Synergistic promotion of angiogenesis after intracerebral hemorrhage by ginsenoside Rh2 and chrysophanol in rats.

BACKGROUND: Intracerebral hemorrhage (ICH) is a debilitating condition characterized by the rupture of cerebral blood vessels, resulting in profound neurological deficits. A significant challenge in the treatment of ICH lies in the brain's limited capacity to regenerate damaged blood vessels. This study explores the potential synergistic effects of Ginsenoside Rh2 and Chrysophanol in promoting angiogenesis following ICH in a rat model. METHODS: Network pharmacology was employed to predict the potential targets and pathways of Ginsenoside Rh2 and Chrysophanol for ICH treatment. Molecular docking was utilized to assess the binding affinity between these compounds and their respective targets. Experimental ICH was induced in male Sprague-Dawley rats through stereotactic injection of type VII collagenase into the right caudate putamen (CPu). The study encompassed various methodologies, including administration protocols, assessments of neurological function, magnetic resonance imaging, histological examination, observation of brain tissue ultrastructure, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), immunofluorescence staining, Western blot analysis, and statistical analyses. RESULTS: Network pharmacology analysis indicated that Ginsenoside Rh2 and Chrysophanol may exert their therapeutic effects in ICH by promoting angiogenesis. Results from animal experiments revealed that rats treated with Ginsenoside Rh2 and Chrysophanol exhibited significantly improved neurological function, reduced hematoma volume, and diminished pathological injury compared to the Model group. Immunofluorescence analysis demonstrated enhanced expression of vascular endothelial growth factor receptor 2 (VEGFR2) and CD31, signifying augmented angiogenesis in the peri-hematomal region following combination therapy. Importantly, the addition of a VEGFR2 inhibitor reversed the increased expression of VEGFR2 and CD31. Furthermore, Western blot analysis revealed upregulated expression of angiogenesis-related factors, including VEGFR2, SRC, AKT1, MAPK1, and MAPK14, in the combination therapy group, but this effect was abrogated upon VEGFR2 inhibitor administration. CONCLUSION: The synergistic effect of Ginsenoside Rh2 and Chrysophanol demonstrated a notable protective impact on ICH injury in rats, specifically attributed to their facilitation of angiogenesis. Consequently, this research offers a foundation for the utilization of Ginsenosides Rh2 and Chrysophanol in medical settings and offers direction for the advancement of novel pharmaceuticals for the clinical management of ICH.

Phosphorus-doped fiber for flat octave spanning supercontinuum generation.

In a fiber supercontinuum (SC) source, the Raman scattering effect plays a significant role in extending the spectrum into a longer wavelength. Here, by using a phosphorus-doped fiber with a broad Raman gain spectrum as the nonlinear medium, we demonstrate flat SC generation spanning from 850 to 2150 nm. Within the wavelength range of 1.1-2.0 µm, the spectral power density fluctuation is less than 7 dB. Compared to a similar SC source based on a germanium-doped fiber with narrower Raman gain spectrum, the wavelength span is 300 nm broader, and the spectral power density fluctuation is 5 dB lower. This work demonstrates the phosphorus-doped fiber's great advantage in spectrally flat SC generation, which is of great significance in many applications such as optical coherence tomography, absorption spectroscopy, and telecommunication.

High power tunable Raman fiber laser at 1.2 µm waveband.

Development of a high power fiber laser at special waveband, which is difficult to achieve by conventional rare-earth-doped fibers, is a significant challenge. One of the most common methods for achieving lasing at special wavelength is Raman conversion. Phosphorus-doped fiber (PDF), due to the phosphorus-related large frequency shift Raman peak at 40 THz, is a great choice for large frequency shift Raman conversion. Here, by adopting 150 m large mode area triple-clad PDF as Raman gain medium, and a novel wavelength-selective feedback mechanism to suppress the silica-related Raman emission, we build a high power cladding-pumped Raman fiber laser at 1.2 µm waveband. A Raman signal with power up to 735.8 W at 1252.7 nm is obtained. To the best of our knowledge, this is the highest output power ever reported for fiber lasers at 1.2 µm waveband. Moreover, by tuning the wavelength of the pump source, a tunable Raman output of more than 450 W over a wavelength range of 1240.6-1252.7 nm is demonstrated. This work proves PDF's advantage in high power large frequency shift Raman conversion with a cladding pump scheme, thus providing a good solution for a high power laser source at special waveband.

