New light on an old syndrome: Role of Api g 7 in mugwort pollen-related celery allergy.

BACKGROUND: Celery root is known to cause severe allergic reactions in patients sensitized to mugwort pollen. OBJECTIVE: We studied clinically well-characterized patients with celery allergy by IgE testing with a comprehensive panel of celery allergens to disentangle the molecular basis of what is known as the celery-mugwort syndrome. METHODS: Patients with suspected food allergy to celery underwent a standardized interview. Main inclusion criteria were a positive food challenge with celery or an unambiguous case history of severe anaphylaxis. IgE to celery allergens (rApi g 1.01, rApi g 1.02, rApi g 2, rApi g 4, nApi g 5, rApi g 6, rApi g 7) and to mugwort allergens (rArt v 1, rArt v 3, rArt v 4) were determined. IgE levels ≥0.35 kUA/L were regarded positive. RESULTS: Seventy-nine patients with allergy to celery were included. Thirty patients had mild oral or rhinoconjunctival symptoms, and 49 had systemic reactions. Sixty-eight percent had IgE to celery extract, 80% to birch pollen, and 77% to mugwort pollen. A combination of Api g 1.01, 1.02, 4, 5, and 7 increased the diagnostic sensitivity for celery allergy to 92%. The lipid transfer proteins Api g 2 and Api g 6 were not relevant in our celery-allergic population. IgE to Api g 7, detected in 52% of patients, correlated closely (r = 0.86) to Art v 1 from mugwort pollen. Eleven of 12 patients with monosensitization to Api g 7 were IgE negative to celery extract. The odds ratio for developing a severe anaphylactic reaction rather than only mild oral symptoms was about 6 times greater (odds ratio, 5.87; 95% confidence interval, 1.08-32.0; P = .0410) for Api g 7-sensitized versus -nonsensitized subjects. CONCLUSION: There is an urgent need for routine diagnostic tests to assess sensitization to Api g 7, not only to increase test sensitivity but also to identify patients at risk of a severe allergic reaction to celery.

Genomics empowering conservation action and improvement of celery in the face of climate change.

MAIN CONCLUSION: Integration of genomic approaches like whole genome sequencing, functional genomics, evolutionary genomics, and CRISPR/Cas9-based genome editing has accelerated the improvement of crop plants including leafy vegetables like celery in the face of climate change. The anthropogenic climate change is a real peril to the existence of life forms on our planet, including human and plant life. Climate change is predicted to be a significant threat to biodiversity and food security in the coming decades and is rapidly transforming global farming systems. To avoid the ghastly future in the face of climate change, the elucidation of shifts in the geographical range of plant species, species adaptation, and evolution is necessary for plant scientists to develop climate-resilient strategies. In the post-genomics era, the increasing availability of genomic resources and integration of multifaceted genomics elements is empowering biodiversity conservation action, restoration efforts, and identification of genomic regions adaptive to climate change. Genomics has accelerated the true characterization of crop wild relatives, genomic variations, and the development of climate-resilient varieties to ensure food security for 10 billion people by 2050. In this review, we have summarized the applications of multifaceted genomic tools, like conservation genomics, whole genome sequencing, functional genomics, genome editing, pangenomics, in the conservation and adaptation of plant species with a focus on celery, an aromatic and medicinal Apiaceae vegetable. We focus on how conservation scientists can utilize genomics and genomic data in conservation and improvement.

Association of exposure factors and their causal relationship with oral cancer: A Mendelian randomization study.

OBJECTIVES: There is a strong association among risk factors for oral cancer (ORCA), such as smoking, alcohol consumption, fiber intake, and red meat intake. The apparent synergistic effects reported in previous observational studies may also underestimate the independent effects. Our study aims to further explore the potential etiology and causality of oral cancer. MATERIALS AND METHODS: This study used the genome-wide associations study database (GWAS) in European populations for Mendelian randomization (MR) analysis to explore exposure factors associated with ORCA and detect the genetic causality between these exposures and ORCA risk. RESULTS: Our results demonstrated that in univariate MR analysis, the five exposure factors (celery intake, average weekly beer and cider intake, spirits intake, and pork intake) were risk factors, and oily fish intake was a safety factor, but in multivariate MR analysis, pork intake had the greatest impact on oral cancer when the five food/drink intakes were simultaneously consumed. CONCLUSIONS: The causal relationship between the five exposure factors (oily fish intake, celery intake, pork intake, average weekly beer and cider intake, and spirits intake) and oral cancer was analyzed. The causal effects of pork on oral cancer may be underestimated. CLINICAL RELEVANCE: Prevention of oral cancer requires better education about lifestyle-related risk factors, and improved awareness and tools for early diagnosis. Our study provides some risk factors that cannot be ignored for the cause prevention of oral cancer, such as pork intake, and its role in oral cancer prevention and control.

