Liver-Resident NK Cells Control Antiviral Activity of Hepatic T Cells via the PD-1-PD-L1 Axis.

The tolerogenic microenvironment of the liver is associated with impaired hepatic T cell function. Here, we examined the contribution of liver-resident natural killer (LrNK) cells, a prominent hepatic NK cell compartment, to T cell antiviral responses in the liver. The number of virus-specific T cells increased in LrNK-cell-deficient mice during both acute and chronic lymphocytic choriomeningitis virus infection. Upon infection with adenovirus, hepatic T cells from these mice produced more cytokines, which was accompanied by reduced viral loads. Transfer of LrNK cells into LrNK-cell-deficient or wild-type mice inhibited hepatic T cell function, resulting in impaired viral clearance, whereas transfer of conventional NK cells promoted T cell antiviral responses. LrNK-cell-mediated inhibition of T cell function was dependent on the PD-1-PD-L1 axis. Our findings reveal a role for LrNK cells in the regulation of T cell immunity and provide insight into the mechanisms of immune tolerance in the liver.

Microbiota profiles in the saliva, cancerous tissues and its companion paracancerous tissues among Chinese patients with lung cancer.

BACKGROUND: Despite the growing interest in the impact of the gut microbiome on cancer, the relationship between the lung microbiome and lung cancer has received limited investigation. Additionally, the composition of the oral microbiome was found to differ from that of individuals with lung cancer, indicating that these microorganisms may serve as potential biomarkers for the detection of lung cancer. METHODS: Forty-three Chinese lung cancer patients were enrolled in the current retrospective study and 16 S rRNA sequencing was performed on saliva, cancerous tissue (CT) and paracancerous tissue (PT) samples. RESULTS: Diversity and species richness were significantly different between the oral and lung microbiota. Lung microbiota were largely composed of the phyla Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria. The relative abundance of Promicromonosporacea and Chloroflexi increased in CT, while Enterococcaceae and Enterococcus were enriched in PT (p<0.05). A cancer-related microbiota model was constructed and produced an area under the curve of 0.74 in the training set, indicating discrimination between subjects with and without cancer. CONCLUSIONS: Characterization of microbiota in saliva, CT and PT from Chinese lung cancer patients revealed little difference between CT and PT, indicating that the tumor and its microenvironment might influence the local microbiome. A model to distinguish between CT and PT was constructed, which has the potential to enhance our comprehension of the involvement of microbiota in the pathogenesis of lung cancer and identify novel therapeutic targets.

Efficient conversion of rebaudioside C to steviol by Paenarthrobacter ilicis CR5301.

To improve the conversion efficiency of rebaudioside C, this study screened the Paenarthrobacter ilicis CR5301 from soil samples and identified it by 16S rRNA. The conversion experiment proved that P. ilicis CR5301 was capable of converting rebaudioside C. The effects of initial pH, temperature, inoculation amount, and substrate concentration on rebaudioside C conversion rate were investigated. The results showed that the conversion rate of rebaudioside C reached up to 100% when CR5301 was incubated in a conversion medium with an initial pH of 7.0 for 8 h at 28°C and 270 rpm. The conversion time was reduced by at least 16 h compared with previous studies. The conversion product was analyzed and identified as steviol by high performance liquid chromatography, ultra performance liquid chromatography-triple-time of flight mass spectrometer, and Fourier transform infrared spectroscopy methods. In addition, stevioside, rebaudioside A, dulcoside A, and some unknown components in steviol glycosides byproduct were all efficiently converted to steviol. These findings provide an efficient approach to the conversion of rebaudioside C and byproduct to steviol to simplify the subsequent industrial process and improve the reuse value of steviol glycosides.

LncRNA HOTAIR modulates chondrocyte apoptosis and inflammation in osteoarthritis via regulating miR-1277-5p/SGTB axis.

