New evidence for gut-muscle axis: Lactic acid bacteria-induced gut microbiota regulates duck meat flavor.

The interaction between gut microbiota and muscles through the gut-muscle axis has received increasing attention. This study attempted to address existing research gaps by investigating the effects of gut microbiota on meat flavor. Specifically, lactic acid bacteria were administered to ducks, and the results of e-nose and e-tongue showed significantly enhanced meat flavor in the treatment group. Further analyses using GC-MS revealed an increase in 6 characteristic volatile flavor compounds, including pentanal, hexanal, heptanal, 1-octen-3-ol, 2,3-octanedione, and 2-pentylfuran. Linoleic acid was identified as the key fatty acid that influences meat flavor. Metagenomic and transcriptomic results further confirmed that cecal microbiota affects the duck meat flavor by regulating the metabolic pathways of fatty acids and amino acids, especially ACACB was related to fatty acid biosynthesis and ACAT2, ALDH1A1 with fatty acid degradation. This study sheds light on a novel approach to improving the flavor of animal-derived food.

Analysis of Transcriptomic Differences in the Ovaries of High- and Low-Laying Ducks.

The egg-laying performance of Shan Ma ducks (Anas Platyrhynchos) is a crucial economic trait. Nevertheless, limited research has been conducted on the egg-laying performance of this species. We examined routine blood indicators and observed higher levels of metabolic and immune-related factors in the high-egg-production group compared with the low-egg-production group. Furthermore, we explored the ovarian transcriptome of both high- and low-egg-production groups of Shan Ma ducks using Illumina NovaSeq 6000 sequencing. A total of 1357 differentially expressed genes (DEGs) were identified, with 686 down-regulated and 671 up-regulated in the high-egg-production (HEP) ducks and low-egg-production (LEP) ducks. Several genes involved in the regulation of ovarian development, including neuropeptide Y (NPY), cell cycle protein-dependent kinase 1 (CDK1), and transcription factor 1 (E2F1), exhibited significant differential expressions at varying stages of egg production. Pathway functional analysis revealed that the DEGs were primarily associated with the steroid biosynthesis pathway, and the neuroactive ligand-receptor interaction pathway exhibited higher activity in the HEP group compared to the LEP group. This study offers valuable information about and novel insights into high egg production.

Investigation into the characteristic volatile flavor of old duck.

In order to explore the characteristic aroma flavor and its formation mechanism of old ducks, two ages (30 days and 60 days) of young ducks and three ages of old ducks (300 days, 900 days, and 1500 days) were selected and studied. An electronic nose was applied to evaluate the overall aroma flavor, and the result showed significant differences between the five duck samples. By gas chromatography-mass spectrometry (GC-MS), forty-eight volatile flavor compounds were detected, including seven aldehydes, six esters, five alcohols, five nitrogen compounds, twenty-one hydrocarbons, and four others. Among these compounds, twelve components, such as hexanal and dimethyl anthranilate, were considered as the characteristic flavor compounds along with duck aging. Furthermore, correlation analysis indicated that meat's unsaturated free fatty acids, especially linoleic acid (C18:2), were responsible for the duck's characteristic flavor formation. These data contribute to the flavor research and identification of old ducks.

Effects of lactic acid bacteria-derived fermented feed on the taste and quality of duck meat.

The present study aimed to examine the impact of lactic acid bacteria- fermented feed (FF) on the taste and quality of duck meat, in addition to elucidating the potential metabolomic mechanism at play. The findings revealed that ducks fed with FF exhibited elevated pH levels and reduced cooking loss in their meat when compared to the control group. In addition, the sensory evaluation and e-tongue analysis revealed that the tenderness, juiciness, umami, richness, saltiness, and sweetness of duck meat were all enhanced by feeding FF. Moreover, an examination of the metabolome using 1H nuclear magnetic resonance (1H NMR) identified the principal differential metabolites that exhibited a correlation with taste, which included 2-aminoadipate, glucose, glycine, N-acetylcysteine, niacinamide, proline, and threonine. Furthermore, the differential metabolites that exhibited the greatest enrichment in duck meat could be primarily traced to glutathione metabolism, glycine, serine and threonine metabolism, taurine and hypotaurine metabolism. The potential factors contributing to the effect of FF and basic commercial duck feed (CF) were found to be primarily regulated via the aforementioned metabolic pathways. The study, therefore, offers a viable approach for enhancing the taste and quality of duck meat.

