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*

In order to increase the expression level of target gene and to simplify the purifying process of separation and purification, we performed the transgenetic research of antigen VP7 gene into peanut via Agrobacterium tumefaciens. The plant binary expression vector is pBOG3VP7 harboring fusion gene oleosin-vp7, which is promoted by ole-promoter. Cotyledon nodes were used as transformation recipients. Transformed individuals were obtained through selection on medium containing 125 mg L-1 Kan. Integration of transgenes was assessed by PCR amplification and PCR-Southern blot hybridization. Taking pBOG3VP7 plasmid as positive control, non-transformed peanut as negative control. 6 plants among 11 plants grown up through seletion medium were detected by PCR and the rate of positive plants is 54.5%. PCR positive plants were further analysed by PCR-Southern blot hybridization. The results showed that 3 plants have DNA bloting bands. The results also showed that the foreign gene was integrated into genome of transformed peanuts. Elevated expression of rotavirus VP7 antigen in transgenic peanuts was a critical factor in the development of efficient and cheap plant oral vaccine.
Agrobacterium tumefaciens ; genetics ; Antigens, Viral ; biosynthesis ; genetics ; Arachis ; genetics ; metabolism ; Capsid Proteins ; biosynthesis ; genetics ; Plants, Genetically Modified ; genetics ; metabolism ; Rotavirus ; genetics ; immunology ; Transformation, Genetic ; Vaccines, Synthetic

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*

Peanut is one of the most popular foods in the world due to its high nutrition; however, it contains multiple seed storage proteins which are identified as allergens and hence are the most common cause of life-threatening, IgE-mediated anaphylaxis among the hypersensitive individuals. Three peanut proteins, Arachis hypogaea allergy 1, 2, 3 (Ara h 1, Ara h 2 and Ara h 3), which have the common biochemical characteristics like resistance to proteases and heat, are considered as the major allergens because they are recognized by serum IgE from a peanut-allergic patient population. The linear IgE-binding epitopes in the allergens lay the foundation of the anaphylaxis in the peanut-allergic individuals. Peanut allergy is often a life-long problem, so many investigators are focusing on decreasing clinical reactivity. In this review, the latest advances in the researches on biochemical characteristics, structure and function of the three major allergens were described and particular attention was given to the immunity properties of the three allergens. The future research directions were also discussed.
2S Albumins, Plant ; chemistry ; genetics ; immunology ; Animals ; Antigens, Plant ; chemistry ; genetics ; immunology ; Arachis ; chemistry ; DNA ; genetics ; Glycoproteins ; chemistry ; genetics ; immunology ; Humans ; Immunoglobulin E ; genetics ; Plant Proteins ; chemistry ; genetics ; immunology