RESUMO
The relative mRNA expression of IgA, TGF-ß4, IL-17, and concentration of secretory IgA (sIgA) in small intestine of chickens pretreated with Enterococcus faecium AL41 and challenged with Salmonella Enteritidis PT4 were studied. Salmonella-free day-old chicks (40) Cobb 500 breed, were divided into four groups of 10 chicks each (n = 10): control (C), treated with E. faecium AL41 strain (EFAL41), challenged with Salmonella Enteritidis PT4 (SE), and combined (EFAL41+SE). Expression of IgA and sIgA concentration was upregulated in EFAL41 group in jejunum and ileum on 4 days post-Salmonella infection (dpi). Chicks in combined group demonstrated upregulation of cytokines and IgA expression, and increased sIgA concentration in the intestine flush on 7 dpi. The experiment demonstrated beneficial effect of E. faecium AL41 on IgA production and secretion in intestine. Findings also indicated that IgA played important role in decrease of S. Enteritidis in the intestine, and cytokines TGF-ß4 and IL-17 contributed to the increased IgA secretion.
Assuntos
Proteínas Aviárias/genética , Galinhas , Citocinas/genética , Enterococcus faecium/química , Doenças das Aves Domésticas/imunologia , Probióticos/metabolismo , Salmonelose Animal/imunologia , Salmonella enteritidis/fisiologia , Ração Animal/análise , Animais , Proteínas Aviárias/metabolismo , Citocinas/metabolismo , Dieta/veterinária , Ensaio de Imunoadsorção Enzimática/veterinária , Imunoglobulina A/genética , Imunoglobulina A/metabolismo , Interleucina-17/genética , Interleucina-17/metabolismo , Intestino Delgado/metabolismo , Doenças das Aves Domésticas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Distribuição Aleatória , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Salmonelose Animal/genética , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Regulação para CimaRESUMO
BACKGROUND AND AIMS: The maize lrt1 (lateral rootless1) mutant is impaired in its development of lateral roots during early post-embryonic development. The aim of this study was to characterize, in detail, the influences that the mutation exerts on lateral root initiation and the subsequent developments, as well as to describe the behaviour of the entire plant under variable environmental conditions. METHODS: Mutant lrt1 plants were cultivated under different conditions of hydroponics, and in between sheets of moist paper. Cleared whole mounts and anatomical sections were used in combination with both selected staining procedures and histochemical tests to follow root development. Root surface permeability tests and the biochemical quantification of lignin were performed to complement the structural data. KEY RESULTS: The data presented suggest a redefinition of lrt1 function in lateral roots as a promoter of later development; however, neither the complete absence of lateral roots nor the frequency of their initiation is linked to lrt1 function. The developmental effects of lrt1 are under strong environmental influences. Mutant primordia are affected in structure, growth and emergence; and the majority of primordia terminate their growth during this last step, or shortly thereafter. The lateral roots are impaired in the maintenance of the root apical meristem. The primary root shows disturbances in the organization of both epidermal and subepidermal layers. The lrt1-related cell-wall modifications include: lignification in peripheral layers, the deposition of polyphenolic substances and a higher activity of peroxidase. CONCLUSIONS: The present study provides novel insights into the function of the lrt1 gene in root system development. The lrt1 gene participates in the spatial distribution of initiation, but not in its frequency. Later, the development of lateral roots is strongly affected. The effect of the lrt1 mutation is not as obvious in the primary root, with no influences observed on the root apical meristem structure and maintenance; however, development of the epidermis and cortex are impaired.