Regulation and role of extracellular polymeric substances in the defensive responses of Dictyosphaerium sp. to enrofloxacin stress.

Algae are susceptible to enrofloxacin (ENR), an antibiotic frequently detected in aquatic environments. However, algal responses, especially the secretion and roles of extracellular polymeric substances (EPS), under ENR exposure remain unknown. This study is the first to elucidate the variation in algal EPS triggered by ENR at both the physiological and molecular levels. The results showed that EPS were significantly (P < 0.05) overproduced along with increased polysaccharide and protein contents in algae exposed to 0.05, 0.5, and 5 mg/L ENR. Secretion of aromatic proteins, especially tryptophan-like substances with more functional groups or aromatic rings, was specifically stimulated. Furthermore, the genes with upregulated expression related to carbon fixation, aromatic protein biosynthesis, and carbohydrate metabolism are direct causes of enhanced EPS secretion. Improved EPS levels increased the cell surface hydrophobicity and provided more adsorption sites for ENR, which strengthened the van der Waals interaction and reduced ENR internalization. The hormesis effects of ENR were alleviated, as illustrated by the less affected cell density, chlorophyll a/b, and carotenoids biosynthesis in algae with EPS. These findings demonstrate the involvement of EPS in algal ENR resistance and promote a deeper understanding of the ecological effects of ENR in aquatic environments.

Colloidal Nanoparticles Isolated from Duck Soup Exhibit Antioxidant Effect on Macrophages and Enterocytes.

Food-derived colloidal nanoparticles (CNPs) have been found in many food cooking processes, and their specific effects on human health need to be further explored. Here, we report on the successful isolation of CNPs from duck soup. The hydrodynamic diameters of the obtained CNPs were 255.23 ± 12.77 nm, which comprised lipids (51.2%), protein (30.8%), and carbohydrates (7.9%). As indicated by the tests of free radical scavenging and ferric reducing capacities, the CNPs possessed remarkable antioxidant activity. Macrophages and enterocytes are essential for intestinal homeostasis. Therefore, RAW 264.7 and Caco-2 were applied to establish an oxidative stress model to investigate the antioxidant characteristics of the CNPs. The results showed that the CNPs from duck soup could be engulfed by these two cell lines, and could significantly alleviate 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH)-induced oxidative damage. It indicates that the intake of duck soup is beneficial for intestinal health. These data contribute to revealing the underlying functional mechanism of Chinese traditional duck soup and the development of food-derived functional components.

Genome-wide DNA methylation differences between conservation and breeding populations of Shaoxing ducks.

The genome-wide DNA methylation assay was used to analyze the difference in methylation between the breeding and conservation populations of Shaoxing ducks. The methylation level of the breeding population was higher than that of the two conservation populations, and the proportion of CG methylation sites was the largest in the three populations, most of the methylation sites were located in the exon region. There were 1247 different methylation regions in the two populations (group A and B), and 927 different methylation regions in the two groups (group A and group C). The differential methylation regions of the three groups were evenly distributed in the gene and intergene regions. GO and KEGG enrichment analysis showed that the differentially expressed genes in the A and B groups were mainly involved in synaptic and cell connections and the signaling pathways were significantly enriched in cAMP and oxytocin signaling pathways. The results showed that the group C was significantly enriched in eight signaling pathways, including the cAMP signaling pathway and long-term enhancement, compared to the group A. There were thirty-five differentially methylated genes, including CACNA1C, GRIA1, GRIA2, GABBR2, PDE10A, BRAF, GRM5, CPEB3, FMn2, GABRB2, PTK2, and CNTN1. These genes were involved in the development and ovulation of ovaries and follicles and were closely related to the excellent production performance of the breeding population. In addition, ATP2B1, ATP2B2, and other genes related to eggshell quality were identified, which can be used as molecular markers to improve eggshell quality in the future.

Toxicity alleviation and metabolism enhancement of nonylphenol in green algae Dictyosphaerium sp. by NaHCO3.