Comparative proteomic analysis identifies proteins associated with arbuscular mycorrhizal symbiosis in Poncirus trifoliata.

Citrus, one of the most widely cultivated fruit crops in the world, relies on arbuscular mycorrhizal fungi (AMF) to absorb nutrients and water from soil. However, the molecular mechanism of AM symbiosis (AMS) in citrus in general have largely been understudied. Here, using a TMT labeling proteomic approach, we identified 365 differentially expressed proteins (DEPs) in roots of Poncirus trifoliata (a common citrus rootstock) upon Rhizophagus irregularis colonization as compared with uninoculated roots, of which 287 were up-regulated and 78 were down-regulated. GO analysis revealed that the DEPs were mainly involved in biological processes such as negative regulation of endopeptidase inhibitor activity, negative regulation of endopeptidase, one-carbon metabolic process and carbohydrate metabolic process. KEGG enrichment analysis indicated that the DEPs were mainly involved in regulating metabolic pathways such as fatty acid biosynthesis, phenylpropanoid biosynthesis and carbon metabolism. Furthermore, 194 of the 365 DEPs were found to be associated with AMS-responsive genes by association analysis with our previous transcriptomes data, which highlighted the important roles of these proteins in AMS. One of the 194 DEPs, neutral ceramidase (PtNCER), was further chosen for function analysis via RNAi interfering its homologous gene MtNCER in a mycorrhizal model plant Medicago truncatula, which confirmed a positive role of NCER in AM establishment. Our results provided basic data and key candidate genes for genetic improvement of efficient nutrient uptake through AM establishment in citrus and other crops.

10 kW tandem pumping fiber amplifier with good beam quality based on tapered ytterbium-doped fiber.

In this paper, we established a high power tandem pumped fiber amplifier based on tapered ytterbium-doped fiber (TYDF). The TYDF is developed in-house with a core/inner cladding diameter of 30/250 µm at the small-core region and 48/400 µm at the large-core region. The key parameters of the amplifier in a co-pumped and counter-pumped configuration are experimentally investigated, such as slope efficiency, stimulated Raman scattering (SRS) threshold, and beam quality evolution. Up to 10.28 kW laser free of SRS or transverse mode instability is obtained from the counter-pumped amplifier, and the beam quality factor M2 is 2.29, which is significantly improved compared with the 48/400 µm uniform YDF. To the best of our knowledge, this is the highest average output power achieved so far based on the TYDF. This work could provide a solution for balancing the SRS suppression and high order modes control in high power tandem pumped YDF lasers.

Increased FGL1 Expression Predicts Poor Prognosis and Promotes EMT in Head and Neck Squamous Cell Carcinoma.

Fibrinogen-like protein 1 (FGL1) is a proliferation- and metabolism-related factor secreted by the liver that is aberrantly expressed and functionally abnormal in human malignancies. However, the role of FGL1 in head and neck squamous cell carcinoma (HNSCC) remains unknown. We analysed FGL1 expression in HNSCC and its impact on patient survival using the TCGA database. The role of FGL1 in HNSCC cells was investigated by Cell Counting Kit-8, colony formation, and Transwell assays. In addition, we conducted in vivo experiments to assess the effect of FGL1 knockdown on tumour growth. We found that FGL1 was highly expressed in HNSCC and correlated with a poor prognosis. Downregulation of FGL1 expression inhibited the proliferation and invasion of HNSCC cells. Furthermore, mechanistic analysis revealed that FGL1 induced an epithelial-mesenchymal transition (EMT) phenotype and, thus, the malignant progression of HNSCC cells. Finally, xenograft models showed that FGL1 knockdown significantly inhibited EMT in HNSCC in vivo. Our study revealed that FGL1, an oncogene, promotes the malignant progression of HNSCC, providing new perspective on and potential therapeutic target for the treatment of HNSCC.

