Overexpression of biologically safe Rorippa indica defensin enhances aphid tolerance in Brassica juncea.

MAIN CONCLUSION: Transgenic mustard plants ( Brassica juncea ) expressing non-allergenic and biologically safe RiD peptide show higher tolerance against Lipaphis erysimi. Rorippa indica defensin (RiD) has previously been reported as a novel insecticidal protein derived from a wild crucifer Rorippa indica. RiD was found to have an effective insecticidal property against mustard aphid, Lipaphis erysimi. In the present study, RiD was highly upregulated in R. indica during aphid infestation initiating a defense system mediated by jasmonic acid (JA), but not by salicylic acid (SA)/abscisic acid (ABA). RiD has also been assessed for biosafety according to the FAO/WHO guideline (allergenicity of genetically modified foods; Food And Agriculture Organisation of the United Nations, Rome, Italy, 2001) and Codex Alimentarius Guideline (Guidelines for the design and implementation of national regulatory food safety assurance programme associated with the use of veterinary drugs in food producing animals. Codex Alimentarius Commission. GL, pp 71-2009, 2009). The purified protein was used to sensitize BALB/c mice and they showed normal histopathology of lung and no elevated IgE level in their sera. As the protein was found to be biologically safe and non-allergenic, it was used to develop transgenic Brassica juncea plants with enhanced aphid tolerance, which is one of the most important oilseed crops and is mostly affected by the devastating pest-L. erysimi. The transgene integration was monitored by Southern hybridization, and the positive B. juncea lines were further analyzed by Western blot, ELISA, immunohistolocalization assays and in planta insect bioassay. Transgenic plants expressing RiD conferred a higher level of tolerance against L. erysimi. All these results demonstrated that RiD is a novel, biologically safe, effective insecticidal agent and B. juncea plants expressing RiD are important components of integrated pest management.

Changes of allergenecity of salted and fermented shrimp / 천식및알레르기

BACKGROUND AND OBJECTIVE: Shrimp is one of the most common food allergens. The salted and fermented shrimp (S/F shrimp) is a traditional food and ingested frequently in the daily life of many Korean people. But few studies have been investigated on the allergenicity of S/F shrimp. The aim of our study is to observe the allergenicity of S/F shrimp and to compare it with the allergenicity of shrimp. MATERIAL AND METHODS: Crude extracts were made from three kinds of S/F shrimps and four kinds of shrimps after boiling. The extracts were used for SDS-PAGE, ELISA, ELISA inhibition test, immunoblotting, and immunoblotting inhibition test with sera from 10 subjects who have shrimp specific IgE by radioallergosorbent (RAST) (3+ or 4+). RESULTS: The protein concentrations of S/F shrimp extracts were less than half of the extracts of shrimps (1.9 mg/ml, 1.2 mg/ml, 1.1 mg/ml vs 4mg/ml, 3.83 mg/ml, 6.8 mg/ml, 6.6 mg/ml). The extracts of S/F shrimp showed weaker and more diffusely distributed protein bands in SDS-PAGE and showed less than half of the O.D. value in IgE-ELISA compared to those of shrimp extracts. The specific IgE immunoblotting of S/F shrimp extracts showed 9 bands (36, 33, 30, 29, 28, 26, 23, 20, 19 kDa). Dose dependent inhibition was observed between shrimps and S/F shrimp in ELISA-inhibition and immnunoblotting inhibition test. The allergen concentration of S/F shrimp needed to inhibit 50% of shrimp-lgE ELISA was five times higher than that of shrimp. CONCLUSION: The crude extracts of S/F shrimps showed less than half the amount of protein compared to crude extracts of shrimps have and also showed reduced allergenicity by salting and fermentation.