Microcystins produced by cyanobacteria pose a great threat to human health by releasing toxins upon cell death. In the present study, we studied microcystin production in the cyanobacterial strains Anabaena cylindrica...Microcystins produced by cyanobacteria pose a great threat to human health by releasing toxins upon cell death. In the present study, we studied microcystin production in the cyanobacterial strains Anabaena cylindrica (B629 and 2949) and Fremyella diplosiphon (SF33) exposed to 1, 2 and 4 g/L sodium chloride (NaCl). Cultures grown for 7 days in BG11/HEPES medium were pelleted, re-grown in the corresponding NaCl levels, and enzyme linked immunosorbent assay (ELISA) performed. ELISA assays revealed enhanced microcystin production in A. cylindrica B629 exposed to 4 g/L NaCl and A. cylindrica 29414 exposed to 2 and 4 g/L NaCl, after growth in the corresponding NaCl levels for 14 days. We observed a significant decrease (p > 0.05) in microcystin levels in the control strains after exposure to NaCl for 5 days. After exposure to 1, 2, or 4 g/L NaCl for 10 days, no microcystin release was observed in A. cylindrica B629, A. cylindrica 29414 or F. diplosiphon SF33. Sodium dodecyl sulfate polyacrylamide gel electrophoresis identified the presence of an additional band at 120 - 130 kDa in A. cylindrica B629 exposed to 2 and 4 g/L NaCl, and at 14 kDa in cultures amended with 1 and 2 g/L NaCl as well as the untreated control, indicating that exposure to salinity induces alterations in protein expression.展开更多
Micropropagation of Psidium guajava L. (guava) is a viable alternative to currently adopted techniques for large-scale plant propagation of commercial cultivars. Assessment of clonal fidelity in micropropagated plants...Micropropagation of Psidium guajava L. (guava) is a viable alternative to currently adopted techniques for large-scale plant propagation of commercial cultivars. Assessment of clonal fidelity in micropropagated plants is the first step towards ensuring genetic uniformity in mass production of planting material. In the present study, 31 plants of guava cultivar “Lucknow 49” regenerated by micropropagation were tested for genetic fidelity by comparing them to the mother plant from which explant material was obtained. Efficient rooting of in vitro proliferated shoots was obtained by culture on 1/2 strength MS medium supplemented with either 9.8 μM indole butyric acid (IBA) or 11.4 μM indole acetic acid (IAA). Leaf samples of 31 regenerated plants were compared to the mother plant using 17 simple sequence repeat (SSR) markers. While 16 SSRs detected the same allele, locus mPgCIR07 detected slight differences, where six micropropagated plants were 1 bp smaller (152 bp) than the parental genotype (153 bp). Differences in leaf tissues for anthocyanin pigmentation were also noted among micropropagated plants. Results of the study indicated efficient rooting of “Lucknow-49” cultivar for rapid propagation of planting material, and revealed that micropropagated plants were identical for 16 of the 17 loci examined. Although most mutations induced by tissue culture may not have an effect on phenotype, the possibility that novel phenotypes can be generated in a commercial setting exists.展开更多
A method to produce transgenic Camelina sativa plants in cvs. PI650159 and PI650161 was developed. Micropropagated shoot meristem cultures were established from in vitro germinated seedlings and used as target tissues...A method to produce transgenic Camelina sativa plants in cvs. PI650159 and PI650161 was developed. Micropropagated shoot meristem cultures were established from in vitro germinated seedlings and used as target tissues for Agrobacterium-mediated transformation. A plasmid harboring enhanced green fluorescent protein, β glucuronidase and neomycin phosphotransferase II genes were used to optimize parameters for transgenic plant production. Kanamycin at 40 mg·l-1 was effective in suppression of non-transformed cells while permitting growth of transgenic tissues. Shoot apical meristems co-cultivated with Agrobacterium exhibited stable enhanced green fluorescence protein (EGFP) and β glucuronidase (GUS) expression after culture on plant regeneration medium. We observed transformation efficiencies of 53.33% in cv. PI650159 and 98.33% in cv. PI650161. The presence of transgenes in both cultivars was confirmed by PCR, while quantitative real-time PCR detected single copy integration in Pl650161 and two copy integration in Pl650159. Transgenic plants exhibited EGFP and GUS expression in all tissues including shoots, leaves, buds, floral organs, seeds, and pods. Our results demonstrate a simple and efficient technique using apical shoot meristems for production of transgenic C. sativa plants that can be used for transfer of desirable traits.展开更多
