Selenium increases antimony uptake in As-hyperaccumulators Pteris vittata and Pteris cretica by promoting antimonate reduction: GSH-GSSG cycle and arsenate reductases HAC1/ACR2.

Selenium-enhanced arsenic uptake by As-hyperaccumulators Pteris vittata and Pteris cretica is known, but how it impacts antimony (Sb) uptake and associated mechanisms are unclear. Here, we investigated the effects of 2.5 µM selenate (Se2.5) on Sb uptake by two plants after growing for 10 days under hydroponics containing 10 or 50 µM antimonate (SbV) (Sb10 or Sb50). Both plants were efficient in taking up SbV, which was reduced to SbIII (17-40 %) and mainly accumulated in the roots (86-97 %). The addition of Se increased the Sb contents by 78-97 and 29-33 % to 242-1358 and 132-697 mg kg-1 in P. vittata and P. cretica roots. Compared with the Sb10 and Sb50 treatments, addition of Se increased the SbV reduction, with more increase in P. vittata than P. cretica roots (181-273 % vs. 17-29 %). Enhanced GSH-GSSG cycle mediated by glutathione peroxidase (GPX) and glutathione reductase (GR) may play an important role in SbV reduction in the roots. Compared with the Sb treatments, addition of Se increased the GPX and GR activity by 71-97 and 2-50 % in P. vittata roots, and 59-153 and 22-63 % in P. cretica roots. Besides, Se upregulated the expression of arsenate reductases PvHAC1 and PvACR2 in P. vittata roots by 1.7-3.4 folds but not in P. cretica. Se-enhanced SbV reduction in P. vittata explains why it was more effective in Sb accumulation than P. cretica. Taken together, Se is effective in increasing the Sb uptake in both plants probably by promoting SbV reduction via GSH-GSSG cycle and/or PvHAC1/PvACR2, suggesting that Se may be used to enhance phytostabilization of Sb-contaminated soils.

A one-way ticket: wheat roots do not functionally refill xylem emboli following rehydration.

Understanding xylem embolism spread in roots is essential for predicting the loss of function across root systems during drought. However, the lasting relevance of root embolism to plant recovery depends on whether roots can refill xylem emboli and resume function after rehydration. Using MicroCT and optical and dye staining methods, we investigated embolism repair in rehydrated intact roots of wheat (Triticum aestivum L.'Krichauff') exposed to a severe water deficit of -3.5 MPa, known to cause approximately 30 % total root network embolism in this species. Air emboli in the xylem vessels of intact roots remained clearly observable using MicroCT after overnight rehydration. This result was verified by xylem staining of the root system and optical quantification of emboli, both of which indicated a lack of functional root xylem recovery 60 hours following soil re-saturation. The absence of root xylem refilling in wheat has substantial implications for how we understand plant recovery after drought. Our findings suggest that xylem embolism causes irreversible damage to the soil-root hydraulic connection in affected parts of the root network.

Early overyielding in a mixed deciduous forest is driven by both above- and below ground species-specific acclimation.

BACKGROUND AND AIMS: Mixed forest plantations are increasingly recognised for their role in mitigating the impacts of climate change and enhancing ecosystem resilience. Yet, there remains a significant gap in understanding the early-stage dynamics of species trait diversity and interspecies interactions, particularly in pure deciduous mixtures. This study aims to explore the timing and mechanisms by which trait diversity of deciduous species and competitive interactions influence yield, carbon allocation, and space occupation in mixed forests, both above- and belowground. METHODS: A forest inventory was conducted in planted monocultures, 2-species, and 4-species mixtures of European Acer, Tilia, Carpinus, and Quercus, representing a spectrum from acquisitive to conservative tree species. Competition effects were assessed with linear mixed-effects models at the level of biomass and space acquisition, including leaf, canopy, stem, and fine root traits. KEY RESULTS: Early aboveground growth effects were observed six years post-planting, with significant biomass accumulation after eight years, strongly influenced by species composition. Mixtures, especially with acquisitive species, exhibited aboveground overyielding, 1.5- to 1.9-times higher than monocultures. Fine roots showed substantial overyielding in high diversity stands. Biomass allocation was species-specific and varied markedly by tree size, the level of diversity, and between acquisitive Acer and the more conservative species. No root segregation was found. CONCLUSIONS: Our findings underscore the critical role of species trait diversity in enhancing productivity in mixed deciduous forest plantations. Allometric changes highlight the need to differentiate between (active) acclimations and (passive) tree size-related changes, but illustrate major consequences of competitive interactions for the functional relation between leaves, stem, and roots. This study points towards the significant contributions of both above- and belowground components to overall productivity of planted mixed-species forests.

