The Methyltransferase HemK Regulates the Virulence and Nutrient Utilization of the Phytopathogenic Bacterium Xanthomonas citri Subsp. citri.

Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (Xcc), seriously affects fruit quality and yield, leading to significant economic losses around the world. Understanding the mechanism of Xcc virulence is important for the effective control of Xcc infection. In this report, we investigate the role of a protein named HemK in the regulation of the virulence traits of Xcc. The hemK gene was deleted in the Xcc jx-6 background, and the ΔhemK mutant phenotypically displayed significantly decreased motility, biofilm formation, extracellular enzymes, and polysaccharides production, as well as increased sensitivity to oxidative stress and high temperatures. In accordance with the role of HemK in the regulation of a variety of virulence-associated phenotypes, the deletion of hemK resulted in reduced virulence on citrus plants as well as a compromised hypersensitive response on a non-host plant, Nicotiana benthamiana. These results indicated that HemK is required for the virulence of Xcc. To characterize the regulatory effect of hemK deletion on gene expression, RNA sequencing analysis was conducted using the wild-type Xcc jx-6 strain and its isogenic ΔhemK mutant strain, grown in XVM2 medium. Comparative transcriptome analysis of these two strains revealed that hemK deletion specifically changed the expression of several virulence-related genes associated with the bacterial secretion system, chemotaxis, and quorum sensing, and the expression of various genes related to nutrient utilization including amino acid metabolism, carbohydrate metabolism, and energy metabolism. In conclusion, our results indicate that HemK plays an essential role in virulence, the regulation of virulence factor synthesis, and the nutrient utilization of Xcc.

Effect of coupling asynchronous acoustoelectric effects on the corrosion behavior, microhardness and biocompatibility of biomedical titanium alloy strips.

The coupling asynchronous acoustoelectric effects (CAAE) of the high-energy electropulsing treatment (EPT) technique and ultrasonic surface strengthening modification (USSM) are innovatively combined in improving the surface microhardness, corrosion behavior and biocompatibility of the pre-deformed titanium alloy strips. Experimental results show that EPT and USSM processes facilitate the surface grain refining and USSM brings in the micro-dimples on the materials surface, which is attributed to the atoms diffusion acceleration under EPT and severe surface plastic deformation under USSM. These microstructure changes can not only enhance the corrosion resistance in the acidic simulated body fluids and fluoridated acidic artificial saliva but also improve the biocompatibility of the titanium alloy strip materials. Moreover, the surface microhardness of the titanium alloy strips is enhanced to improve the wear resistance. Therefore, CAAE processing is a high-efficiency and energy-saving method for obtaining biomedical titanium alloys with superior anti-corrosion performance, microhardness and biocompatibility, which can be widely applied in dental implants and artificial joint.

Effects of microplastics on litter decomposition in wetland soil.

Microplastics (MPs) may interfere with the primary ecological processes of soil, which has become a growing global environmental issue. In terrestrial ecosystems, litter decomposition is the main process of nutrient cycling, particularly for carbon (C) and nitrogen (N). However, how microplastic pollution could alter wetland litter decomposition has barely been investigated. Therefore, a 100-day lab-scale litter decomposition experiment was conducted using Shengjin Lake wetland soil, which was treated with two types of MPs (polyethylene, PE and polyvinyl chloride, PVC) at three concentrations (0.1%, 0.5%, and 2.5%, w/w), to explore if and how MPs accumulation could affect wetland litter decomposition processes. According to our research, the PE and PVC greatly slowed the decomposition rate of wetland litter. Compared with control treatments, the addition of MPs decreased litter quality (high C:N), reduced litter decomposition-related soil enzyme activity, decreased the diversity of bacteria, and altered microbial community structure and potential functional gene abundance linked to litter decomposition. These findings revealed that MPs could affect the main process of C and N cycling in wetland ecosystems, providing important cues for further research on the wetland ecosystem function.

Unveil of the role of fungal taxa in iron(III) reduction in paddy soil.

