Identification of Per a 13 as a novel allergen in American cockroach.

BACKGROUND: Cockroaches are an important source of indoor allergens. Environmental exposure to cockroach allergens is closely associated with the development of immunoglobulin E (IgE)-mediated allergic diseases. However, the allergenic components in the American cockroaches are not fully studied yet. In order to develop novel diagnostic and therapeutic strategies for cockroach allergy, it is necessary to comprehensively investigate this undescribed allergen in the American cockroach. METHODS: The full-length cDNA of the potential allergen was isolated from the cDNA library of the American cockroach by PCR cloning. Both the recombinant and natural protein molecules were purified and characterized. The allergenicity was further analyzed by enzyme linked immunosorbent assay, immunoblot, and basophil activation test using sera from cockroach allergic patients. RESULTS: A novel allergen belonging to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was firstly identified in the American cockroach and named as Per a 13. The cDNA of this allergen is 1255 base pairs in length and contains an open reading frame of 999 base pairs, encoding 332 amino acids. The purified Per a 13 was fully characterized and assessed to react with IgEs from 49.3 % of cockroach allergic patients, and patients with allergic rhinitis were more sensitized to it. Moreover, the allergenicity was further confirmed by immunoblot and basophil activation test. CONCLUSIONS: We firstly identified GAPDH (Per a 13) in the American cockroach, which is a novel type of inhalant allergen derived from animal species. These findings could be useful in developing novel diagnostic and therapeutic strategies for cockroach allergy.

[Effects of Platycodon grandiflorum/pepper intercropping on root growth, yield and quality of Platycodon grandiflorum].

In order to investigate effects of Platycodon grandiflorum and pepper intercropping on root growth, yield and quality of P. grandiflorum, field experiments were conducted in the soils of continuously cultivated P. grandiflorum for three years. The cultivation model was designed as monoculture and intercropping. The monoculture of P. grandiflorum was denoted as CK and the intercrop association of P. grandiflorum/pepper was arranged as follow: in intercrops every two rows of pepper was planted between every three, four and five rows of P. grandiflorum, respectively, and denoted as JC32, JC42 and JC52. Results showed that taproot length and diameter of P. grandiflorum in intercropping association of JC32 was higher than those of P. grandiflorum in monoculture association. This fact suggested that P. grandiflorum intercropped with pepper facilitated its root growth. Compared with monoculture association, the number of lateral root in intercropping association was significantly decreased and the location of lateral root at taproot also altered. This fact suggested that P. grandiflorum intercropped with pepper enhanced appearance quality of P. grandiflorum root. Total root yield and taproot yield of P. grandiflorum in JC42 and JC52 intercropping associations were increased by 4.88%, 8.91% and 14.23%, 12.92%, respectively, compared with monoculture, while root rot incidence decreased significantly. Compared with JC52 intercropping association, JC42 intercropping association significantly increased total saponin and protein contents of P. grandiflorum, decreased root rot incidence, but did not affect taproot yield significantly. Considering root yield and quality, when P. grandiflorum planted in the soil having continuously cultivated P. grandiflorum for three years, the optimal cultivation model was every two rows of pepper was planted between four rows P. grandiflorum.

[Effects of applying controlled-release compound fertilizer on Platycodon grandiflorum growth].

A pot experiment was conducted in 2008 to study the effects of applying controlled-release compound fertilizer (N:P2O5:K2O = 14:14:14) on the growth of Platycodon grandiflorum in the medicinal herbal farm of Shandong Agricultural University. Comparing with the application of common compound fertilizer (N:P2O5: K2O=15: 15: 15), applying equivalent amount of the controlled-release fertilizer increased the leaf chlorophyll content, root volume, root activity, and root diameter of P. grandiflorum at the late growth stage, but decreased the root length. When the N application rate was 0.24 and 0.32 g x kg(-1) soil, applying the controlled-release compound fertilizer increased the root yield by 26.78% and 22.50%, and the root soluble sugar, protein, and total saponin contents by 9.77% and 6.99%, 11.38% and 2.20%, and 8.85% and 5.47%, respectively, compared with applying the common compound fertilizer. More nitrogen application made the root soluble sugar content decreased but the total saponin content increased. Under our experimental condition, applying the controlled-release compound fertilizer with an application rate of 0.24 g N x kg(-1) soil could obtain the best effect for P. grandiflorum.

[Effects of two controlled-release fertilizers with different proportions of N, P and K on the nutrient uptake and growth of Chrysanthemum morifolium Ramat].

A pot experiment was conducted to study the effects of two controlled-release fertilizers CRFA (4% resin-coated, N: P2O5: K2O = 14: 14: 14) and CRFB (4% resin-coated, N: P2O5: K2O = 20: 8:10) on the nutrient uptake and growth of Chrysanthemum morifolium, with common compound fertilizer CCF (N: P2O5: K2O = 15: 15: 15) as the control. Six treatments were installed, i. e., CCF1 (CCF, 6 g N x pot(-1)), CCF2 (CCF, 3 g N x pot(-1)), CRFA1 (CRFA, 6 g x pot(-1)), CRFA2 (CRFA, 3 g x pot(-1)), CRFB1 (CRFB, 6 g x pot(-1)), and CRFB (CRFB, 3 g x pot(-1)). On the 30th day of applying common compound fertilizer CCF1 and CCF2, soil available N, P and K contents were 163.29 and 145.26 mg x kg(-1), 180.39 and 163.13 mg x kg(-1), and 300.08 and 213.15 mg x kg(-1), respectively, and decreased rapidly since then. In treatments CRFA1, CRFB1, CRFA2, and CRFB, soil available N content increased slowly, and reached the peak on the 60th day after fertilizing, being 129.51, 138.65, 118.36, and 126.31 mg x kg(-1), respectively. Soil available P content had the same variation trend. Its maximum concentration was 169.54 and 133.46 mg x kg(-1) in treatments CRFA1 and CRFA2 on the 30th day after fertilizing, and 137.13 and 84.68 mg x kg(-1) in treatments CRFB1 and CRFB2 on the 60th day after fertilizing, and decreased slowly then. The agronomic traits such as leaf area, leaf area index, branch number, flowering rate, flower number, and flower diameter, etc., in treatments CRFA and CRFB were obviously better than those of the control, and CRFB was better than CRFA, suggesting that CRFB more matched the nutrient demand of C. morifolium. Under the conditions of present experiment, applying CRFB2 obtained the highest yield.