Multiomic Profiling and Neuroprotective Bioactivity of Salvia Hairy Root-Derived Extracellular Vesicles in a Cellular Model of Parkinson's Disease.

Purpose: Extracellular vesicles (EVs) are promising tools for nanomedicine and nanobiotechnology. The purification of mammalian-derived EVs involves intensive processes, and their therapeutic application raises multiple safety and regulatory issues. Plants have the potential to serve as nonconventional sources of therapeutically relevant EVs. In this context, we recently identified hairy roots (HRs) of medicinal plants as a novel biotechnological platform to produce EVs for human health. Methods: Herein, we report the purification, omics profiling, and bioactivity of EVs isolated from HRs of the medicinal plants S. sclarea and S. dominica. EVs were isolated from conditioned media of HR cultures using differential ultracentrifugation (dUC) and size exclusion chromatography (SEC). The isolated EVs were characterized by nanoparticle tracking analysis (NTA) and electron microscopy. The proteomic and metabolomic profiles of the EVs were determined using mass spectrometry. Uptake studies and bioactivity assays, including confocal microscopy, MTT, flow cytometry, ROS quantification, and untargeted metabolomics analyses, were conducted in SH-SY5Y cells treated with the neurotoxin 6-hydroxydopamine (6-OHDA) to evaluate the therapeutic potential of EVs in an in vitro model of Parkinson's disease. Results: S. sclarea HRs released nanosized round-shaped EVs with a distinctive molecular signature. HR EVs from S. sclarea and S. dominica revealed conserved cargo of secondary metabolites, predominantly triterpenoids, which are known for their antioxidant properties. We showed that HR EVs are safe, enter the cells, and strongly inhibit apoptosis in a cellular model of Parkinson's disease. Cellular metabolomics revealed that EVs preserved metabolic homeostasis and mitigated cellular oxidative stress when co-administered with 6-OHDA. Mechanistically, HR EVs inhibited 6-OHDA autoxidation and substantially reduced the accumulation of its oxidative products, which are responsible for 6-OHDA-induced toxicity. Conclusion: Collectively, our findings provide compelling evidence that EVs isolated from the hairy roots of Salvia species are promising, non-mammalian alternative for the design of novel therapies targeting neurological disorders.

Lateral meniscus posterior root repairs show superior healing, reduced meniscal extrusion and improved clinical outcomes compared to medial meniscus posterior root repairs: A systematic review.

PURPOSE: To systematically review and summarize the available literature on (1) postoperative healing rates, meniscal extrusion (ME) and clinical outcomes following lateral (LMPRR) versus medial (MMPRR) root repair and (2) potential correlations between residual ME and healing outcomes. METHODS: A comprehensive literature search was conducted using the Scopus, PubMed and Embase databases. Clinical studies evaluating healing status on second-look arthroscopy and magnetic resonance imaging (MRI) after LMPRR and MMPRR were included. Study quality was assessed using the Methodological Index for Non-Randomized Studies criteria and the modified Coleman Methodology Score. RESULTS: Twenty-three studies comprising 871 patients with LMPRR (n = 406) and MMPRR (n = 465) were included. Overall, 223 (54.9% of total) and 149 (32.04% of total) patients underwent second-look arthroscopy in the LMPRR and MMPRR groups, respectively. Complete root healing was observed in 190 (85.2%) patients in the LMPRR group versus 78 (52.3%) in the MMPRR group (p < 0.001). There were six (2.7%) failed repairs in the LMPRR group compared to 21 (14.09%) in the MMPRR group (p < 0.001). On postoperative MRI, 109 (75.7%) root repairs were healed in the LMPRR group compared to 192 (53.3%) in the MMPRR group (p < 0.001). Failure rates were lower after all-inside and transtibial pullout repairs in the LMPRR group but higher in the MMPRR group, with no significant mean difference between preoperative and postoperative ME in the MMPRR group (p = 0.95). Significantly better clinical outcomes were observed in the LMPRR group compared to the MMPRR group. A greater degree of postoperative ME was associated with lower healing rates (R = -0.78, p < 0.0005). Postoperative ME did not influence clinical outcomes (R = 0.28, p = 0.29). CONCLUSIONS: Lateral meniscus posterior root repairs showed higher healing rates compared to MMPRR on both second-look arthroscopy and postoperative MRI. Meniscal extrusion decreased after LMPRR but not after MMPRR. Greater residual ME correlated inversely with healing rates, as more extrusion was associated with lower healing. Postoperative clinical improvement did not affect ME or healing status. STUDY DESIGN: Systematic review of level III and IV studies. LEVEL OF EVIDENCE: Level IV.

