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Sweet potato tuberous roots are susceptible to chilling injury (CI) when stored below 10 °C. In this study, we investigated the mitigating effects of hot air (HA) treatment on CI. Results showed that HA45°C-3h treatment delayed the CI and internal browning during cold storage. After HA45°C-3h treatment, the cells' structural integrity was maintained, malondialdehyde accumulation and ion leakage were inhibited. Additionally, the osmoregulatory substances, such as total soluble solids, proline were maintained, and soluble protein was enhanced. Higher activity of antioxidant enzymes including superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase, and the antioxidant substances including ascorbic acid, glutathione, total phenols, and flavonoids were observed in sweet potato tuberous roots treated by HA45°C-3h than untreated group. Our study suggested that HA45°C-3h treatment could reduce CI and maintain a better quality of sweet potato tuberous roots following cold storage., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: The extract from Metasequoia glyptostroboides Hu et Cheng, a rare and endangered species native to China, exhibits numerous biological and pharmacological activities. The species is recalcitrant to rooting during micropropagation, a challenge that has yet to be resolved. In this study, transcriptomic and hormonal analyses were conducted to appreciate the molecular mechanism of adventitious root (AR) formation in optimized rooting conditions., Results: The use of 2/5-strength Woody Plant Medium (WPM) significantly promoted AR formation of M. glyptostroboides shoots while the content of endogenous auxin, cytokinins and gibberellins (GAs) varied at different stages of AR formation. Transcriptomic analysis showed the significant up- or down-regulation of differentially expressed genes (DEGs) associated with plant hormone signal transduction and the phenylpropanoid biosynthesis pathway in response to 2/5-strength WPM. DEGs related to the biosynthesis of indole-3-acetic acid, cytokinins and GAs were identified. Transcript factors involved in 13 families were also revealed. A weighted gene co-expression network analysis indicated a strong correlation between hormones and genes involved in plant hormone signal transduction and the phenylpropanoid biosynthetic pathway., Conclusions: These results indicate that the AR-promoting potential of 2/5-strength WPM in M. glyptostroboides was due to complex interactions between hormones and the expression of genes related to plant hormone signal transduction and the phenylpropanoid biosynthetic pathway., Competing Interests: Declarations Ethics approval and consent to participate Not applicable. Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Main Conclusion: Association analysis identified 77 marker-trait associations (MTAs) for PUE traits, of which 10 were high-confidence MTAs. Candidate-gene mining and in-silico expression analysis identified 13 putative candidate genes for PUE traits. Bread wheat (Triticum aestivum L.) is a major cereal crop affected by phosphorus (P) deficiency, which affects root characteristics, plant biomass, and other attributes related to P-use efficiency (PUE). Understanding the genetic mechanisms of PUE traits helps in developing bread wheat cultivars that perform well in low-P environments. With this objective, we evaluated a bread wheat panel comprising 304 accessions for 14 PUE traits with high-throughput phenotyping under low-P and optimum-P treatments and observed a significant genetic variation among germplasm lines for studied traits. Genome-wide association study (GWAS) using 14,025 high-quality single-nucleotide polymorphisms identified 77 marker-trait associations (MTAs), of which 10 were chosen as high-confidence MTAs as they had > 10% phenotypic variation with logarithm of odds (LOD) scores of more than five. Candidate-gene (CG) mining from high-confidence MTAs identified 180 unique gene models, of which 78 were differentially expressed (DEGs) with at least twofold change in expression under low-P over optimum-P. Of the 78-DEGs, 13 were thought to be putative CGs as they exhibited functional relevance to PUE traits. These CGs mainly encode for important proteins and their products involved in regulating root system architecture, P uptake, transport, and utilization. Promoter analysis from 1500 bp upstream of gene start site for 13 putative CGs revealed the presence of light responsive, salicylic-acid responsive, gibberellic-acid (GA)-responsive, auxin-responsive, and cold responsive cis-regulatory elements. High-confidence MTAs and putative CGs identified in this study can be employed in breeding programs to improve PUE traits in bread wheat., Competing Interests: Declarations Conflict of interest On behalf of all authors, the corresponding author states that there is no conflict of interest. Ethical approval and consent to participate Not applicable. Consent to participate Not applicable. Consent for publication Not applicable., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The growth of industrialization growth the risk of vanadium (V) contamination. The objective of this study was to examine the impact of 200 µg L - 1 VCI 3 -induced toxicity as well as the potential protective effect of 187.5 mg L - 1 and 375 mg L - 1 Hypericum perforatum (H. perforatum) extracts against this toxicity on the Allium cepa (A. cepa) model organism. For this purpose, a series of investigations were conducted on the growth physiology alterations (germination percentage, root elongation, weight gain), cytogenetic alterations (mitotic index, micronucleus, chromosomal aberrations), biochemical alterations (malondialdehyde, superoxide dismutase, catalase) and defects in meristematic tissue in A. cepa. In addition, the phenolic compound content of H. perforatum extract was determined by the LC/MS-MS method. V application negatively affected all the investigated parameters and caused a serious phytotoxic and genotoxic effect as well as oxidative stress in A. cepa. Conversely, no statistical difference was observed between the parameters of the groups treated with H. perforatum extract and those of the control group. The administration of H. perforatum extract combined with V resulted in a notable enhancement in germination percentage, root elongation, weight gain, mitotic index value, chlorophyll a level and chlorophyll b level. Additionally, it led to a reduction in micronucleus and chromosomal aberrations frequencies, as well as meristematic tissue defects. Furthermore, LC/MS-MS analysis demonstrated that H. perforatum extract contains phenolic compounds, including catechin, epicatechin, quercetin, oleuropein and rutin, which confer antioxidant properties to the extract. The study provided clear evidence that H. perforatum extract attenuates the toxic effects of V in A. cepa, which can be attributed to its high content of bioactive phenols. The findings of the study indicate that H. perforatum extract may serve as a protective natural agent for daily use against heavy metal toxicity., Competing Interests: Declarations Statement regarding experimental research on plants Experimental research and field studies on plants and plant parts, including the collection of plant material, comply with relevant institutional, national, and international guidelines and legislation. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Cadmium (Cd) is a potentially harmful metal with significant biological toxicity that adversely affects plant growth and physiological metabolism. Excessive Cd exposure in plants leads to stunted plant growth owing to its negative impact on physiological functions such as photosynthesis, nutrient uptake, and water balance. Potassium-enriched biochar (KBC) and Bacillus altitudinis rhizobacteria (RB) can effectively overcome this problem. Potassium-enriched biochar (KBC) significantly enhances plant growth by improving the soil structure, encouraging water retention, and enhancing microbial activity as a slow-release nutrient. Rhizobacteria promote plant growth by improving root ion transport and nutrient availability while promoting soil health and water conservation through RB production. This study examined the effects of combining RB + KBC as an amendment to rice, both with and without Cd stress. Four treatments (control, KBC, RB, and RB + KBC) were applied using a completely randomized design (CRD) in four replications. The results showed that the combination of RB + KBC increased rice plant height (38.40%), shoot length (53.90%), and root length (12.49%) above the control under Cd stress. Additionally, there were notable improvements in chlorophyll a (15.31%), chlorophyll b (25.01%), and total chlorophyll (19.37%) compared to the control under Cd stress, which also showed the potential of RB + KBC treatment. Moreover, increased N, P, and K concentrations in the roots and shoots confirmed that RB + KBC could improve rice plant growth under Cd stress. Consequently, these findings suggest that RB + KBC is an effective amendment to alleviate Cd stress in rice. Farmers should use RB + KBC to achieve better rice growth under cadmium stress., Competing Interests: Declarations Ethics approval and consent to participate I declare that manuscript reporting studies do not involve human participants, data, or tissue. So, it is not applicable. Experimental research and field studies on plants (cultivated or wild), including the collection of plant material, must comply with relevant institutional, national, and international guidelines and legislation I confirmed that all methods were performed according to the relevant guidelines/regulations/legislation. The seeds were purchased from a local certified seed dealer of the Government of Punjab, Pakistan. Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Oriented cell divisions are crucial for determining the overall morphology and size of plants, but what controls the onset and duration of this process remains largely unknown. Here, we identified a small molecule that activates root apical meristem (RAM) expression of SQUAMOSA PROMOTER BINDING PROTEIN-LIKE13 (SPL13) a known player in the shoot's juvenile-to-adult transition. This expression leads to oriented cell divisions in the RAM through SHORT ROOT (SHR) and cell cycle regulators. We further show that the RAM has distinct juvenile and adult phases typed by morphological and molecular characteristics and that SPL factors are crucially required for this transition in Arabidopsis and rice ( Oryza sativa ). In summary, we provide molecular insights into the age-dependent morphological changes occurring in the RAM during phase change.

