Ethylene Production Research Articles

Unveiling Active Al3+ Sites for Ethanol Dehydration on γ-Al2O3 with Solid-State Nuclear Magnetic Resonance Spectroscopy.

γ-Al2O3 is a crucial catalyst widely used in industrial alcohol dehydration processes. However, the specific nature of its active sites has remained unclear. In this study, we utilize two-dimensional heteronuclear correlation solid-state nuclear magnetic resonance and density functional theory calculations to uncover the active Al sites on the surface of γ-Al2O3 that facilitate ethanol dehydration. We show the formation of stable pentacoordinated AlV-ethanol complexes upon the adsorption of ethanol on the tetracoordinated AlIV sites. This interaction significantly enhances synergy with adjacent AlV-OH sites, resulting in a marked reduction of the activation energy barrier for ethene production. Furthermore, we reveal an interchange between AlIV and AlV-OH species, allowing hexacoordinated AlVI-OH sites to participate in the dehydration pathway through the migration of ethanol between these coordination sites.

Cold Storage Effects on Ethylene Emission, Co₂ Accumulation, and TSS Variation in Golden Delicious Apples at 3°C

The study investigates the ethylene production and respiratory metabolism of Golden Delicious apples stored at 3°C for 13 weeks. Apples were all picked at a maturity stage corresponding to the commercial harvest date and stored at 3°C with a relative humidity of 85±5 %. The results showed that TSS increased at the beginning of the storage while the ethylene release increased slowly under the 3⁰C cold storage. The results of this study show that after 7 weeks of storage, the ethylene release rate peaked at 35.5 μL∙kg-1∙h-1, followed by 14.9 μL∙kg-1∙h-1 after 11 weeks. Then it progressively reduced and remained at a low level. Fruit respiration rate decreased during cold storage at 3⁰C and gradually rose after storage. The goal is to develop strategies to extend the shelf life of apples while reducing post-harvest food waste. By reducing food waste, we reduce the ecological footprint of apple cultivation.

Modelling Ethylene Production in Packaged Tomatoes and Simulating Ethylene Scavenger Addition for Shelf-Life Extension

Modelling Ethylene Production in Packaged Tomatoes and Simulating Ethylene Scavenger Addition for Shelf-Life Extension

Harnessing ethylene-producing bacteria for fruit bio-ripening: a comprehensive review

Fruit ripening is a complex biological process regulated by various endogenous and exogenous factors, with ethylene playing a pivotal role as a gaseous hormone. Traditionally, ethylene for commercial use has been derived from environmentally hazardous processes. However, the discovery of ethylene-producing bacteria presents a sustainable alternative for fruit ripening. This review explores the mechanisms and potential of utilizing ethylene-producing bacteria in the bio-ripening of fruits. Through an analysis of current research, we elucidate the synthesis pathways of ethylene in microorganisms, optimization techniques to enhance ethylene production, and the compatibility among microbial strains for the development of effective microbial consortia. Recent studies have demonstrated the efficacy of ethylene-producing bacteria, such as Bacillus and Pseudomonas species, in bio-ripening fruits like kiwifruit, plums, bananas, and apples. The optimization of growth conditions and the development of microbial consortia aim to maximize ethylene production efficiency While minimizing environmental impacts. This review underscores the importance of ethylene-producing bacteria in revolutionizing fruit ripening technology and advancing sustainable agricultural practices. By providing insights into the opportunities and challenges associated with bio-ripening fruits by ethylene-producing bacteria, this review seeks to guide future research and innovation in the field. Ultimately, using ethylene-producing bacteria offers a promising avenue for achieving safe, environmentally friendly, and efficient fruit ripening methods in agricultural practices.

Synthesis, characterization, and CO2methanation over hierarchical ZSM-5-NiCoAl layered double hydroxide nanocomposites:Improvement of C-C coupling to ethane.