Genome-wide analysis of the WOX gene family and function exploration of RhWOX331 in rose (R. 'The Fairy').

WOXs are a class of plant-specific transcription factors that play key roles in plant growth and stress responses. However, the mechanism by which WOXs influence adventitious root development in Rosa hybrida remains unclear. In this study, RcWOX gene family in rose was identified and phylogenetically analyzed using bioinformatics analysis. A total of 381 RcWOX gene members were localized on seven chromosomes except of nine members. The main cis-acting elements involved in hormonal, light, developmental, and abiotic stress responses were identified in the promoters of RcWOX genes, suggesting their regulation by these signals. Nine RhWOX genes had significant different expression during rooting process of rose. RhWOX331, RhWOX308, RhWOX318 were positive with the formation of rose roots. RhWOX331 was positively involved in the formation of adventitious root primordia, which gene coding a transcription factor localized in the nucleus. The HOX conserved domain in the protein contributed to the self-activating activity of RhWOX331. We obtained genetically modified Arabidopsis to validate the function of RhWOX331. Overexpression of RhWOX331 gene alleviated the inhibition of root length of A. thaliana primary roots by high concentration of IBA and NPA, and significantly increased the number of lateral roots on the primary roots, as well as the height of A. thaliana plants. Additionally, RhWOX331 promoted adventitious root formation in A. thaliana and mitigated hormonal inhibition by exogenous 6-BA, NPA, and GA3. The RhWOX331 promoter contained cis-acting elements such as ABRE, Box 4 and CGTCA-motif et.al. GUS activity analysis showed that the gene acted at the cotyledon attachment site. Taken together, these studies identified a significant expansion of the RcWOX gene family, inferred roles of certain branch members in adventitious root formation, elucidated the function of RhWOX331 in adventitious root initiation, and laid the foundation for further research on the function of WOX gene family in roses.

The quantification of root exudation by an in-situ method based on root morphology over three incubation periods.

Investigating the quantity and spatiotemporal dynamics of metabolite release from plant roots is essential if we are to understand the ecological significance of root exudates in the rhizosphere; however, this is difficult to quantify. In the present study, we quantified in situ root exudation rates during three incubation periods (0-24, 24-48, and 48-72 h) and fine roots within four diameter ranges (<0.8, 0.8-1.0, 1.0-1.2, and 1.2-2.0 mm), and also measured nine morphological traits in the fine roots of Pinus massoniana. Higher root carbon (C) exudation rates were detected during the 0-24 h period. During the 0-24 h and 24-48 h periods, nitrogen (N) uptake rates were higher than N exudation rates, while during the 48-72 h period, N exudation rates exceeded uptake rates. As C exudation increased during 0-48h incubation period, the uptake of N tended to level out. We concluded that the 24-48 h incubation period was the most suitable for capturing root exudates from P. massoniana. The exudation of C from the roots was positively associated with root mass, length, surface area, volume, the number of root tips, and the root tissue density, when incubated for 0-24 h and 24-48 h. Furthermore, length-specific C exudation rates, along with N exudation and uptake rates, all increased as the diameter of the fine roots increased. The release of root exudates could be efficiently predicted by the fine root morphological traits, although the accuracy of prediction depended on the incubation period. Higher values for fine root morphological traits were generally indicative of higher nutrient requirements and tissue investment, as well as higher C exudation rates.