Tubular Cellulose Composite as a Vehicle for the Development of Meat Products with Low Nitrite Content.

Research background: Nitrite salts are among the most used preservatives in meat products as they ensure their safe consumption. Despite their positive effects on food safety and stability, many side effects on human health have been reported, leading to the need to reduce their use. Therefore, the aim of this study is to produce veal products with low nitrite content through low diffusion of potassium nitrite and to study their microbiological characteristics. Experimental approach: Edible tubular cellulose from leaf celery was produced and KNO2 was encapsulated in this material. This was achieved in two ways: by impregnation of tubular cellulose in a KNO2 solution under stirring and using starch gel as a stabilizer. Two samples of impregnated cellulose were applied on the surface of two veal samples of which one was stored at room temperature and the other at 3 °C. Similarly, two samples of cellulose with starch gel were applied on the surface of two veal samples of which one was stored at room temperature and the other at 3 °C. The KNO2 diffusion in different depths of the meat was measured and its effect on the microbiological characteristics of the meat was evaluated. Τhe experiment was carried out in duplicate. Results and conclusions: A satisfactory percentage of about 70 % of the initially encapsulated amount of KNO2 was diffused in the meat, while the rest remained in the pores of the delignified leaf celery. The migrating amount of KNO2 proved to be effective in preserving meat, as the microbiological load decreased significantly (especially within the first 12 h, from a decrease of 0.6 log CFU/g up to 2.4 log CFU/g). Novelty and scientific contribution: The demand for meat products with low nitrite content is constantly increasing and the results of the present study are promising for the development of this technology in scale-up systems and on an industrial scale. This innovative approach could lead to products with controlled diffusion of the preservatives.

Evaluation of physiochemical, heavy metals, and bacteriological parameters of celery and its irrigation water within Sulaymaniyah city of Iraq.

This study rigorously assesses the physicochemical, heavy metal concentrations, and bacteriological parameters of celery and its irrigation water across three rural areas of Sulaymaniyah city, Iraq. The investigation revealed that irrigation water's pH ranged significantly from 6.9 to 8.9. Notably, phosphate concentrations (PO43-) exceeded permissible levels in Tanjaro and Kanaswra across all seasons, with the highest recorded concentration being 10.4 mg L-1 during autumn in Kanaswra. Conversely, sulfate (SO42-) and sodium (Na+) concentrations remained within standard limits, with SO42- peaking at 115.1 mg L-1 in Tanjaro during summer. Celery samples reflected high Na+ concentrations in some seasons, with values exceeding 570 mg·kg in Kanaswra during summer. Heavy metal analysis indicated remarkably low levels in irrigation water, yet celery samples from Tanjaro and Aziz Awa exhibited Pb concentrations above the safety threshold of 0.3 mg·kg in all seasons. Furthermore, bacterial contamination, including total aerobic count and coliform in both water and celery, surpassed standard limits, highlighting significant health risks. This study underscores the imperative need for stringent water treatment processes to mitigate contamination and safeguard agricultural productivity and human health.

Complete Genome Sequence Resource for Cercospora apii Causing Leaf Spot of Celery.

Cercospora apii is an important seedborne pathogenic fungus causing severe Cercospora leaf spot of celery worldwide. Here, we first present a complete genome assembly of C. apii QCYBC from celery, based on Illumina paired-end and PacBio long-read sequencing data. The high-quality genome assembly contains 34 scaffolds with a 34.81 Mb genome size, 330 interspersed repeat genes, 114 noncoding RNAs, and 12,631 protein-coding genes. The benchmarking universal single-copy ortholog (BUSCO) analysis indicated that 98.2% of the BUSCOs were complete, whereas 0.3, 0.7, and 1.1% were duplicated, fragmented, and missing, respectively. Based on annotation, 508 carbohydrate-active enzymes, 243 cytochromes P450 enzymes, 1,639 translocators, 1,358 transmembrane proteins, and 1,146 virulence genes were identified. This genome sequence provides a valuable reference for future studies to improve understanding of the C. apii-celery pathosystem. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

AgMYB5, an MYB transcription factor from celery, enhanced ß-carotene synthesis and promoted drought tolerance in transgenic Arabidopsis.