Nonylphenol (NP) toxicity limits the improvements in its algal remediation efficiency. This study comprehensively investigated the performance and mechanism of NaHCO3-driving effects on NP-exposed algae. The results showed that NaHCO3 enhanced algal resistance to NP and the corresponding EC50 values increased 1.31-4.25 times. Further, the toxicological effects of NP reduced with increasing pyrenoid volume and chlorophyll and carotenoids production, and decreasing cellular damage degree. Moreover, the concentration of extracellular polymeric substances was enhanced and more NP adsorption sites were formed. Consistently, RNA-seq demonstrated significant expression alterations in genes related to energy metabolism, cellular synthesis, photosynthesis, and carbon fixation. Besides, NP biodegradation rate was increased by 15.2 % and 11.1 % in the 1, and 4 mg/L NP treatments, respectively. Identification of degradation intermediates and their toxicity via Ecological Structure Activity Relationship program showed that NaHCO3 accelerated sequential α-C removal from NP in algae with faster generation of less toxic metabolites, namely, 4-ethylphenol, 4-cresol and 4-hydroxybenzoic acid. This study provides new insights into the role of NaHCO3 in toxicity alleviation and metabolism enhancement of NP in algae and can assist NP bioremediation efforts in aquatic environment.

Transformation of sulfidized nanoscale zero-valent iron particles and its effects on microbial communities in soil ecosystems.

Sulfidized nanoscale zero-valent iron (S-nZVI) is a promising material for in situ soil remediation. However, its transformation (i.e., aging) and effects on the microbial community in soil ecosystems are largely unknown. In this study, S-nZVI having low (S-nZVI (L)) and high sulfur-doping (S-nZVI (H)) were incubated in soil microcosms and bare nZVI was used as a control. Their aged products were characterized using microspectroscopic analyses and the changes in the corresponding soil microbial community were determined using high-throughput sequencing analyses. The results indicate that severe corrosion of both bare and S-nZVI occurred over 56 days of aging with significant morphological and mineral changes. Magnetite, lepidocrocite, and goethite were detected as the main aged products. In addition, sulfate ions, pyrite, and iron polysulfide were formed in the aged products of S-nZVI. Cr(VI) removal test results indicated that S-nZVI(L) achieved the best results after aging, likely because of the optimal FeS arrangement on its nanoparticle surfaces. The presence of nZVI and S-nZVI increased the abundance of some magnetotactic microorganisms and altered bacterial and fungal community structures and compositions. Moreover, the addition of S-nZVI enriched some bacterial and fungal genera related to sulfur cycling because of the presence of sulfide-bearing material. The findings reveal the transformation of S-nZVI during aging and its effects on microbial communities in soil ecosystems, thereby helping to the evaluation of S-nZVI application in soil remediation.

Quality properties of chicken meatballs prepared with varying proportions of woody breast meat.

The objective of this study was to explore the effect of woody breast (WB) on quality characteristics of chicken meatballs paired with the feasibility of its inclusion. Cook loss (CL), color (CIE L*, a*, b*), texture (hardness, springiness, chewiness and resilience), low-field NMR (bound water, immobilized water, and free water), microstructure, and sensory characteristics of chicken meatballs with different WB inclusion levels (0%, 25%, 50%, 75%, 100%) were analyzed. The results showed that the impairment of product quality traits such as CL, color, texture (hardness, chewiness), free water, microstructure, and sensory scores (appearance, organization, total score) increased as the percentage of WB meat increased in the product formulation, particularly when the WB incorporation level exceeded 25%. Indeed, cook loss, L*, a*, b* parameters, bound water, and immobilized water increased when the WB inclusion level was higher than 25% (P ≤ 0.05). However, free water, sensory characteristics, hardness, and chewiness parameters decreased (P ≤ 0.05). The microstructure of chicken meatballs also changed as the proportion of WB meat increased. Even though data suggest that the inclusion of WB meat up to 30% could be feasible to produce acceptable chicken meatballs, the optimal maximum incorporation rate of WB meat into chicken meatball recipes was 25% based on economic feasibility and final overall quality.

Nanoscale zero-valent iron alters physiological, biochemical, and transcriptomic response of nonylphenol-exposed algae (Dictyosphaerium sp.).