Ethylene plays diverse roles in post-harvest processes of horticultural crops. However, its impact and regulation mechanism on the postharvest physiological deterioration (PPD) of cassava storage roots is unknown. In this study, a notable delay in PPD of cassava storage roots was observed when ethephon was utilized as an ethylene source. Physiological analyses and quantitative acetylproteomes were employed to investigate the regulation mechanism regulating cassava PPD under ethephon treatment. Ethephon was found to enhance the reactive oxygen species (ROS) scavenging system, resulting in a significant decrease in H 2 O 2 and malondialdehyde (MDA) content. The comprehensive acetylome analysis identified 12,095 acetylation sites on 4403 proteins. Subsequent analysis demonstrated that ethephon can regulate the acetylation levels of antioxidant enzymes and members of the energy metabolism pathways. In summary, ethephon could enhance the antioxidant properties and regulate energy metabolism pathways, leading to the delayed PPD of cassava., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Bacillus species are extensively documented as plant growth-promoting rhizobacteria, contributing significantly to the enhancement of soil fertility, nutrient recycling, and the control of phytopathogens. Utilizing them as biocontrol agents represents an environmentally friendly strategy, particularly within the rhizospheric community. This study presents the comprehensive genome sequences of three B. velezensis strains (LGMB12, LGMB319, and LGMB426) which were previously isolated from root samples of maize (Zea mays L.), along with a type strain FZB42. The research assesses the capability of the three strains for antagonizing fungi, specifically Fusarium graminearum, Fusarium verticillioides, Colletotrichum graminicola, and Stenocarpella sp. In paired cultures involving maize fungi, treatments containing bacteria B. velezensis exhibited statistically significant differences compared to both negative and positive treatments in terms of antagonism. Furthermore, genome mining techniques were employed to explore their inherent antagonistic potential. The assembly revealed that strains LGMB12, LGMB319, LGMB426, and FZB42 exhibit genome sizes of 4,187,541 bp, 4,244,954 bp, 3,976,537 bp, and 3,990,518 respectively. Their respective G + C content stands at 46.42 %, 46.50 %, 46.51 %, and 46.38 %. Moreover, the genomes present multiple gene clusters responsible for the synthesis of secondary metabolites and carbohydrate-active enzymes (CAZymes). These clusters highlight a diverse array of antibacterial and antifungal properties, complemented by numerous plant growth-promoting genes. These results highlight the potential of B. velezensis LGMB12, LGMB319, and LGMB426 strains as biocontrol and plant growth promotion agents, being promising candidates for further studies in agricultural production, including field trials., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Temporal variation during the assembly of arbuscular mycorrhizal (AM) fungal communities within plant roots have been posited as critical drivers of the plant-fungal symbiotic outcomes. However, functional implications of these dynamics for the host plant remain poorly understood. We conducted a controlled pot experiment with Sorghum bicolor to investigate how temporal shifts in AM fungal community composition and phylogenetic diversity influence plant growth and phosphorus responses to the symbiosis. We characterised the root-colonising AM fungal communities across three time points and explored their community assembly processes by analysing their phylogenetic diversity and employing joint species distribution modelling with the Hierarchical Modelling of Species Communities (HMSC) framework. We found strong AM fungal turnover through time with a high phylogenetic signal, indicating recruitment of phylogenetically clustered AM fungal species in the host. This temporal phylogenetic clustering of communities coincided with marked increases in plant biomass and phosphorus responses to the AM fungal symbiosis, suggesting that host selection for specific fungi may be a key determinant of these benefits., Competing Interests: Declarations Competing Interests The authors declare no competing interests., (© 2024. The Author(s).)

Protein phosphatase 2AB'' (PP2A B'') family subunits have calcium-binding EF-hand motifs, facilitating interaction with PP2A substrates. In Arabidopsis thaliana, the PP2A B'' family subunits consist of six members, AtB''α-ε and FASS. These subunits can interact with a basic leucine zipper transcription factor, VIP1, and its close homologs. Mechanical stress triggers PP2A-mediated dephosphorylation of VIP1 and its close homologs, leading to nuclear localization and gene upregulation to alleviate touch-induced root bending and leaf damage. However, the physiological roles of PP2A B'' family subunits in the mechanical stress response in Arabidopsis remain unclear. This study aims to characterize such roles. A quadruple knockout mutant with T-DNA insertions in AtB''α, AtB''β, AtB''γ, and AtB''δ was generated. atb''αβγδ mutants exhibited no significant damage upon brushing or touch-induced root bending compared to the wild type. Transcriptome analysis showed a significant decrease in the expression of CYP707A3, a gene potentially targeted by VIP1 that regulates abscisic acid (ABA) catabolism, in the atb''αβγδ mutant compared to wild type leaves. However, other genes, including XTH23, EXLA1, and CYP707A1, also VIP1 targets, exhibited similar induction in both brushed atb''αβγδ mutants and wild type leaves. We observed an enrichment of the CAMTA motif, CGCG(C/T) in the promoters of genes showing downregulated expression levels in brushed atb''αβγδ leaves compared to brushed wild type leaves. These findings suggest that PP2A B'' family subunits exhibit functional redundancy in the VIP1-dependent pathway but influence CAMTA-dependent gene expression under mechanical stress. Under calcium-deficient and ABA-supplemented conditions, growth of atb''αβγδ seedlings was retarded when compared to wild type and single knockout mutants, atb''γ and atb''δ, indicating a crucial role in plant development by modulating calcium or ABA signaling., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Yoon et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Cadmium (Cd) can harm the yield and quality of vegetables, threatening food safety. Essential microelements such as iron are crucial for plant growth and can help alleviate heavy metal stress. Recently, nanoparticles have been studied as eco-friendly solutions for mitigating heavy metal stress in plants. In the present study, iron nanoparticles (FeNPs) at 0, 100, and 300 mg/L were applied as soil drenches and foliar sprays to tomato plants under cadmium stress. A comparison was made between the application methods of FeNPs by evaluating the growth parameters of tomato plants, including shoot length (SL), root length (RL), number of branches (NB), number of leaves per plant (NL), and leaf area (LA), as well as by assessing biochemical and antioxidant enzyme parameters. In the Cd stress treatment, the protein content decreased by 24.71%, and the phenolic and flavonoid content of the tomato plants also decreased due to cadmium stress, with levels decreasing from 16.07 to 6.9 µg and from 0.36 to 0.16 µg, respectively. Compared with the soil drench, 100 mg/L FeNPs significantly improved the parameters of Cd-stressed plants when used as a foliar spray, leading to increases in shoot length, root length, fruit weight, number of fruits, number of leaves, and number of branches by 42%, 66%, 24%, 66%, 173%, and 45%, respectively. Tomato plants treated with this spray presented increased carotenoid and lycopene contents. FeNP foliar spray also reduced Cd accumulation in plant tissues. This technique shows promise in alleviating Cd stress in vulnerable vegetable plants such as tomatoes., Competing Interests: Declarations Competing interests The authors declare no competing interests. Ethical approval and consent to participate We declare that the manuscript reporting studies do not involve any human participants, human data or human tissues. So, it is not applicable. Our experiment follows with the relevant institutional, national, and international guidelines and legislation., (© 2024. The Author(s).)

Programmed cell death occurring during plant development (dPCD) is a fundamental process integral for plant growth and reproduction. Here, we investigate the connection between developmentally controlled PCD and fungal accommodation in Arabidopsis thaliana roots, focusing on the root cap-specific transcription factor ANAC033/SOMBRERO (SMB) and the senescence-associated nuclease BFN1. Mutations of both dPCD regulators increase colonization by the beneficial fungus Serendipita indica , primarily in the differentiation zone. smb-3 mutants additionally exhibit hypercolonization around the meristematic zone and a delay of S. indica -induced root-growth promotion. This demonstrates that root cap dPCD and rapid post-mortem clearance of cellular corpses represent a physical defense mechanism restricting microbial invasion of the root. Additionally, reporter lines and transcriptional analysis revealed that BFN1 expression is downregulated during S. indica colonization in mature root epidermal cells, suggesting a transcriptional control mechanism that facilitates the accommodation of beneficial microbes in the roots., Competing Interests: NC, EL, CD, DV, MN, AZ No competing interests declared, (© 2024, Charura, Llamas et al.)

Histolocalization and quantification of secondary metabolites established the occurrence of alkaloids, phenols and acetogenins in various plant organs of A. muricata at different stages of plant growth. Annona muricata L. possesses broad assemblage of ethno-pharmaceutical and therapeutic upsides ascribed to biosynthesis of secondary metabolites. Currently, the bioactivity is characterized by the production of acetogenins (ACGs), and also by the biosynthesis of alkaloids, primarily benzylisoquinolines derived from tyrosine and phenolic compounds. As a result of high variability of metabolite production in A. muricata, the present study evaluated the histochemical analysis of various plant parts at different developmental stages of growth. Presences of phytometabolites were determined using in-situ histochemical localization of alkaloids, phenolic compounds and acetogenins, while its estimation employing spectroscopic quantification techniques to understand structure, development, time-course deposition, content and distribution of secondary phytoconstituents. Study revealed distinct presence of secondary metabolites in cells and tissues of all plant organs in various intensities and patterns. Alkaloids and acetogenins occurred mostly in secretory cavities or idioblast cells while sparsely associated with other cells or tissues. Phenolic compounds emerged widely, with no confined distribution patterns occurring in storage cells and tissues. Quantitative analysis revealed highest accumulation of alkaloids, phenols and acetogenins in mature root-barks, mature unripe fruit rind and mature leaf respectively. Secondary metabolites generally occurred in young stages at low concentrations as compared to matured growth stages of plant parts. Such in-situ histochemical and biochemical approach will help in identifying the cells and tissues responsible for synthesis, storage and biological effects of potential secondary metabolites which could be further used for culturing and enhancing its production with biotechnological aids., Competing Interests: Declarations Competing interests The authors declare that they have no conflicts of interest to disclose. Data availability All data generated or analyzed during this study are included in the published article. In case, one wished to consult further information, it will be made available through the corresponding author on reasonable request., (© 2024. The Author(s).)