All-fiberized linearly polarized superfluorescent fiber source with 5 kW power output.

A superfluorescent fiber source (SFS) is a special fiber source that commonly possesses high temporal stability and a wide spectral linewidth. In this work, an all-fiberized linearly polarized SFS with, to our knowledge, record output power and near-diffraction-limited beam quality is presented. Up to 5.03 kW SFS is achieved at a pump power of 6.18 kW with a corresponding conversion efficiency of ∼81.1%. At maximum output power, the signal-to-noise ratio to background spectral noise is over 50 dB, the polarization extinction ratio is ∼17d B, and the beam quality factor is M x 2=1.49, M y 2=1.44. Further comparisons confirm the power scalability of fiber amplifiers employing SFSs as seed lasers. Overall, this work could provide a good reference for potential exploration of high-power fiber laser systems.

Towards a tapered Yb-doped fiber-based narrow linewidth single-mode fiber laser with a high signal to Raman ratio.

We demonstrate an all-fiber high-power narrow-linewidth fiber laser based on a homemade tapered Yb-doped fiber (T-YDF). The laser performance is investigated and systematically compared with different seed powers and pump manners. The experimental results reveal that the injected seed power requires a trade-off designed to take into account the impact of spectral broadening, nonlinear effects, and transverse mode instability (TMI). Compared with the co-pump manner, the counter-pump manner performs well in inhibiting nonlinearities, spectral broadening, and improving the TMI threshold. Under the counter-pump manner, this narrow-linewidth T-YDF amplifier realized a 2.09 kW output power with a 3 dB spectral linewidth of ∼0.34 nm, a beam quality of M2∼1.28 and a high Raman suppression ratio over 53.5 dB, the highest reported power for such a T-YDF-based narrow-linewidth single-mode laser, to the best of our knowledge. This work provides a promising pathway towards implementing monolithic high-power narrow-linewidth single-mode fiber lasers.

Broadband tunable Raman fiber laser with monochromatic pump.

Raman fiber laser (RFL) has been widely adopted in astronomy, optical sensing, imaging, and communication due to its unique advantages of flexible wavelength and broadband gain spectrum. Conventional RFLs are generally based on silica fiber. Here, we demonstrate that the phosphosilicate fiber has a broader Raman gain spectrum as compared to the common silica fiber, making it a better choice for broadband Raman conversion. By using the phosphosilicate fiber as gain medium, we propose and build a tunable RFL, and compare its operation bandwidth with a silica fiber-based RFL. The silica fiber-based RFL can operate within the Raman shift range of 4.9 THz (9.8-14.7 THz), whereas in the phosphosilicate fiber-based RFL, efficient lasing is achieved over the Raman shift range of 13.7 THz (3.5-17.2 THz). The operation bandwidths of the two RFLs are also calculated theoretically. The simulation results agree well with experimental data, where the operation bandwidth of the phosphosilicate fiber-based RFL is more than twice of that of the silica fiber-based RFL. This work reveals the phosphosilicate fiber's unique advantage in broadband Raman conversion, which has great potential in increasing the reach and capacity of optical communication systems.

Probiotics Alleviate Chemotherapy-Associated Intestinal Mucosal Injury via the TLR4-NFκB Signaling Pathway.