To date, preparing materials with highly dispersed metal nanoparticles without metal agglomeration on a solid support is challenging. This work presents an alternative approach for synthesizing NiCo species on hierarchical ZSM-5 materials derived from a core-shell ZSM-5@NiCoAl-LDHs composite. The designed material was prepared by the growth of a NiCo-LDHsprecursor on the surface of hierarchical ZSM-5 nanosheets. The effect of the weight ratio of NiCo-LDHs precursor to ZSM-5 on the composite properties has been studied. The results show that 45 wt.% LDHs is the most suitable condition for preparing NiCoAl-LDHs/ZSM-5 composite with a core-shell structure, which promotes a strong interaction between bimetallic NiCo and hierarchical ZSM-5. The ZSM-5@NiCoAl-LDHs-45 showed a BET surface of 386 m2.g-1, in which the surface area has been re-allocated between microspores and mesopores due to the presence of NiCoAl-LDHs composite. The catalyst wasalsotested for CO2methanation at 380 °C under atmospheric hydrogen pressure. The results show that the catalyst could provide CO2conversion of up to 40% at WSHV of 2.91 h-1. Interestingly, it could not only promote methane but also provide a high selectivity of ethane, approximately 20.4%. Moreover, the excellent catalytic stability of ethane production was illustrated over 24 hours of time-on-stream.

Regulating Interfacial Hydrogen‐Bonding Networks by Implanting Cu Sites with Perfluorooctane to Accelerate CO2 Electroreduction to Ethanol

Efficient CO2 electroreduction (CO2RR) to ethanol holds promise to generate value‐added chemicals and harness renewable energy simultaneously. Yet, it remains an ongoing challenge due to the competition with thermodynamically more preferred ethylene production. Herein, we presented a CO2 reduction predilection switch from ethylene to ethanol (ethanol‐to‐ethylene ratio of ~5.4) by inherently implanting Cu sites with perfluorooctane to create interfacial non‐covalent interactions. The 1.83%F‐Cu2O organic‐inorganic hybrids (OIHs) exhibited an extraordinary ethanol faradaic efficiency (FEethanol) of ∼55.2%, with an impressive ethanol partial current density of 166 mA cm‐2 and excellent robustness over 60 hours of continuous operation. This exceptional performance ranks our 1.83%F‐Cu2O OIHs among the best‐performing ethanol‐oriented CO2RR electrocatalysts. Our findings identified that C8F18 could strengthen the interfacial hydrogen bonding connectivity, which consequently promotes the generation of active hydrogen species and preferentially favors the hydrogenation of *CHCOH to *CHCHOH, thus switching the reaction from ethylene‐preferred to ethanol‐oriented. The presented investigations highlight opportunities for using noncovalent interactions to tune the selectivity of CO2 electroreduction to ethanol, bringing it closer to practical implementation requirements.

Regulating Interfacial Hydrogen-Bonding Networks by Implanting Cu Sites with Perfluorooctane to Accelerate CO2 Electroreduction to Ethanol.

Efficient CO2 electroreduction (CO2RR) to ethanol holds promise to generate value-added chemicals and harness renewable energy simultaneously. Yet, it remains an ongoing challenge due to the competition with thermodynamically more preferred ethylene production. Herein, we presented a CO2 reduction predilection switch from ethylene to ethanol (ethanol-to-ethylene ratio of ~5.4) by inherently implanting Cu sites with perfluorooctane to create interfacial non-covalent interactions. The 1.83%F-Cu2O organic-inorganic hybrids (OIHs) exhibited an extraordinary ethanol faradaic efficiency (FEethanol) of ∼55.2%, with an impressive ethanol partial current density of 166 mA cm-2 and excellent robustness over 60 hours of continuous operation. This exceptional performance ranks our 1.83%F-Cu2O OIHs among the best-performing ethanol-oriented CO2RR electrocatalysts. Our findings identified that C8F18 could strengthen the interfacial hydrogen bonding connectivity, which consequently promotes the generation of active hydrogen species and preferentially favors the hydrogenation of *CHCOH to *CHCHOH, thus switching the reaction from ethylene-preferred to ethanol-oriented. The presented investigations highlight opportunities for using noncovalent interactions to tune the selectivity of CO2 electroreduction to ethanol, bringing it closer to practical implementation requirements.

