ACC oxidase (ACO) is one of the key enzymes that catalyze the synthesis of ethylene. Ethylene is involved in salt stress response in plants, and salt stress seriously affects the yield of peanut. In this study, AhACO genes were cloned and their functions were investigated with the aim to explore the biological function of AhACOs in salt stress response, and to provide genetic resources for the breeding of salt-tolerant varieties of peanut. AhACO1 and AhACO2 were amplified from the cDNA of salt-tolerant peanut mutant M29, respectively, and cloned into the plant expression vector pCAMBIA super1300. The recombinant plasmid was transformed into Huayu22 by pollen tube injection mediated by Agrobacterium tumefaciens. After harvest, the small slice cotyledon was separated from the kernel, and the positive seeds were screened by PCR. The expression of AhACO genes was analyzed by qRT-PCR, and the ethylene release was detected by capillary column gas chromatography. Transgenic seeds were sowed and then irrigated with NaCl solution, and the phenotypic changes of 21-day-seedings were recorded. The results showed that the growth of transgenic plants were better than that of the control group Huayu 22 upon salt stress, and the relative content of chlorophyll SPAD value and net photosynthetic rate (Pn) of transgenic peanuts were higher than those of the control group. In addition, the ethylene production of AhACO1 and AhACO2 transgenic plants were 2.79 and 1.87 times higher than that of control peanut, respectively. These results showed that AhACO1 and AhACO2 could significantly improve the salt stress tolerance of transgenic peanut.
Salt Tolerance/genetics* ; Arachis/genetics* ; Plant Breeding ; Ethylenes/metabolism* ; Plants, Genetically Modified/genetics* ; Gene Expression Regulation, Plant ; Plant Proteins/genetics*

To study the molecular mechanism of salt stress response of peanut small GTP binding protein gene AhRabG3f, a 1 914 bp promoter fragment upstream of the start codon of AhRabG3f gene (3f-P) from peanut was cloned. Subsequently, five truncated fragments (3f-P1-3f-P5) with lengths of 1 729, 1 379, 666, 510 and 179 bp were obtained through deletion at the 5' end, respectively. Plant expression vectors where these six promoter fragments were fused with the gus gene were constructed and transformed into tobacco by Agrobacterium-mediated method, respectively. GUS expression in transgenic tobacco and activity analysis were conducted. The gus gene expression can be detected in the transgenic tobacco harboring each promoter segment, among which the driving activity of the full-length promoter 3f-P was the weakest, while the driving activity of the promoter segment 3f-P3 was the strongest. Upon exposure of the transgenic tobacco to salt stress, the GUS activity driven by 3f-P, 3f-P1, 3f-P2 and 3f-P3 was 3.3, 1.2, 1.9 and 1.2 times compared to that of the transgenic plants without salt treatment. This suggests that the AhRabG3f promoter was salt-inducible and there might be positive regulatory elements between 3f-P and 3f-P3 in response to salt stress. The results of GUS activity driven by promoter fragments after salt treatment showed that elements included MYB and GT1 between 1 930 bp and 1 745 bp. Moreover, a TC-rich repeat between 682 bp and 526 bp might be positive cis-elements responsible for salt stress, and an MYC element between 1 395 bp and 682 bp might be a negative cis-element responsible for salt stress. This study may facilitate using the induced promoter to regulate the salt resistance of peanut.
Arachis/genetics* ; Fabaceae/genetics* ; GTP-Binding Proteins/metabolism* ; Gene Expression Regulation, Plant ; Glucuronidase/metabolism* ; Plant Proteins/metabolism* ; Plants, Genetically Modified/genetics* ; Salt Stress ; Stress, Physiological/genetics* ; Tobacco/genetics*