Increasing biological nitrogen (N) fixation (BNF) in maize production could reduce the environmental impacts of N fertilizer use, but reactive N in the rhizosphere of maize limits the BNF process. Using non-transgenic methods, we developed gene-edited strains of Klebsiella variicola (Kv137-2253) and Kosakonia sacchari (Ks6-5687) bacteria optimized for root-associated BNF and ammonium excretion in N-rich conditions. The aim of this research was to elucidate the mechanism of action of these strains. We present evidence from in vitro, in planta and field experiments that confirms that our genetic remodeling strategy derepresses BNF activity in N-rich systems and increases ammonium excretion by orders of magnitude above the respective wildtype strains. BNF is demonstrated in controlled environments by the transfer of labeled 15 N 2 gas from the rhizosphere to the chlorophyll of inoculated maize plants. This was corroborated in several 15 N isotope tracer field experiments where inoculation with the formulated, commercial-grade product derived from the gene-edited strains (PIVOT BIO PROVEN® 40) provided on average 21 kg N ha -1 to the plant by the VT-R1 growth stages. Data from small-plot and on-farm trials suggest that this technology can improve crop N status pre-flowering and has potential to mitigate the risk of yield loss associated with a reduction in synthetic N fertilizer inputs., Competing Interests: Declarations Competing interests Authors affiliated with Pivot Bio, Inc. declare a competing financial interest given that Pivot Bio, Inc. has obtained patents (World Intellectual Property Organization Patent No. WO2021221690A1) and is developing and commercializing products based on the microbial strains included in this study. All the remaining authors declare no conflict of interest., (© 2024. The Author(s).)

Humic substances associated with cattle manure can enhance and reduce the costs of organic fertilization. In this sense, the objective was to evaluate the application of humic substances in association with cattle manure on soil fertility, growth and root nutrition in pepper plants. The experimental design used was randomized blocks, arranged in a factorial scheme with 4 doses of cattle manure (8, 18, 28 and 38 Mg ha-1), 3 doses of humic substances (0, 8 and 12 kg ha-1), with 4 replicates. The variables analyzed were plant height, stem diameter, leaf area, root growth, fresh and root dry weight, root macronutrient contents and soil fertility. Increases in plant height, leaf area and root dry matter (21.2, 58.21 and 8% respectively) were obtained by associating the application of humic substances with manure. Humic substances (12 kg ha-1) in association with manure (8 Mg ha-1) provided an increase in nitrogen content in the roots (36.05%) compared to the application of manure alone, and the application of humic substances (12 kg ha-1) promoted an increase of 10.62% in potassium content in the roots. The availability of calcium in the soil regulated primary root growth. The association of humic substances with cattle manure promoted shoot growth, root dry weight and root nutritional increase in pepper plants.

The Rhizobium rhizogene-transformed root culture from Physalis peruviana L. (P. peruviana) may be a promising and novel source of valuable phenolics, including caffeoylputrescine (CP), which is known for antioxidant, antidiabetic, insect-resistant, disease-resistant, and neuroprotective properties. In this study, to improve the production efficiency of phytochemical components in P. peruviana hairy root cultures, we optimized various culture conditions, including the inoculum size, liquid volume, culture media type, carbon source, sucrose concentration, initial pH, and application of elicitors, to enhance the total phenolic content and CP yield in these hairy root cultures. The findings indicate that the use of sucrose as carbon source resulted in the highest biomass (13.28 g DW/L), total phenolic content (6.26 mg/g), and CP yield (2.40 mg/L). The White medium excelled in enhancing the total phenolic content (9.35 mg/g), whereas the B5 medium was most effective for the biomass (13.38 g DW/L) and CP yield (6.30 mg/L). A sucrose concentration of 5% was best for the biomass (18.40 g DW/L), whereas a sucrose concentration of 4% was ideal for the CP yield. Optimal culture conditions were as follows: an inoculum size of 0.5 g/100 mL, a liquid volume of 100 mL in a 250-mL flask, B5 medium, 4% sucrose, and a pH of 5.5. Among the tested elicitors, methyl jasmonate (MeJA) at 100 µM significantly increased the biomass (21.3 g/L), total phenolic content (23.34 mg/g), and CP yield (141.10 mg/L), which represent 0.96-, 2.12-, and 13.04-fold increases, respectively, over the control after 8 days. The optimized HR culture of P. peruviana provides a promising system to enhance the production of CP for pharmaceutical applications., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

To verify an effective approach for alleviating problems associated with the consecutive monoculture of sweet potato, five fertilizer treatments were designed under plastic film-mulched, drip-fertigated conditions in fields continuously planted with sweet potato over five years. These treatments included: (1) no fertilizer application, (2) basic application of water-soluble (WS) fertilizer, (3) basic application of biofertilizer (BF) and WS fertilizer, (4) split application of WS fertilizer, and (5) combined basic application of BF and split application of WS fertilizer. The effects of BF and WS fertilizer applications on yield, quality, and soil properties were evaluated. Fertilizer applications had positive effects on increasing soil activities and nutrients compared with no fertilizer application. Split fertigation with WS fertilizer increased the activities of soil dehydrogenase (DHA) by 10.94 ~ 14.74%, alkaline phosphatase (ALP) by 4.97 ~ 5.13%, and soil organic matter (SOM) by 10.43 ~ 12.47% in the second year compared with a single application. In both years, split fertigation exerted positive effects on increasing dry matter (DM) accumulation in tuberous roots and increased the productive efficiency in nitrogen (N), phosphorus (P), and potassium (K) fertilizers. BF application for two consecutive years increased the activities of soil sucrase by 7.05 ~ 17.83%, DHA by 18.65 ~ 21.34%, ALP by 6.87 ~ 7.03%, soil available P by 18.34 ~ 28.10%, and SOM by 8.18 ~ 10.17% compared with the no BF application. BF also increased the root yield by 8.88 ~ 14.14%, the carotenoid content in tuberous roots by 20.38 ~ 30.64%, and the K utilization efficiency by 11.09 ~ 14.97%. The combination of BF and split fertigation for two consecutive years was most conducive to the activation of soil nutrients, maintenance of soil fertility, and improvement in yield and quality, which could mitigate problems associated with the consecutive monoculture of sweet potato., Competing Interests: Declarations Competing interests The authors declare no competing interests. Ethics approval Experimental research and field studies on plants, including the collection of plant material, was carried out in accordance with relevant institutional, national, and international guidelines and legislation., (© 2024. The Author(s).)