BACKGROUND: Water shortage caused by global warming seriously affects the yield and quality of vegetable crops. ß-carotene, the lipid-soluble natural product with important pharmacological value, is abundant in celery. Transcription factor MYB family extensively disperses in plants and plays regulatory roles in carotenoid metabolism and water scarcity response. RESULTS: Here, the AgMYB5 gene encoding 196 amino acids was amplified from celery cv. 'Jinnanshiqin'. In celery, the expression of AgMYB5 exhibited transactivation activity, tissue specificity, and drought-condition responsiveness. Further analysis proved that ectopic expression of AgMYB5 increased ß-carotene content and promoted drought tolerance in transgenic Arabidopsis thaliana. Moreover, AgMYB5 expression promoted ß-carotene biosynthesis by triggering the expression of AtCRTISO and AtLCYB, which in turn increased antioxidant enzyme activities, and led to the decreased contents of H2O2 and MDA, and the inhibition of O2- generation. Meanwhile, ß-carotene accumulation promoted endogenous ABA biosynthesis of transgenic Arabidopsis, which resulted in ABA-induced stomatal closing and delayed water loss. In addition, ectopic expression of AgMYB5 increased expression levels of AtERD1, AtP5CS1, AtRD22, and AtRD29. CONCLUSIONS: The findings indicated that AgMYB5 up-regulated ß-carotene biosynthesis and drought tolerance of Arabidopsis.

Transcriptomic and Proteomic Analyses of Celery Cytoplasmic Male Sterile Line and Its Maintainer Line.

Male sterility is a common phenomenon in the plant kingdom and based on the organelles harboring the male-sterility genes, it can be classified into the genic male sterility (GMS) and the cytoplasmic male sterility (CMS). In every generation, CMS can generate 100% male-sterile population, which is very important for the breeders to take advantage of the heterosis and for the seed producers to guarantee the seed purity. Celery is a cross-pollinated plant with the compound umbel type of inflorescence which carries hundreds of small flowers. These characteristics make CMS the only option to produce the commercial hybrid celery seeds. In this study, transcriptomic and proteomic analyses were performed to identify genes and proteins that are associated with celery CMS. A total of 1255 differentially expressed genes (DEGs) and 89 differentially expressed proteins (DEPs) were identified between the CMS and its maintainer line, then 25 genes were found to differentially expressed at both the transcript and protein levels. Ten DEGs involved in the fleece layer and outer pollen wall development were identified by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, most of which were down-regulated in the sterile line W99A. These DEGs and DEPs were mainly enriched in the pathways of "phenylpropanoid/sporopollenin synthesis/metabolism", "energy metabolism", "redox enzyme activity" and "redox processes". Results obtained in this study laid a foundation for the future investigation of mechanisms of pollen development as well as the reasons for the CMS in celery.

Characterization of Volatile Organic Compounds in Five Celery (Apium graveolens L.) Cultivars with Different Petiole Colors by HS-SPME-GC-MS.

Celery (Apium graveolens L.) is an important vegetable crop cultivated worldwide for its medicinal properties and distinctive flavor. Volatile organic compound (VOC) analysis is a valuable tool for the identification and classification of species. Currently, less research has been conducted on aroma compounds in different celery varieties and colors. In this study, five different colored celery were quantitatively analyzed for VOCs using HS-SPME, GC-MS determination, and stoichiometry methods. The result revealed that γ-terpinene, d-limonene, 2-hexenal,-(E)-, and ß-myrcene contributed primarily to the celery aroma. The composition of compounds in celery exhibited a correlation not only with the color of the variety, with green celery displaying a higher concentration compared with other varieties, but also with the specific organ, whereby the content and distribution of volatile compounds were primarily influenced by the leaf rather than the petiole. Seven key genes influencing terpenoid synthesis were screened to detect expression levels. Most of the genes exhibited higher expression in leaves than petioles. In addition, some genes, particularly AgDXS and AgIDI, have higher expression levels in celery than other genes, thereby influencing the regulation of terpenoid synthesis through the MEP and MVA pathways, such as hydrocarbon monoterpenes. This study identified the characteristics of flavor compounds and key aroma components in different colored celery varieties and explored key genes involved in the regulation of terpenoid synthesis, laying a theoretical foundation for understanding flavor chemistry and improving its quality.