Hydrogen peroxide-induced ethylene production promotes calycosin-7-O-β-d-glucoside accumulation in Astragalus membranaceus adventitious roots

Hydrogen peroxide-induced ethylene production promotes calycosin-7-O-β-d-glucoside accumulation in Astragalus membranaceus adventitious roots

Effects of rhizobacteria producing deaminase enzymes for aminocyclopropane‐1‐carboxylate on drought tolerance and post‐stress recovery in creeping bentgrass under field conditions

AbstractSome endophytic rhizobacteria, including species producing deaminase enzymes for 1‐aminocyclopropane‐1‐carboxylic acid (ACC) suppressing ethylene production (ACCd), form symbiosis with plant roots to enhance plant growth and stress tolerance. The objectives of this study were to determine growth‐promoting effects and effective rates of inoculation with ACCd‐producing Paraburkholderia aspalathi (WSF23 and WSF14) on creeping bentgrass (Agrostis stolonifera L.) performance under deficit irrigation in field conditions and effectiveness on post‐stress recovery during re‐watering. Turf field plots established with ‘L‐93’ creeping bentgrass were inoculated with P. aspalathi strains (WSF23 and WSF14) through soil drenching either as a single strain or as a combination of both strains. After inoculation, plots were subjected to drought stress with deficit irrigation to replace 60% of the daily evapotranspiration rate, followed by re‐watering for post‐stress recovery. Three inoculant rates of 1.0, 1.5, and 2.0 × 107 colony‐forming units (CFUs) were evaluated to determine the most effective dosage to apply under field conditions. Inoculation of plants with the consortium of the two strains at 1.5 × 107 CFUs was most effective in enhancing turf quality, percent green cover, normalized difference vegetation index, and dark green color index during drought stress and recovery periods. These results suggest that creeping bentgrass tolerance to drought stress and improved post‐stress recovery could benefit from inoculation with P. aspalathi strains under field conditions and also ACC deaminase‐producing rhizobacteria could be incorporated into turf management programs to maintain creeping bentgrass during abiotic stress conditions.

Interdisciplinary studies on a distribution property of tomato fruit: What is the initial abnormal response of their chilling injury occurrence?

Tomatoes develop chilling injury after low-temperature storage, which is often indicated by ion leakage from the tissues caused by cell membrane damage. However, the chilling injury causes a decline in tomato quality, which was already serious due to ion leakage. This study assumed that other physiological reactions precede cell membrane damage in tomatoes exposed to chilling stress. This hypothesis was investigated by measuring several physical, chemical and physiological parameters of tomatoes. Using samples stored at 2 or 5°С without chilling injury-induced cell membrane damage, this study confirmed other abnormal physiological reactions, such as ethylene production, respiration, electrochemical resistance in extracellular fluids, gene expression of heat shock protein, succinic acid content, and others. The obtained information can help clarify the initial response of chilling injury and is useful to determine the distribution property of tomatoes for avoiding chilling injury-induced cell membrane damage.

Production and analysis of ethyl and butyl ethers from fatcontaining waste of the food and pulp and paper industries

In the conditions of natural resources depletion, and Climate changes caused by the greenhouse effect, world community is focused on exploring new raw materials, secondary raw materials, including waste that can be usefully used. Fat-containing waste generated in the food, pulp and paper, leather and other industries, catering facilities have significant potential in this field. Analysis of official statistics on the fat-containing waste management in the Russian Federation shows that about 22% of such waste is disposed in landfills and is irretrievably lost as raw materials. And those fat-containing wastes that are utilized are used in the production of low-profit products. At the same time, fatcontaining waste can be used to receive products that fully replace analogs produced from petrochemical and chemical raw materials. In the total mass of fat-containing waste, a significant part is made up of products with a high content of free fatty acids, which serve as raw materials for receiving a wide range of useful products. Therefore, research in this way is relevant and promising. In this study, ethyl and butyl ethers were received from waste from the food and pulp and paper industries and studied. Then ethyl and butyl ethers received from waste were tested as plasticizers for compatibility with polyvinyl chloride. A toxicity assessment was carried out for the initial waste, ethyl and butyl ethers thereof, and plasticizers with polyvinyl chloride. Based on the analysis of results, recommendations were formulated for the practical application of the method for the utilization of such waste. The novelty of the research is demonstrating the possibility of using esters received from fatcontaining waste to replace petrochemical synthesis products such as plasticizers for polymers.