The present study evaluated the effects of biochar derived from sugarcane straw on the physicochemical and biological properties of soil and the initial development of sugarcane. Microcosm and pot experiments were conducted over 60 days to monitor variables such as pH, water retention capacity, microbial activity, initial growth, and the metabolomic profile of the plant leaves. The results indicated that biochar increased the soil water retention capacity without significantly affecting the pH. The biochar significantly promoted root length and mass and favored the growth of the soil microbiota, as reflected by an increase in the amount of microbial biomass carbon. Metabolomic analysis of sugarcane leaves revealed that soil conditioning with biochar at application rates of 3 and 5% w/w led to increased concentrations of the amino acids isoleucine and valine, accompanied by a reduction in galactose, maltose, and glucose levels. Furthermore, biochar treatment resulted in a decrease in aconitic acid and an increase in acetic and succinic acid concentrations. These findings suggest that biochar may be a promising strategy for enhancing the productivity and sustainability of sugarcane cultivation., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Two principal growth regulators, cytokinins and ethylene, are known to interact in the regulation of plant growth. However, information about the underlying molecular mechanism and positional specificity of cytokinin/ethylene crosstalk in the control of root growth is scarce. We have identified the spatial specificity of cytokinin-regulated root elongation and root apical meristem (RAM) size, both of which we demonstrate to be dependent on ethylene biosynthesis. Upregulation of the cytokinin biosynthetic gene ISOPENTENYLTRANSFERASE (IPT) in proximal and peripheral tissues leads to both root and RAM shortening. By contrast, IPT activation in distal and inner tissues reduces RAM size while leaving the root length comparable to that of mock-treated controls. We show that cytokinins regulate two steps specific to ethylene biosynthesis: production of the ethylene precursor 1-aminocyclopropane-1-carboxylate (ACC) by ACC SYNTHASEs (ACSs) and its conversion to ethylene by ACC OXIDASEs (ACOs). We describe cytokinin- and ethylene-specific regulation controlling the activity of ACSs and ACOs that are spatially discrete along both proximo/distal and radial root axes. Using direct ethylene measurements, we identify ACO2, ACO3, and ACO4 as being responsible for ethylene biosynthesis and ethylene-regulated root and RAM shortening in cytokinin-treated Arabidopsis. Direct interaction between ARABIDOPSIS RESPONSE REGULATOR 2 (ARR2), a member of the multistep phosphorelay cascade, and the C-terminal portion of ETHYLENE INSENSITIVE 2 (EIN2-C), a key regulator of canonical ethylene signaling, is involved in the cytokinin-induced, ethylene-mediated control of ACO4. We propose tight cooperation between cytokinin and ethylene signaling in the spatially specific regulation of ethylene biosynthesis as a key aspect of the hormonal control of root growth., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Tetrandrine, a bioactive active compound mainly found in the roots of Stephania tetrandra, exhibits various pharmacological properties. In vitro hairy root (HR) culture may serve as a promising solution for the extraction of tetrandrine, overcoming the limitations of natural cultivation. The present study describes the consistent production of tetrandrine from S. tetrandra hairy roots induced by different strains of Agrobacterium rhizogenes. Cultivation in woody plant medium (WPM) resulted in the highest HR biomass (0.056 g/petri-dish) and tetrandrine content (7.28 mg/L) as compared to other media. The maximum HR biomass (6.95 g dw/L) and tetrandrine production (68.69 mg/L) were obtained in the fifth week of cultivation. The presence of ammonium nitrate (800 mg/L), calcium nitrate (1156 mg/L), sucrose (20 g/L) and casein (2 g/L) enhanced the tetrandrine production. Moreover, the fed-batch cultivation demonstrated that the NH 4 NO 3 (1200 mg/L) was an important growth limiting factor that yielded the highest tetrandrine amount (119.59 mg/L). The cultivation of hairy roots in a mist trickling bioreactor for eight weeks was less (26.24 mg/L) than in the flask. Despite a lower tetrandrine yield observed in bioreactors compared to flask cultures, refining the growth medium and fine-tuning bioreactor operations hold promise for boosting tetrandrine yield., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests Yung-Chuan Liu reports financial support was provided by National Science and Technology Council of Taiwan. Parushi Nargotra reports financial support was provided by National Science and Technology Council of Taiwan. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Rhizomania is the most destructive sugar beet disease in the world, and in recent years, it has widespread in most of the sugar beet growing areas in Iran. Since the control of this soil-borne disease is a difficult task, the use of resistant genotypes is known as the best measure against the disease. The ultimate goal of sugar beet breeders is to produce genotypes that can be used in both infected and non-infected fields without any reduction in terms of yield and quality. Twenty-one sugar beet genotypes along with four controls were evaluated in randomized complete block design with four replications in fields with natural infection to rhizomania in five research stations. Important sugar beet traits including root yield, sugar yield, sugar content, and white sugar yield were evaluated for two years (2021 and 2022). For all traits, location was the main source of variation that spanned 33 to 55% of the total sum of the square followed by the location×year×genotype accounted for 3-40% of the variation. Based on the results of analysis of variance, multivariate stability parameters were computed to evaluate the genotypes' stability. The first two principal components (IPCA1 and IPCA2) generated by GGE biplot contributed for 31.3 and 17.5% difference in genotype×environment interaction for root yield, respectively. According to the GGE biplot, genotypes RM-11 and RM-12 were identified as the winning genotypes across environments for both root yield and white sugar yield traits whereas AMMI model identified RM-14 and RM-9 (for root yield) and RM-1 (for white sugar yield) as best genotypes. Based on the ideal genotype ranking, RM-11 and RM-10 were the best performer with a high mean yield as well as stability in the studied environments. The biplot rendered using the weighted average of absolute scores (WAASB) and root yield and white sugar yield identified RM-11 and RM-9 as superior genotypes in terms of yield and stability. The selected genotypes can be used in breeding programs to transfer the disease resistance and cultivar development., (© 2024. The Author(s).)

Wood constitutes the largest reservoir of terrestrial biomass. Composed of xylem, it arises from one side of the vascular cambium, a bifacial stem cell niche that also produces phloem on the opposing side. It is currently unknown which molecular factors endow cambium stem cell identity. Here we show that TRACHEARY ELEMENT DIFFERENTIATION INHIBITORY FACTOR (TDIF) ligand-activated PHLOEM INTERCALATED WITH XYLEM (PXY) receptors promote the expression of CAMBIUM-EXPRESSED AINTEGUMENTA-LIKE (CAIL) transcription factors to define cambium stem cell identity in the Arabidopsis root. By sequestrating the phloem-originated TDIF, xylem-expressed PXY confines the TDIF signaling front, resulting in the activation of CAIL expression and stem cell identity in only a narrow domain. Our findings show how signals emanating from cells on opposing sides ensure robust yet dynamically adjustable positioning of a bifacial stem cell layer.

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., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Main Conclusion: The dwarfing mechanism in apple clonal rootstocks is driven by complex interactions between anatomical, hormonal, genetic, and phenolic factors, offering potential for advanced genetic manipulation to optimize tree size and enhance orchard productivity. The widespread adoption of dwarfing rootstocks is pivotal to modern commercial apple (Malus × domestica Borkh) orchards due to their ability to control tree size, shorten the juvenile period, and enhance reproductive growth and overall productivity. The underlying mechanisms of rootstock-induced dwarfism are multifaceted and involve interactions between phenotypic, anatomical, genetic, and phytohormonal factors. This review consolidates current understanding, highlighting the importance of auxin (IAA), cytokinins (CKs), gibberellins (GAs), and abscisic acid (ABA) in mediating growth suppression through impaired transport and hormone signaling. The phenotypic impacts, including reduced root growth, shorter sylleptic shoots, and higher floral bud densities, are discussed alongside genetic loci such as Dw1, Dw2, and Dw3, and the influence of key genes/TFs like MdWRKY9, RGL, and PIN. Anatomically, dwarf rootstocks exhibit a higher bark-to-wood ratio and restricted hydraulic conductivity, which contribute to reduced scion vigour. Furthermore, the accumulation of phenolic compounds in the graft union of dwarfing rootstocks further modulates the growth inhibition. These insights lay the groundwork for advanced molecular breeding strategies, incorporating gene-editing technologies to improve dwarf rootstock development, providing avenues for enhanced orchard management and apple productivity., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Decabromodiphenyl ethane (DBDPE) and cadmium (Cd) are typical pollutants in e-waste, seriously threatening crop growth. This study investigated the bioaccumulation and toxicity mechanisms of DBDPE and Cd in a soil-rice system. The results showed that 50 mg/kg DBDPE could reduce the level of accumulation of Cd in rice roots. DBDPE and Cd induced the antioxidant system (SOD, POD, and MDA) in rice seedlings. The combined exposure reduced the contents of carbohydrates, lipids, amino acids, and organic acids. Phenylalanine and phenylpropanoid metabolisms were identified as the key detoxification metabolic pathways under combined exposure. DBDPE and Cd disrupted the functional cycling of carbon and nitrogen in rhizosphere soil, while Gemmatimonadetes, Actinobacteria, and Bacteroidetes were the key bacterial groups responding to DBDPE and Cd stress. This work provides data for the toxicity risk evaluation of DBDPE and Cd combined exposure to food crops.

Desert shrubs play a crucial role in controlling desertification and promoting revegetation, but drought often hinders their growth. Investigating the hydraulic strategies of desert shrubs is important in order to understand their drought adaptation and predict future dynamics under climate change. In this study, we measured the hydraulic-related characteristics of roots, stems and leaves in 19 desert shrub species from northern China. We aimed to explore the hydraulic coordination and segmentation between different plant organs. The results were as follows: (i) specific root length was positively correlated with the water potential inducing a 50% loss in stem hydraulic conductivity (P50stem) and negatively correlated with stem hydraulic safety margin. This suggested that water uptake efficiency of the fine roots was traded off with stem embolism resistance and hydraulic safety. (ii) The water potential inducing a 50% loss in leaf hydraulic conductance was significantly less negative than P50stem, and fine root turgor loss point was significantly less negative than P50stem, indicating a hydraulic segmentation between the main stem and terminal organs. (iii) The most negative leaf turgor loss point indicated that leaf wilting occurred after substantial leaf and stem embolism. The high desiccation resistance of the leaves may serve as an important physiological mechanism to increase carbon gain in a relatively brief growth period. In summary, this study elucidated the hydraulic strategies employed by desert shrubs from a whole-plant perspective., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)

