Lectin and leghemoglobin in legumes play the important roles, respectively, in recognition of host plants to their rhizobial bacteria, and lowering the oxygen partial pressure around bacteroids and protecting nitrogen...Lectin and leghemoglobin in legumes play the important roles, respectively, in recognition of host plants to their rhizobial bacteria, and lowering the oxygen partial pressure around bacteroids and protecting nitrogenase from oxygen in symbiotic nitrogen-fixing nodules. In order to extend the host range of the rhizobial bacteria and to make them fix nitrogen in non-legumes, pea lectin gene (pl) and Parasponia hemoglobin gene ( phl,) have been constructed into a plant expression vector (pCBHUL) and the vector pCBHUL was introduced into rice calli from immature young embryos by particle bombardment. After the calli were regenerated into plantlets on the resistant-selecting media containing hygromycin, they were identified by PCR and Southern blot hybridization. It was indicated that the pi and phb genes were integrated into nucleic genome of the transformed rice plants. GUS activity and the product of the pi gene were determined by GUS staining, Western blot and in situ hybridization at translational level. Eighteen out of 40 plants resistant to hygromycin were positively identified by PCR analysis with the rate of 45%. The pi gene was expressed in 3 out of 18 plants with 17% and 7.5% in 40 plants. The results may provide a clue for exploring whether Rhizobium leguminosarum by. viceae could extend its host range and make the transgenic rice plants have the possibility of being symbiotic, or associative to nitrogen fixation.展开更多
Lectins and leghemoglobins in legumes play the important roles, respectively, in recognition of host plants to their own rhizobia, and lowering the oxygen partial pressure surround the bacteroids and protecting nitrog...Lectins and leghemoglobins in legumes play the important roles, respectively, in recognition of host plants to their own rhizobia, and lowering the oxygen partial pressure surround the bacteroids and protecting nitrogenase from oxygen in symbiotic nitrogen_fixing nodules.In order to investigate the non_leguminous recognition of rhizobial bacteria relating to nitrogen fixation, plant expression vectors containing pea lectin gene ( pl ) and Parasponia hemoglobin gene ( phb ) have been, respectively, constructed in a plasmid and the plasmid has been introduced into tobacco ( Nicotiana tabacum L.) using Agrobacterium tumefaciens (Smith et Townsend) Conn as a vehicle for transformation. PCR and Southern blot demonstrated that the two genes were integrated into the genome of the tobacco plants. Histochemical staining for GUS activity, Western blotting,and in situ hybridization of pea lectin showed that they were expressed at translational level in the plants. These results may provide a clue for exploring whether Rhizobium leguminosarum bv. viciae could extend its host range and make the transgenic tobacco plants have the possibility of being symbiotic, or associative to nitrogen fixation.展开更多
C-type lectins are among the most significant pattern recognition receptors（PRRs） found in invertebrate. They are a class of carbohydrate-binding proteins that can recognize specific sugar moieties on the surface of...C-type lectins are among the most significant pattern recognition receptors（PRRs） found in invertebrate. They are a class of carbohydrate-binding proteins that can recognize specific sugar moieties on the surface of pathogens. In the present study, a novel C-type lecitn（termed Mj Lectin） from kuruma shrimp Marsupenaeus japonicus was identified. The full-length c DNA of Mj Lectin was 1 245 bp with a 1 011 bp open reading frame（ORF） that encoded a polypeptide of 336 amino acid residues. Mj Lectin consisted of two tandemly arrayed carbohydrate-recognition domains（CRDs）, unlike other reported M. japonicus C-type lectins with only one CRD. It showed a high similarity to other shrimp dual-CRD lectins. Among the Ca2＋-binding Site 2, the tripeptide motif dictating the carbohydrate binding specificity was exhibited as a rare mutant LPN（Leu134-Pro135-Asn136） in CRD1 and a traditional EPN（Glu299-Pro300-Asn301） in CRD2, respectively. Mj Lectin showed a specific expression pattern in both tissue and cellular levels, for its m RNA transcript was mainly expressed in the F-cells of the hepatopancreas. After white spot syndrome virus（WSSV） challenge（3.6×108 virions/μL）, the expression of Mj Lectin in the hepatopancreas was up-regulated significantly at 48 h（P〈0.01） compared with the control group. These results suggested that Mj Lectin might be involved in the innate immune defense against WSSV infection.展开更多