Inhibition of continuous cropping obstacle of celery by chemically modified biochar: An efficient approach to decrease bioavailability of phenolic allelochemicals.

The accumulation of allelochemicals released by plants is commonly found in continuous monocropping systems. These chemicals, such as phenolic acids, were shown to be the major sources of autotoxin or pathogen accumulation in soils, leading to a direct or indirect continuous cropping obstacle. In this study, three types of agricultural residuals, i.e., rice husk, tea waste, and wood meal, were chosen as feedstocks. Biochar samples were prepared from these feedstocks to examine their abilities to remove gallic acid, a representative phenolic acid. Biochar, which was prepared from wood meal soaked with H3PO4 (1:1.5, w/w) and pyrolyzed at 400 °C (symbolized as WP400), exhibited the highest adsorption capacities of gallic acids and other phenolic acids. The mechanisms of phenolic acid removal by WP400 were evaluated via experimental and spectroscopic investigations to elucidate the notable adsorption capacity of WP400. The adsorption of gallic acids was pH-dependent and followed a pseudo-second-order kinetic model. The combination of high surface area, the existence of O-containing groups, and the enhancement of H bonds between CC groups and phenolic acids may contribute to the high adsorption capacity of WP400. In a pot experiment, we found that celery growth was promoted with the addition of 0.3% (w/w) WP400 to soils that were continuously monocropped with celery. A large decrease in the water-soluble phenolic compound by more than 40% may be responsible for the results. However, WP400 scavenged nitrate, and this study showed that the synergistic actions of WP400 and nutrients exhibited the greatest efficiencies in mitigating the continuous cropping obstacles of celery.

Identification of Xanthine Oxidase Inhibitors from Celery Seeds Using Affinity Ultrafiltration-Liquid Chromatography-Mass Spectrometry.

Celery seeds have been used as an effective dietary supplement to manage hyperuricemia and diminish gout recurrence. Xanthine oxidase (XOD), the critical enzyme responsible for uric acid production, represents the most promising target for anti-hyperuricemia in clinical practice. In this study, we aimed to establish a method based on affinity ultrafiltration-liquid chromatography-mass spectrometry (UF-LC-MS) to directly and rapidly identify the bioactive compounds contributing to the XOD-inhibitory effects of celery seed crude extracts. Chemical profiling of celery seed extracts was performed using UPLC-TOF/MS. The structure was elucidated by matching the multistage fragment ion data to the database and publications of high-resolution natural product mass spectrometry. Thirty-two compounds, including fourteen flavonoids and six phenylpeptides, were identified from celery seed extracts. UF-LC-MS showed that luteolin-7-O-apinosyl glucoside, luteolin-7-O-glucoside, luteolin-7-O-malonyl apinoside, luteolin-7-O-6'-malonyl glucoside, luteolin, apigenin, and chrysoeriol were potential binding compounds of XOD. A further enzyme activity assay demonstrated that celery seed extract (IC50 = 1.98 mg/mL), luteolin-7-O-apinosyl glucoside (IC50 = 3140.51 µmol/L), luteolin-7-O-glucoside (IC50 = 975.83 µmol/L), luteolin-7-O-6'-malonyl glucoside (IC50 = 2018.37 µmol/L), luteolin (IC50 = 69.23 µmol/L), apigenin (IC50 = 92.56 µmol/L), and chrysoeriol (IC50 = 40.52 µmol/L) could dose-dependently inhibit XOD activities. This study highlighted UF-LC-MS as a useful platform for screening novel XOD inhibitors and revealed the chemical basis of celery seed as an anti-gout dietary supplement.

Green Chemometric-Assisted Characterization of Common and Black Varieties of Celery.