Plants affect soil microorganisms through the release of root exudates under pollution stress. This process may affect rhizosphere priming effect (RPE) and alter the rate of soil organic matter decomposition. However, the influence of plants on the decomposition of organic matter in soil subjected to pollution stress remains unclear. We studied the effects of exposure to perfluorooctanesulfonic (PFOS) and its alternative, chlorinated polyfluoroalkyl ether sulfonic (F-53B), at concentrations of 0.1 mg/kg and 50 mg/kg on the RPE of reed. We conducted our experiments in an artificial climate chamber and used the natural 13 C tracer method to determine RPE. In the PFOS-exposed groups, the RPE was negative, with values of -11.45 mg C kg -1 soil d -1 in the low PFOS group and -8.04 mg C kg -1 soil d -1 in the high PFOS group. In contrast, in the F-53B-exposed groups, the RPE was positive, with values of 8.26 mg C kg -1 soil d -1 in the low F-53B group and 12.18 mg C kg -1 soil d -1 in the high F-53B group. Exposure of reeds to PFOS/F-53B stress resulted in differential effects on extracellular enzyme activities. The observed positive and negative RPE phenomena could be attributed to variations in extracellular enzyme activities. In conclusion, RPE responded differently under PFOS/F-53B exposure., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Green agriculture faced challenges due to the shortage of efficient cadmium (Cd)-resistant plant growth-promoting bacteria (CdR-PGPB) and their low survival rate and activity during application. In this study, a diverse range of efficient CdR-PGPB were isolated from the rhizosphere soil of Desmodium elegans, especially those with high phosphate-solubilizing capabilities (272.87-450.45 mg L -1 ). Two highly efficient CdR-PGPB namely, XH1 and XH3 were loaded on to rice husk biochar (RHB) and pig bone biochar (PBB), labelled as RHBM and PBBM respectively. This study aimed to explore their effectiveness and mechanisms in promoting maize growth in a Cd-contaminated planting system. Results showed that PBBM performed best among all treatments. It significantly decreased soil phytoavailable Cd by 53.19 % and Cd content in maize shoot by 85.89 %. It also increased soil available phosphorus by 145.72 %, soil alkaline phosphatase activity by 76.34 %, maize shoot/root biomass by 47.06 %/67.98 %, Chlorophyll (a/b) content by 66.80 %/134.13 % and peroxidase activity by 171.96 %. These results were achieved through the synergistic action of efficient CdR-PGPB and PBB. Therefore, PBBM proved to be a promising and innovative application technique for sustainable agricultural development in Cd-contaminated farmland ecosystems., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Phytoremediation of cadmium (Cd)-polluted soil by using sweet sorghum displays a tremendous potential as it is a fast-growing, high biomass and Cd tolerant energy plant. Previous study has demonstrated SbNRT1.1B expression change is in accordance with enhanced Cd accumulation by external nitrate supply in sweet sorghum. Nevertheless, underlying mechanism of SbNRT1.1B response to Cd stress is still elusive. SbNRT1.1B exhibited a positive response to Cd stress in sweet sorghum. Overexpressing SbNRT1.1B increased primary root length, shoot fresh weight, nitrate and chlorophyll concentrations compared with Col-0 under Cd stress, while complementary SbNRT1.1B rescued these decreased values in mutant chl1-5. Cd concentrations in overexpressing SbNRT1.1B, complementary SbNRT1.1B and Col-0 lines were 3.2-4.1, 2.5-3.1 and 1.2-2.1 folds of that in chl1-5. Consistent with Cd concentrations, non-protein thiol (NPT), reduced glutathione (GSH) and phytochelatins (PCs) concentrations as well as the related genes expression levels showed the same trends under Cd stress. GSH biosynthesis inhibitor failed to reverse the patterns of GSH-dependent PCs concentrations changes in different lines, suggesting that SbNRT1.1B plays an upstream role in GSH-dependent PCs biosynthesis under Cd treatment. Altogether, SbNRT1.1B enhances nitrate concentrations contributing to increased chlorophyll concentrations and GSH-dependent PCs metabolites biosynthesis, thereby improving growth and Cd concentrations in plants., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Constitutive overexpression of phosphate (Pi) transporter family 1 often results in the accumulation of toxic levels of Pi, which causes growth retardation in plants. In contrast, we had previously reported that root epidermis-specific overexpression of the phosphate transporter TaPT2 in Arabidopsis leads to improved growth and Pi use efficiency. In the present study, we used promoters AtHKT1;1 and SKOR, which are predominantly expressed in the vascular bundle tissues, to overexpress TaPT2. Transgenic lines exhibited increased shoot growth compared to wild type plants under normal- and low-Pi conditions, along with elevated root Pi and total P content, and higher xylem sap Pi concentration, specifically under low-Pi conditions. This was attributed to moderate Pi accumulation in the xylem parenchyma cells, enhancing the Pi uploading capacity to the xylem. SKOR-TaPT2, however, did not complement pho1 mutant, which was defective in uploading Pi to the xylem. The transcriptional levels of VPT1 and VPT3, which are responsible for transporting excess Pi into a vacuole, were upregulated in SKOR promoter lines under normal-Pi conditions. Our results suggested that root vascular bundle-specific expression of TaPT2 is another promising strategy for increasing biomass production, Pi uptake, and Pi use efficiency while preventing growth retardation in transgenic plants., (© 2024. The Author(s).)

Background: Continuous cropping of the same crop leads to land degradation. This is also called the continuous-cropping obstacle. Currently, intercropping tobacco with other crops can serve as an effective strategy to alleviate continuous cropping obstacles., Results: In this study, tobacco K326 and insectary floral plants were used as materials, and seven treatments of tobacco monoculture (CK), tobacco intercropped with Tagetes erecta, Vicia villosa, Fagopyrum esculentum, Lobularia maritima, Trifolium repens, and Argyranthemum frutescens respectively, were set up to study their effects on rhizosphere soil chemical properties and composition and structure of rhizosphere soil microbial community of tobacco. The 16 S rRNA gene and ITS amplicons were sequenced using Illumina high-throughput sequencing. tobacco/insectary floral plants intercropping can influence rhizosphere soil chemical properties, which also change rhizosphere microbial communities. The CK and treatment groups tobacco rhizosphere soil microorganisms had significantly different genera, such as tobacco intercropping with T. repens and A. frutescens significantly increased the number of Fusarium and intercropping T. erecta, V. villosa, L. maritima, T. repens, and A. frutescens significantly increased the number of Sphingomonas and unknown Gemmatimonadaceae. Additionally, intercropping T. erecta, V. villosa and L. maritima changed the rhizosphere fungal and bacteria community and composition of tobacco and the positive correlation between tobacco rhizosphere the genera of fungi and bacterial were greater than CK. The pathway of the carbohydrate metabolism, amino acid metabolism, and energy metabolism in rhizosphere bacteria were significantly decreased after continuous cropping. Fungal symbiotic trophic and saprophytic trophic were significantly increased after intercropping V. villosa, L. maritima and plant pathogen and animal pathogen were increased after intercropping T. repens and A. frutescens. Additionally, bacterial and fungal communities significantly correlated with soil chemical properties, respectively., Conclusion: This study reveals that intercropping tobacco with insectary floral plants, particularly T. erecta, V. villosa, L. maritima and A. frutescens significantly affects soil chemical properties and alters rhizosphere microbial communities, increasing the abundance of certain microbial genera. Additionally, intercropping enhances pathways related to carbohydrate, amino acid, and energy metabolism in rhizosphere bacteria. These findings suggest that intercropping could provide a promising strategy to overcome challenges associated with continuous tobacco cropping by regulating the rhizosphere environment., (© 2024. The Author(s).)

This study aimed at isolation of native plant growth-promoting bacteria (PGPB) associated with organic tea plantations. Most research on tea and associated microbes have been on Darjeeling and Assam, known for their world-class tea. However, emerging tea plantations in remote Northeast India are gaining prominence due to their unique geographical location, favorable climate, and organic practices. This study investigated PGBP associated with these organic tea plantations, aimed to assess their potential cross-infectivity on non-host plants. A total of 58 PGP bacterial isolates were isolated from four organic tea plantations. Six potential isolates were further evaluated individually and as consortium for their PGP on rice and maize. Bacillus, Pseudomonas, and Serratia spp. as individual and in consortium were found to have potent cross-infectivity with significant growth promotion in non-host plants indicated by plant height, root length, shoot, and root weight. The present findings suggest that PGPB native to organic tea plantations have potential cross-infectivity for use as a biofertilizers to improve the growth and productivity of non-host crops. This provides prospectives of using native bacteria on non-host plants paving the way for their potential application in sustainable agriculture practices for growth promotion of staple food crops., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Cold stress during early development limits maize (Zea mays L.) production in temperate zones. Low temperatures restrict root growth and reprogram gene expression. Here, we provide a systematic transcriptomic landscape of maize primary roots, their tissues, and cell types in response to cold stress. The epidermis exhibited a unique transcriptomic cold response, and genes involved in root hair formation were dynamically regulated in this cell type by cold. Consequently, activation of genes involved in root hair tip growth contributed to root hair recovery under moderate cold conditions. The maize root hair defective mutants roothair defective 5 (rth5) and roothair defective 6 (rth6) displayed enhanced cold tolerance with respect to primary root elongation. Furthermore, DEHYDRATION RESPONSE ELEMENT-BINDING PROTEIN 2.1 (DREB2.1) was the only member of the dreb subfamily of AP2/EREB transcription factor genes upregulated in primary root tissues and cell types but exclusively downregulated in root hairs upon cold stress. Plants overexpressing dreb2.1 significantly suppressed root hair elongation after moderate cold stress. Finally, the expression of rth3 was regulated by dreb2.1 under cold conditions, while rth6 transcription was regulated by DREB2.1 irrespective of the temperature regime. We demonstrated that dreb2.1 negatively regulates root hair plasticity at low temperatures by coordinating the expression of root hair defective genes in maize., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