Mannose binding lectin (MBL) is an important component of innate immunity particularly in neonates whose adaptive immunity is not fully developed. Polymorphism in MBL2 gene promoter and exon1 determines MBL serum leve...Mannose binding lectin (MBL) is an important component of innate immunity particularly in neonates whose adaptive immunity is not fully developed. Polymorphism in MBL2 gene promoter and exon1 determines MBL serum level and function. The aim of this study was to investigate the frequency of different MBL2 genotypes in neonatal sepsis among patients of neonatal intensive care unit (NICU). Two hundred and forty-five neonates were enrolled in this study (127 infected and 118 uninfected controls). Multiplex PCR and double amplification refractory mutation system (dARMS) were used for typing of MBL2 exon1 and promoter respectively. Klebsiella species were the most frequently isolated organisms (22.8%). There is no statistical significance difference in the distribution of different expression genotypes between infected group and controls (P = 0.11). However, prevalence of low MBL2 expression genotypes (XA/O and O/O) was higher in infected patients compared to control group (patients 25.2% and controls 15.3%). Low and medium MBL2 expression genotypes were mostly associated with Gram-negative bacterial infections (18.9% and 22.8%) respectively. A statistically significant association of Gram-negative bacterial infections with low MBL2 expression genotypes was found (P = 0.02). Higher frequency of AB and BB genotypes was observed (31.5% and 7.9%) in patients group compared to control, but without statistical significant difference.展开更多
The NF-κB family member, c-Rel plays a critical role in the regulation of immune function. It was found that mice with c-Rel deficiency exhibited extensive defects in the survival of lymphocytes and cell cycle progre...The NF-κB family member, c-Rel plays a critical role in the regulation of immune function. It was found that mice with c-Rel deficiency exhibited extensive defects in the survival of lymphocytes and cell cycle progression, and were tolerant to allografts. To further characterize the regulatory function of c- Rel, a representational difference analysis （RDA） was performed on mRNAs derived from B lymphocytes of wild type and the c-Rel knockout mice. By using this approach, a novel gene designated as lympho- cyte-derived C-type lectin-1 （LCL-1） was identified, whose expression was dependent on the intact c-Rel molecule. In the present study, LCL-1 was demonstrated to be a type Ⅱ transmembrane protein with a single extracellular carbohydrate recognition domain （CRD） that exhibited significant degree of homology to C-type lectin-like receptors, including CD69. This LCL-1 gene was found to be located at the NK gene complex （NKC） on mouse chromosome 6 and could encode at least 4 alternatively spliced isofonns. In addition to its expression on B lymphocytes, it was also expressed on immature as well as mature dendritic cells （DCs）, especially with higher expression level on mature DCs. Together, our findings explore one new member of the NKC family and demonstrate for the first time that a lectin-like receptor of the the NKC family is the target gene of c-Rel.展开更多
文摘Lectin and leghemoglobin in legumes play the important roles, respectively, in recognition of host plants to their rhizobial bacteria, and lowering the oxygen partial pressure around bacteroids and protecting nitrogenase from oxygen in symbiotic nitrogen-fixing nodules. In order to extend the host range of the rhizobial bacteria and to make them fix nitrogen in non-legumes, pea lectin gene (pl) and Parasponia hemoglobin gene ( phl,) have been constructed into a plant expression vector (pCBHUL) and the vector pCBHUL was introduced into rice calli from immature young embryos by particle bombardment. After the calli were regenerated into plantlets on the resistant-selecting media containing hygromycin, they were identified by PCR and Southern blot hybridization. It was indicated that the pi and phb genes were integrated into nucleic genome of the transformed rice plants. GUS activity and the product of the pi gene were determined by GUS staining, Western blot and in situ hybridization at translational level. Eighteen out of 40 plants resistant to hygromycin were positively identified by PCR analysis with the rate of 45%. The pi gene was expressed in 3 out of 18 plants with 17% and 7.5% in 40 plants. The results may provide a clue for exploring whether Rhizobium leguminosarum by. viceae could extend its host range and make the transgenic rice plants have the possibility of being symbiotic, or associative to nitrogen fixation.
文摘Lectins and leghemoglobins in legumes play the important roles, respectively, in recognition of host plants to their own rhizobia, and lowering the oxygen partial pressure surround the bacteroids and protecting nitrogenase from oxygen in symbiotic nitrogen_fixing nodules.In order to investigate the non_leguminous recognition of rhizobial bacteria relating to nitrogen fixation, plant expression vectors containing pea lectin gene ( pl ) and Parasponia hemoglobin gene ( phb ) have been, respectively, constructed in a plasmid and the plasmid has been introduced into tobacco ( Nicotiana tabacum L.) using Agrobacterium tumefaciens (Smith et Townsend) Conn as a vehicle for transformation. PCR and Southern blot demonstrated that the two genes were integrated into the genome of the tobacco plants. Histochemical staining for GUS activity, Western blotting,and in situ hybridization of pea lectin showed that they were expressed at translational level in the plants. These results may provide a clue for exploring whether Rhizobium leguminosarum bv. viciae could extend its host range and make the transgenic tobacco plants have the possibility of being symbiotic, or associative to nitrogen fixation.