Introduction: Temozolomide (TMZ) induces intestinal mucosa injury that cannot be fully counteracted by supportive treatment. Probiotics regulate gut microbial composition and the host immune system and may alleviate this side effect. We aimed to investigate the potential and mechanism of Lactobacillus rhamnosus GG (LGG) in relieving intestinal mucosal injury induced by TMZ. Methods: Glioblastoma mice were divided into four groups: CON (control), LGG (109 CFU/mL, treated for 7 days), TMZ (50 mg/kg·d, treated for 5 days), LGG+TMZ (LGG for 7 days and TMZ subsequently for 5 days). Body weight, food intake, and fecal pH were recorded. Intestinal tissue samples were collected 1 day after the end of TMZ treatment. Degree of damage to intestine, expression of IL1ß, IL6, TNFα, and IL10 in jejunum were determined. Levels of tight-junction proteins (ZO1, occludin), TLR4, IKKß, IκBα, and P65 with their phosphorylation in jejunum were measured. Results: Decreases in body weight, food intake, spleen index in the TMZ group were mitigated in the LGG+TMZ group, and the degree of intestinal shortening and damage to jejunum villus were also alleviated. The expression of tight-junction proteins in the LGG+TMZ group was significantly greater than that in the TMZ group. IκBα in intestinal tissue significantly decreased in the TMZ group, phos-IKKß and phos-P65 increased compared to the CON group, and LGG reversed such changes in IκBα and phos-P65 in the LGG+TMZ group. Intestinal inflammatory cytokines were significantly increased in the TMZ group, but lower in the LGG+TMZ group. Moreover, expression of TLR4 in LGG group was significantly lower than that in the CON group. LGG inhibited the rise of TLR4 after TMZ in the LGG+TMZ group compared to the TMZ group. Conclusion: LGG inhibits the activation of the TLR4-NFκB pathway and alleviates intestinal mucosal inflammation induced by TMZ, thereby protect the jejunum villi and mucosal physical barrier.

Mitigation of TMI in an 8†kW tandem pumped fiber amplifier enabled by inter-mode gain competition mechanism through bending control.

In this work, the impact of fiber bending and mode content on transverse mode instability (TMI) is investigated. Based on a modified stimulated thermal Rayleigh scattering (STRS) model considering the gain competition between transverse modes, we theoretically detailed the TMI threshold under various mode content and bending conditions in few-mode fibers. Our theoretical calculations demonstrate that larger bending diameters increase the high order mode (HOM) components in the amplifier, which in turn reduces the frequency-shifted Stokes LP11o mode due to the inter-mode gain competition mechanism, thus improving the TMI threshold of few-mode amplifiers. The experimental results agree with the simulation. Finally, by optimizing the bending, an 8.38 kW output tandem pumped fiber amplifier is obtained with a beam quality M2 of 1.8. Both TMI and stimulated Raman scattering (SRS) are well suppressed at the maximum power. This work provides a comprehensive analysis of the TMI in few-mode amplifiers and offers a practical method to realize high-power high-brightness fiber lasers.

Plant lysin motif extracellular proteins are required for arbuscular mycorrhizal symbiosis.

Arbuscular mycorrhizal fungi (AMF) can form a mutually beneficial symbiotic relationship with most land plants. They are known to secrete lysin motif (LysM) effectors into host root cells for successful colonization. Intriguingly, plants secrete similar types of LysM proteins; however, their role in plant-microbe interactions is unknown. Here, we show that Medicago truncatula deploys LysM extracellular (LysMe) proteins to facilitate symbiosis with AMF. Promoter analyses demonstrated that three M. truncatula LysMe genes MtLysMe1/2/3, are expressed in arbuscule-containing cells and those adjacent to intercellular hyphae. Localization studies showed that these proteins are targeted to the periarbuscular space between the periarbuscular membrane and the fungal cell wall of the branched arbuscule. M. truncatula mutants in which MtLysMe2 was knocked out via CRISPR/Cas9-targeted mutagenesis exhibited a significant reduction in AMF colonization and arbuscule formation, whereas genetically complemented transgenic plants restored wild-type level AMF colonization. In addition, knocking out the ortholog of MtLysMe2 in tomato resulted in a similar defect in AMF colonization. In vitro binding affinity precipitation assays suggested binding of MtLysMe1/2/3 with chitin and chitosan, while microscale thermophoresis (MST) assays revealed weak binding of these proteins with chitooligosaccharides. Moreover, application of purified MtLysMe proteins to root segments could suppress chitooctaose (CO8)-induced reactive oxygen species production and expression of reporter genes of the immune response without impairing chitotetraose (CO4)-triggered symbiotic responses. Taken together, our results reveal that plants, like their fungal partners, also secrete LysM proteins to facilitate symbiosis establishment.