Stabilization of cuσ+ via strong Cu‐O‐Si interface for efficient electrocatalytic acetylene semi‐hydrogenation

AbstractThe development of a high‐performance electrocatalytic acetylene semi‐hydrogenation catalyst is the key to the selective removal of acetylene from industrial ethylene gas and non‐oil route to ethylene production. However, it is still hampered by the deactivation of the catalyst and hydrogen evolution interference. Here, we proposed an interface engineering strategy involving the Cu and cupric oxide nanoparticles dispersed on amorphous SiO2 (Cu/CuOx/SiO2) by a simple stöber method. x‐ray photoelectron spectroscopy demonstrated the strong interfacial interaction between cupric oxide nanoparticles and SiO2. The formed Cu‐O‐Si interface stabilized the Cuσ+ at high reduction potentials, thus improving the activity and stability of the acetylene reduction reaction, as confirmed by in situ Raman spectroscopy. Consequently, the electrochemical test results showed that at 0.5 M KHCO3, the maximum Faraday efficiency (FE) of ethylene on the optimized Cu/CuOx/SiO2 reached 96%. And ethylene FE remains above 85% at −100 mA cm−2 for 40 h.

Ethane Triggered Gate-Opening in a Flexible-Robust Metal-Organic Framework for Ultra-high Purity Ethylene Purification.

Priority recognition separation of inert and larger ethane molecules from high-concentration ethylene mixtures instead of traditional thermodynamic or size sieving strategy is a fundamental challenge. Herein, we report the ethane triggered gate-opening in the flexible-robust metal-organic framework Zn(ad)(min), the 3-methylisonicotinic acid ligand can spin as a flexible gate when adsorbing the cross-section well-matched ethane molecule, thus achieving the unprecedent ethane adsorption capacity (62.6cm3 g-1) and ethane/ethylene uptake ratio (3.34) under low-pressure region (0.1 bar and 298 K). The ethane-induced structural transition behavior is uncovered by a collaboration of single-crystal X-ray diffraction, in-situ variable pressure X-ray diffraction and theoretical calculations, elucidating the synergetic mechanism of cross-section matching and multiple supramolecular interactions within the tailor-made pore channels. Dynamic breakthrough experiments revealed the outstanding separation performance of Zn(ad)(min) in the production of ultra-high purity ethylene (> 99.995%) with a productivity of up to 39.2 L/kg under ambient conditions.

Copper electrocatalyst modified with pyridinium-based ionic liquids for the efficient synthesis of ethylene through electrocatalytic CO2 reduction reaction

Reducing carbon dioxide (CO2) emissions from industrial production and improving carbon capture and utilization have emerged as focal points in engineering disciplines. This study focuses on electrochemical catalysis for converting CO2 into valuable raw materials, with the aim of enhancing the selectivity and productivity of high value-added multi-carbon (C2+) products. To address limitations associated with copper cathodes such as low selectivity for ethylene (C2H4) product, low catalytic activity, and high energy consumption during CO2 reduction reaction (CO2RR), pyridinium-based ionic liquids (PyILs) are employed as modifiers for the cathode material. Flow cell is utilized to conduct CO2RR experiment and evaluate the catalytic properties of gas diffusion electrode (GDE) loaded with PyILs modified Cu-based materials (Cu@PyILs). The results suggest that the incorporation of PyILs layers enhances conductivity and facilitates high current density in flow cell. At a cathodic potential of −1.15 V (vs. RHE), Cu@[BPy]Br-2.4 exhibits the highest Faradaic efficiency for C2H4 (FEC2H4 = 31.88 %) and achieves a high current density of 275 mA·cm−2. Additionally, Cu@[BPy]BF4-2.4 and Cu@[BPy]PF6-2.4 exhibit FEC2H4 values surpassing 25 %. Meanwhile, the hydrogen evolution reaction (HER) in the flow cell is effectively suppressed, resulting in a FEH2 below 40 %. The present study highlights the exceptional catalytic activity of Cu@PyILs in CO2RR, demonstrating an enhanced selectivity towards C2H4 production. The findings suggest that PyILs have great potential as electrode modifiers.

Manipulating C-C coupling pathway in electrochemical CO2 reduction for selective ethylene and ethanol production over single-atom alloy catalyst.