A Bayesian approach for estimating the uncertainty on the contribution of nitrogen fixation and calculation of nutrient balances in grain legumes.

BACKGROUND: The proportion of nitrogen (N) derived from the atmosphere (Ndfa) is a fundamental component of the plant N demand in legume species. To estimate the N benefit of grain legumes for the subsequent crop in the rotation, a simplified N balance is frequently used. This balance is calculated as the difference between fixed N and removed N by grains. The Ndfa needed to achieve a neutral N balance (hereafter θ ) is usually estimated through a simple linear regression model between Ndfa and N balance. This quantity is routinely estimated without accounting for the uncertainty in the estimate, which is needed to perform formal statistical inference about θ . In this article, we utilized a global database to describe the development of a novel Bayesian framework to quantify the uncertainty of θ . This study aimed to (i) develop a Bayesian framework to quantify the uncertainty of θ , and (ii) contrast the use of this Bayesian framework with the widely used delta and bootstrapping methods under different data availability scenarios. RESULTS: The delta method, bootstrapping, and Bayesian inference provided nearly equivalent numerical values when the range of values for Ndfa was thoroughly explored during data collection (e.g., 6-91%), and the number of observations was relatively high (e.g., ≥ 100 ). When the Ndfa tested was narrow and/or sample size was small, the delta method and bootstrapping provided confidence intervals containing biologically non-meaningful values (i.e. < 0% or > 100%). However, under a narrow Ndfa range and small sample size, the developed Bayesian inference framework obtained biologically meaningful values in the uncertainty estimation. CONCLUSION: In this study, we showed that the developed Bayesian framework was preferable under limited data conditions ─by using informative priors─ and when uncertainty estimation had to be constrained (regularized) to obtain meaningful inference. The presented Bayesian framework lays the foundation not only to conduct formal comparisons or hypothesis testing involving θ , but also to learn about its expected value, variance, and higher moments such as skewness and kurtosis under different agroecological and crop management conditions. This framework can also be transferred to estimate balances for other nutrients and/or field crops to gain knowledge on global crop nutrient balances.

Substrate heterogeneities cause root growth trajectories to switch from vertical to oblique.

Hard pans, soil compaction, soil aggregation and stones create physical barriers that can affect the development of a root system. Roots are known to exploit paths of least resistance to avoid such obstacles, but the mechanism through which this is achieved is not well understood. Here, we combined 3D-printed substrates with a high-throughput live imaging platform to study the responses of plant roots to a range of physical barriers. Using image analysis algorithms, we determined the properties of growth trajectories and identified how the presence of rigid circular obstacles affects the ability of a primary root to maintain its vertical trajectory. Results showed the types of growth responses were limited, both vertical and oblique trajectories were found to be stable and influenced by the size of the obstacles. When obstacles were of intermediate sizes, trajectories were unstable and changed in nature through time. We formalised the conditions for root trajectory to change from vertical to oblique, linking the angle at which the root detaches from the obstacle to the root curvature due to gravitropism. Exploitation of paths of least resistance by a root may therefore be constrained by the ability of the root to curve and respond to gravitropic signals.

Determination of the Protein and Amino Acid Content of Fruit, Vegetables and Starchy Roots for Use in Inherited Metabolic Disorders.