Meningioangiomatosis Combined with Calcifying Pseudoneoplasms of Neuraxis.

Meningioangiomatosis (MA) is a rare hamartomatous or meningovascular lesion involving the central nervous system, and is sometimes associated with intracranial meningiomas. Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare, slow-growing benign tumor-like lesions that can occur anywhere along the neuraxis. Here, we report a rare case of MA combined with CAPNON. A 31-year-old woman was admitted to our hospital because of a high-density mass in the left frontal lobe, detected by computed tomography (CT) during a physical examination. She had a 3-year history of obsessive-compulsive disorder. We describe the imaging, histopathological, and molecular characteristics of the patient. To our knowledge, this is the first report describing MA combined with CAPNON. We reviewed the literature on MA and CAPNON over the last decade and summarized the points for differential diagnosis and treatment. It is difficult to preoperatively distinguish between MA and CAPNON. However, this coexisting condition should be considered when intra-axial calcification lesions are observed on radiological imaging. Accurate diagnosis and appropriate treatment are likely to benefit this patient group.

Intraoperative ultrasound in recurrent gliomas surgery: Impact on residual tumor volume and patient outcomes.

Background: Reoperation may be beneficial for patients with recurrent gliomas. Minimizing the residual tumor volume (RTV) while ensuring the functionality of relevant structures is the goal of the reoperation of recurrent gliomas. Intraoperative ultrasound (IoUS) may be helpful for intraoperative tumor localization, intraoperative real-time imaging to guide surgical resection, and postoperative evaluation of the RTV in the reoperation for recurrent gliomas. Objective: To assess the effect of real-time ioUS on minimizing RTV in recurrent glioma surgery compared to Non-ioUS. Methods: We retrospectively analyzed the data from 92 patients who had recurrent glioma surgical resection: 45 were resected with ioUS guidance and 47 were resected without ioUS guidance. RTV, Karnofsky Performance Status (KPS) at 6 months after the operation, the number of recurrent patients, and the time to recurrence were evaluated. Results: The average RTV in the ioUS group was significantly less than the Non-ioUS group (0.27 cm3 vs. 1.33 cm3, p = 0.0004). Patients in the ioUS group tended to have higher KPS scores at 6 months of follow-up after the operation than those in the Non-ioUS group (70.00 vs. 60.00, p = 0.0185). More patients in the Non-ioUS group experienced a recurrence than in the ioUS group (43 (91.49%) vs. 32 (71.11%), p = 0.0118). The ioUS group had a longer mean time to recurrence than the Non-ioUS group (7.9 vs. 6.3 months, p = 0.0013). Conclusion: The use of ioUS-based real-time for resection of recurrent gliomas has been beneficial in terms of both RTV and postoperative outcomes, compared to the Non-ioUS group.

Confined-doped fiber enabled kilowatt-level all-fiber laser with 1.28†GHz linewidth.

In this manuscript, a narrow linewidth fiber amplifier based on confined-doped fiber is established, and the power scaling and beam quality maintaining capabilities of this amplifier are investigated. Benefitted from the large mode area of the confined-doped fiber and precisely controlling the Yb-doped region in the fiber core, the stimulated Brillouin scattering (SBS) and transverse mode instability (TMI) effects are effectively balanced. As a result, a 1007 W signal laser with just 1.28 GHz linewidth is obtained by combining the advantages of confined-doped fiber, near-rectangular spectral injection, and 915 nm pump manner. As far as we know, this result is the first beyond kilowatt-level demonstration of all-fiber lasers with GHz-level linewidth, which could provide a well reference for simultaneously controlling spectral linewidth, suppressing the SBS and TMI effects in high-power, narrow-linewidth fiber lasers.

AVPR2 is a potential prognostic biomarker and correlated with immune infiltration in head and neck squamous cell carcinoma.