Osteoarthritis (OA) is a common degenerative joint disease in the elderly. This study aimed to investigate the role and mechanism of lncRNA HOX transcript antisense RNA (HOTAIR) in lipopolysaccharide (LPS)-treated chondrocytes in OA. CHON-001 chondrocytes treated with LPS were used as a cell model of OA. The levels of HOTAIR, miR-1277-5p and small glutamine rich tetratricopeptide repeat containing beta (SGTB) were measured via quantitative real-time polymerase chain reaction or western blot. Cell viability and apoptosis were assessed using Cell Counting Kit-8 and flow cytometry. The levels of inflammation-related factors were examined via enzyme-linked immunosorbent assay (ELISA). Aggrecan and Collagen II protein levels were detected using western blot. The interaction among HOTAIR, miR-1277-5p and SGTB were validated by dual-luciferase reporter analysis. HOTAIR and SGTB were up-regulated, while miR-1277-5p was down-regulated in OA cartilages and LPS-stimulated CHON-001 chondrocytes. HOTAIR depletion inhibited LPS-induced apoptosis and inflammation in chondrocytes. Moreover, down-regulation of HOTAIR attenuated LPS-triggered chondrocyte apoptosis and inflammation via sponging miR-1277-5p. Also, miR-1277-5p repressed LPS-induced chondrocyte apoptosis and inflammation by targeting SGTB. Furthermore, HOTAIR enhanced SGTB expression by sponging miR-1277-5p. HOTAIR aggravated chondrocyte apoptosis and inflammation in OA via regulating miR-1277-5p/SGTB pathway.

Feeding on tea GH19 chitinase enhances tea defense responses induced by regurgitant derived from Ectropis grisescens.

Multiple isoforms of chitinases participate in plant defense against outside invaders. However, the functions of hydrolase family 19 (GH19) chitinases on pest control remain largely unknown. Here we reported the isolation and functional analysis of a gene CsChi19, which encodes a GH19 endochitinase protein of 332 amino acid residues from tea plant (Camellia sinensis). CsChi19 expression levels were upregulated in response to mechanical wounding, infestation by two important pests: the tea geometrid Ectropis grisescens and the tea green leafhopper Empoasca (Matsumurasca) onukii, a fungal pathogen Colletotrichum fructicola, and treatment with two phytohormones: jasmonic acid (JA) and salicylic acid. CsChi19 was heterologously expressed in Escherichia coli, and its catalytic function was further elucidated. The protein could hydrolyze colloidal chitin, and the optimum temperature and pH for its activity was 40°C and pH 5.0. CsChi19 were found to be toxic to tea pests when they were fed on artificial diets containing this protein. Interestingly, the regurgitant derived from E. grisescens fed with artificial diets containing CsChi19 protein induced stronger expression of CsMPK3, more JA burst, more accumulation of defense-related secondary metabolites, and more emission of volatiles than the regurgitant derived from E. grisescens fed only with artificial diets. Our results provide first evidence that CsChi19 is involved in mediating a novel defense mechanism of tea plant through altering the composition of the regurgitant.

A novel spleen-resident immature NK cell subset and its maturation in a T-bet-dependent manner.

NK cells are thought to develop primarily in the bone marrow during adult life. However, increasing evidence shows that NK cell developmental intermediates can be found in different peripheral tissues with unique characteristics. Here, we identified a unique NK cell subset with the CD49a-CD49b- phenotype in the spleen. These cells displayed an immature phenotype and weak abilities in cytotoxicity and cytokine production. Adoptive transfer experiments revealed that they could develop into mature conventional NK (cNK) cells. Transcriptome analysis further confirmed their immature features. Parabiosis experiments revealed that these cells maintained tissue-resident properties in the spleen. Moreover, T-bet deficiency intrinsically impaired the ability of these cells to develop into mature cNK cells. Thus, our study identified a spleen-resident immature NK cell subset that could undergo extramedullary maturation in a T-bet dependent manner.

Green Ferrate(VI) for Multiple Treatments of Fracturing Wastewater: Demulsification, Visbreaking, and Chemical Oxygen Demand Removal.

Fracturing wastewater is often highly emulsified, viscous, and has a high chemical oxygen demand (COD), which makes it difficult to treat and recycle. Ferrate(VI) is a green oxidant that has a high redox potential and has been adopted for the efficient oxidation of fracturing wastewater to achieve triple effects: demulsification, visbreaking, and COD removal. Firstly, optimal conditions were identified to build a model for fast and efficient treatment. Secondly, wastewater treatment using ferrate oxidation was investigated via demulsification, visbreaking, and COD removal. Finally, a mechanism for ferrate oxidation was proposed for the three effects using Fourier-transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The theoretical and experimental data demonstrated that the ferrate oxidation achieved the three desired effects. When ferrate was added, the demulsification efficiency increased from 56.2% to 91.8%, the total viscosity dropped from 1.45 cp to 1.10 cp, and the total removal rate of COD significantly increased to 74.2%. A mechanistic analysis showed that the strongly-oxidizing ferrate easily and efficiently oxidized the O/W interfacial film materials, viscous polymers, and compounds responsible for the COD, which was a promising result for the triple effects.

