New multiple-stress related gene isolated from sweet potato and designated it as MusI (multiple stress responsible gene I). Sequence analysis revealed that its full length cDNA was 998 bp long and included a 717 bp open reading frame encoding for 238 amino acids. Comparison of its cDNA and genomic DNA sequence showed that 3 exons were divided by 2 introns in its ORF region. Its deduced amino acid sequence contained a conserved rubber elongation factor (REF) domain and showed high homology with many stress-related proteins. Therefore, it was named MuSI (multiple stress responsible gene I). Southern hybridization analysis indicated that the MuSI gene may belong to a multi-gene family. Expression pattern of the MuSI gene showed that it was differently expressed among roots, stems, leaves, and flowers of a sweet potato, and its expression level was especially high in flowers andThe first two authors, SGS and JSK, contributed equally. white fibrous roots. Its expression was also highly induced by various stress signals including dehydration, high salt, heavy metal, oxidation, and plant hormones. Stress tolerance experiment using transgenic plants overexpressing the MuSI gene showed that all independent transgenic tobacco lines have enhanced tolerance to high temperature stress. Among them, transgenic line 6 particularly showed tolerance to salt, heavy metal, and osmotic stress as well. These results suggest that the MuSI gene functions as a positive regulator of various stress responses and may be useful in improving stress tolerance of transgenic plants.

The fruit of trifoliate orange (Poncirus trifoliate) is widely used for treating allergies including allergenic dermatitis and inflammation in oriental medicine. Increased blood IgE concentration and histamine level following dermatitis, coughing and asthma are the most important clinical symptoms of allergic diseases. Decreases in the elevated serum IgE concentrations are essential in the treatment of allergy because increased IgE blood levels are initiated in allergenic immune disorders. This study was conducted to investigate the activities of an extract of trifoliate orange fruit using 100% methanol followed by extraction with boiling water on the regulation of blood IgE concentration in the U266B1 human myeloma cell line and a 1-chloro-2,4-dinitrobenzene (DNCB) sensitized mouse model. The results revealed that the extracts of trifoliate orange suppressed IgE production in U266B1 cells in a dose dependent manner with or without lipopolysaccharide (LPS) stimulation of the cells. In addition, chemically elevated blood IgE concentrations were dramatically decreased by oral administration, ventral injection, and topical application of the trifoliate orange extracts (TOE). The results indicated that the fraction of TOE should contain an important compound of the fruit of trifoliate orange, and TOE had the ability to reduce IgE concentrations in cultured cells and a chemically sensitized in vivo mouse model.