Hitherto, research on iron(III)-reduction has mainly focused on bacteria rather than fungal communities. To acquire insight into fungi involved in iron(III) reduction, typical organic matters (containing cellulose, glucose, lactate, and acetate) and ferrihydrite were used as electron donors and acceptors, respectively, in the presence of antibiotics. After antibiotic addition, microbial iron(III) reduction was still detected at quite high rates. In comparison, rates of iron(III) reduction were significantly lower in cellulose-amended groups than those with glucose, lactate, and acetate under the antibiotic-added condition. Patterns of intermediate (e.g., acetate, pyruvate, glucose) turnover were markedly different between treatments with and without antibiotics during organic degradation. A total of 20 genera of potential respiratory and fermentative iron(III)-reducing fungi were discovered based on ITS sequencing and genome annotation. This study provided an insight into the diversity of iron(III)-reducing fungi, indicating the underestimated contribution of fungi to iron and the coupled carbon biogeochemical cycling in environments.

Isolation of the Novel Strain Bacillus amyloliquefaciens F9 and Identification of Lipopeptide Extract Components Responsible for Activity against Xanthomonas citri subsp. citri.

Citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), is a quarantine disease that seriously affects citrus production worldwide. The use of microorganisms and their products for biological control has been proven to be effective in controlling Xanthomonas disease. In this study, a novel Xcc antagonistic strain was isolated and identified as Bacillus amyloliquefaciens F9 by morphological and molecular analysis. The lipopeptide extract of B. amyloliquefaciens F9 (F9LE) effectively inhibited the growth of Xcc in an agar diffusion assay and restrained the occurrence of canker lesions in a pathogenicity test under greenhouse conditions. Consistent with these findings, F9LE treatment significantly inhibited the production of extracellular enzymes in Xcc cells and induced cell wall damage, with leakage of bacterial contents revealed by scanning electron microscopy and transmission electron microscopy analyses. In addition, F9LE also showed strong antagonistic activity against a wide spectrum of plant pathogenic bacteria and fungi. Furthermore, using electrospray ionization mass spectrometry analysis, the main antimicrobial compounds of strain F9 were identified as three kinds of lipopeptides, including homologues of surfactin, fengycin, and iturin. Taken together, our results show that B. amyloliquefaciens F9 and its lipopeptide components have the potential to be used as biocontrol agents against Xcc, and other plant pathogenic bacteria and fungi.

Protective Effects of Reduced Glutathione and Ulinastatin on Xeno-transplanted Human Ovarian Tissue Against Ischemia and Reperfusion Injury.

Recently, transplantation of cryopreserved ovarian tissue is the method for fertility preservation for oncologic and nononcologic reasons. The main challenge of ovarian cryopreservation followed by transplantation is that ischemia reperfusion injury (IRI) induced the loss of follicles. The aim of this study was to evaluate the effects of glutathione (GSH), ulinastatin (UTI) or both (GSH+UTI) on preventing ischemia reperfusion-induced follicles depletion in ovarian grafts.Ovarian fragments were collected from 20 women aged 29±6 years. Frozen-thawed human ovarian tissue was xenografted into SCID mice, at the same time GSH, UTI and GSH+UTI was administrated respectively. The ovarian grafts were collected at the 1st, 3rd, 7th, 14th, 28th, 56th, and 85th day after xenotransplantation. Follicle survival rate was measured by H&E staining and Live/Dead staining. Angiogenic activity and macrophage recruitment was evidenced by immunohistochemical staining. The oxidative stress and inflammatory cytokines in human ovarian xenografts were measured by real-time PCR. The results indicated that after the treatments of GSH, UTI and GSH+UTI in the hosts, follicular survival in ovarian grafts were improved. The level of VEGF, CD31, and antioxidant enzymes superoxide dismutase 1 and superoxide dismutase 2 in ovarian grafts were increased. Accumulation of macrophages, level of IL6 and TNF-α, as well as malondialdehyde was decreased in ovarian grafts from treated groups. In conclusion, administration of GSH, UTI and GSH+UTI decreased the depletion of follicles in human grafts post-transplantation by inhibiting IRI-induced antiangiogenesis, oxidative stress and inflammation.