Adsorption behaviors of methylene blue on sunflower stem pith.

Adsorption behaviors of methylene blue (MB) from aqueous solution using sunflower stem pith (SSP) as adsorbent were investigated. The effects of adsorption conditions such as adsorption time, initial concentration of MB and dosage of SSP on the detoxification of MB were examined. The equilibrium adsorption data were analyzed using three well-known isotherms: Langmuir, Freundlich and Temkin. The results indicated that the Langmuir isotherm fitted well to the data as compared with another isotherm model. The maximum adsorption capacity calculated by the Langmuir isotherm model was 277 mg/g at 338 K. Kinetic analyses were conducted using pseudo first order, pseudo second order and the Elovich model. The regression results showed that the MB adsorption was described by the pseudo second order model. Different thermodynamic parameters such as Gibb's free energy (ΔGo), standard enthalpy change (ΔHo) and standard entropy change (ΔSo) were also evaluated. The results showed that the detoxification of MB using SSP as adsorbent was feasible, non-spontaneous and exothermic under experimental conditions.

Preparation of high thermal stability polysulfone microcapsules containing lubricant oil and its tribological properties of epoxy composites.

Polysulfone (PSF) microcapsules containing lubricant oil have been successfully prepared using solvent evaporation method. The results show that lubricant oil was successfully encapsulated and the encapsulation capacity of about 56.0 wt.% was achieved. The uniform microcapsules have nearly spherical shape and quite smooth outer surface. The mean diameter is approximately 156 and 169 µm by using different dispersant solutions. The wall material is porous in structure with wall thickness of about 20 µm. The initial decomposition temperature of PSF is 480 °C. It is higher than traditional poly(urea-formaldehyde) (PUF) and poly(melamine-formaldehyde) (PMF) wall materials with 245 °C and 260 °C initial decomposition temperature, respectively. High thermal stability of PSF microcapsules can be considered as additives in high temperature resistant polymer materials. The frictional coefficient and wear rate of epoxy composites decreased significantly by incorporating microcapsules containing lubricant oil into epoxy. When the concentration of microcapsules was 25 wt.%, the frictional coefficient and specific wear rate were reduced by 2.3 and 18.3 times, respectively, as compared to the neat epoxy.

[Role and mechanism of all-trans retinoic acid in up-regulating apelin expression in vascular smooth muscle cells].

This study was aimed to investigate the mechanism of all-trans retinoic acid (ATRA) up-regulating apelin expression in vascular smooth muscle cells (VSMCs). The effect of ATRA on apelin expression in the VSMCs was investigated by RT-PCR, real-time PCR and Western blot analysis. To further define whether retinoic acid receptor α (RARα) mediated the induction of apelin by ATRA, endogenous RARα was down regulated by transfection of siRNA against RARα (si-RARα) or RARα was over-expressed by infection of the adenovirus vector pAd-GFP-RARα in the VSMCs. The results showed that ATRA significantly induced apelin expression in a time- and dose-dependent manner in the VSMCs. Although RARα expression was increased in a time-dependent manner, the expressions of RARß and RARγ were little changed by the ATRA treatment. When VSMCs were treated with a RARα antagonist Ro 41-5253 prior to the addition of ATRA, or si-RARα was used to down regulate endogenous RARα expression, the blockade of RARα signaling partially reduced the response of apelin to ATRA. Moreover, RARα over-expression, induced by infection of pAd-GFP-RARα, further increased the induction of apelin by ATRA. In conclusion, ATRA may up-regulate apelin expression in VSMCs, and the mechanism may be RARα dependent.

Effect of blood viscosity on the hemodynamics of arteriovenous fistulae based on numerical investigation.

