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991.
Priya Joyce Melissa Kuwahata Nicole Turner Prakash Lakshmanan 《Plant cell reports》2010,29(2):173-183
A reproducible method for transformation of sugarcane using various strains of Agrobacterium tumefaciens (A. tumefaciens) (AGL0, AGL1, EHA105 and LBA4404) has been developed. The selection system and co-cultivation medium were the most important
factors determining the success of transformation and transgenic plant regeneration. Plant regeneration at a frequency of
0.8–4.8% occurred only when callus was transformed with A. tumefaciens carrying a newly constructed superbinary plasmid containing neomycin phosphotransferase (nptII) and β-glucuronidase (gusA) genes, both driven by the maize ubiquitin (ubi-1) promoter. Regeneration was successful in plants carrying the nptII gene but not the hygromycin phosphotransferase (hph) gene. NptII gene selection was imposed at a concentration of 150 mg/l paromomycin sulphate and applied either immediately or 4 days after
the co-cultivation period. Co-cultivation on Murashige and Skoog (MS)-based medium for a period of 4 days produced the highest
number of transgenic plants. Over 200 independent transgenic lines were created using this protocol. Regenerated plants appeared
phenotypically normal and contained both gusA and nptII genes. Southern blot analysis revealed 1–3 transgene insertion events that were randomly integrated in the majority of the
plants produced. 相似文献
992.
993.
Setaria viridis: A Model for C4 Photosynthesis 总被引:2,自引:0,他引:2
Thomas P. Brutnell Lin Wang Kerry Swartwood Alexander Goldschmidt David Jackson Xin-Guang Zhu Elizabeth Kellogg Joyce Van Eck 《The Plant cell》2010,22(8):2537-2544
C4 photosynthesis drives productivity in several major food crops and bioenergy grasses, including maize (Zea mays), sugarcane (Saccharum officinarum), sorghum (Sorghum bicolor), Miscanthus x giganteus, and switchgrass (Panicum virgatum). Gains in productivity associated with C4 photosynthesis include improved water and nitrogen use efficiencies. Thus, engineering C4 traits into C3 crops is an attractive target for crop improvement. However, the lack of a small, rapid cycling genetic model system to study C4 photosynthesis has limited progress in dissecting the regulatory networks underlying the C4 syndrome. Setaria viridis is a member of the Panicoideae clade and is a close relative of several major feed, fuel, and bioenergy grasses. It is a true diploid with a relatively small genome of ~510 Mb. Its short stature, simple growth requirements, and rapid life cycle will greatly facilitate genetic studies of the C4 grasses. Importantly, S. viridis uses an NADP-malic enzyme subtype C4 photosynthetic system to fix carbon and therefore is a potentially powerful model system for dissecting C4 photosynthesis. Here, we summarize some of the recent advances that promise greatly to accelerate the use of S. viridis as a genetic system. These include our recent successful efforts at regenerating plants from seed callus, establishing a transient transformation system, and developing stable transformation. 相似文献
994.
Joyce E. Karlinsey Michael E. Maguire Lynne A. Becker Marie‐Laure V. Crouch Ferric C. Fang 《Molecular microbiology》2010,78(3):669-685
The phage shock protein (Psp) system is induced by extracytoplasmic stress and thought to be important for the maintenance of proton motive force. We investigated the contribution of PspA to Salmonella virulence. A pspA deletion mutation significantly attenuates the virulence of Salmonella enterica serovar Typhimurium following intraperitoneal inoculation of C3H/HeN (Ityr) mice. PspA was found to be specifically required for virulence in mice expressing the natural resistance‐associated macrophage protein 1 (Nramp1) (Slc11a1) divalent metal transporter, which restricts microbial growth by limiting the availability of essential divalent metals within the phagosome. Salmonella competes with Nramp1 by expressing multiple metal uptake systems including the Nramp‐homologue MntH, the ABC transporter SitABCD and the ZIP family transporter ZupT. PspA was found to facilitate Mn2+ transport by MntH and SitABCD, as well as Zn2+ and Mn2+ transport by ZupT. In vitro uptake of 54Mn2+ by MntH and ZupT was reduced in the absence of PspA. Transport‐deficient mutants exhibit reduced viability in the absence of PspA when grown under metal‐limited conditions. Moreover, the ZupT transporter is required for Salmonella enterica serovar Typhimurium virulence in Nramp1‐expressing mice. We propose that PspA promotes Salmonella virulence by maintaining proton motive force, which is required for the function of multiple transporters mediating bacterial divalent metal acquisition during infection. 相似文献
995.