Ecological stoichiometric characteristics of Carbon (C), Nitrogen (N) and Phosphorus (P) in leaf, root, stem, and soil in four wetland plants communities in Shengjin Lake, China.

Ecological stoichiometric should be incorporated into management and nutrient impacted ecosystems dynamic to understand the status of ecosystems and ecological interaction. The present study focused on ecological stoichiometric characteristics of soil, and leaves, stems, and roots of different macrophytes after the banning of seine fishing in Shengjin Lake. For C, N, and P analysis from leaves, stems, roots, and soil to explore their stoichiometric ratio and deriving environmental forces, four dominant plant communities (Vallisneria natans, Zizania latifolia, Trapa natans and Carex schmidtii) were collected. The concentration of C, N, P and C: N: P ratio in leaves, stems, roots, and soil among the plant communities varied significantly. Along the depth gradient high C: N was measured in C.schmidtii soil (7.08±1.504) but not vary significantly (P >0.05). High C: P result was found in T.natans (81.14±43.88) and in V.natans soil (81.40±42.57) respectively with no significant difference (p>0.05). Besides, N: P ratio measured high in V. natans (13.7±4.05) and showed significant variation (P<0.05). High leaf C: N and N: P ratio was measured in C. schmidtii and V. natans respectively. Nevertheless, high leaf C: P ratio was measured in Z. latifolia. From the three studied organs, leaf C: N and N: P ratio showed high values compared to root and stems. The correlation analysis result showed that at 0-10cm depth soil organic carbon (SOC) correlated negatively with stem total phosphorus (STP), and root total nitrogen (RTN) (P<0.05) but positively strongly with leaf total phosphorus (LTP) and leaf total nitrogen (LTN) (P<0.01) respectively. Soil total nitrogen (STN) at 0-10cm strongly positively correlated with leaf total phosphorus (LTP) (P<0.01) and positively with RN: P and leaf total carbon (LTC) (P<0.05). Soil basic properties such as soil moisture content (SMC), bulky density (BD) and pH positively correlated with soil ecological stoichiometric characteristics. Redundancy analysis (RDA) result showed available nitrogen (AN), soil total nitrogen (STN), and available phosphorus (AP) were the potential determinants variables on plants stoichiometric characteristics.

Neutrophil extracellular traps are not produced in pediatric patients with one-lung ventilation: a prospective, single-center, observational study.

BACKGROUND: One-lung ventilation (OLV) may cause lung injury and induce pulmonary pro-inflammation; this ventilator-induced lung injury is associated with neutrophil infiltration. The infiltrated neutrophils release neutrophil extracellular traps (NETs), which are associated with tissue damage. It is not known whether NETs are involved in the pathogenesis of one-lung injury and if they could be a potential therapeutic target. In the present study, we quantified NETs in bronchoalveolar lavage fluid from pediatric patients who underwent OLV and assessed their relationship with prognosis. METHODS: Eighteen patients with congenital pulmonary cysts or pulmonary sequestration were enrolled in this prospective monocentric study. Myeloperoxidase (MPO) levels, NET markers [i.e., citrullinated histone-3 (CH-3) and free double-stranded DNA (dsDNA)], and inflammatory cytokine levels in bronchoalveolar lavage fluid were assessed. Continuous variables were compared using the paired t-test. The association of NET concentration in bronchoalveolar lavage fluid and clinical parameters was assessed using linear regression analyses. RESULTS: dsDNA concentration in bronchoalveolar lavage fluid was higher after OLV than before OLV in both the affected lung (0.23±0.30 vs. 0.97±1.05, P<0.05) and the healthy lung (0.28±0.19 vs. 2.45±2.23, P<0.05). However, there were no significant differences in concentrations of MPO, CH-3, and inflammatory cytokines before and after OLV. Serum interleukin (IL)-6 concentration was higher after OLV than before (t=-3.222, P=0.007). Moreover, no associations between dsDNA concentration in bronchoalveolar lavage fluid and the duration of postoperative mechanical ventilation, postoperative hospital stay, and chest high-resolution computed tomography score were observed. The durations of OLV, anesthesia, and operation, as well as the amount of blood loss, had no significant influence on postoperative dsDNA concentration in bronchoalveolar lavage fluid. CONCLUSIONS: NETs in bronchoalveolar lavage fluid are not involved in patients who undergo OLV.