Amino acid (AA)-related inherited metabolic disorders (IMDs) and urea cycle disorders (UCDs) require strict dietary management including foods low in protein such as fruits, vegetables and starchy roots. Despite this recommendation, there are limited data on the AA content of many of these foods. The aim of this study is to describe an analysis of the protein and AA content of a range of fruits, vegetables and starchy roots, specifically focusing on amino acids (AAs) relevant to AA-related IMDs such as phenylalanine (Phe), methionine (Met), leucine (Leu), lysine (Lys) and tyrosine (Tyr). AA analysis was performed using high-performance liquid chromatography (HPLC) on 165 food samples. Protein analysis was also carried out using the Dumas method. Foods were classified as either 'Fruits', 'Dried fruits', 'Cruciferous vegetables', 'Legumes', 'Other vegetables' or 'Starchy roots'. 'Dried fruits' and 'Legumes' had the highest median values of protein, while 'Fruits' and 'Cruciferous vegetables' contained the lowest median results. 'Legumes' contained the highest and 'Fruits' had the lowest median values for all five AAs. Variations were seen in AA content for individual foods. The results presented in this study provide useful data on the protein and AA content of fruits, vegetables and starchy roots which can be used in clinical practice. This further expansion of the current literature will help to improve diet quality and metabolic control among individuals with AA-related IMDs and UCDs.

Biomechanical study of spinal cord and nerve root in idiopathic scoliosis: based on finite element analysis.

BACKGROUND: Current research lacks comprehensive investigation into the biomechanical changes in the spinal cord and nerve roots during scoliosis correction. This study employs finite element analysis to extensively explore these biomechanical variations across different Cobb angles, providing valuable insights for clinical treatment. METHODS: A personalized finite element model, incorporating vertebrae, ligaments, spinal cord, and nerve roots, was constructed using engineering software. Forces and displacements were applied to achieve Cobb angle improvements, designating T1/2-T4/5 as the upper segment, T5/6-T8/9 as the middle segment, and T9/10-L1/2 as the lower segment. Simulations under traction, pushing, and traction + torsion conditions were conducted, and biomechanical changes in each spinal cord segment and nerve roots were analyzed. RESULTS: Throughout the scoliosis correction process, the middle spinal cord segment consistently exhibited a risk of injury under various conditions and displacements. The lower spinal cord segment showed no significant injury changes under traction + torsion conditions. In the early correction phase, the upper spinal cord segment demonstrated a risk of injury under all conditions, and the lower spinal cord segment presented a risk of injury under pushing conditions. Traction conditions posed a risk of nerve injury on both sides in the middle and lower segments. Under pushing conditions, there was a risk of nerve injury on both sides in all segments. Traction + torsion conditions implicated a risk of injury to the right nerves in the upper segment, both sides in the middle segment, and the left side in the lower segment. In the later correction stage, there was a risk of injury to the upper spinal cord segment under traction + torsion conditions, the left nerves in the middle segment under traction conditions, and the right nerves in the upper segment under pushing conditions. CONCLUSION: When the correction rate reaches 61-68%, particular attention should be given to the upper-mid spinal cord. Pushing conditions also warrant attention to the lower spinal cord and the nerve roots on both sides of the main thoracic curve. Traction conditions require attention to nerve roots bilaterally in the middle and lower segments, while traction combined with torsion conditions necessitate focus on the right-side nerve roots in the upper segment, both sides in the middle segment, and the left-side nerve roots in the lower segment.

Bilateral Symmetrical Mandibular Canines with Two Roots and Two Separate Canals: A Case Report and Literature Review.

BACKGROUND: The permanent canine usually has a single root and a single root canal. A one-rooted canine with two canals or a canine with two roots and two separate canals may also occur at a lower incidence in the permanent dentition. However, bilateral symmetrical mandibular canines with two roots and two separate canals are less common. CASE PRESENTATION: This study reported a lower incidence case of bilateral symmetrical mandibular canines with two roots and two separate canals, which was found based on a CBCT examinaton. The patient visited our department and was consulted for orthodontic treatment due to the irregularity of her lower anterior teeth. As the abnormal root morphology of bilateral mandibular canines greatly increased the difficulty of orthodontic treatment, the patient finally gave up orthodontic treatment after communication. CONCLUSION: This case report provides supplementary data to better understand the complexities of the root canal system of canines.

Getting to the root of root-microbe interactions.