BACKGROUND: The prevalence of peanut allergy (PA) among children has increased significantly over the past decade. Even though the prevalence of PA in Singapore is considered low, peanut is the top trigger for food-induced anaphylaxis in Singaporean children.OBJECTIVE: To describe the demographic characteristics and clinical features of children with PA.METHODS: This is a 5-year retrospective review of children diagnosed with PA based on clinical history coupled with a positive skin prick test to peanut or positive oral food challenge results.RESULTS: There were 269 patients (53.9% males) with a clinical diagnosis of PA. The median age at first allergic presentation for the PA group was 24 months old, with interquartile range of 13–39 months. The most common form of peanut introduced was roasted peanut. The rate of peanut anaphylaxis was 7.1%. Concomitant tree nut sensitization was found in 32.3% of this cohort, predominantly to cashew nut. Majority of them have a personal history of atopy – 75.8% with eczema, 63.6% with allergic rhinitis, and 19.7% with asthma.CONCLUSION: This is the first large review of peanut-allergic children in Singapore. Prospective population-based studies are needed to establish the true prevalence and risk factors associated with the development of this potentially life-threatening condition.
Anacardium ; Anaphylaxis ; Arachis ; Asia ; Asthma ; Child ; Cohort Studies ; Diagnosis ; Eczema ; Humans ; Nuts ; Peanut Hypersensitivity ; Prevalence ; Prospective Studies ; Retrospective Studies ; Rhinitis, Allergic ; Risk Factors ; Singapore ; Skin ; Trees

Creating new germplasms and breeding new cultivars in peanut by radiation mutagenesis and tissue culture were conducted in this study, aiming to develop new breeding method of peanut. Mature seeds from Luhua 11, the most commonly grown peanut cultivar in Northern China, were treated by fast neutron irradiation. Then the embryo leaflets were separated from the irradiated seeds and inoculated on the media, and the regenerated seedlings were obtained through somatic embryogenesis pathway. The regenerated seedlings were grafted, acclimated and then transplanted into field and the selfed pods were harvested from 83 regenerated plants. The progenies were selected by the pedigree method, and 107 mutants were obtained from the progenies of the 83 regenerated plants. Different mutants showed obvious variation in many agronomic traits, including main stem height, branch number, pod shape and size, seed coat color, inner seed coat color, oil content and protein content etc. Yuhua 7, a new peanut variety with low oil content, early maturity and waterlogging tolerance was obtained. The yield of Yuhua 7 was over 14% higher than that of the mutagenic parent Luhua 11, and the oil content of kernels was 47.0%, lower than that of parent Luhua 11 with 52.1% oil content. Yuhua 7 had passed peanut variety regional multi-location trials in Liaoning Province in 2016 and its average yield was 13.8% higher than that of the control variety Baisha 1017. It had also passed national peanut variety registration, and the registration ID is "GPD peanut (2018) 370105". The results show that irradiation mutagenesis combined with tissue culture is an effective method for creating new germplasm and breeding new varieties of peanut.
Arachis ; Breeding ; China ; Fast Neutrons ; Plant Breeding ; Seeds

Yuhua91 is a new peanut variety with high oleic acid content bred by Qingdao Agricultural University. The crossing was conducted with Luhua11 as female parent and with Kainong1715, an F435-type variety with high oleic acid content as male parent. The real F1 hybrids were screened by sequencing on PCR amplification products, and those homozygotes with bb genotype in F2 populations were screened by the same sequencing method as above. The content of oleic and linoleic acid was measured on the kernels harvested from F2 single plants by near infrared ray method, and those kernels whose content of oleic was above 80%, oleic and linoleic acid ratio was above 10.0 were obtained and planted into a row, with pedigree method for subsequent selection breeding. Yuhua91 has some characters of small pod, light and obvious pod texture, 148.06 g per 100 pods, 63.31 g per 100 kernels, 75.15% shelling percentage, long elliptic seed kernel, pink seed coat, without crack, white endotesta. Its content of protein, oil, oleic acid, linoleic acid and palmitic acid was 26.57%, 52.72%, 80.40%, 2.50% and 5.57% respectively. Yuhua91 has other characters of strong seedlings, compact pod areas, and moderate resistance to leaf spot disease and bacterial wilt. Average pod yield is 215.79 kg per Mu, 15.27% higher than the control variety Huayu20. Average seed kernels yield is 157.33 kg per Mu, 21.64% higher than the control variety Huayu20. Yuhua 91 has been registered on department of agriculture in 2018, and the registration No. is GPD peanut (2018) 370210, fit for growing in Shandong Province.
Arachis ; Oleic Acid ; Plant Breeding ; Seeds