Ultrafast clustering of single-cell flow cytometry data using FlowGrid.

BACKGROUND: Flow cytometry is a popular technology for quantitative single-cell profiling of cell surface markers. It enables expression measurement of tens of cell surface protein markers in millions of single cells. It is a powerful tool for discovering cell sub-populations and quantifying cell population heterogeneity. Traditionally, scientists use manual gating to identify cell types, but the process is subjective and is not effective for large multidimensional data. Many clustering algorithms have been developed to analyse these data but most of them are not scalable to very large data sets with more than ten million cells. RESULTS: Here, we present a new clustering algorithm that combines the advantages of density-based clustering algorithm DBSCAN with the scalability of grid-based clustering. This new clustering algorithm is implemented in python as an open source package, FlowGrid. FlowGrid is memory efficient and scales linearly with respect to the number of cells. We have evaluated the performance of FlowGrid against other state-of-the-art clustering programs and found that FlowGrid produces similar clustering results but with substantially less time. For example, FlowGrid is able to complete a clustering task on a data set of 23.6 million cells in less than 12 seconds, while other algorithms take more than 500 seconds or get into error. CONCLUSIONS: FlowGrid is an ultrafast clustering algorithm for large single-cell flow cytometry data. The source code is available at https://github.com/VCCRI/FlowGrid .

Optimal duration of mechanical ventilation and influencing factors following mandibular distraction osteogenesis in infants with Pierre Robin sequence.

Mandibular distraction osteogenesis (MDO) is an effective treatment for tongue-based airway obstruction in infants with severe Pierre Robin sequence (PRS). Most infants receiving MDO require postoperative mechanical ventilation (MV) to assist breathing. Optimal MV time for each individual patient and factors influencing the time must be identified to guide clinical decision-making.A retrospective analysis was performed on 75 infants with PRS receiving MDO from November 2016 to August 2018. Twenty-six were females and 47 were males. Data extracted from the hospital information system included sex, age, weight, history of preterm labor, preoperative pulmonary infection, laryngomalacia/tracheomalacia, laryngoscope exposure classification, anesthesia duration, operation duration, postoperative treatment site, situation of distraction, postoperative complications and MV duration. Statistical analyses were conducted to investigate the potential associations of these factors with MV time.Seventy-three PRS syndrome patients received anesthesia for MDO device procedures were considered eligible for study. Patient sex, history of preterm labor, preoperative pulmonary infection, laryngomalacia/tracheomalacia, laryngoscopy exposure difficulty, postoperative treatment site (neonatal or pediatric intensive care unit), ventilator-associated pneumonia, age, weight, anesthesia duration, and operation duration had no significant influence on postsurgical MV time (P > .05). Amount of distraction at the time of extubation had statistically significant influence on postoperative MV time (P < .05). In addition, scatter plots revealed linear relationships between postoperative MV time and amount of distraction at extubation.According to this analysis, amount of distraction was associated with MV time following MDO for severe PRS and roughly 6 days post-surgery is a generally safe extubation time.

Scutellarin Prevents Angiogenesis in Diabetic Retinopathy by Downregulating VEGF/ERK/FAK/Src Pathway Signaling.