Manipulation C-C coupling pathway is of great importance for selective CO2 electroreduction but remain challenging. Herein, two model Cu-based catalysts, by modifying Cu nanowires with Ag nanoparticles (AgCu NW) and Ag single atoms (Ag1Cu NW), respectively, are rationally designed for exploring the C-C coupling mechanisms in electrochemical CO2 reduction reaction (CO2RR). Compared to AgCu NW, the Ag1Cu NW exhibits a more than 10-fold increase of C2 selectivity in CO2 reduction to ethanol, with ethanol-to-ethylene ratio increased from 0.41 over AgCu NW to 4.26 over Ag1Cu NW. Via a variety of operando/in-situ techniques and theoretical calculation, the enhanced ethanol selectivity over Ag1Cu NW is attributed to the promoted H2O dissociation over the atomically dispersed Ag sites, which effectively accelerated *CO hydrogenation to form *CHO intermediate and facilitated asymmetric *CO-*CHO coupling over paired Cu atoms adjacent to single Ag atoms. Results of this work provide deep insight into the C-C coupling pathways towards target C2+ product and shed light on the rational design of efficient CO2RR catalysts with paired active sites.

Energy, exergy, environmental and economic analysis of solvent-based post-combustion carbon capture for ethylene production

Ethylene production is an energy-intensive process with significant CO2 emissions. As demand for ethylene rises, integrating carbon capture technology in ethylene plants is crucial for mitigating emissions. This study provides a thermodynamic, exergy, comparative life cycle assessment (LCA) and economic analysis of post-combustion carbon capture (PCC) for large-scale ethylene plants using chemical absorption with 30 wt% monoethanolamine (MEA) and 40 wt% piperazine (PZ) as solvent. In addition, a case study involving the integration of solar-assisted post-combustion carbon capture (SPCC) and photovoltaic (PV) power generation with ethylene production is built to evaluate future CO2 emission reduction potential. The results show that 0.98 tons of CO2 are captured per ton of ethylene, potentially reducing life cycle CO2 emissions by 30.3% to 68.9% for different PCC scenarios. Integrating SPCC and PV significantly reduces CO2 emissions, highlighting the potential of solar power in carbon reduction. Furthermore, feedstock acquisition of ethylene production emits large amount of greenhouse gas (GHG), indicating that low-carbon feedstock production can further reduce life cycle GHG emissions. This work is significant for the ethylene industry’s low-carbon transition and clean production, offering insights into enhancing sustainability and environmental performance through advanced carbon capture technologies and renewable energy integration.

In Situ Phase Transformation-Enabled Metal-Organic Frameworks for Efficient CO2 Electroreduction to Multicarbon Products in Strong Acidic Media.

The electrochemical CO2 reduction reaction (CO2RR) has been acknowledged as a promising strategy to relieve carbon emissions by converting CO2 to essential chemicals. Despite significant progresses that have been made in neutral and alkaline media, the implementation of CO2RR in acidic conditions remains challenging due to the harsh conditions, especially in producing high-value multicarbon products. Here, we report that Cu-btca (btca = benzotriazole-5-carboxylic acid) metal-organic framework (MOF) nanostructures can act as a stable catalyst for the CO2RR in an acidic environment. The Cu-btca MOF undergoes phase transformation and morphology evolution during electrolysis, forming a stable porous Cu-btca MOF network. The resultant MOF network exhibits excellent selectivity toward ethylene and multicarbon products with Faradaic efficiencies of 51.2% and 81.9%, respectively, in a strong acidic electrolyte with a flow cell at 300 mA/cm2. Mechanism studies uncover that the Cu-btca MOF network can limit the proton reduction to suppress hydrogen evolution and maintain high local *CO concentration to promote CO2RR. Theoretical calculations suggest that two adjacent Cu sites in the Cu-btca MOF provide a favorable microenvironment for carbon-carbon coupling, facilitating the multicarbon production. This work reveals that rational structure control of MOFs can enable highly selective and efficient CO2 electroreduction to multicarbon products in strong acidic conditions toward practical applications.

Ethylene-mediated root endodermal barrier development in impeding Cd radial transport and accumulation in rice (Oryza sativa L.)

