significantly enhance AR growth, as evidenced by increased root length, surface area, volume, and quantity. Moreover, the co-expression network analysis involving JrWOX11 and JrWOX5 in walnut cuttings elucidates complex genetic interactions, underscoring their pivotal role in the formation of AR. Our data supported the following molecular mechanism of IBA-induced adventitious root formation. Firstly, IBA is converted to free IAA in peroxisomes. Then, the highly concentrated IAA in the procambium and parenchyma cells induces WUSCHEL-related homeobox 11 (WOX11) expression at two days. Finally, WOX11 acts redundantly to up-regulate WOX5, initiating the development of root primordia cells. [ABSTRACT FROM AUTHOR]

Summary: Light and brassinosteroids (BR) are indispensable for plant growth and control cell division in the apical meristem. However, how external light signals cooperate with internal brassinosteroids to program root meristem development remains elusive.We reveal that the photoreceptor phytochrome B (phyB) guides the scaffold protein RACK1 to coordinate BR signaling for maintaining root meristematic activity. phyB and RACK1 promote early root meristem development.Mechanistically, RACK1 could reinforce the phyB–SPA1 association by interacting with both phyB and SPA1, which indirectly affects COP1‐dependent RACK1 degradation, resulting in the accumulation of RACK1 in roots. Subsequently, RACK1 interacts with BES1 to repress its DNA‐binding activity toward the target gene CYCD3;1, leading to the release of BES1‐mediated inhibition of CYCD3;1 transcription, and hence the promotion of root meristem development.Our study provides mechanistic insights into the regulation of root meristem development by combination of light and phytohormones signals through the photoreceptors and scaffold proteins. [ABSTRACT FROM AUTHOR]

Studies on the clinical outcomes and prognostic factors of regenerative endodontic procedures (REPs) in a large population and long-term recall period have been limited. Therefore, the aims of this study were to evaluate treatment outcomes and prognostic factors of REPs. Immature permanent teeth treated with REPs with a minimum one-year follow-up period were included. Treatment outcomes (functional retention, healed rate, root development, and sensibility test response) and any prognostic factors were analyzed with multivariable Cox regression, linear regression, and modified Poisson regression. One-hundred-twenty REPs teeth with a mean 41.7-month recall period were included with a functional retention rate of 97.5%. The healed, healing, and diseased rates of REPs were 80%, 9.2%, and 10.8%, respectively. Significant prognostic factors for healed were age (<12 years old) and root development stage (stages 4 and 5). Changes in the apical diameter, root length, root width, and radiographic root area after REPs were 56.8%, 8.3%, 23.2%, and 21.7%, respectively. Significant prognostic factors for continued root developmevnt were age and etiology of pulpal disease (from caries or dental anomalies). The sensibility test response rate was 41.7% with significant positive factors of ethylenediaminetetraacetic acid irrigation and capping material level above the cemento-enamel junction. REPs demonstrated high functional retention and healed rates. Patients <12 years old presented a higher healed rate and continued root development (excluding root length). Dental caries or anomalies had higher continued root development compared with dental trauma. The sensibility test response was related to ethylenediaminetetraacetic acid irrigation and level capping material. [ABSTRACT FROM AUTHOR]

The 'polycrisis' of global capitalism has regional and national particularities that are worthy of exploration. In the case of East Asia, we see rising military, political and economic tensions which mirror global trends, but take a specific concrete regional form. We offer an explanation for these tensions in East Asia that highlight their roots in developments within the national models of capitalism that make up the region, in this case from the perspective of Japan. Drawing on a regulation theory framework, we show how Japan's faltering national regime of accumulation has been through a constant process of neoliberalization since the early 1990s. This has prompted a number of institutional shifts, one of which includes increasing integration within the East Asian region. This, however, has produced a number of new problems, which we might consider to be general pathologies of late-stage neoliberalization and that are typically experienced at the regional level. In particular, we identify four interconnected and mutually reinforcing pathologies: heightened national economic and political rivalries; heightened market competition; increased vulnerability to disruption to region-wide commodity chains; and declining popular support that is being met by political attempts to adopt nationalist legitimation strategies. Such an account allows us to understand the obstacles and tensions preventing moves towards a smoother process of accumulation in the case of Japan in East Asia, and more generally throughout the contemporary global political economy, as well as offering a more complete account of the complexity and contradictions associated with the growing assertiveness of the Japanese state. [ABSTRACT FROM AUTHOR]

C2H2-type zinc finger protein (C2H2-ZFP) transcription factors play evident roles in regulating plant growth and development and abiotic stress responses. However, the role of C2H2-ZFP from Mentha canadensis remains uncertain. We identified the multifunctional C2H2-ZFP gene McZFP1 from M. canadensis based on phylogenetic analysis. The McZFP1 gene was highly expressed in stems, responding to abiotic stress and phytohormone treatments. McZFP1 localized in the nucleus and showed no transcriptional autoactivation activity in yeast. McZFP1 overexpression in Arabidopsis thaliana significantly reduced the number of trichomes and root hairs, root hair length, and salt stress tolerance. Further study revealed that McZFP1 overexpression increased the expression of negative regulator genes and decreased that of positive regulator genes to inhibit plant trichome and root hair development. Malondialdehyde accumulation was promoted, but the proline content and catalase, superoxide dismutase, and peroxidase activities were reduced and the expression of stress response genes was inhibited in McZFP1 overexpression lines under salt treatment, thereby compromising plant salt tolerance. Overall, these results indicate that McZFP1 is a novel C2H2-ZFP transcription factor that plays negative roles in trichome and root hair development and salt stress tolerance. [ABSTRACT FROM AUTHOR]