Arteriovenous fistula (AVF) is the most commonly used vascular access for hemodialysis in patients with end-stage renal disease. Vascular diseases such as atherosclerosis and thrombosis, triggered by altered hemodynamic conditions, are the main causes of access failure. Changes in blood viscosity accelerate access dysfunction by affecting local velocities and wall shear stress (WSS) distribution in the circulation. Numerical simulation was employed to analyze and compare the hemodynamic behavior of AVF under different blood viscosities (0.001-0.012 Pa∙s). An idealized three-dimensional model with end-to-side anastomosis was established. Transient simulations were conducted using pulsatile inlet velocity and outflow as boundary conditions. The simulation results reveal the blood flow state of AVF under different viscosity physiological conditions and derive the rule of change. When blood viscosity increases, the local velocity in the disturbed region slows down and the stagnation time becomes longer, resulting in increased deposition of substances. As blood viscosity increases, the level of shear stress on the entire wall of the fistula increases accordingly. WSS values at high viscosities above 0.007 Pa∙s showed significantly larger low-shear regions near the anastomosis and increased chances of inducing atheromatous plaques. This research has revealed the correlation between blood dynamic viscosity and the hemodynamic behavior of AVF. Elevated whole blood viscosity increases the incidence of access obstruction and vascular disease leading to fistula failure. The study provides a basis for optimizing the distribution of hemodynamic parameters in the fistula for hemodialysis patients.

Dynamic observation and risk factors analysis of deep vein thrombosis after hip fracture.

OBJECTIVE: To dynamically observe the occurrence of deep vein thrombosis (DVT) after a hip fracture and analyze of the risk factors affecting the dynamic alteration of DVT. METHODS: Data of patients with hip fractures from January 1, 2017 to August 31, 2021 were collected. Patients were divided into DVT and non-DVT groups according to their daily Doppler ultrasonography findings. Survival analysis was used to describe dynamic changes in DVT occurrence with time. Log-rank tests were used to compare the influence of individual factors of patients with DVT occurrence, and a Cox proportional hazards regression model was used to identify the risk factors affecting the dynamic alteration of DVT occurrence. RESULTS: A total of 331 patients were included: 148(44.7%) had preoperative DVT, and 143 (96.6%) had DVT in the first 3days after admission. The probability of DVT was 0.42 on Day 1, 0.11 on Day 2, 0.10 on Day 3, 0.08 on Day 4, 0.20 on Day 5, and 0.00 on Day 6-7, with a median survival time of 3.30 d. Age>70 years, intertrochanteric fracture, admission hemoglobin<130g/L, and admission hematocrit<40% had a significantly higher occurrence rate of DVT. A hematocrit level of <40% (Hazard Ratio 2.079, 95% Confidence Interval:1.148-3.764, P = 0.016) was an independent risk factor for DVT. CONCLUSION: DVT after hip fractures mainly occurred in the first three days after admission, the trend was stabilized within one week, and day 1 had the highest rate of DVT incidence. Age, fracture type, HGB level, and Hct level affected dynamic occurrence of DVT. At constant other factors, Hct<40% was 2.079-fold incidence in the risk of preoperative DVT formation than those with Hct≥40% after hip fracture.

The rice hydroperoxide lyase OsHPL3 functions in defense responses by modulating the oxylipin pathway.

As important signal molecules, jasmonates (JAs) and green leaf volatiles (GLVs) play diverse roles in plant defense responses against insect pests and pathogens. However, how plants employ their specific defense responses by modulating the levels of JA and GLVs remains unclear. Here, we describe identification of a role for the rice HPL3 gene, which encodes a hydroperoxide lyase (HPL), OsHPL3/CYP74B2, in mediating plant-specific defense responses. The loss-of-function mutant hpl3-1 produced disease-resembling lesions spreading through the whole leaves. A biochemical assay revealed that OsHPL3 possesses intrinsic HPL activity, hydrolyzing hydroperoxylinolenic acid to produce GLVs. The hpl3-1 plants exhibited enhanced induction of JA, trypsin proteinase inhibitors and other volatiles, but decreased levels of GLVs including (Z)-3-hexen-1-ol. OsHPL3 positively modulates resistance to the rice brown planthopper [BPH, Nilaparvata lugens (Stål)] but negatively modulates resistance to the rice striped stem borer [SSB, Chilo suppressalis (Walker)]. Moreover, hpl3-1 plants were more attractive to a BPH egg parasitoid, Anagrus nilaparvatae, than the wild-type, most likely as a result of increased release of BPH-induced volatiles. Interestingly, hpl3-1 plants also showed increased resistance to bacterial blight (Xanthomonas oryzae pv. oryzae). Collectively, these results indicate that OsHPL3, by affecting the levels of JA, GLVs and other volatiles, modulates rice-specific defense responses against different invaders.