Celery (Apium graveolens L., var. Dulce), is a biennial herbaceous plant belonging to the Apiaceae family, cultivated in humid soils in the Mediterranean basin, in Central-Southern Europe, and in Asia. Despite its wide diffusion and although it is well-known that cultivar/origin strongly influences plant composition, only a few studies have been carried out on the different types of celery. The present work aims to investigate four different Italian types of celery (two common, Elne and Magnum celery, and two black, Torricella Peligna Black and Trevi Black celery), and to test, whether the combination of FT-IR spectroscopy and chemometrics allows their ecotype discrimination. The peculiarity of this study lies in the fact that all the analyzed celeries were grown in the same experimental field under the same soil and climate conditions. Consequently, the differences captured by the FT-IR-based tool are mainly imputable to the different ecotypes. In order to achieve this goal, FT-IR profiles were handled by two diverse classifiers: sequential preprocessing through ORThogonalization (SPORT) and soft independent modeling by class analogy (SIMCA). Eventually, the highest classification rate (90%, on an external set of 100 samples) has been achieved by SPORT.

Beneficial effects of celery seed extract (Apium graveolens), as a supplement, on anxiety and depression in hypertensive patients: a randomized clinical trial.

BACKGROUND: Anxiety and depression are crucial public health issues, affecting the rising in hospitalizations and death. Anxiety and depression can worsen hypertension and vice versa. OBJECTIVE: The current study has investigated the effects of celery seed extract, as a drug supplement, with the active ingredient of 3-n-butylphthalide, on mental problems primarily anxiety and secondary depression in hypertensive patients. DESIGN: The current study was a randomized, triple-blind, placebo-controlled, cross-over, 4-week clinical trial with a 4-week washout period. Fifty hypertensive patients received 4 placebo or celery seed extract capsules (1.34 g per day) for 4 weeks as a supplement to their usual medication regimen. The blood pressure parameters were assessed using 24-h ambulatory blood pressure monitoring device. Anxiety and depression and their wide range of symptoms were evaluated using Beck anxiety and depression inventories (BAI and BDI). RESULTS: In the celery treatment step, the mean reduction in BAI and BDI scores were 6.78 (P < 0.001) and 3.63 (P < 0.01), respectively. Some symptoms of anxiety including unable to relax, nervousness, numbness, dizziness, flushed face, sweating, and breathing difficulty were significantly improved by celery consumption (P < 0.001). Celery could decrease symptoms of depression such as sadness, crying, loss of energy, insomnia, irritability, fatigue, loss of interest in sex, and punishment feeling (P < 0.01). The mean reduction in blood pressure parameters was also significant during celery therapy (P < 0.001). CONCLUSIONS: The psychometric properties of anxiety and depression were investigated and the results were promising. The results indicated the anti-anxiety and anti-depressive properties of celery seed extract as a supplement in hypertensive patients. CLINICAL TRIAL REGISTRATION: Registry name: Iranian Registry of Clinical Trials (IRCT), Registration number: IRCT20130418013058N8, Registration link: https://www.irct.ir/trial/30021 . The study was carried out between 2018-09-21 and 2020-07-20.

Neurological Applications of Celery (Apium graveolens): A Scoping Review.

Apium graveolens is an indigenous plant in the family Apiaceae, or Umbelliferae, that contains many active compounds. It has been used traditionally to treat arthritic conditions, gout, and urinary infections. The authors conducted a scoping review to assess the quality of available evidence on the overall effects of celery when treating neurological disorders. A systematic search was performed using predetermined keywords in selected electronic databases. The 26 articles included upon screening consisted of 19 in vivo studies, 1 published clinical trial, 4 in vitro studies and 2 studies comprising both in vivo and in vitro methods. A. graveolens and its bioactive phytoconstituent, 3-n-butylphthalide (NBP), have demonstrated their effect on neurological disorders such as Alzheimer's disease, Parkinson's disease, stroke-related neurological complications, depression, diabetes-related neurological complications, and epilepsy. The safety findings were minimal, showing that NBP is safe for up to 18 weeks at 15 mg/kg in animal studies, while there were adverse effects (7%) reported when consuming NBP for 24 weeks at 600 mg daily in human trials. In conclusion, the safety of A. graveolens extract and NBP can be further investigated clinically on different neurological disorders based on their potential role in different targeted pathways.

The feasibility of using micro concentrated multiple reflection ATR FTIR accessory in pesticide analysis.