Nanoparticles and organic pollutants are two major contaminants found in aquatic environments. Algae are regarded as the model organism for the risk assessment of pollutants in water. In our previous study, we investigated the toxic effects of nonylphenol (NP), a typical organic water pollutant, on algae; however, it remains unclear how algae respond to the coexistence of NP and nanoparticles. In this study, a concentration gradient of nanoscale zero-valent iron (nZVI; 10, 50, 100, and 200 mg/L) was added to NP-exposed Dictyosphaerium sp. to investigate both the toxic effects of this combination and the potential for NP removal. nZVI had a dose-dependent effect on NP-exposed algae, with high nZVI concentrations significantly decreasing algal biomass and pigment content, as well as severely damaging algal cellular ultrastructure. In addition, genes involved in antioxidant response, photosynthesis, and ribosome synthesis were significantly altered when NP-exposed algae were incubated with nZVI. In contrast to high nZVI concentrations, adding a small concentration of nZVI led to reduced toxicity in NP-exposed algae, while significantly enhancing the NP removal rate. This study improves our understanding of algal responses to various pollutants and suggests that nZVI may assist in the remediation of NP in aquatic ecosystems.

Physiological and transcriptional responses of Dictyosphaerium sp. under co-exposure of a typical microplastic and nonylphenol.

Microplastics (MPs) and nonylphenol (NP) are typical pollutants that are frequently detected in aquatic environments and can pose a risk to aquatic organisms. However, the responses of algae, the producers in aquatic ecosystems, to MP and NP co-exposure have not been extensively investigated. In this study, polystyrene (PS, 50 mg/L) was selected as a representative MP to evaluate its short-term effects on algae treated with NP (4 mg/L). The results showed that PS mitigated the toxicity of NP to algae after 96 h of exposure, as illustrated by the higher cell densities and pigment concentrations, as well as lower extracellular protein contents and better integrity of intracellular structures, in algae subjected to PS + NP treatment compared with those subjected to NP treatment. Moreover, the upregulated expression of genes involved in photosynthesis and downregulated expression of ribosomal genes as well as genes encoding ATPase and antioxidase, analyzed through RNA-sequencing analysis, further indicated the potential repair and defense mechanisms of PS in NP-treated algae.

Low-Field NMR Analysis of Chicken Patties Prepared with Woody Breast Meat and Implications to Meat Quality.

The scope of this paper was to investigate the effects of water distribution differences on the quality and feasibility of chicken patties supplemented with woody breast (WB). Chicken patties, containing differing amounts of WB (0%, 25%, 50%, 75%, 100%) were analyzed using low-field NMR. Quality differences between chicken patties were further evaluated by combining lipid and protein properties, fry loss (FL), color (L*, a*, b*), texture (hardness, springiness, chewiness, cohesiveness, resilience), microstructure, and sensory characteristics. The results expressed that both lipid and protein oxidation increased and immobilized water in chicken patties can be converted to free water more easily with increasing levels of WB. Additionally, the free water ratio decreased, water freedom increased, and the bound water ratio increased (p < 0.05). Fry loss, color, texture (hardness, springiness, chewiness), microstructure, and sensory (character, organization, taste) characteristics deteriorated significantly when the WB inclusion level exceeded 25%. Particularly, characteristics of texture (chewiness and character) and sensory (character and organization) decreased significantly as WB inclusion increased past 25% (p < 0.01). Furthermore, fry loss, texture, and overall microstructure partially confirmed the moisture variation of chicken patties as the potential cause of the abnormal quality. Although the experimental data expressed that mixing to 35% WB inclusion was feasible, the practical and economic impact recommends inclusion levels to not exceed 30%.

Effects of Fe2O3 nanoparticles on extracellular polymeric substances and nonylphenol degradation in river sediment.

In this study, the impact of Fe2O3 nanoparticles (nFe2O3) on microbial extracellular polymeric substances (EPS) and nonylphenol (NP) degradation in sediment were investigated. The results showed that the addition of nFe2O3 lowered the degree of EPS overproduction and the amount of polysaccharides and proteins secreted in NP contaminated sediment. Particularly, the secretion of colloidal EPS (C-EPS) lowered significantly (P < 0.05), and the content of tyrosine-like, tryptophan-like, and soluble microbial by-product-like substances in C-EPS also decreased, leading to a lower aromaticity, humification, and hydrophobicity of C-EPS. Furthermore, with lower C-EPS content in water, NP was adsorbed to sediment more easily, and the weakened toxic effect of NP to bacteria as well as a higher proportion of organic matter degrading microbes stimulated NP degradation. These findings revealed the vital role of nFe2O3 in alleviating NP toxicity to microbes and reducing NP ecological risk in aquatic environments.

Enhanced excretion of extracellular polymeric substances associated with nonylphenol tolerance in Dictyosphaerium sp.