Leaf water potential of peanut subjected to drought stress is positively related to the oil content of peanut kernels. The aim of this study was to directly screen the high oil mutants of peanut and create the new peanut varieties using hydroxyproline as water potential regulator. In vitro mutagenesis was carried out with the embryonic leaflets of peanut variety Huayu 20 as explants and pingyangmycin as a mutagen added into the somatic embryo formation medium. The formed somatic embryos were successively transferred to somatic embryo germination and selection medium containing 6 mmol/L hydroxyproline (at -2.079 MPa water potential ) to induce regeneration and directionally screen high oil content mutants. After that, these plantlets were grafted and transplanted to the experimental field and 132 high oil mutants with oil content over 55% were obtained from the offspring of regenerated plants. Finally, among them, the oil contents of 27 lines were higher than 58% and of 2 lines were higher than 60%. A new peanut variety Yuhua 9 with high yield and oil content was bred from the regenerated plant progenies combining the pedigree breeding method. The yield was 14.0% higher than that of the control cultivar in the testing new peanut varieties of Liaoning province, and also it has passed the national registration of non-major crop varieties. Yuhua 9 with an oil content of 61.05%, which was 11.55 percentage points higher than that of the parent Huayu 20, was the peanut cultivar with the highest oil content in the world. The result showed that it was an effective way for directional breeding of high oil peanut varieties by means of the three-step technique including in vitro mutagenesis, directional screening by reducing water potential in medium and pedigree selection of regenerated plant progenies.
Arachis ; Droughts ; Germination ; Mutagenesis ; Plant Breeding

BACKGROUND: Peanut allergy is an increasing problem in Singapore and strict avoidance is difficult as peanut is ubiquitous in Asian cuisine. OBJECTIVE: We aimed to assess the efficacy and safety of peanut oral immunotherapy (OIT) in children with obvious peanut allergy in Singapore. METHODS: This was an open-label study of peanut OIT in children living in Singapore, with 2 weekly dose escalation until final maintenance dose of 3,000 mg of peanut protein and a maintenance phase of 12 months. An oral food challenge was performed at 6 months to assess for desensitisation and at 4 weeks after discontinuation of OIT having completed 12 months of maintenance therapy to assess for possible sustained unresponsiveness. The adverse events were monitored using the symptom diaries. RESULTS: Nine subjects were started on OIT, with 7 managing to complete maintenance phase of therapy. Of these 7, all were able to tolerate at least 3,000 mg of peanut protein by 6 months of maintenance therapy, showing that the OIT was effective. Of these 7, 3 patients complied with the 4-week abstinence period after completion of OIT before another peanut challenge; 2 of the 3 subjects showed a significant decrease from the initial ability to tolerate 3,000 mg of peanut protein. Side effects were mainly gastrointestinal in nature and were more common during the updosing phase than the maintenance phase. No episodes of anaphylaxis were observed in this study. CONCLUSION: Peanut OIT seemed to be effective and safe in our cohort of Singaporean children.
Anaphylaxis ; Arachis ; Asian Continental Ancestry Group ; Child ; Cohort Studies ; Humans ; Hypersensitivity ; Immunotherapy ; Peanut Hypersensitivity ; Pilot Projects ; Probiotics ; Singapore