Micro-Multiple Reflection ATR (CMRATR) spectroscopy is a technique, using specialized equipment, which allows the enhanced sensitivity of multiple reflection ATR analysis of small amounts of liquids in a confined area hitherto reserved for single reflection equipment. This technique has demonstrated a high level of sensitivity, especially when used in conjunction with an evaporative technique. In this work, the technique will be used with a miniature CMRATR accessory, which has the added advantage of compatibility with the smallest current FTIR spectrometers, to analyze pesticides. The results presented here indicate that the CMRATR/evaporative technique can serve as both qualitative and quantitative support to the existing standard methodology.

Macro-, micro-, and heavy metal element levels in different parts of celery (Apium graveolens L.) plant.

Potassium (K) was found in the highest amount in the macroelements of the celery plant, followed by P, Ca, Mg, and S in decreasing order. P and K amounts of celery plant parts were measured between 619.57 (leaf of celery) and 1244.80 mg/kg (root of celery) to 5594.83 (head of celery) and 7587.35 mg/kg (root of celery), respectively. Exterior and interior parts of celery body contained 866.51 and 1017.45 mg/kg P, 6786.97 and 7325.07 mg/kg K, 615.13 and 491.59 mg/kg Ca, and 286.34 and 224.74 mg/kg Mg, respectively. In general, the celery part with the richest microelements was the leaves, followed in descending order by the head of celery, exterior of celery body, interior of celery body, and root. Fe and Mn contents of the parts of celery plants were recorded between 0.351 (interior of celery body) and 67.79 mg/kg (leaf of celery) to 2.70 (root) and 6.84 mg/kg (leaf of celery), respectively. The lowest and highest concentrations of each heavy metal were found in different parts of the celery plant. In general, the leaves were the part of the celery plant with the most heavy metals. As and Pb accumulated in large amounts in the inner parts of the celery tuber. The highest Pb (0.530 µg/g) was determined in interior of celery body. The highest Co (0.409 µg/g), Cr (0.377 µg/g), Mo (0.854 µg/g), and Ni (0.741 µg/g) were found in the leaf of celery plant.

Molecular mechanisms and hormonal regulation underpinning morphological dormancy: a case study using Apium graveolens (Apiaceae).

Underdeveloped (small) embryos embedded in abundant endosperm tissue, and thus having morphological dormancy (MD) or morphophysiological dormancy (MPD), are considered to be the ancestral state in seed dormancy evolution. This trait is retained in the Apiaceae family, which provides excellent model systems for investigating the underpinning mechanisms. We investigated Apium graveolens (celery) MD by combined innovative imaging and embryo growth assays with the quantification of hormone metabolism, as well as the analysis of hormone and cell-wall related gene expression. The integrated experimental results demonstrated that embryo growth occurred inside imbibed celery fruits in association with endosperm degradation, and that a critical embryo size was required for radicle emergence. The regulation of these processes depends on gene expression leading to gibberellin and indole-3-acetic acid (IAA) production by the embryo and on crosstalk between the fruit compartments. ABA degradation associated with distinct spatiotemporal patterns in ABA sensitivity control embryo growth, endosperm breakdown and radicle emergence. This complex interaction between gibberellins, IAA and ABA metabolism, and changes in the tissue-specific sensitivities to these hormones is distinct from non-MD seeds. We conclude that the embryo growth to reach the critical size and the associated endosperm breakdown inside MD fruits constitute a unique germination programme.

Evolutionary analysis and functional characterization of BZR1 gene family in celery revealed their conserved roles in brassinosteroid signaling.

BACKGROUND: Brassinosteroids (BRs) are a group of essential steroid hormones involved in diverse developmental and physiological processes in plants. The Brassinazole-resistant 1 (BZR1) transcription factors are key components of BR signaling and integrate a wide range of internal and environmental signals to coordinate plant development, growth, and resistance to abiotic and biotic stresses. Although the BZR1 family has been fully studied in Arabidopsis, celery BZR1 family genes remain largely unknown. RESULTS: Nine BZR1 genes were identified in the celery genome, and categorized into four classes based on phylogenetic and gene structure analyses. All the BZR1 proteins shared a typical bHLH (basic helix-loop-helix) domain that is highly conserved across the whole family in Arabidopsis, grape, lettuce, ginseng, and three Apiaceae species. Both duplications and losses of the BZR1 gene family were detected during the shaping of the celery genome. Whole-genome duplication (WGD) or segmental duplication contributed 55.56% of the BZR1 genes expansion, and the γ as well as celery-ω polyploidization events made a considerable contribution to the production of the BZR1 paralogs in celery. Four AgBZR1 members (AgBZR1.1, AgBZR1.3, AgBZR1.5, and AgBZR1.9), which were localized both in the nucleus and cytoplasm, exhibit transcription activation activity in yeast. AgBZR1.5 overexpression transgenic plants in Arabidopsis showed curled leaves with bent, long petioles and constitutive BR-responsive phenotypes. Furthermore, the AgBZR1 genes possessed divergent expression patterns with some overlaps in roots, petioles, and leaves, suggesting an extensive involvement of AgBZR1s in the developmental processes in celery with both functional redundancy and divergence. CONCLUSIONS: Our results not only demonstrated that AgBZR1 played a conserved role in BR signaling but also suggested that AgBZR1 might be extensively involved in plant developmental processes in celery. The findings lay the foundation for further study on the molecular mechanism of the AgBZR1s in regulating the agronomic traits and environmental adaptation of celery, and provide insights for future BR-related genetic breeding of celery and other Apiaceae crops.