Sustainability performance evaluation involving internal resource imbalance: an additive aggregation network DEA approach.

Environmental pollution, as a byproduct of economic growth, causes negative pressure on human health. Its sustainability management performance is closely bound up with the ecological carrying capacity. Due to the limited carrying capacity of ecosystems to pollutants, the hidden costs of pollutants may increase when pollutants flow and spread. This is an external manifestation of the internal resource imbalance within the ecosystem, restricting the sustainability of economy and environment and overlooked by most studies that target sustainability performance evaluation. Thus, this study considers the internal resource imbalance during the sustainability performance evaluation for the first time in the context of the interaction among economy, environment, and human health, by constructing a production-treatment-health framework, proposing an internal resource imbalance index and developing an additive aggregation network data envelopment analysis model with the semidefinite programming technology. This study takes 30 Chinese provinces from 2012 to 2017 as the research objects and confirms the effectiveness of sustainability management in terms of water pollution purification and water ecological construction.

Integrated metabolite profiling and transcriptome analysis unraveling mechanism of RC catabolism in Paenarthrobacter ilicis CR5301.

Steviol glycosides are ideal sweeteners that are widely used in food, medicine, and cosmetics. Rebaudioside C (RC) is considered to be the third most abundant steviol glycoside, which has a bitter aftertaste that limits its application. Hydrolysis of RC to generate other bioactive steviol glycosides is an effective way to promote its additional utilization. In our previous study, a bacterium Paenarthrobacter ilicis CR5301 was isolated and identified for hydrolyzing RC with high efficiency. Herein, the expression profiles of P. ilicis CR5301 in the deletion and presence of RC were investigated by RNA-seq. The RC metabolites were identified by high-performance liquid chromatography and ultra-performance liquid chromatography-triple-time of flight mass spectrometry. Novel results were discovered in four aspects of research. First, the identification of metabolites revealed that four metabolites, namely, dulcoside A, dulcoside B, dulcoside A1, and steviol, were produced during RC metabolism. Second, RNA-seq analyses unraveled that 105 genes of P. ilicis CR5301 were significantly differentially expressed, and 7 pathways were significantly enriched. Third, independent RT-qPCR verified the accuracy and reliability of the RNA-seq results. Finally, a complete catabolic model of RC in P. ilicis CR5301 was proposed, and key genes were indicated in the RC catabolic metabolism by combining them with literature and sequence alignments. This study comprehensively unraveled the genes and pathways of RC catabolism in P. ilicis CR5301 at the transcriptional and metabolic levels. It provided new insights and evidence for understanding the mechanism of RC catabolism in bacteria. Key candidate genes may potentially contribute to the RC hydrolysis and preparation of other functional steviol glycosides in the future.

Perforating ocular injury caused by acupuncture: A case report.

Acpuncture as a branch of traditional Chinese medicine is popular in China. It can regulate the running of meridian qi to stimulate the ocular nerve activity and increase blood supply. Periocular acupuncture treatment is very frequent, but it can lead to safety hazards that cannot be ignored. For instance, ocular trauma may develop if done improperly, resulting in impaired vision and even blindness. We report a rare case of perforating ocular injury caused by acupuncture.

The admission pH is a risk factor of preoperative deep vein thrombosis in geriatric hip fracture: a retrospective cohort study.

This study evaluated the association between body pH value and preoperative deep vein thrombosis (DVT) in geriatric hip fractures. Older adult patients with hip fractures were screened between January 2015 and September 2019. The demographic and clinical characteristics of the patients were collected. Multivariate binary logistic regression and generalized additive models were used to identify the linear and nonlinear associations between pH value and preoperative DVT. Analyses were performed using EmpowerStats and R software. A total of 1465 patients were included in the study. DVT occurred in 476 (32.6%) of these admitted older adults. We observed a nonlinear association between the serum pH value and preoperative DVT in geriatric patients with hip fractures. A pH value of 7.39 was the inflection point in the curve, with pH highly correlated with DVT at pH < 7.39 (odds ratio [OR] 19.47; 95% confidence interval [CI] 1.45-260.91; P = 0.0249). Patients with lower pH had a lower chance of preoperative DVT formation, and the risk of DVT increased 18.47-fold for every 0.1 unit change in pH. Although at pH > 7.39, pH was not correlated with DVT (OR 1.26; 95% CI 0.85-1.86; P = 0.2561), the odds of DVT did not vary with pH, and the highest risk of thrombosis was reached. The body pH value is nonlinearly associated with preoperative DVT in geriatric patients with hip fractures, and it could be considered a predictor of the risk of DVT.Registered information This study is registered in the website of Chinese Clinical Trial Registry (ChiCTR: ChiCTR2200057323).

