Identification And Molecular Evolution Of Allergen Protein In Cultivated Peanut(arachis Hypogaea)

As a legume crop,peanut one of the main sources of high-quality edible oil is an important cash crop.There are more than 100 countries planting peanuts in the world,and Asia is the most common zone.Among the major peanut producing countries,India and China have the largest cultivation area and production volume.Peanuts are rich in nutritional value,containing up to 26% protein,which is twice as much as wheat,and can be easily absorbed and utilized by the human body.In order to obtain high-protein nutritious foods,peanut production is gradually developed in the direction of food.However,for a small number of people,specific proteins in peanuts can cause human allergies.When the human immune system mistakes food proteins as a threat,an allergic reaction will occur over time.Peanut allergy is a serious and life-threatening health problem.There has been a large expenditure of research effort into understanding and characterizing these proteins associated with human disease.However,the complexity of the peanut genome prevents comprehensive identification and analysis of allergen proteins in the peanut genome.In this study,a comprehensive identification and analysis of allergen proteins from two cultivated peanuts was made using bioinformatic methods.Comprehensively searching the allergen database,17 medically named or reviewed peanut allergens were summarized: Ara h 1,Ara h 2,Ara h 3,Ara h 5,Ara h 6,Ara h 7,Ara h 8,Ara h 9,Ara h 10,Ara h 11,Ara h 12,Ara h 13,Ara h 14,Ara h 15,Ara h 16,Ara h 17 and Agglutinin.Seventeen peanut allergens belong to seven protein families: Lectin?leg B(PF00139),Cupin?1(PF00190),Tryp?alpha?amyl(PF00234),Profilin(PF00235),Gamma-thionin(PF00304),Bet?v?1(PF00407),and Oleosin(PF01277).Based on the genome,we identified more genes encoding peanut allergen protein,93 genes were identified in sparsely subspecies,and 87 genes were identified in densely subspecies,which is twice as many as the previously identified genes.Based on the transcriptome,we found that the gene expression of different peanut allergen protein families has obvious tissue specificity.In addition to the highest expression in seeds,other tissue parts also have certain expressions,indicating that in addition to the seeds being allergens,other peanut tissues may also Causes allergies.Based on immune linear epitope prediction,we define Cupin?1(PF00190)and Tryp?alpha?amyl(PF00234)as the main peanut allergen protein family,and Ara h 1,Ara h 2,Ara h 3,and Ara h 6 as the major allergies.Molecular evolution studies have shown that most of the peanut allergen protein genes are doubled in the peanut genome by doubling the number of genomes,and some also increase the number of copies by tandem repeats.Multiple copies of the gene may increase the expression level,and the increase in expression level makes the protein be the strong allergen.In summary,this study used bioinformatics,comparative genomics,and phylogeny mothods to comprehensively identify allergen proteins in cultivated peanuts and to study molecular evolution,and aims to reduce the potentially harmful effects of these proteins through targeted genetic modification methods such as selective breeding or gene editing.That will have important reference value for peanut cultivation and molecular biology research of allergen proteins.