Microbial relationships with roots influence many ecosystem functions and nutrient fluxes, including their sometimes-profound effects on plant health and productivity. Fine roots were often classified with a diameter less than 2 mm, but fine roots under that size perform distinct functional roles in the environment. Importantly, two broad functional categories of fine roots are absorptive and transportive, with absorptive fine roots acting as metabolic hotspots for root activity. In two of our recent studies, we have shown that several microbial community characteristics differ between absorptive and transportive fine roots, including composition, abundance, and function, as well as the root metabolome. This highlights a growing recognition within microbial ecology that we must consider fine-scale environmental variability, such as root physiology and morphology, when interpreting microbial patterns. In this commentary, we summarize the findings of our latest article, further speculate on some of these patterns, and suggest future studies for examining decomposition and applying cutting-edge single-cell sequencing techniques.

Unraveling the molecular response of Brassica napus hairy roots in the active Naphthol blue-black removal: Insights from proteomic analysis.

In vitro plant cultures are able to remove and metabolise xenobiotics, making them promising tools for decontamination strategies. In this work, we evaluated Brassica napus hairy roots (HRs) to tolerate and remove high concentrations of the azo dye Naphthol Blue-Black (NBB). Experiments were performed using both growing and resting culture systems at different pHs. Reuse of HRs biomass was evaluated in successive decolourisation cycles. Proteomics was applied to understand the molecular responses likely to be involved in the tolerance and removal of NBB. The HRs tolerated up to 480 µg mL-1 NBB, and 100 % removal was achieved at 180 µg mL-1 NBB after 10 days using both culture systems. Interestingly, the HRs are robust enough to be reused, showing 55-60 % removal even after three reuse cycles. The highest dye removal rates were achieved during the first 2 days of incubation, as initial removal is mainly driven by passive processes. Active mechanisms are triggered later by regulating the expression of proteins with different biological functions, mainly those related to xenobiotic metabolism, such as hydrolytic and redox enzymes. These results suggest that B. napus HRs are a robust tool that could make a significant contribution to textile wastewater treatment.

Tapping the potential of Calotropis procera hairy roots for cardiac glycosides production and their identification using UHPLC/QTOF-MS.

The present work deals with the establishment of hairy root cultures from different explants of C. procera using Agrobacterium rhizogenes strain A4. A high transformation frequency (95%) was obtained from leaves followed by cotyledons (81.6%) and hypocotyls (38.3%). Genetic transformation of hairy roots was confirmed through PCR by amplifying a 400 bp fragment of the rolB gene. Hairy roots were highly branched, possessed plagiotropic and rapid growth on hormone-free ½ B5 medium. Ten cardiac glycosides, including calotropagenin, calotoxin, frugoside, coroglaucigenin, calotropin, calactin, uzarigenin, asclepin, uscharidin, and uscharin, based on their specific masses and fragmentation properties were identified in ethanolic extracts of hairy roots by ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry UHPLC/QTOF-MS. This protocol could be used as a powerful tool for large-scale in vitro production of highly valued cardiac glycosides and for further transcriptomics or metabolomics studies.

Mechanical wounding improves salt tolerance by maintaining root ion homeostasis in a desert shrub.

Soil salinization, especially in arid environments, is a leading cause of land degradation and desertification. Excessive salt in the soil is detrimental to plants. Plants have developed various sophisticated regulatory mechanisms that allow them to withstand adverse environments. Through cross-adaptation, plants improve their resistance to an adverse condition after experiencing a different kind of adversity. Our analysis of Ammopiptanthus nanus, a desert shrub, showed that mechanical wounding activates the biosynthesis of jasmonic acid (JA) and abscisic acid (ABA), enhancing plasma membrane H+-ATPase activity to establish an electrochemical gradient that promotes Na+ extrusion via Na+/H+ antiporters. Mechanical wounding reduces K+ loss under salt stress, improving the K/Na and maintaining root ion balance. Meanwhile, mechanical damage enhances the activity of antioxidant enzymes and the content of osmotic substances, working together with cellular ions to alleviate water loss and growth inhibition under salt stress. This study provides new insights and approaches for enhancing salt tolerance and stress adaptation in plants by elucidating the signaling mechanisms of cross-adaptation.

Dynamic soil hydraulic resistance regulates stomata.