BACKGROUND: Diabetic retinopathy (DR) is a serious microvascular complication of diabetes. This study demonstrates the antiangiogenic effects of scutellarin (SCU) on high glucose- and hypoxia-stimulated human retinal endothelial cells (HRECs) and on a diabetic rat model by oral administration. The antiangiogenic mechanisms of SCU in vitro and in vivo were investigated. METHOD: HRECs were cultured in high glucose- (30 mM D-glucose) and hypoxia (cobalt chloride-treated)-stimulated diabetic condition to evaluate the antiangiogenic effects of SCU by CCK-8 test, cell migration experiment (wound healing and transwell), and tube formation experiment. A streptozotocin-induced type II diabetic rat model was established to measure the effects of oral administration of SCU on protecting retinal microvascular dysfunction by Doppler waveforms and HE staining. We further used western blot, luciferase reporter assay, and immunofluorescence staining to study the antiangiogenic mechanism of SCU. The protein levels of phospho-ERK, phospho-FAK, phospho-Src, VEGF, and PEDF were examined in HRECs and retina of diabetic rats. RESULT: Our results indicated that SCU attenuated diabetes-induced HREC proliferation, migration, and tube formation and decreased neovascularization and resistive index in the retina of diabetic rats by oral administration. SCU suppressed the crosstalk of phospho-ERK, phospho-FAK, phospho-Src, and VEGF in vivo and in vitro. CONCLUSIONS: These results suggested that SCU can be an oral drug to alleviate microvascular dysfunction of DR and exerts its antiangiogenic effects by inhibiting the expression of the crosstalk of VEGF, p-ERK, p-FAK, and p-Src.

Hyperglycemia induced testicular damage in type 2 diabetes mellitus rats exhibiting microcirculation impairments associated with vascular endothelial growth factor decreased via PI3K/Akt pathway.

As an endocrine disease, type 2 diabetes mellitus (T2DM) can cause testicular damage which induces male infertility. However, the underlying mechanism is still not clear. We prove that T2DM induced testicular microcirculation impairment involves the decrease of VEGF and these actions are regulated by PI3K/Akt pathway. In our study, rats were divided into three groups (n=8): control group, diabetes group and diabetes + VEGF group. Intraperitoneal injection of streptozotocin (STZ, 65mg/Kg, at 9th week) and daily high-fat diet were used to establish T2DM rat model. Serum glucose in diabetes group and diabetes + VEGF group obviously exceeded 13mmol/L after STZ injection. Immunohistochemical studies indicated that VEGF level in diabetes group significantly decreased. In diabetes group, testicular blood velocity and vascular area reduced evaluated by Doppler and FITC. Furthermore, atrophic testicular morphology and increasing apoptosis cells were evaluated by haematoxylin and eosin staining and TUNEL assay. In diabetes + VEGF group, the administration of VEGF (intraperitoneally, 10mg/kg) can significantly alleviated hyperglycemia-induced impairment of testes in above aspects. Finally, we used Western blot to analyze the mechanism of hyperglycemia-induced testicular VEGF decrease. The results indicated that hyperglycemia-induced VEGF decreased is regulated by PI3K/Akt pathway in Rats testicular sertoli cells (RTSCs). Together, we demonstrate that T2DM can reduce testicular VEGF expression, which results in testicular microcirculation impairment, and then induces testicular morphological disarrangement and functional disorder. These actions are triggered by PI3K/Akt pathway. Our findings provide solid evidence for VEGF becoming a therapeutic target in T2DM related male infertility.

RETRACTED: Mechanical properties and phase transition of biomedical titanium alloy strips with initial quasi-single phase state under high-energy electropulses.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The authors have reused figures and text that have already appeared in their previous articles. Figure 4 duplicates figure 4 in Reference [1], figure 6 in Reference [2], figure 8 in Reference [3] and figure 4 in Reference [4], while Figure 7a-b duplicates figure 7a-b in Reference [4]. The article also duplicates significant parts of the text that appeared in References [1] and [4]. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. Journal records indicate that confirmation of the submission and publication of the article was sent to the first author's email address but not to the corresponding author's email address. The corresponding author and the first author wish to mention that the co-author Zion T.H. Tse was not involved in the preparation and handling of this article. He was not informed about the publication nor granted the use of his name and affiliation in the publication. References [1] J Mater Res 30 (2015) 206-223, http://dx.doi.org/10.1557/jmr.2014.367. [2] Mat Sci Eng A 622 (2015) 1-6, http://dx.doi.org/10.1016/j.msea.2014.11.003. [3] J Mater Res 29 (2014) 1500-1512, http://dx.doi.org/10.1557/jmr.2014.171. [4] Adv Eng Mater 17 (2015) 995-1007, http://dx.doi.org/10.1002/adem.201400273.