EARLY NODULIN 93 (ENOD93) has been genetically associated with biological nitrogen fixation in legumes and nitrogen use efficiency in cereals, but its precise function is unknown. We show that hidden Markov models define ENOD93 as a homolog of the N-terminal domain of RESPIRATORY SUPERCOMPLEX FACTOR 2 (RCF2). RCF2 regulates cytochrome oxidase (CIV), influencing the generation of a mitochondrial proton motive force in yeast (Saccharomyces cerevisiae). Knockout of ENOD93 in Arabidopsis (Arabidopsis thaliana) causes a short root phenotype and early flowering. ENOD93 is associated with a protein complex the size of CIV in mitochondria, but neither CIV abundance nor its activity changed in ruptured organelles of enod93. However, a progressive loss of ADP-dependent respiration rate was observed in intact enod93 mitochondria, which could be recovered in complemented lines. Mitochondrial membrane potential was higher in enod93 in a CIV-dependent manner, but ATP synthesis and ADP depletion rates progressively decreased. The respiration rate of whole enod93 seedlings was elevated, and root ADP content was nearly double that in wild type without a change in ATP content. We propose that ENOD93 and HYPOXIA-INDUCED GENE DOMAIN 2 (HIGD2) are the functional equivalent of yeast RCF2 but have remained undiscovered in many eukaryotic lineages because they are encoded by 2 distinct genes., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists.)

Breeding annual crops for enhanced root depth and biomass is considered a promising intervention to accrue soil organic carbon (SOC) in croplands, with benefits for climate change mitigation and soil health. In annual crops, genetic technology (seed) is replaced every year as part of a farmer's fixed costs, making breeding solutions to climate change more scalable and affordable than management approaches. However, mechanistic understanding and quantitative estimates of SOC accrual potentials from crops with enhanced root phenotypes are lacking. Maize is the highest acreage and yielding crop in the US, characterized by relatively low root biomass confined to the topsoil, making it a suitable candidate for improvement that could be rapidly scaled. We ran a 2-year field experiment to quantify the formation and composition (i.e., particulate (POM), coarse and fine mineral-associated organic matter (chaOM and MAOM, respectively) of new SOC to a depth of 90 cm from the decomposition of isotopically labeled maize roots and exudates. Additionally, we used the process-based MEMS 2 model to simulate the SOC accrual potential of maize root ideotypes enhanced to either shift root production to deeper depths or increase root biomass allocation, assuming no change in overall productivity. In our field experiment, maize root decomposition preferentially formed POM, with doubled efficiency below 50 cm, while root exudates preferentially formed MAOM. Modeling showed that shifting root inputs to deeper layer or increasing allocation to roots resulted in a deterministic increase in SOC, ranging from 0.05 to 0.15 Mg C ha -1 per year, which are at the low end of the range of published SOC per hectare annual accrual estimates from adoption of a variety of crop management practices. Our analysis indicates that for maize, breeding for increasing root inputs as a strategy for SOC accrual has limited impact on a per-hectare basis, although given that globally maize is produced on hundreds of millions of hectares each year, there is potential for this technology and its effect to scale. For maize-soy system that dominates US acres, changes in the overall cropping system are needed for sizable greenhouse gas reductions and SOC accrual. This study demonstrated a modeling and experimental framework to quantify and forecast SOC changes created by changing crop root inputs., (© 2024 The Author(s). Global Change Biology published by John Wiley & Sons Ltd.)

The microgravity conditions experienced in space prevent the proper distribution of water throughout root modules of plant growth hardware, and the lack of convective mixing and buoyancy reduces gas exchange. To overcome this problem, cultivation technologies should be designed that take advantage of the unique traits of the spaceflight environment instead of attempting to recreate Earth-like conditions. Such technologies should be adaptable to both the microgravity of spaceflight and the low gravity environments of the lunar and Martian surface. Current space plant cultivation relies on traditional terrestrial practices and uses porous substrates that are nutrient poor and difficult to regenerate, and does not consider the dominance of surface- or thermal gradient-controlled rather than gravity-controlled water flow in space as a potential beneficial property. We propose systems that control water dispensation and removal by parallel but independent means in a soil-free cultivation system that is adaptable and expandable to crops of varying sizes and shallow or deep rooting plants. Water dispensation and removal in a substrate-free hydroponic system can be achieved through the misting of nutrient solutions combined with special root module geometry and temperature gradients. The use of hydrogels as substrate, and a means of providing required nutrients and water for plant cultivation in space, can aid in the transition to low-gravity systems by eventual incorporation of on-site regolith to establish Earth-like soil., Competing Interests: Conflict of interest The authors declare no conflict of interest., (Copyright © 2024 The Committee on Space Research (COSPAR). Published by Elsevier B.V. All rights reserved.)

Polar tip growth in plants occurs only in root hairs and pollen tubes. In particular, root hair growth is considered very important in the growth of plants, as it is critical for water and nutrient absorption. Polar tip growth is regulated by various factors, including plant hormones such as abscisic acid (ABA) and gibberellin (GA) and cell wall modifications. We aimed to elucidate the effects and mechanisms on tip growth of a novel gene containing the domain of unknown function (DUF) 3511. We found that Protein Involved in Tip Elongation (PITE) is involved in root hair development in rice (Oryza sativa L.). PITE protein was observed in the plasma membrane and cytoplasm of root hairs. Pite mutants generated by the CRISPR/Cas9 system showed a shorter root hair phenotype compared to the wild type. Through RNA sequencing and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis, we found that the expression of genes that affect cell wall rigidity and GA metabolism-related genes were differently regulated in pite mutants. PITE could interact with acyl transferase and haloacid dehalogenase-like hydrolase (HAD9) in the nucleus and cytoplasm. Our study suggests that PITEs containing the DUF3511 domain regulate root hair growth in rice by mediating the expression of genes that can regulate cell wall rigidity or cause changes in GA metabolism through interactors such as HAD9., (© 2024 Scandinavian Plant Physiology Society.)

Although plant-derived smoke solutions (SSs) have exhibited growth-promoting properties in various plant species, their potential role in mitigating heavy metal stress, specifically in grapevines, has remained unexplored and unreported. This knowledge gap prompted the present study to evaluate the efficacy of foliar application of SSs derived from vineyard pruning waste at concentrations of 0%, 0.5%, 1%, and 2% in mitigating Cadmium (Cd) phytotoxicity in grape saplings. In our study, cadmium stress was induced by applying 10 mg/kg CdCl 2 to the root area of the saplings, in conjunction with fertilizers. Our findings showed that exposure to Cd toxicity impeded the growth of grapevine saplings, adversely affecting shoot and root length, as well as fresh weight. Furthermore, it resulted in a reduction in chlorophyll content, stomatal conductance, and leaf water content while significantly increasing membrane damage and lipid peroxidation. Notably, the application of 0.5% SS enhanced grapevine sapling growth and alleviated Cd stress-induced damage by more effectively regulating physiological and biochemical responses compared to the control and other concentrations. Based on our results, under Cd stress conditions, the application of 0.5% SS effectively increased chlorophyll content, relative water content (RWC), stomatal conductance (1.79 mmol.m -2 .sn -1 ), and total phenolic content (1.89 mg.g -1 ), whereas it significantly reduced malondialdehyde (MDA) levels and membrane damage (1.35 nmol.g -1 ). Additionally, it significantly elevated the activities of antioxidant enzymes, including superoxide dismutase (SOD) (2.16 U.mg -1 ), catalase (CAT) (1.55 U.mg -1 ), and ascorbate peroxidase (APX) (3.03 U.mg -1 ). The study demonstrated that plant-derived SS mitigates Cd stress in grapevines by enhancing antioxidative defence mechanisms., (© 2024 Scandinavian Plant Physiology Society.)

Auxins play a critical role in several plant developmental processes and their endogenous levels are regulated at multiple levels. The enzymes of the GRETCHEN HAGEN 3 (GH3) protein family catalyze the conjugation of amino acids to indoleacetic acid (IAA), the major endogenous auxin. The GH3 proteins are encoded by multiple redundant genes in plant genomes, making it difficult to perform functional genetic studies to understand their role in auxin homeostasis. To address these challenges, we used a chemical approach that exploits the reaction mechanism of GH3 proteins to identify small molecule inhibitors of their activity from a defined chemical library. The study evaluated receptor-ligand complexes based on their binding energy and classified them accordingly. Docking algorithms were used to correct any deviations, resulting in a list of the most important inhibitory compounds for selected GH3 enzymes based on a normalized sum of energy. The study presents atomic details of protein-ligand interactions and quantifies the effect of several of the identified small molecule inhibitors on auxin-mediated root growth processes in Arabidopsis thaliana. The direct effect of these compounds on endogenous auxin levels was measured using appropriate auxin sensors and endogenous hormone measurements. Our study has identified novel compounds of the flavonoid biosynthetic pathway that are effective inhibitors of GH3 enzyme-mediated IAA conjugation. These compounds play a versatile role in hormone-regulated plant development and have potential applications in both basic research and agriculture., (© 2024 Scandinavian Plant Physiology Society.)