Mala Ranghoo‐Sanmukhiya Joyce Govinden‐Soulange Christophe Lavergne Shannoo Khoyratty Denis Da Silva Michel Frederich Hippolyte Kodja 《Phytochemical analysis : PCA》2010,21(6):566-574
Introduction – Aloe tormentorii, A. purpurea and A. macra are used as multipurpose folk medicines in Réunion and Mauritius Islands and are mistaken for the introduced Aloe vera. Objective – To compare the phytochemical, antimicrobial and DNA profiles of Aloe endemic to Mauritius and Réunion with the profiles of A. vera. Methodology – Leaf extracts of these Aloe species were analysed using standard phytochemical screening techniques, TLC and by HPLC. These extracts were also assayed for antimicrobial activity using microdilution techniques. Genetic diversity was studied using RAPD markers. Results – Phytochemical and antimicrobial assays and RAPD analysis showed that Mascarene Aloe species were very different from A. vera. Conclusion – This study is the first report highlighting the differences between Aloe sp.p from Mascarene and Aloe vera at the metabolic and genomic level. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
996.
997.
Aparna Chandrashekar Jessica A. Knierim Sohail Khan Dominique L. Raboin Sateesh Venkatesh Tara A. Clarke Frank P. Cuozzo Marni LaFleur Richard R. Lawler Joyce A. Parga Hantanirina R. Rasamimanana Kim E. Reuter Michelle L. Sauther Andrea L. Baden 《Ecology and evolution》2020,10(15):8030-8043
Madagascar's ring‐tailed lemurs (Lemur catta) are experiencing rapid population declines due to ongoing habitat loss and fragmentation, as well as increasing exploitation for bushmeat and the illegal pet trade. Despite being the focus of extensive and ongoing behavioral studies, there is comparatively little known about the genetic population structuring of the species. Here, we present the most comprehensive population genetic analysis of ring‐tailed lemurs to date from across their likely remaining geographic range. We assessed levels of genetic diversity and population genetic structure using multilocus genotypes for 106 adult individuals from nine geographically representative localities. Population structure and FST analyses revealed moderate genetic differentiation with localities being geographically partitioned into northern, southern, western and also potentially central clusters. Overall genetic diversity, in terms of allelic richness and observed heterozygosity, was high in the species (AR = 4.74, HO = 0.811). In fact, it is the highest among all published lemur estimates to date. While these results are encouraging, ring‐tailed lemurs are currently affected by ongoing habitat fragmentation and occur at lower densities in poorer quality habitats. The effects of continued isolation and fragmentation, coupled with climate‐driven environmental instability, will therefore likely impede the long‐term viability of the species. 相似文献
998.
Peter W. Cook Thomas Stark Joyce Jones Rebecca Kondor Natosha Zanders Jeffrey Benfer Samantha Scott Yunho Jang Alicia Janas-Martindale Stephen Lindstrom Lenee Blanton John Schiltz Rachel Tell Richard Griesser Peter Shult Erik Reisdorf Tonya Danz Alicia Fry John Barnes Amy Vincent David E. Wentworth C. Todd Davis 《Journal of virology》2021,95(2)
999.
DDX6 and other P-body proteins are required for efficient replication of Hepatitis C Virus (HCV) by unknown mechanisms. DDX6 has been implicated in miRNA induced gene silencing, and since efficient HCV replication and translation relies on the cellular microRNA, miR-122, we hypothesized that DDX6 had a role in the mechanism of action of miR-122. However, by using multiple HCV translation and replication assays we have found this is not the case. DDX6 silencing decreased HCV replication and translation, but did not affect the ability of miR-122 to stimulate HCV translation or promote HCV RNA accumulation. In addition, the negative effect of DDX6 silencing on HCV replication and translation was not dependent on miR-122 association with the HCV genome. Thus, DDX6 does not have a role in the activity of miR-122, and it appears that DDX6 and miR-122 modulate HCV through distinct pathways. This effect was seen in both Huh7.5 cells and in Hep3B cells, indicating that the effects are not cell type specific. Since infections by other viruses in the Flaviviridae family, including Dengue and West Nile Virus, also disrupt P-bodies and are regulated by DDX6, we speculate that DDX6 may have a common function that support the replication of several Flaviviruses. 相似文献
1000.