Microbes produce various bioactive metabolites that can influence plant growth and stress tolerance. In this study, a plant growth-promoting rhizobacterium (PGPR), strain S14, was identified as Micrococcus luteus (designated as MlS14) using de novo whole-genome assembly. The MlS14 genome revealed major gene clusters for the synthesis of indole-3-acetic acid (IAA), terpenoids, and carotenoids. MlS14 produced significant amounts of IAA, and its volatile organic compounds (VOCs), specifically terpenoids, exhibited antifungal activity, suppressing the growth of pathogenic fungi. The presence of yellow pigment in the bacterial colony indicated carotenoid production. Treatment with MlS14 activated the expression of β-glucuronidase (GUS) driven by a promoter containing auxin-responsive elements. The application of MlS14 reshaped the root architecture of Arabidopsis seedlings, causing shorter primary roots, increased lateral root growth, and longer, denser root hairs; these characteristics are typically controlled by elevated exogenous IAA levels. MlS14 positively regulated seedling growth by enhancing photosynthesis, activating antioxidant enzymes, and promoting the production of secondary metabolites with reactive oxygen species (ROS) scavenging activity. Pretreatment with MlS14 reduced H2O2 and malondialdehyde (MDA) levels in seedlings under drought and heat stress, resulting in greater fresh weight during the post-stress period. Additionally, exposure to MlS14 stabilized chlorophyll content and growth rate in seedlings under salt stress. MlS14 transcriptionally upregulated genes involved in antioxidant defense and photosynthesis. Furthermore, genes linked to various hormone signaling pathways, such as abscisic acid (ABA), auxin, jasmonic acid (JA), and salicylic acid (SA), displayed increased expression levels, with those involved in ABA synthesis, using carotenoids as precursors, being the most highly induced. Furthermore, MlS14 treatment increased the expression of several transcription factors associated with stress responses, with DREB2A showing the highest level of induction. In conclusion, MlS14 played significant roles in promoting plant growth and stress tolerance. Metabolites such as IAA and carotenoids may function as positive regulators of plant metabolism and hormone signaling pathways essential for growth and adaptation to abiotic stress. [ABSTRACT FROM AUTHOR]

The large-scale dieback of spruce monocultures, especially in the lower alpine, has become a significant problem and has necessitated the restoration of these areas, mainly using seedlings produced in forest nurseries. The primary source of nutrients for seedlings can be slow-release fertilizers and an appropriate dose of fertilizer improves the efficiency of its use and minimizes the negative environmental impact associated with the excessive use of mineral fertilizers. Aims: This study aimed to evaluate the effect of applying different fertilizer dose combinations on the accumulation of macronutrients in different parts of the seedlings (roots, shoots, and leaves) and on the morphology and development of fine roots. Methods: This research was carried out on producing beech seedlings with the application of starter soil fertilization with Yara Mila Complex (YMC) and Osmocote Exact Standard 3-4M (OES) fertilizers in four varying doses. Results: No deficiency of the analyzed macronutrients was noted in any of the tested fertilization variants. The highest content of all analyzed macronutrients was recorded in the leaves of beech seedlings, with values in roots and shoots being several times lower. The mixed fertilization variant OES 1.0 + YMC 1.0 shows a positive correlation with all analyzed elements and the parameters DQI (Dickson Quality Index), SA (Surface Area), RV (Root Volume), and mass. Conclusions: Results confirm the hypothesis that applying a mixture of fast-acting (YMC) and slow-acting (OES) fertilizer positively affects the nutrition and accumulation of macronutrients and the development of root systems in beech seedlings compared to fertilization with a single fertilizer. [ABSTRACT FROM AUTHOR]

Aims An ectomycorrhizal fungus (ECMF) may enhance plant drought resistance. However, there is limited information regarding the effects of ECMFs on drought resistance in Pinus massoniana Lamb., a native species representing an afforestation pioneer tree in subtropical regions of China. Methods In this study, a pot experiment was conducted to determine the effects of ECMF Suillus luteus inoculation on the root morphology and endogenous hormones of P. massoniana, including roots, leaves, and stems, under various water treatment conditions. Four water levels (regular, light, moderate, and severe drought) and three inoculations (inoculated Suillus luteus, numbered S12 and S13, and non-ECMF-inoculated) were compared using a factorial design. Results Under drought stress, P. massoniana seedlings inoculated with S12 and S13 had significantly increased root morphology development (p < 0.05). Light drought positively influenced root development, resulting in a more than twofold increase in root length and root surface area compared to non-inoculated seedlings. Concentrations of gibberellic acid (GA), zeatin riboside (ZR), and indole-3-acetic acid (IAA) in roots, stems, and leaves of inoculated S12 and S13 plants were elevated, whereas abscisic acid (ABA) concentrations were significantly lower, compared to non-inoculated seedlings. The ABA concentrations in the roots of S12 and S13 inoculated seedlings under light drought stress were 1.5 times lower than those in non-inoculated controls. Moreover, root development was positively correlated with plant total GA, IAA, and ZR but negatively correlated with ABA. ConclusionsS. luteus can promote the root growth and development of P. massoniana seedlings, notably by regulating the balance in the concentration of endogenous hormones, thus improving the drought resistance of P. massoniana seedlings. [ABSTRACT FROM AUTHOR]