Ethylene plays crucial roles in the adaptation to cadmium (Cd) stress. Nevertheless, the impact of endogenous ethylene on radial transport of Cd in different rice cultivars are insufficiently understood. Herein, we investigated how ethylene involved in the formation of endodermal barriers in roots of Nipponbare with low-Cd accumulation and IR32307 with high-Cd accumulation ability and further assessed its influence on Cd radial transport. Our analysis indicated that both Cd stress and external ACC (1-aminocyclopropane-1-carboxylic acid, ethylene biosynthesis precursor) promoted the ethylene production. Intriguingly, the positive response of ethylene signal to Cd was more intensive in roots of Nipponbare than that of IR32307. The increased endogenous ethylene in rice roots promoted development of casparian strips (CSs) and suberin lamellae (SL). Specifically, external addition of ACC decreased the percentage of the DTIP-CS/DTIP-SL to root length by 44.4–79.6%/49.3–11.4% in Nipponbare and 18.7–19.9%/10.7–35.3% in IR32307, individually. The intrinsic molecular mechanism was mainly due to changes in the genes expression levels related to CSs/SL biosynthesis. Simultaneously, the analyses of apoplastic tracer (Propidium Iodide, PI) and cell-to-cell tracer (Fluorescein Diacetate, FDA) confirmed that the ethylene-mediated endodermal barriers were functional, which were in accordance with the increased/reduced Cd transport in roots. Eventually, the results of transcriptome analysis further shed a comprehensive insight that ethylene constructed the endodermal barrier through phenylpropanoid and cutin, suberine and wax biosynthesis to reduce Cd radial transport in rice, which are beneficial for the breeding of rice with low-Cd accumulating capacity in the future.

The RING-type E3 ligase RIE1 sustains leaf longevity by specifically targeting AtACS7 to fine-tune ethylene production in Arabidopsis

Ethylene is widely recognized as a positive regulator of leaf senescence. However, how plants coordinate the biosynthesis of ethylene to meet the requirements of senescence progression has not been determined. The rate-limiting enzyme in the ethylene biosynthesis pathway is ACC synthase. AtACS7 was previously considered one of the major contributors to the synthesis of "senescence ethylene" in Arabidopsis. However, the "brake signal" that fine-tunes the expression of AtACS7 to ensure optimal ethylene production during leaf development has yet to be identified. In the present study, the RING-H2 zinc-finger protein RIE1 was found to specifically interact with and ubiquitinate AtACS7, among all functional ACSs in Arabidopsis, to promote its degradation. Overexpression of RIE1 markedly decreased ethylene biosynthesis and delayed leaf senescence, whereas loss of function of RIE1 significantly increased ethylene emission and accelerated leaf senescence. The ethylene-related phenotypes of RIE1 overexpressing or knockout mutants were effectively rescued by the ethylene precursor ACC or the competitive inhibitor of ACS, respectively. In particular, AtACS7-induced precocious leaf senescence was strongly enhanced by the loss of RIE1 but was significantly attenuated by the overexpression of RIE1. The specific regions of interaction between AtACS7 and RIE1, as well as the major ubiquitination sites of AtACS7, were further investigated. All results demonstrated that RIE1 functions as an important modulator of ethylene biosynthesis during leaf development by specifically targeting AtACS7 for degradation, thereby enabling plants to produce the optimal levels of ethylene needed.

Endophytic Pseudomonas fluorescens relieves intraspecific allelopathy of Atractylodes lancea by reducing ethylene transportation

BackgroundEndophytes play an important role in promoting plant growth. To date, although many reports provided insight into the function of endophytes in their hosts, few reports focus on their impact on nearby plants. Intraspecific allelopathy in plant community is common and presents a notable challenge to medicinal plant yield and productivity. Atractylodes lancea is a perennial herb that has relatively low yields due to intraspecific allelopathy. The bacterial endophyte Pseudomonas fluorescens ALEB7B has previously been found to increase essential oil content of A. lancea, but the role of ALEB7B in A. lancea allelopathy is still unknown.ResultsNoninoculated A. lancea exhibited growth retardation when it was grown in a community, which was related to ethylene-induced intraspecific allelopathy. Further experiment showed that exposing A. lancea to volatile from noninoculated A. lancea or same concentration of ethylene reduced growth of A. lancea. P. fluorescens-inoculated plants showed reduced ethylene emission and relieved growth retardation on neighboring noninoculated A. lancea. Moreover, P. fluorescens inoculation had little allelopathic effect when receivers were treated with ethylene receptor inhibitor or when emitters were treated with ethylene production inhibitor. Transcriptomic analysis revealed that endophyte ALEB7B altered transcriptional response associated with ethylene response and essential oil production in neighboring A. lancea.ConclusionsOur results demonstrated that the bacterial endophyte ALEB7B provides fitness benefits for both hosts and neighbors. The allelopathic effect on nearby plants can be alleviated by altering airborne signals, such as ethylene, in endophytic bacteria.