PURPOSE: To explore the potential of AVPR2 in the immunotherapy of head and neck squamous cell carcinoma (HNSCC), thus providing insights into a novel antitumour strategy. METHODS: In this study, we performed a comprehensive analysis of the AVPR2 gene in HNSCC using public datasets from The Cancer Genome Atlas and Gene Expression Omnibus. We explored the potential molecular mechanism of HNSCC in clinical prognosis and tumour immunity from the aspects of gene expression, prognosis, immune subtypes, and immune infiltration. RESULTS: AVPR2 expression was significantly downregulated in primary HNSCC tissue compared with normal tissue. HNSCC patients with high AVPR2 expression had a better prognosis. Moreover, the results of GSEA showed that immune subtype surface AVPR2 is involved in immune modulation. Furthermore, significant strong correlations between AVPR2 expression and infiltrating immune cells existed in HNSCC, and marker genes of infiltrating immune cells were also significantly related to AVPR2 expression in HNSCC. These results suggest that AVPR2 expression can influence the infiltration of tumour immune cells. Finally, we found that only high levels of B-cell infiltration, rather than those of other immune cells, can predict a longer overall survival in patients with HNSCC. Future studies are needed to explore the role of AVPR2 and tumour-infiltrating B cells in HNSCC. CONCLUSIONS: The AVPR2 gene may be a prognostic biomarker of HNSCC. Moreover, AVPR2 may play a role in HNSCC immune modulation, and the regulation of tumour-infiltrating B cells by AVPR2 may be a key link.

Analysis of the molecular and biochemical mechanisms involved in the symbiotic relationship between Arbuscular mycorrhiza fungi and Manihot esculenta Crantz.

Introduction: Plants and arbuscular mycorrhizal fungi (AMF) mutualistic interactions are essential for sustainable agriculture production. Although it is shown that AMF inoculation improves cassava physiological performances and yield traits, the molecular mechanisms involved in AM symbiosis remain largely unknown. Herein, we integrated metabolomics and transcriptomics analyses of symbiotic (Ri) and asymbiotic (CK) cassava roots and explored AM-induced biochemical and transcriptional changes. Results: Three weeks (3w) after AMF inoculations, proliferating fungal hyphae were observable, and plant height and root length were significantly increased. In total, we identified 1,016 metabolites, of which 25 were differentially accumulated (DAMs) at 3w. The most highly induced metabolites were 5-aminolevulinic acid, L-glutamic acid, and lysoPC 18:2. Transcriptome analysis identified 693 and 6,481 differentially expressed genes (DEGs) in the comparison between CK (3w) against Ri at 3w and 6w, respectively. Functional enrichment analyses of DAMs and DEGs unveiled transport, amino acids and sugar metabolisms, biosynthesis of secondary metabolites, plant hormone signal transduction, phenylpropanoid biosynthesis, and plant-pathogen interactions as the most differentially regulated pathways. Potential candidate genes, including nitrogen and phosphate transporters, transcription factors, phytohormone, sugar metabolism-related, and SYM (symbiosis) signaling pathway-related, were identified for future functional studies. Discussion: Our results provide molecular insights into AM symbiosis and valuable resources for improving cassava production.

Integrated miRNA-mRNA analysis reveals candidate miRNA family regulating arbuscular mycorrhizal symbiosis of Poncirus trifoliata.

Over 70% land plants live in mutualistic symbiosis with arbuscular mycorrhizal (AM) fungi, and maintenance of symbiosis requires transcriptional and post-transcriptional regulation. The former has been widely studied, whereas the latter mediated by symbiotic microRNAs (miRNAs) remains obscure, especially in woody plants. Here, we performed high-throughput sequencing of the perennial woody citrus plant Poncirus trifoliata and identified 3750 differentially expressed genes (DEGs) and 42 miRNAs (DEmiRs) upon AM fungal colonization. By analyzing cis-regulatory elements in the promoters of the DEGs, we predicted 329 key AM transcription factors (TFs). A miRNA-mRNA regulatory network was then constructed by integrating these data. Several candidate miRNA families of P. trifoliata were identified whose members target known symbiotic genes, such as miR167h-AMT2;3 and miR156e-EXO70I, or key TFs, such as miR164d-NAC and miR477a-GRAS, thus are involved in AM symbiotic processes of fungal colonization, arbuscule development, nutrient exchange and phytohormone signaling. Finally, analysis of selected miRNA family revealed that a miR159b conserved in mycorrhizal plant species and a Poncirus-specific miR477a regulate AM symbiosis. The role of miR477a was likely to target GRAS family gene RAD1 in citrus plants. Our results not only revealed that miRNA-mRNA network analysis, especially miRNA-TF analysis, is effective in identifying miRNA family regulating AM symbiosis, but also shed light on miRNA-mediated post-transcriptional regulation of AM symbiosis in woody citrus plants.