Iron (Fe) deficiency in calcareous soils is a significant agricultural challenge, affecting crop productivity and nutritional quality. This study aimed to isolate, characterize, and evaluate Fe solubilizing rhizobacterial isolates from maize rhizosphere in calcareous soils as potential biofertilizers. Forty bacterial isolates coded as SG1, SG2, …, SG40 were isolated and screened for siderophore production, with ten showing significant Fe solubilizing capabilities. These isolates were further assessed for phosphate solubilization and exopolysaccharides production. The selected bacterial isolates were also screened under axenic conditions for their ability to improve maize growth. The isolates SG8, SG13, SG24, SG30 and SG33 significantly enhanced growth parameters of maize. Notably, SG30 showed highest increment in shoot length (58%), root length (54%), root fresh and dry biomass (67% and 76%), SPAD value (67%), relative water contents (69%), root surface area (61%), and Fe concentration in shoots (79%) as compared to control. The biochemical characterization of these strains showed that all these strains have capability to solubilize insoluble phosphorus, produce indole-3-acetic acid (IAA), and ammonia with catalase, urease and protease activity. Molecular identification through 16s rRNA gene sequencing confirmed high similarity (99.7-100%) of the selected isolates to various Bacillus species, including B. pyramidoids, B. firmicutes, and B. cereus. The study provides a strong base for developing eco-friendly, cost-effective biofertilizers to address Fe deficiency in crops and promote sustainable agriculture., (© 2024. The Author(s).)

Rice growth and yield response to salinity can be influenced by the duration and the timing of salt stress. The present study tested the effects of saline water irrigation from vegetative growth to maturity on rice growth and yield and ion concentrations in the straw and root and related them to changes in soil salinity and soil solute potential. The treatments consisted of five levels of saline water irrigation (electrical conductivity ~0.25 (control), 4, 6, 8, and 10 dS m-1) with two rice cultivars (BRRI dhan67 and BRRI dhan99) grown in pots in a rain shelter. Grain weight per pot, dry straw weight, and root weight were significantly reduced with increasing water salinity, but BRRI dhan99 was less affected. With prolonged saline water irrigation, salt concentration increased in the soil and lowered the soil solute potential. Increased saline water induced higher concentrations of Na+ in the straw (527-1200 mmol kg-1 at 4-10 dS m-1) relative to the root. By contrast, higher Cl- concentrations accumulated in the root than in the straw. The decrease of K+ in the straw and root for increasing salinity was inconsistent, but the Na+/K+ ratio sharply increased in the straw with higher water salinity. The increased Na+/K+ explained most grain weight loss due to higher salinity (R2 = 0.93) followed by Na+ (R2 = 0.87) and Cl-1 (R2 = 0.53). We conclude that the prolonged saline water irrigation has a cumulative effect on root zone salinity and solute potential that depresses grain yield in rice by increasing the Na+/K+ ratio in plants., Competing Interests: The authors have declared that no competing interests exist., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)

Pesticides including insecticides are applied in agricultural practices to control insect pests. However, their excessive usage often poses a severe threat to the growth, physiology, and biochemistry of plants. Here, responses of chickpea and greengram seedlings exposed to three fipronil (FIP) concentrations i. e. 100 (1×), 200 (2×) and 300 (3×) μg mL -1 was evaluated under in vitro. Among doses, 3× had a greater negative impact on germination attributes, root-shoot elongation, vigor indices, length ratios, and survival of seedlings. Besides, the morphological distortion in root tips, oxidative stress generation, and cellular death in fipronil-supplemented root seedlings were observed under scanning electron (SEM) and confocal laser scanning (CLSM), respectively. A significant (p ≤ 0.05) and pronounced upsurge in plant stressor metabolites such as proline, malondialdehyde (MDA), electrolyte leakage (EL), hydrogen peroxide (H 2 O 2 ) content, and antioxidants enzymes in plant seedlings further confirmed the fipronil toxicity. In addition, a concentration-dependent decrease in respiration efficiency (RE) and ATP content in FIP-treated seedlings was observed. Reduced mitotic index (MI) and numerous chromosomal anomalies (CAs) in root meristematic cells of seedlings are a clear indication of insecticide-induced cytotoxicity. Furthermore, a dose-dependent increase in DNA damage in root meristematic cells of greengram revealed the genotoxic potential of fipronil. Conclusively, fipronil suggested phyto and cyto-genotoxic effects that emphasize their careful monitoring in soils before application and their optimum addition in soil-plant systems. It is high time to prepare both target-specific and slow-released agrochemical formulations for crop protection with concurrent safeguarding of the soil., Competing Interests: Declaration of competing interest The authors certify that the work mentioned in this publication has not been influenced by competing financial or personal links between them., (Copyright © 2024. Published by Elsevier Inc.)

Boron (B) is an important limiting factor for plant growth and yield in saline soils, but the underlying molecular mechanisms remain poorly understood. In this study, we found that appropriate B supply obviously complemented rapeseed (Brassica napus L.) growth under salinity accompanied by higher biomass production and less reactive oxygen species accumulation. Determination of Na + content in shoots and roots indicated that B significantly repressed root-to-shoot Na + translocation, and non-invasive micro-tests of root xylem sap demonstrated that B increased xylem Na + unloading in the roots of rapeseed plants under salinity. Comparative transcriptomic profiling revealed that B strongly upregulated BnaHKT1s expression, especially BnaA2.HKT1, in rapeseed roots exposed to salinity. In situ hybridizations analysis showed that BnaA2.HKT1 was significantly induced in root stelar tissues by high B (HB) under salinity. Green fluorescent protein and yeast heterologous expression showed that BnaA2.HKT1 functioned as a plasma membrane-localized Na + transporter. Knockout of BnaA2.HKT1 by CRISPR/Cas9 resulted in hypersensitive of rapeseed plants to salinity even under HB condition, with higher shoot Na + accumulation and lower biomass production. By contrast, overexpression of BnaA2.HKT1 ameliorated salinity-induced growth inhibition under B deficiency and salinity. Overall, our results proposed that B functioned as a positive regulator for the rapeseed growth and seed production under salt stress through facilitating BnaA2.HKT1-mediated root xylem Na + unloading. This study may also provide an alternative strategy for the improvement of crop growth and development in saline soils., (© 2024 Society for Experimental Biology and John Wiley & Sons Ltd.)

Chromium (Cr) contamination in agricultural soils, largely due to industrial activities, poses a significant threat to plant growth and productivity. This study examines the effects of Cr stress at concentrations of 100 and 200 mg of K 2 Cr 2 O 7 per kg soil on rapeseed (Brassica napus) roots and evaluates the mitigating potential of biochar. Biochar, produced through both slow and fast pyrolysis and applied at 30 g per kg soil, was investigated for its ability to neutralize Cr toxicity. Our findings indicate that Cr stress significantly decreased the growth and physiological functions of rapeseed roots. However, biochar application improved soil pH, cation exchange capacity, and the uptake of essential nutrients such as nitrogen, phosphorus, potassium, calcium, and magnesium. Additionally, biochar enhanced the production of osmotic regulators like glycine betaine and soluble proteins, as well as indole acetic acid, promoting better root growth and water uptake under Cr stress. Notably, biochar reduced Cr availability and absorption in rapeseed roots, leading to lower levels of stress-related hormones such as abscisic acid, salicylic acid, and jasmonic acid. Among the biochars tested, slow pyrolysis biochar was more effective than fast pyrolysis biochar in mitigating Cr toxicity. These results highlight the potential of slow pyrolysis biochar as a sustainable strategy to alleviate Cr pollution and enhance plant resilience in contaminated soils., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