BACKGROUND: The predictive decision points for both peanut skin prick test (SPT) wheal size and serum IgE concentrations, in peanut-sensitized children, have not been evaluated in Singapore. OBJECTIVE: We aim to derive clinically useful predictive decision points to be used for risk stratification of oral food challenge (OFC) in peanut-sensitized patients. METHODS: Patients with a positive SPT to peanut, performed during a 4-year period between 2012 and 2016, were included in a retrospective chart review. The patients were assessed for their peanut allergy status based on a convincing clinical history. Their first SPT and serum IgE results done at presentation to our centre were used. RESULTS: There were 269 patients with a clinical diagnosis of peanut allergy based on recent immediate reaction to peanut and 59 patients whom were tolerating peanuts regularly. There were 251 patients sensitized to peanut, without prior known peanut exposure. A wheal size of ≥8 mm and a peanut-specific IgE of ≥6 kU/L each provided for a 95% positive predictive value of clinical reaction to peanuts; the larger the wheal size on SPT, the higher the probability. CONCLUSION: The cutoff values derived in this study can help clinicians in the risk assessment of OFC in peanut-sensitized patients. Prospective studies using OFCs for the diagnosis of peanut allergy are needed to confirm the diagnostic performance of these tests in predicting OFC outcomes.
Arachis ; Child ; Diagnosis ; Humans ; Immunoglobulin E ; Peanut Hypersensitivity ; Prospective Studies ; Retrospective Studies ; Risk Assessment ; Singapore ; Skin

PURPOSE: Many studies have reported that pollen-food allergy syndrome (PFAS) can cause anaphylaxis. No comprehensive investigations into anaphylaxis in PFAS have been conducted, however. In this study, we investigated the clinical manifestations and risk factors for anaphylaxis in PFAS in Korean patients with pollinosis. MATERIALS AND METHODS: Data were obtained from a nationwide cross-sectional study that previously reported on PFAS in Korean patients with pollinosis. Data from 273 patients with PFAS were collected, including demographics, list of culprit fruits and vegetables, and clinical manifestations of food allergy. We analyzed 27 anaphylaxis patients and compared them with patients with PFAS with oropharyngeal symptoms only (n=130). RESULTS: The most common cause of anaphylaxis in PFAS was peanut (33.3%), apple (22.2%), walnut (22.2%), pine nut (18.5%), peach (14.8%), and ginseng (14.8%). Anaphylaxis was significantly associated with the strength of sensitization to alder, hazel, willow, poplar, timothy, and ragweed (p<0.05, respectively). Multivariable analysis revealed that the presence of atopic dermatitis [odds ratio (OR), 3.58; 95% confidence interval (CI), 1.25–10.23; p=0.017]; sensitization to hazel (OR, 5.27; 95% CI, 1.79–15.53; p=0.003), timothy (OR, 11.8; 95% CI, 2.70–51.64; p=0.001), or ragweed (OR, 3.18; 95% CI, 1.03–9.87; p=0.045); and the number of culprit foods (OR, 1.25; 95% CI, 1.15–1.37; p<0.001) were related to the development of anaphylaxis in PFAS. CONCLUSION: The most common culprit foods causing anaphylaxis in PFAS were peanut and apple. The presence of atopic dermatitis; sensitization to hazel, timothy, or ragweed; and a greater number of culprit foods were risk factors for anaphylaxis in PFAS.
Alnus ; Ambrosia ; Anaphylaxis ; Arachis ; Cross-Sectional Studies ; Demography ; Dermatitis, Atopic ; Food Hypersensitivity ; Fruit ; Humans ; Hypersensitivity ; Juglans ; Nuts ; Panax ; Pollen ; Prunus persica ; Rhinitis, Allergic, Seasonal ; Risk Factors ; Salix ; Vegetables

PURPOSE: Egg is the most common food allergen in infants. However, the natural course of egg allergy has not been fully elucidated. This study aimed to describe clinical characteristics and to identify prognostic factors associated with tolerance acquisition of immunoglobulin E (IgE)-mediated egg allergy in children.
Arachis ; Child ; Dermatitis, Atopic ; Diagnosis ; Egg Hypersensitivity ; Egg White ; Follow-Up Studies ; Food Hypersensitivity ; Humans ; Hypersensitivity ; Immunoglobulin E ; Immunoglobulins ; Infant ; Ovum ; Triticum