RETRACTED: Effects of high-energy electro-pulsing treatment on microstructure, mechanical properties and corrosion behavior of Ti-6Al-4V alloy.

This article has been retracted: please see Elsevier Policy on Article Withdrawal Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor. Figure 5 duplicates figure 8 of the article that had already appeared in Materials Characterization 98 (2014) 147-161, http://dx.doi.org/10.1016/j.matchar.2014.10.026, figure 12 of the paper that had appeared in Applied Physics A 117 (2014) 2251-2264, http://dx.doi.org/10.1007/s00339-014-8655-1, as well as panels from figure 12 of the article that had appeared in the Journal of Alloys and Compounds 616 (2014) 173-183, http://dx.doi.org/10.1016/j.jallcom.2014.07.143. Figure 6 duplicates figure 9 of the article that had already appeared in Materials Characterization 98 (2014) 147-161, http://dx.doi.org/10.1016/j.matchar.2014.10.026 and figure 13 of the article that had appeared in the Journal of Alloys and Compounds 616 (2014) 173-183, http://dx.doi.org/10.1016/j.jallcom.2014.07.143. Figure 7 duplicates figure 10 of the article that had already appeared in Surface & Coatings Technology 258 (2014) 467-484, http://dx.doi.org/10.1016/j.surfcoat.2014.08.052. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. Journal records indicate that confirmation of the submission and publication of the article was sent to the first author's email address, in addition to an email that used the corresponding author's name (guoyitangforwork@163.com). The corresponding author and the first author wish to mention that the co-author Zion T.H. Tse was not involved in the preparation and handling of this article. He was not informed about the publication and he did not grant the use of his name and affiliation in the publication. Prof. S. Petter Lyngstadaas, Dr. Hanna Tiainen and Dr. Sebastian Geissler from University of Oslo are acknowledged for the considerable effort put into collecting the evidence and reporting this case of multiple publication.

RETRACTED: Effect of electropulsing treatment and ultrasonic striking treatment on the mechanical properties and microstructure of biomedical ti-6Al-4V alloy.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The authors have reused figures and text that have already appeared in their previous articles. Figure 6a duplicates figure 6a (horizontally flipped) in Reference [1], while figure 6c duplicates figure 6c in Reference [1] and figure 3c in Reference [2] (albeit different scale is reported for each of these three figures). Figure 7 duplicates panels from figure 9 in Reference [3]. The article also duplicates parts of the text that appeared in Reference [1]. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. Journal records indicate that confirmation of the submission and publication of the article was sent to the first author's email address but not to the corresponding author's email address. References [1] Surf Coat Tech 258 (2014) 467-484, http://dx.doi.org/10.1016/j.surfcoat.2014.08.052. [2] J Alloys Compd 616 (2014) 173-183, http://dx.doi.org/10.1016/j.jallcom.2014.07.143. [3] J Mater Res 29 (2014) 1500-1512, http://dx.doi.org/10.1557/jmr.2014.171.

Some soybean cultivars have ability to induce germination of sunflower broomrape.

Sunflower broomrape is a noxious parasitic weed which has caused severe damage to crop ecosystems. Trap crops can release a mixture of allelochemicals to induce the germination of sunflower broomrape. We studied the allelopathic effects of soybean on sunflower broomrape. Fourteen common soybean cultivars were grown in pots. Samples were collected from soybean plants and rhizosphere soil at five growth stages (V1, V3, V5, R2, and R4). The allelopathic effects of soybean reached highest at the V3 stage. Methanolic extracts of soybean roots induced higher broomrape germination than methanolic extracts of stems or leaves. The germination rates induced by root extracts (10-fold dilution) were positively correlated with germination rates induced by stem (10-fold dilution) and leaf extracts (10-fold dilution). The broomrape germination rates induced by root extracts were also positively correlated with soybean nodule diameter and dry weight. The results indicated that soybeans could induce sunflower broomrape germination. We conclude that soybean has the potential to be used as a trap crop for sunflower broomrape.