In forest ecosystems, changes in the expression of tree absorptive root traits following management interventions are expected to influence post-thinning forest structure and function. Fine root traits are expected to be especially responsive to forest thinning-one of the most common forest management interventions and the focus of our research here-influencing tree-level responses to environmental change, and thereby contributing to post-thinning stand-level dynamics and ecosystem processes. However, there remains limited understanding surrounding whether or not forest thinning influences the expression of root morphological, chemical, and physiological traits associated with belowground resource acquisition. We conducted a global meta-analysis to evaluate the response of 13 fine root traits to forest thinning. Our study included analysis of 769 paired observations of root traits values pre- and post-thinning, derived from 89 peer-reviewed publications. Our meta-analysis found that forest thinning leads to a decrease in fine root biomass by 11.7% on average, while other root traits including fine root length, root C and N concentrations, root lifespan, and root respiration rates, are largely unresponsive to thinning treatments. Thinning tended to reduce fine root biomass at early stand recovery stages, with increases in fine root biomass being detected at later seral stages, especially in heavy thinning experiments. The effect of thinning on fine root biomass was most pronounced in deeper soil horizons. The influence of thinning on fine root trait expression was not affected by ecosystem or stand type, with the exception of biomass which decreased in temperate and coniferous forests. Our results demonstrate variations of fine root traits to forest management, as well as the importance of stand recovery time and thinning intensity in regulating fine root trait expression in retention trees. These patterns may have strong implications for governing soil carbon stocks in managed forests associated with decreased root inputs into deeper soils. Overall, our findings can enhance our comprehension of how forest management affects fine root trait expression, and relationship between managed forests and belowground ecosystem structure and function., Competing Interests: Declaration of competing interest No conflict of interest exits in the submission of this manuscript, and manuscript is approved by all authors for publication. I would like to declare on behalf of my coauthors that the work described was original research that has not been published previously, and not under consideration for publication elsewhere, in whole or in part. All the authors listed have approved the manuscript that is enclosed., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Cytokinin is central to coordinating plant adaptation to environmental stresses. Here, we first demonstrated the involvement of cytokinin in Arabidopsis responses to arsenite [As(III)] stress. As(III) treatment reduced cytokinin contents, while cytokinin treatment repressed further primary root growth in Arabidopsis plants under As(III) stress. Subsequently, we revealed that the cytokinin signaling members ARR1 and ARR12, the type-B ARABIDOPSIS RESPONSE REGULATORs, participate in cytokinin signaling-mediated As(III) responses in plants as negative regulators. A comprehensive transcriptome analysis of the arr1 and arr12 single and arr1,12 double mutants was then performed to decipher the cytokinin signaling-mediated mechanisms underlying plant As(III) stress adaptation. Results revealed important roles for ARR1 and ARR12 in ion transport, nutrient responses, and secondary metabolite accumulation. Furthermore, using hierarchical clustering and regulatory network analyses, we identified two NODULIN 26-LIKE INTRINSIC PROTEIN (NIP)-encoding genes, NIP1;1 and NIP6;1, potentially involved in ARR1/12-mediated As(III) uptake and transport in Arabidopsis. By analyzing various combinations of arr and nip mutants, including high-order triple and quadruple mutants, we demonstrated that ARR1 and ARR12 redundantly function as negative regulators of As(III) tolerance by acting upstream of NIP1;1 and NIP6;1 to modulate their function in arsenic accumulation. ChIP-qPCR, EMSA, and transient dual-LUC reporter assays revealed that ARR1 and ARR12 transcriptionally activate the expression of NIP1;1 and NIP6;1 by directly binding to their promoters and upregulating their expression, leading to increased arsenic accumulation under As(III) stress. These findings collectively provide insights into cytokinin signaling-mediated plant adaptation to excessive As(III), contributing to the development of crops with low arsenic accumulation., (© 2024 Society for Experimental Biology and John Wiley & Sons Ltd.)

NAR2 (Nitrate assimilation related protein) is a protein chaperone involved in transporting nitrate across membranes. However, the expression pattern and function of NAR2 genes in wheat are still largely unknown. Here, we cloned two TaNAR2 genes (TaNAR2.1 and TaNAR2.2). To assess and compare the functional differences of TaNAR2.1 and TaNAR2.2, we analyzed the subcellular localization and expression pattern of the two genes in wheat under low nitrogen (LN) and high nitrogen (HN) conditions, as well as the nitrate influx and root system architecture of TaNAR2.1 and TaNAR2.2 overexpression wheat under LN and HN. Additionally, we investigated the effects of TaNAR2.1 and TaNAR2.2 overexpression on the growth phenotype, nitrogen uptake and yield of wheat throughout the growth period. There are significant differences in the expression patterns and functions of TaNAR2.1 and TaNAR2.2. TaNAR2.1 is located in the cytoplasm, nucleus and the plasma membrane, whereas TaNAR2.2 is a cytoplasm-specific protein. TaNAR2.1 appears to exhibit larger changes in expression levels and a higher capacity for nitrate influx than TaNAR2.2 under external nitrate supply. Overexpression of TaNAR2.1 significantly improves grain nitrogen use efficiency and increases grain yield, whereas overexpression of TaNAR2.2 enhances vegetative and reproductive growth of wheat roots. These findings indicate that TaNAR2.1 plays a crucial role in wheat nitrogen accumulation and yield, while TaNAR2.2 is pivotal for wheat root growth., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2024. Published by Elsevier B.V.)

Sustainable agriculture has become prime importance to feed growing population. To achieve this goal application of exogenous hormones and signaling molecules are gaining important. In this context, we have investigated potential of ethylene (25 μM ethephon; donor) and H 2 S (10 μM NaHS; donor) in mitigating hexavalent chromium [Cr (VI), 50 μM] toxicity in two pulse seedlings: black bean and mung bean. Cr(VI) declined growth and gas exchange parameters (photosynthetic rate, stomatal conductance, sub cellular CO 2 concentration, and transpiration level) which was accompanied by intracellular accumulation of Cr in both pulse crops and the damaging effect was greater in mung bean seedlings. The suppression in the growth and related parameters was occurred due to higher buildup of oxidative stress markers; O 2 • ‾, H 2 O 2 , lipid peroxidation (as malondialdehyde, MDA equivalents) and membrane injury in leaf and root of both pulse crops. Cr induced disturbance in AsA-GSH cycle (reduction in the activity of glutathione reductase, ascorbate peroxidase, monodehydroascorbate reductase and dehydroascorbate reductase, and the amount of ASA and GSH) could be one of the reasons for greater accumulation of H 2 O 2 . Further, exogenous application of ethylene and H 2 S significantly ameliorated Cr toxicity on growth and photosynthetic activity by significantly lowering the intracellular Cr accumulation and oxidative biomarkers, and also by strengthening the activity of AsA-GSH cycle. The exogenous application of biosynthesis inhibitors of ethylene (AVG) and H 2 S (PAG) caused greater damaging effect on these parameters due to more accumulation of Cr(VI), thereby suggesting that the endogenous levels of these regulators are critical for Cr(VI) tolerance. Interestingly, ET did not rescue adverse effects of Cr(VI) in absence of endogenous H 2 S, while H 2 S could do so even without endogenous ethylene, suggesting that H 2 S played downstream signaling to ethylene in regulating Cr(VI) toxicity. Hence, being cheap and easily available theses growth regulators may be considered for sustainable agriculture., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Nitrogen levels and distribution in the rhizosphere strongly regulate the root architecture. Nitrate is an essential nutrient and an important signaling molecule for plant growth and development. Hydroponic experiments were conducted to investigate the differences in endodermal suberization in tobacco (Nicotiana tabacum L.) roots at three nitrate levels. Nitrogen accumulation was detected in the roots, shoots, and xylem sap. Nitrate influx on the root surface was also measured using the non-invasive self-referencing microsensor technique (SRMT). RNA-Seq analysis was performed to identify the genes related to endodermal suberization, nitrate transport, and endogenous abscisic acid (ABA) biosynthesis. The results showed that root length, root-shoot ratio, nitrate influx on the root surface, and NiA and NRT2.4 genes were regulated to maintain the nitrogen nutrient supply in tobacco under low nitrate conditions. Low nitrate levels enhanced root endodermal suberization and hence reduced the apoplastic transport pathway, and genes from the KCS, FAR, PAS2, and CYP86 families were upregulated. The results of exogenous fluridone, an ABA biosynthesis inhibitor, indicated that suberization of the tobacco root endodermis had no relevance to radial nitrate transport and accumulation. However, ABA enhances suberization, relating to ABA biosynthesis genes in the CCD family and degradation gene ABA8ox1., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Evolvulus alsinoides, a therapeutically valuable shrub can provide consistent supply of secondary metabolites (SM) with pharmaceutical significance. Nonetheless, because of its short life cycle, fresh plant material for research and medicinal diagnostics is severely scarce throughout the year. The effects of exogenous carbon quantum dot (CD) application on metabolic profiles, machine learning (ML) prediction of metabolic stress response, and SM yields in hairy root cultures of E. alsinoides were investigated and quantified. The range of the particle size distribution of the CDs was between 3 and 7 nm. The CDs EPR signal and spin trapping experiments demonstrated the formation of O2 -• spin-adducts at (g = 2.0023). Carbon dot treatment increased the levels of hydrogen peroxide and malondialdehyde concentrations as well as increased antioxidant enzyme activity. CD treatments (6 μg mL-1) significantly enhanced the accumulation of squalene and stigmasterol (7 and 5-fold respectively). The multilayer perceptron (MLP) algorithm demonstrated remarkable prediction accuracy (MSE value = 1.99E-03 and R2 = 0.99939) in both the training and testing sets for modelling. Based on the prediction, the maximum oxidative stress index and enzymatic activities were highest in the medium supplemented with 10 μg mL-1 CDs. The outcome of this study indicated that, for the first time, using CD could serve as a novel elicitor for the production of valuable SM. MLP may also be used as a forward-thinking tool to optimize and predict SM with high pharmaceutical significance. This study would be a touchstone for understanding the use of ML and luminescent nanomaterials in the production and commercialization of important SM., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)