Solar engineering of wastewater treatment for full mineralization of organic pollutants.

Full mineralization of organic pollutants is a tough task with existing technologies. Even if all conventional energies and extremes are exhausted, high-temperature wastewater treatment is not worth the loss from the perspective of energy. Solar engineering holds promise for the full mineralization of organic pollutants to tackle the global fossil energy shortage. Here, we report solar engineering for full mineralization and efficient solar utilization. The solar energies and spectrum were fully utilized to initiate the solar heat and solar electricity. Two energies were applied to trigger the thermochemical and electrochemical oxidation of the organic pollutants. Our study bridges the gap between the energy and environment towards efficient solar utilization and effective water treatment. As a proof-of-concept study, this demonstrates a solar engineering of full phenol mineralization in wastewater. A record phenol mineralization rate was achieved to reach an oxidation rate of 98% and COD of 93% under a constant current density of 50mA/cm2 at 150°C. UV and HPLC were used to detect the intermediate products during variable time intervals. The results showed that the intermediate products are composed of maleic acid, hydroquinone and p-benzoquinone. In the extreme high temperature (90°C), the solar oxidation time and pathway are greatly altered. The reaction rate constant at 150°C is about 11 times than that at 90°C. More solar heat significantly reduces the activated energy of the pollutant oxidation and lowers the potential of electrolysis.

Fermentation-mediated variations in structure and biological activity of polysaccharides from Tetrastigma hemsleyanum Diels et Gilg.

Variations in the structure and activities of polysaccharides from Tetrastigma hemsleyanum Diels et Gilg fermented by Sanghuangporus sanghuang fungi were investigated. Compare with the unfermented polysaccharide (THDP2), the major monosaccharide composition and molecular weight of polysaccharide after fermentation (F-THDP2) altered dramatically, which caused galactose-induced conversion from glucose and one-third of molecular weight. F-THDP2 had a molecular weight of 1.23 × 104 Da. Moreover, the glycosidic linkage of F-THDP2 varied significantly, a 1, 2-linked α-d-Galp and 1, 2-linked α-d-Manp backbone was established in F-THDP2, which differed from that of 1, 4-linked α-d-Glcp and 1, 4-linked ß-d-Galp in THDP2. In addition, F-THDP2 showed a more flexible chain conformation than that of THDP2 in aqueous solution. Strikingly, F-THDP2 exhibited superior inhibitory effects on HeLa cells via Fas/FasL-mediated Caspase-3 signaling pathways than that of the original polysaccharide. These variations in both structure and biological activities indicated that fermentation-mediated modification by Sanghuangporus sanghuang might a promising novel method for the effective conversion of starch and other polysaccharides from Tetrastigma hemsleyanum Diels et Gilg into highly bioactive biomacromolecules, which could be developed as a potential technology for use in the food industry.

The broad-leaf herbicide 2,4-dichlorophenoxyacetic acid turns rice into a living trap for a major insect pest and a parasitic wasp.

Synthetic chemical elicitors of plant defense have been touted as a powerful means for sustainable crop protection. Yet, they have never been successfully applied to control insect pests in the field. We developed a high-throughput chemical genetics screening system based on a herbivore-induced linalool synthase promoter fused to a ß-glucuronidase (GUS) reporter construct to test synthetic compounds for their potential to induce rice defenses. We identified 2,4-dichlorophenoxyacetic acid (2,4-D), an auxin homolog and widely used herbicide in monocotyledonous crops, as a potent elicitor of rice defenses. Low doses of 2,4-D induced a strong defensive reaction upstream of the jasmonic acid and ethylene pathways, resulting in a marked increase in trypsin proteinase inhibitor activity and volatile production. Induced plants were more resistant to the striped stem borer Chilo suppressalis, but became highly attractive to the brown planthopper Nilaparvata lugens and its main egg parasitoid Anagrus nilaparvatae. In a field experiment, 2,4-D application turned rice plants into living traps for N. lugens by attracting parasitoids. Our findings demonstrate the potential of auxin homologs as defensive signals and show the potential of the herbicide to turn rice into a selective catch crop for an economically important pest.