Rhizobia, crucial for nitrogen fixation in leguminous plants, play a vital role in soybean cultivation. This study, conducted in Mexico, a major soybean importer, aimed to identify bacteria from nodules of five soybea...Rhizobia, crucial for nitrogen fixation in leguminous plants, play a vital role in soybean cultivation. This study, conducted in Mexico, a major soybean importer, aimed to identify bacteria from nodules of five soybean varieties in high-production regions. Multilocus sequence analysis (MLSA) was employed for enhanced species resolution. The study identified six Bradyrhizobium species: Bradyrhizobium japonicum USDA 110, Bradyrhizobium japonicum USDA 6, Bradyrhizobium elkanii USDA 76, Bradyrhizobium neotropicale, Bradyrhizobium lablabi, and Bradyrhizobium icense. Bradyrhizobium japonicum USDA 110 predominated in the soils, displaying symbiotic preference for the Huasteca 400 variety. However, phylogenetic analysis didn't reveal a clear association between strains, soil, and soybean variety. This research sheds light on the diversity of rhizobia in Mexican soybean cultivation, contributing to the understanding of symbiotic relationships in soybean production systems.展开更多
The novel strain H1N1 caused the outbreak of first pandemic influenza in 21 century. Now it is a common component of current seasonal influenza viruses. The recent transmission and plentiful genome sequences available...The novel strain H1N1 caused the outbreak of first pandemic influenza in 21 century. Now it is a common component of current seasonal influenza viruses. The recent transmission and plentiful genome sequences available provided a good opportunity to study the origin and evolution of epitopes on the proteins of human influenza virus. In the present study, the B-cell epitope compositions in the pandemic strains, circulating traditional seasonal strains, swine strains as well as highly virulent avian strain H5N1 were identified with the aid of the Immune Epitope DataBase (IEDB) and were compared at genomic level. A total of 14210 distinct sequences down-loaded from NCBI database were used for analysis. Some epitopes on proteins HA or NA, not conserved in recent seasonal strains, were found in 2009 pandemic strains but existed in the early human strains (1919-1935). The pandemic strain shared higher conserved epitopes with “bird flu” virus H5N1than classic human seasonal strains. The epitopes that could exist at common antigenic regions of HA protein are needed to further identify. The genetic exchanges between human and swine population by transmission was very active but the princepal side of the transmission could be from swine to human. These results provided valuable information on influenza A virus evolution and transmission by means of epitope analysis at genomic level.展开更多
Rhizosphere soil samples of three Pinus chiapensis sites were analyzed for their physicochemical properties,soil bacteria isolated and screened in vitro for growthpromoting abilities.Nine isolates that showed promise ...Rhizosphere soil samples of three Pinus chiapensis sites were analyzed for their physicochemical properties,soil bacteria isolated and screened in vitro for growthpromoting abilities.Nine isolates that showed promise were identified to five genera Dyella,Luteimonas,Euterobacter,Paraburkholderia and Bacillus based on the sequences of16 S rRNA gene.All the strains were isolated from nondisturbed stands.These bacteria significantly decreased germination time and increased sprout sizes.Indole acetic acid and gibberellin production and phosphate solubilisation were detected.Results indicate that these biochemicals could be essential for P.chiapensis distribution and suggest the possibility that PGPR inoculation on P.chiapensis seeds prior to planting could improve germination and possibly seedling development.展开更多
文摘Rhizobia, crucial for nitrogen fixation in leguminous plants, play a vital role in soybean cultivation. This study, conducted in Mexico, a major soybean importer, aimed to identify bacteria from nodules of five soybean varieties in high-production regions. Multilocus sequence analysis (MLSA) was employed for enhanced species resolution. The study identified six Bradyrhizobium species: Bradyrhizobium japonicum USDA 110, Bradyrhizobium japonicum USDA 6, Bradyrhizobium elkanii USDA 76, Bradyrhizobium neotropicale, Bradyrhizobium lablabi, and Bradyrhizobium icense. Bradyrhizobium japonicum USDA 110 predominated in the soils, displaying symbiotic preference for the Huasteca 400 variety. However, phylogenetic analysis didn't reveal a clear association between strains, soil, and soybean variety. This research sheds light on the diversity of rhizobia in Mexican soybean cultivation, contributing to the understanding of symbiotic relationships in soybean production systems.
文摘The novel strain H1N1 caused the outbreak of first pandemic influenza in 21 century. Now it is a common component of current seasonal influenza viruses. The recent transmission and plentiful genome sequences available provided a good opportunity to study the origin and evolution of epitopes on the proteins of human influenza virus. In the present study, the B-cell epitope compositions in the pandemic strains, circulating traditional seasonal strains, swine strains as well as highly virulent avian strain H5N1 were identified with the aid of the Immune Epitope DataBase (IEDB) and were compared at genomic level. A total of 14210 distinct sequences down-loaded from NCBI database were used for analysis. Some epitopes on proteins HA or NA, not conserved in recent seasonal strains, were found in 2009 pandemic strains but existed in the early human strains (1919-1935). The pandemic strain shared higher conserved epitopes with “bird flu” virus H5N1than classic human seasonal strains. The epitopes that could exist at common antigenic regions of HA protein are needed to further identify. The genetic exchanges between human and swine population by transmission was very active but the princepal side of the transmission could be from swine to human. These results provided valuable information on influenza A virus evolution and transmission by means of epitope analysis at genomic level.
基金supported by SEP,Grant DSA/103.5/15/10976 and VIEP-BUAP,Grant 20 Sub-Program。
文摘Rhizosphere soil samples of three Pinus chiapensis sites were analyzed for their physicochemical properties,soil bacteria isolated and screened in vitro for growthpromoting abilities.Nine isolates that showed promise were identified to five genera Dyella,Luteimonas,Euterobacter,Paraburkholderia and Bacillus based on the sequences of16 S rRNA gene.All the strains were isolated from nondisturbed stands.These bacteria significantly decreased germination time and increased sprout sizes.Indole acetic acid and gibberellin production and phosphate solubilisation were detected.Results indicate that these biochemicals could be essential for P.chiapensis distribution and suggest the possibility that PGPR inoculation on P.chiapensis seeds prior to planting could improve germination and possibly seedling development.