The Effect of Temperature on Disease Severity and Growth of Fusarium oxysporum f. sp. apii Races 2 and 4 in Celery.

Fusarium oxysporum f. sp. apii race 4, which is in F. oxysporum species complex (FOSC) Clade 2, causes a new Fusarium wilt of celery. We compared F. oxysporum f. sp. apii race 4 with race 2, which causes Fusarium yellows of celery and is in FOSC Clade 3. Optimal temperatures for celery yield are 16 to 18°C. Soil temperatures in California celery production areas can range up to 26°C, and the maximal rate of hyphal extension of F. oxysporum f. sp. apii races 2 and 4 in culture are 25 and 28°C, respectively. Here, we compared the effect of temperatures from 16 to 26°C on growth of F. oxysporum f. sp. apii races 4 and 2 in two celery cultivars: Challenger, which is resistant to F. oxysporum f. sp. apii race 2 and susceptible to race 4; and Sonora, which is susceptible to both F. oxysporum f. sp. apii races 2 and 4. Based on linear regressions, as temperature increases, there is an increase in the log of F. oxysporum f. sp. apii race 4 DNA concentration in celery crowns and in the reduction in plant height. Based on logistic regressions, as temperature increases, the incidence of vascular discoloration increases in celery with either F. oxysporum f. sp. apii race 2 or 4 infection. In both cultivars, temperatures of 22°C and above resulted in a significantly (α = 0.05) greater concentration of F. oxysporum f. sp. apii race 4 than race 2 in planta. The concentration of F. oxysporum f. sp. apii race 2 in crowns in 'Challenger' is temperature-independent and comparatively low; consequently, 'Challenger' is, at least partly, resistant rather than tolerant to F. oxysporum f. sp. apii race 2.

AgMYB12, a novel R2R3-MYB transcription factor, regulates apigenin biosynthesis by interacting with the AgFNS gene in celery.

KEY MESSAGE: Overexpression of AgMYB12 in celery improved the accumulation of apigenin by interacting with the AgFNS gene. Celery is a common vegetable, and its essential characteristic is medicine food homology. A natural flavonoid and a major pharmacological component in celery, apigenin plays an important role in human health. In this study, we isolated a novel R2R3-MYB transcription factor that regulates apigenin accumulation from the celery cultivar 'Jinnan Shiqin' through yeast one-hybrid screening and designated it as AgMYB12. The AgMYB12 protein was located in the nucleus. It showed transcriptional activation activity and bound specifically to the promoter of AgFNS, a gene involved in apigenin biosynthesis. Phylogenetic tree analysis demonstrated that AgMYB12 belongs to the flavonoid branch. It contains two flavonoid-related motifs, SG7 and SG7-2, and shared a highly conserved R2R3 domain with flavonoid-related MYBs. The homologous overexpression of AgMYB12 induced the up-regulation of AgFNS gene expression and accumulation of apigenin and luteolin in celery. Additionally, the expression levels of apigenin biosynthesis-related genes, including AgPAL, AgCHI, AgCHS, Ag4CL, and AgC4H, increased in transgenic celery plants. These results indicated that AgMYB12 acted as a positive regulator of apigenin biosynthesis and activated the expression of AgFNS gene. The current study provides new information about the regulation mechanism of apigenin metabolism in celery and offers a strategy for cultivating the plants with high apigenin content.