Co-expression of the Arabidopsis SOS genes enhances salt tolerance in transgenic tall fescue (Festuca arundinacea Schreb.).

Crop productivity is greatly affected by soil salinity; therefore, improvement in salinity tolerance of crops is a major goal in salt-tolerant breeding. The Salt Overly Sensitive (SOS) signal-transduction pathway plays a key role in ion homeostasis and salt tolerance in plants. Here, we report that overexpression of Arabidopsis thaliana SOS1+SOS2+SOS3 genes enhanced salt tolerance in tall fescue. The transgenic plants displayed superior growth and accumulated less Na+ and more K+ in roots after 350 mM NaCl treatment. Moreover, Na+ enflux, K+ influx, and Ca2+ influx were higher in the transgenic plants than in the wild-type plants. The activities of the enzyme superoxide dismutase, peroxidase, catalase, and proline content in the transgenic plants were significantly increased; however, the malondialdehyde content decreased in transgenic plants compared to the controls. These results suggested that co-expression of A. thaliana SOS1+SOS2+SOS3 genes enhanced the salt tolerance in transgenic tall fescue.

[Effect of acupuncture serum on the number of osteclast cultured in vitro].

OBJECTIVE: To observe effects of acupuncture serum of ovariectomized rats on the number of in vitro cultural osteoclast of newborn rats. METHODS: Forty 12-month-old SD female rats were randomly divided into 4 groups: sham-operation control group, ovariectomized (model) group, acupuncture prevention group and acupuncture treatment group. Osteoclasts isolated from long bone of the newborn SD rat were cultured on 24-well culture plates with DMEM containing 10% the test serum. Forty-eight hours later, the osteoclasts were stained with tartrate resistant acid phosphatase (TRAP) and the number of TRAP-positive multinucleated cells were counted. RESULTS: The number of TRAP-positive multinucleated cells in the model group significantly increased as compared with the sham-operation control group (P < 0.01), and in the acupuncture prevention group and the acupuncture treatment group significantly declined compared with the model group (P < 0.05). CONCLUSION: Acupuncture serum can equally reduce the number of osteoclasts in the two group.

Promotive effect of C/EBPepsilon overexpression on differentiation of human myelomonocytic leukemia cell line U-937.

BACKGROUND & OBJECTIVE: CCAAT-enhancer binding protein omega (C/EBPepsilon) is a kind of nuclear transcriptional factor expressed predominantly in myeloid cells, and may be a critical regulator of myeloid differentiation, which can activate the transcription of a subset of myeloid-specific genes. This study was to detect the cell-specific expression of C/EBPepsilon, and to investigate the effect of C/EBPepsilon overexpression on c-Myc expression, cell cycle distribution, and cell differentiation of human myelomonocytic leukemia cell line U-937. METHODS: The expression of C/EBPepsilon in 5 hematopoietic cell lines (U-937, NB4, HL-60, K-562 and Jurkat T cell lines) was tested by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). According to the RT-PCR results, human myelomonocytic leukemia cell line U-937 was selected and transfected with pcDNA3.1-C/EBPepsilon32 expression vector by electroperforation, and screened by G418 to yield positive clones which were termed U-937-C/EBPepsilon32. The expression of C/EBPepsilon and c-Myc in U937-C/EBPepsilon32 cells was detected by RT-PCR and Western blot; cell cycle and differentiation of U937-C/EBPepsilon32 cells was analyzed by flow cytometry. RESULTS: C/EBPepsilon overexpression obviously increased the expression of CD11b (a cell surface marker of granulocyte maturity). The positive rate of CD11b was significantly higher in U-937-C/EBPepsilon32 cells than in U-937 and U-937-pcDNA3.1 cells(92.56% vs. 77.46% and 74.81%), while c-Myc expression and cell cycle had no changes. CONCLUSION: C/EBPepsilon might be an essential transcriptional regulator for U-937 cells differentiating into granulocytes.