MsHDZ23, a Novel Miscanthus HD-ZIP Transcription Factor, Participates in Tolerance to Multiple Abiotic Stresses.

The homeodomain-leucine zipper (HD-ZIP) transcription factors, representing one of the largest plant-specific superfamilies, play important roles in the response to various abiotic stresses. However, the functional roles of HD-ZIPs in abiotic stress tolerance and the underlying mechanisms remain relatively limited in Miscanthus sinensis. In this study, we isolated an HD-ZIP TF gene, MsHDZ23, from Miscanthus and ectopically expressed it in Arabidopsis. Transcriptome and promoter analyses revealed that MsHDZ23 responded to salt, alkali, and drought treatments. The overexpression (OE) of MsHDZ23 in Arabidopsis conferred higher tolerance to salt and alkali stresses compared to wild-type (WT) plants. Moreover, MsHDZ23 was able to restore the hb7 mutant, the ortholog of MsHDZ23 in Arabidopsis, to the WT phenotype. Furthermore, MsHDZ23-OE lines exhibited significantly enhanced drought stress tolerance, as evidenced by higher survival rates and lower water loss rates compared to WT. The improved drought tolerance may be attributed to the significantly smaller stomatal aperture in MsHDZ23-OE lines compared to WT. Furthermore, the accumulation of the malondialdehyde (MDA) under abiotic stresses was significantly decreased, accompanied by dramatically enhanced activities in several antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in the transgenic plants. Collectively, these results demonstrate that MsHDZ23 functions as a multifunctional transcription factor in enhancing plant resistance to abiotic stresses.

Four new cytotoxic oligosaccharidic derivatives of 12-oleanene from Lysimachia heterogenea Klatt.

Cytotoxicity-guided phytochemical analysis on the extract of Lysimachia heterogenea Klatt led to the isolation of 3beta,16beta-12-oleanene-3,16,23,28-tetrol (1) and its four new oligosaccharidic derivatives heterogenosides A, B, C, and D (2-5). Their structural elucidation was mainly based on NMR and mass spectral data. The time course experimental results indicated that unlike the likely lysis activity of heterogenosides B-D, heterogenoside A showed a significantly time-dependent cytotoxicity.

A new poly-substituted benzaldehyde from the leaves of Lysimachia fordiana Oliv.

A new poly-substituted benzaldehyde, 1, and a known compound quercetin (2) were isolated from the leaves of Lysimachia fordiana Oliv. The structure of compound 1, named fordianol, was determined as 2-heptyl-3,6-dihydroxy-4- methoxybenzaldehyde on the basis of spectroscopic methods. Fordianol did not inhibit the growth of SWO-38 (human brain neuroglioma), MCF-7 (human breast cancer) or HeLa (human cervical carcinoma) cell lines.

[Autoantibodies and autoimmunity in simian immunodeficiency virus-infected monkeys].

OBJECTIVE: To study the relationship between simian acquired immunodeficiency syndromn (SAIDS) and autoimmunity in simian immunodeficiency virus (SIV)-infected monkeys. METHODS: Indirect immunofluorescence assays were performed to detect plasma or serum autoantibodies in SIV-infected monkeys. The heart, liver, spleen, lung, kidney, and lymph node of BALB/c mice, a strain of endothelial cell ECV304, and granulocytes were used as target antigens. These results were compared with HE stained slides of SIV-infected monkeys. RESULTS: The levels of various autoantibodies, including anti-lymphocyte autoantibodies, anti-endothelial cell autoantibodies, and anti-granulocyte antibodies, increased after SIV infection in monkeys. Moreover, pathological examinations showed injuries in the lymphoid tissue and vascular pathological changes in cerebral cortex, submucosa of gastrointestinal tract, interstitial capillaries of myocardium, nephron of the kidney, and sinusoid cell of liver. CONCLUSION: The increased autoantibodies and the pathological changes of tissues and organs confirm the existence of autoimmunity in SIV-infected monkeys.