Dictyosphaerium sp. is tolerant to nonylphenol (NP); however, knowledge regarding the mechanisms involved in NP tolerance is limited. In this study, a batch of algal culture experiments were carried out to elucidate the underlying mechanisms by investigating the production and composition of extracellular polymeric substances (EPS) in algae exposed to NP. The excretion of EPS was significantly enhanced (P < 0.001) in algae exposed to 4 and 8 mg/L of NP. The polysaccharides in soluble EPS and the proteins in bound EPS were specifically overproduced. The three-dimensional excitation and emission matrix fluorescence spectra analyses indicated that tyrosine- and tryptophan-like substances were the main functional compositions in the proteins of EPS. In addition, enhanced EPS secretion significantly alleviated the toxicity of NP to the algae by the reduction of cell internalization, as indicated by the higher IC50, biomass, and cell growth rate in the algae with EPS. These discoveries along with the characterizations by algal cell surface hydrophobicity analysis, scanning electron microscopy, and Fourier transform infrared spectra spectroscopy demonstrated the vital role of EPS in the algal resistance to NP.

Bioaccumulation, growth performance, and transcriptomic response of Dictyosphaerium sp. after exposure to nonylphenol.

Algal cultures of Dictyosphaerium sp. were treated with a wide range (0-8 mg/L) of nonylphenol (NP) applications to investigate the species' potential to perform bioremediation of NP-contaminated wastewater and explore the mechanism of NP toxicity in algal cell. The algal species exhibited a high tolerance for NP and efficiently removed even high concentrations of NP. The accumulation of NP in algal cells tended to increase and the percentage of NP adhered to the cell walls tended to decrease as the NP concentration increased. The thylakoid density and the pyrenoid size also tended to decrease as the NP concentration rose. The key genes involved in the antioxidative pathways and photosynthetic pathways were down-regulated in the NP-treated algal cells. Algal ribosome genes were especially sensitive to NP. The results indicated that NP could induce oxidative stress in algal cells and that Dictyosphaerium sp. showed potential as a bioremediation agent.

Dynamics, biodegradability, and microbial community shift of water-extractable organic matter in rice-wheat cropping soil under different fertilization treatments.

Although fertilization plays an important role in determining the contents of soil dissolved organic matters or water-extractable organic matter (DOM, WEOM), knowledge regarding the dynamics, biodegradability, and microbial community shifts of WEOM in response to different fertilization treatments is very limited, particularly in rice-wheat cropping soil. Thus, in the present study, we performed biodegradation experiments using WEOM extracted from samples of soil that had been subjected to four different fertilization treatments: unfertilized control (CK), chemical fertilizer (CF), 50% chemical fertilizer plus pig manure (PMCF), and 100% chemical fertilizer plus rice straw (SRCF). UV spectrum and fluorescence 3D excitation-emission matrix analyses applied to investigate the chemical composition of WEOM revealed that all examined WEOMs were derived from microbial activity and the dominant portion comprised humic acid-like compounds. After the incubation, 31.17, 31.63, 43.47, and 33.01% of soil WEOM from CK, CF, PMCF, and SRCF treatments, respectively, were biodegraded. PMCF- derived WEOM had the highest biodegradation rate. High-throughput sequencing analyses performed to determine the microbial community before and after the incubation indicated that Sphingomonas, Bacillus, and Flavisolibacter were the predominant bacterial genera in the original inoculum derived from the four fertilization treatments. Following biodegradation, we observed that the dominant bacteria differed according to fertilization treatments: Curvibacter (43.25%) and Sphingobium (10.47%) for CK, Curvibacter (29.68%) and Caulobacter (20.00%) for CF, Azospirillum (23.68%) and Caulobacter (13.29%) for PMCF, and Ralstonia (51.75%) for SRCF. Canonical correspondence analysis revealed that, shifts in the microbial community were closely correlated with pH and specific UV absorbance at 254 nm. We speculated that the inherent traits of different WEOM and the properties of soil solutions under different fertilization treatments shaped the soil microbial community structure, thereby influencing the biodegradation of WEOM.

Increasing cyclic electron flow is related to Na+ sequestration into vacuoles for salt tolerance in soybean.