基金The National High-Technology R&D Program(863 Program) of China under contract No.2012AA10A409China Agriculture Research System under contract No.CARS-47
文摘C-type lectins are among the most significant pattern recognition receptors（PRRs） found in invertebrate. They are a class of carbohydrate-binding proteins that can recognize specific sugar moieties on the surface of pathogens. In the present study, a novel C-type lecitn（termed Mj Lectin） from kuruma shrimp Marsupenaeus japonicus was identified. The full-length c DNA of Mj Lectin was 1 245 bp with a 1 011 bp open reading frame（ORF） that encoded a polypeptide of 336 amino acid residues. Mj Lectin consisted of two tandemly arrayed carbohydrate-recognition domains（CRDs）, unlike other reported M. japonicus C-type lectins with only one CRD. It showed a high similarity to other shrimp dual-CRD lectins. Among the Ca2＋-binding Site 2, the tripeptide motif dictating the carbohydrate binding specificity was exhibited as a rare mutant LPN（Leu134-Pro135-Asn136） in CRD1 and a traditional EPN（Glu299-Pro300-Asn301） in CRD2, respectively. Mj Lectin showed a specific expression pattern in both tissue and cellular levels, for its m RNA transcript was mainly expressed in the F-cells of the hepatopancreas. After white spot syndrome virus（WSSV） challenge（3.6×108 virions/μL）, the expression of Mj Lectin in the hepatopancreas was up-regulated significantly at 48 h（P〈0.01） compared with the control group. These results suggested that Mj Lectin might be involved in the innate immune defense against WSSV infection.
文摘Mannose binding lectin (MBL) is an important component of innate immunity particularly in neonates whose adaptive immunity is not fully developed. Polymorphism in MBL2 gene promoter and exon1 determines MBL serum level and function. The aim of this study was to investigate the frequency of different MBL2 genotypes in neonatal sepsis among patients of neonatal intensive care unit (NICU). Two hundred and forty-five neonates were enrolled in this study (127 infected and 118 uninfected controls). Multiplex PCR and double amplification refractory mutation system (dARMS) were used for typing of MBL2 exon1 and promoter respectively. Klebsiella species were the most frequently isolated organisms (22.8%). There is no statistical significance difference in the distribution of different expression genotypes between infected group and controls (P = 0.11). However, prevalence of low MBL2 expression genotypes (XA/O and O/O) was higher in infected patients compared to control group (patients 25.2% and controls 15.3%). Low and medium MBL2 expression genotypes were mostly associated with Gram-negative bacterial infections (18.9% and 22.8%) respectively. A statistically significant association of Gram-negative bacterial infections with low MBL2 expression genotypes was found (P = 0.02). Higher frequency of AB and BB genotypes was observed (31.5% and 7.9%) in patients group compared to control, but without statistical significant difference.
文摘The NF-κB family member, c-Rel plays a critical role in the regulation of immune function. It was found that mice with c-Rel deficiency exhibited extensive defects in the survival of lymphocytes and cell cycle progression, and were tolerant to allografts. To further characterize the regulatory function of c- Rel, a representational difference analysis （RDA） was performed on mRNAs derived from B lymphocytes of wild type and the c-Rel knockout mice. By using this approach, a novel gene designated as lympho- cyte-derived C-type lectin-1 （LCL-1） was identified, whose expression was dependent on the intact c-Rel molecule. In the present study, LCL-1 was demonstrated to be a type Ⅱ transmembrane protein with a single extracellular carbohydrate recognition domain （CRD） that exhibited significant degree of homology to C-type lectin-like receptors, including CD69. This LCL-1 gene was found to be located at the NK gene complex （NKC） on mouse chromosome 6 and could encode at least 4 alternatively spliced isofonns. In addition to its expression on B lymphocytes, it was also expressed on immature as well as mature dendritic cells （DCs）, especially with higher expression level on mature DCs. Together, our findings explore one new member of the NKC family and demonstrate for the first time that a lectin-like receptor of the the NKC family is the target gene of c-Rel.
