Hypoglycemic Effect of Acidic Polysaccharide from Schisandra chinensis on T2D Rats Induced by High-Fat Diet Combined with STZ.

Polysaccharide is a key bioactive component of Schisandra chinensis and has significant pharmacological activities. The aim of this study was to evaluate the anti-diabetic effect of acidic polysaccharide from Schisandra chinensis (SCAP). Type 2 diabetic (T2D) rats were developed by giving a high-fat diet (HFD) combined with low-dose streptozotocin (STZ), and administered orally with SCAP (25, 50 mg/kg) for 8 weeks. Fasting blood glucose (FBG), fasting insulin (FINS), triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), malondialdehyde (MDA), and superoxide dismutase (SOD) in the rat's serum were measured. Oral glucose tolerance test (OGTT) and pathological changes of pancreas were observed. Furthermore, expressions of c-Jun N-terminal kinase (JNK), B-cell lymphoma 2-associated X protein (BAX), B-cell lymphoma 2 (Bcl-2), and Cleaved Caspase-3 in pancreatic islet were detected. The results showed that SCAP decreased FBG, TG, TC, LDL-C and MDA levels, increased insulin, HDL-C levels and SOD activity, improved the pathological changes in pancreatic islet. Furthermore, SCAP inhibited the up-regulation of phosphorylated JNK, BAX and Cleaved Caspase-3 proteins, and increased Bcl-2 protein expression. These data indicate that SCAP has a therapeutic effect in T2D rats, and the mechanism may be related to its protection against ß-cells apoptosis by regulating apoptosis-related proteins expression to alleviate the injury caused by the oxidative stress.

The broad bacterial blight resistance of rice line CBB23 is triggered by a novel transcription activator-like (TAL) effector of Xanthomonas oryzae pv. oryzae.

Bacterial blight (BB), caused by Xanthomonas oryzae pv. oryzae (Xoo), is not only a disease devastating rice production worldwide, but also an ideal model system for the study of the interaction between plants and their bacterial pathogens. The rice near-isogenic line (NIL) CBB23, derived from a cross between a wild rice Oryza rufipogon accession (RBB16) and a susceptible indica rice variety (Jingang 30), is highly resistant to all field Xoo strains tested so far. Although the BB resistance of CBB23 has been widely used in rice breeding programmes, the mechanism of its extremely broad-spectrum resistance remains unknown. Here, we report the molecular cloning of an avirulence gene, designated as avrXa23, from Xoo strain PXO99(A) . We validate that AvrXa23, a novel transcription activator-like effector, specifically triggers the broad-spectrum BB resistance in CBB23. The prevalence of avrXa23 in all 38 Xoo strains surveyed may explain the broad-spectrum feature of BB resistance in CBB23. The results will significantly facilitate the molecular cloning of the corresponding resistance (R) gene in the host, and provide new insights into our understanding of the molecular mechanism for broad-spectrum disease resistance in plants.