A novel bud mutant of navel orange (Citrus sinensis) shows tolerance to chlorosis in acidic and magnesium-deficient soils.

Interveinal chlorosis in old leaves is a common occurrence in citrus orchards in southern China. The present study investigates the 'Langfeng' navel orange (LF, Citrus sinensis) grafted onto a Trifoliate orange (TO, Poncirus trifoliata) rootstock, which exhibits healthy green leaves, and the 'Newhall' navel orange (NHE, C. sinensis) grafted onto TO, which has typical magnesium (Mg) deficiency-induced chlorosis. Chemical analysis of the rhizosphere soil revealed that the pH values were around 3.92 and that both Mg and calcium (Ca) were significantly deficient in the rhizosphere soil of both grafting combinations (LF/TO and NHE/TO). Furthermore, the chlorotic leaves of NHE/TO had significantly lower levels of Mg, Ca, and phosphorus (P), and the green leaves of NHE/TO had significantly lower levels of Mg and Ca compared to the green leaves of the LF/TO. This suggests that Mg deficiency may be the primary cause of chlorosis in NHE/TO. A greenhouse study using the same graft combinations showed that the LF/TO plants had better growth than the NHE/TO, possibly by promoting Mg uptake and/or improving Mg distribution to leaves, thereby increasing carbon dioxide (CO2) assimilation and photosynthesis, optimizing carbohydrate distribution, and increasing plant biomass. This results in a phenotype that is tolerant to Mg deficiency. In conclusion, these findings suggest that the LF navel orange could be utilized in the development of new citrus varieties with improved Mg-use efficiency.

Stochastic nuclear organization and host-dependent allele contribution in Rhizophagus irregularis.

BACKGROUND: Arbuscular mycorrhizal (AM) fungi are arguably the most important symbionts of plants, offering a range of benefits to their hosts. However, the provisioning of these benefits does not appear to be uniform among AM fungal individuals, with genetic variation between fungal symbionts having a substantial impact on plant performance. Interestingly, genetic variation has also been reported within fungal individuals, which contain millions of haploid nuclei sharing a common cytoplasm. In the model AM fungus, Rhizophagus irregularis, several isolates have been reported to be dikaryotes, containing two genetically distinct types of nuclei recognized based on their mating-type (MAT) locus identity. However, their extremely coenocytic nature and lack of a known single nucleus stage has raised questions on the origin, distribution and dynamics of this genetic variation. RESULTS: Here we performed DNA and RNA sequencing at the mycelial individual, single spore and single nucleus levels to gain insight into the dynamic genetic make-up of the dikaryote-like R. irregularis C3 isolate and the effect of different host plants on its genetic variation. Our analyses reveal that parallel spore and root culture batches can have widely variable ratios of two main genotypes in C3. Additionally, numerous polymorphisms were found with frequencies that deviated significantly from the general genotype ratio, indicating a diverse population of slightly different nucleotypes. Changing host plants did not show consistent host effects on nucleotype ratio's after multiple rounds of subculturing. Instead, we found a major effect of host plant-identity on allele-specific expression in C3. CONCLUSION: Our analyses indicate a highly dynamic/variable genetic organization in different isolates of R. irregularis. Seemingly random fluctuations in nucleotype ratio's upon spore formation, recombination events, high variability of non-tandemly repeated rDNA sequences and host-dependent allele expression all add levels of variation that may contribute to the evolutionary success of these widespread symbionts.