In land plants, the NAD(P)H dehydrogenase (NDH) complex reduces plastoquinones and drives cyclic electron flow (CEF) around PSI. It also produces extra ATP for photosynthesis and improves plant fitness under conditions of abiotic environmental stress. To elucidate the role of CEF in salt tolerance of the photosynthetic apparatus, Na(+) concentration, chlorophyll fluorescence, and expression of NDH B and H subunits, as well as of genes related to cellular and vacuolar Na(+) transport, were monitored. The salt-tolerant Glycine max (soybean) variety S111-9 exhibited much higher CEF activity and ATP accumulation in light than did the salt-sensitive variety Melrose, but similar leaf Na(+) concentrations under salt stress. In S111-9 plants, ndhB and ndhH were highly up-regulated under salt stress and their corresponding proteins were maintained at high levels or increased significantly. Under salt stress, S111-9 plants accumulated Na(+) in the vacuole, but Melrose plants accumulated Na(+) in the chloroplast. Compared with Melrose, S111-9 plants also showed higher expression of some genes associated with Na(+) transport into the vacuole and/or cell, such as genes encoding components of the CBL10 (calcineurin B-like protein 10)-CIPK24 (CBL-interacting protein kinase 24)-NHX (Na(+)/H(+) antiporter) and CBL4 (calcineurin B-like protein 4)-CIPK24-SOS1 (salt overly sensitive 1) complexes. Based on the findings, it is proposed that enhanced NDH-dependent CEF supplies extra ATP used to sequester Na(+) in the vacuole. This reveals an important mechanism for salt tolerance in soybean and provides new insights into plant resistance to salt stress.

Arbuscular mycorrhizal fungal phylogenetic groups differ in affecting host plants along heavy metal levels.

Arbuscular mycorrhizal fungi (AMF) are important components of soil microbial communities, and play important role in plant growth. However, the effects of AMF phylogenetic groups (Glomeraceae and non-Glomeraceae) on host plant under various heavy metal levels are not clear. Here we conducted a meta-analysis to compare symbiotic relationship between AMF phylogenetic groups (Glomeraceae and non-Glomeraceae) and host plant functional groups (herbs vs. trees, and non-legumes vs. legumes) at three heavy metal levels. In the meta-analysis, we calculate the effect size (ln(RR)) by taking the natural logarithm of the response ratio of inoculated to non-inoculated shoot biomass from each study. We found that the effect size of Glomeraceae increased, but the effect size of non-Glomeraceae decreased under high level of heavy metal compared to low level. According to the effect size, both Glomeraceae and non-Glomeraceae promoted host plant growth, but had different effects under various heavy metal levels. Glomeraceae provided more benefit to host plants than non-Glomeraceae did under heavy metal condition, while non-Glomeraceae provided more benefit to host plants than Glomeraceae did under no heavy metal. AMF phylogenetic groups also differed in promoting plant functional groups under various heavy metal levels. Interacting with Glomeraceae, herbs and legumes grew better than trees and non-legumes did under high heavy metal level, while trees and legumes grew better than herbs and non-legumes did under medium heavy metal level. Interacting with non-Glomeraceae, herbs and legumes grew better than trees and non-legumes did under no heavy metal. We suggested that the combination of legume with Glomeraceae could be a useful way in the remediation of heavy metal polluted environment.

OsABCB14 functions in auxin transport and iron homeostasis in rice (Oryza sativa L.).

Members of the ATP Binding Cassette B/Multidrug-Resistance/P-glyco-protein (ABCB/MDR/PGP) subfamily were shown to function primarily in Oryza sativa (rice) auxin transport; however, none of the rice ABCB transporters have been functionally characterized. Here, we describe that a knock-down of OsABCB14 confers decreased auxin concentrations and polar auxin transport rates, conferring insensitivity to 2,4-dichlorophenoxyacetic acid (2,4-D) and indole-3-acetic acid (IAA). OsABCB14 displays enhanced specific auxin influx activity in yeast and protoplasts prepared from rice knock-down alleles. OsABCB14 is localized at the plasma membrane, pointing to an important directionality under physiological conditions. osabcb14 mutants were surprisingly found to be insensitive to iron deficiency treatment (-Fe). Their Fe concentration is higher and upregulation of Fe deficiency-responsive genes is lower in osabcb14 mutants than in wild-type rice (Nipponbare, NIP). Taken together, our results strongly support the role of OsABCB14 as an auxin influx transporter involved in Fe homeostasis. The functional characterization of OsABCB14 provides insights in monocot auxin transport and its relationship to Fe nutrition.