The onset of stomatal closure reduces transpiration during drought. In seed plants, drought causes declines in plant water status which increases leaf endogenous abscisic acid (ABA) levels required for stomatal closure. There are multiple possible points of increased belowground resistance in the soil-plant atmospheric continuum that could decrease leaf water potential enough to trigger ABA production and the subsequent decreases in transpiration. We investigate the dynamic patterns of leaf ABA levels, plant hydraulic conductance and the point of failure in the soil-plant conductance in the highly embolism-resistant species Callitris tuberculata using continuous dendrometer measurements of leaf water potential during drought. We show that decreases in transpiration and ABA biosynthesis begin before any permanent decreases in predawn water potential, collapse in soil-plant hydraulic pathway and xylem embolism spread. We find that a dynamic but recoverable increases in hydraulic resistance in the soil in close proximity to the roots is the most likely driver of declines in midday leaf water potential needed for ABA biosynthesis and the onset of decreases in transpiration.

Grasslands and flood mitigation - Contrasting forages improve surface water infiltration rates.

Grasslands globally deliver many ecosystem services, including water management to alleviate flood risk reduction. Two replicated field experiments were conducted to study how agricultural forage species with diverse rooting systems, sown as single species, affected rooting, soil structure and earthworm populations, and consequently water infiltration to understand how they each might influence flood risk from grasslands. Experiment One showed soils under red clover (Trifolium pratense), white clover (Trifolium repens) and chicory (Cichorium intybus) had higher infiltration rates three years after establishment, compared to perennial ryegrass (Lolium perenne). Higher red clover and chicory root biomass or increased earthworm abundance under white clover may have caused these effects. Experiment Two monitored infiltration at intervals over several years post establishment to understand the timeframe for changes in rates; plantain (Plantago lanceolata) was sown as an additional forage. Infiltration declined post establishment, the timing and extent of decline varying with forages; forage effects were significant after 27 months (P < 0.05). Infiltration rates were higher under red and white clover compared to ryegrass, with chicory and plantain intermediate (P < 0.05). Forages again differed in likely mechanisms delivering higher water infiltration, notably between the two clover species. White clover had higher earthworm biomass (P < 0.05), whereas red clover had a higher average root diameter compared to the other forages (P < 0.05). Drivers of intermediate benefits of chicory and plantain also differed: chicory had higher earthworm abundance (month 38) compared to plantain, which had higher average root diameter compared to ryegrass (month 41); 30 months post-establishment soil bulk density was lower under both forages compared to ryegrass and red clover, with white clover intermediate (P < 0.05); bulk density and penetration resistance did not relate to infiltration. Findings demonstrate that a shift from perennial ryegrass-dominated pastures to swards with more contrasting forages provides an ecohydrological approach to mitigating flood risk and climate adaptation.

Combined salt and low nitrate stress conditions lead to morphophysiological changes and tissue-specific transcriptome reprogramming in tomato.

Despite intense research towards the understanding of abiotic stress adaptation in tomato, the physiological adjustments and transcriptome modulation induced by combined salt and low nitrate (low N) conditions remain largely unknown. Here, three traditional tomato genotypes were grown under long-term single and combined stresses throughout a complete growth cycle. Physiological, molecular, and growth measurements showed extensive morphophysiological modifications under combined stress compared to the control, and single stress conditions, resulting in the highest penalty in yield and fruit size. The mRNA sequencing performed on both roots and leaves of genotype TRPO0040 indicated that the transcriptomic signature in leaves under combined stress conditions largely overlapped that of the low N treatment, whereas root transcriptomes were highly sensitive to salt stress. Differentially expressed genes were functionally interpreted using GO and KEGG enrichment analysis, which confirmed the stress and the tissue-specific changes. We also disclosed a set of genes underlying the specific response to combined conditions, including ribosome components and nitrate transporters, in leaves, and several genes involved in transport and response to stress in roots. Altogether, our results provide a comprehensive understanding of above- and below-ground physiological and molecular responses of tomato to salt stress and low N treatment, alone or in combination.

Development of Stephania tetrandra S. MOORE hairy root culture process for tetrandrine production.

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 NH4NO3 (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.