文摘Microcystins produced by cyanobacteria pose a great threat to human health by releasing toxins upon cell death. In the present study, we studied microcystin production in the cyanobacterial strains Anabaena cylindrica (B629 and 2949) and Fremyella diplosiphon (SF33) exposed to 1, 2 and 4 g/L sodium chloride (NaCl). Cultures grown for 7 days in BG11/HEPES medium were pelleted, re-grown in the corresponding NaCl levels, and enzyme linked immunosorbent assay (ELISA) performed. ELISA assays revealed enhanced microcystin production in A. cylindrica B629 exposed to 4 g/L NaCl and A. cylindrica 29414 exposed to 2 and 4 g/L NaCl, after growth in the corresponding NaCl levels for 14 days. We observed a significant decrease (p > 0.05) in microcystin levels in the control strains after exposure to NaCl for 5 days. After exposure to 1, 2, or 4 g/L NaCl for 10 days, no microcystin release was observed in A. cylindrica B629, A. cylindrica 29414 or F. diplosiphon SF33. Sodium dodecyl sulfate polyacrylamide gel electrophoresis identified the presence of an additional band at 120 - 130 kDa in A. cylindrica B629 exposed to 2 and 4 g/L NaCl, and at 14 kDa in cultures amended with 1 and 2 g/L NaCl as well as the untreated control, indicating that exposure to salinity induces alterations in protein expression.
文摘Micropropagation of Psidium guajava L. (guava) is a viable alternative to currently adopted techniques for large-scale plant propagation of commercial cultivars. Assessment of clonal fidelity in micropropagated plants is the first step towards ensuring genetic uniformity in mass production of planting material. In the present study, 31 plants of guava cultivar “Lucknow 49” regenerated by micropropagation were tested for genetic fidelity by comparing them to the mother plant from which explant material was obtained. Efficient rooting of in vitro proliferated shoots was obtained by culture on 1/2 strength MS medium supplemented with either 9.8 μM indole butyric acid (IBA) or 11.4 μM indole acetic acid (IAA). Leaf samples of 31 regenerated plants were compared to the mother plant using 17 simple sequence repeat (SSR) markers. While 16 SSRs detected the same allele, locus mPgCIR07 detected slight differences, where six micropropagated plants were 1 bp smaller (152 bp) than the parental genotype (153 bp). Differences in leaf tissues for anthocyanin pigmentation were also noted among micropropagated plants. Results of the study indicated efficient rooting of “Lucknow-49” cultivar for rapid propagation of planting material, and revealed that micropropagated plants were identical for 16 of the 17 loci examined. Although most mutations induced by tissue culture may not have an effect on phenotype, the possibility that novel phenotypes can be generated in a commercial setting exists.
文摘A method to produce transgenic Camelina sativa plants in cvs. PI650159 and PI650161 was developed. Micropropagated shoot meristem cultures were established from in vitro germinated seedlings and used as target tissues for Agrobacterium-mediated transformation. A plasmid harboring enhanced green fluorescent protein, β glucuronidase and neomycin phosphotransferase II genes were used to optimize parameters for transgenic plant production. Kanamycin at 40 mg·l-1 was effective in suppression of non-transformed cells while permitting growth of transgenic tissues. Shoot apical meristems co-cultivated with Agrobacterium exhibited stable enhanced green fluorescence protein (EGFP) and β glucuronidase (GUS) expression after culture on plant regeneration medium. We observed transformation efficiencies of 53.33% in cv. PI650159 and 98.33% in cv. PI650161. The presence of transgenes in both cultivars was confirmed by PCR, while quantitative real-time PCR detected single copy integration in Pl650161 and two copy integration in Pl650159. Transgenic plants exhibited EGFP and GUS expression in all tissues including shoots, leaves, buds, floral organs, seeds, and pods. Our results demonstrate a simple and efficient technique using apical shoot meristems for production of transgenic C. sativa plants that can be used for transfer of desirable traits.
