Identification of QTL underlying the main stem related traits in a doubled haploid barley population.

Lodging reduces grain yield in cereal crops. The height, diameter and strength of stem are crucial for lodging resistance, grain yield, and photosynthate transport in barley. Understanding the genetic basis of stem benefits barley breeding. Here, we evaluated 13 stem related traits after 28 days of heading in a barley DH population in two consecutive years. Significant phenotypic correlations between lodging index (LI) and other stem traits were observed. Three mapping methods using the experimental data and the BLUP data, detected 27 stable and major QTLs, and 22 QTL clustered regions. Many QTLs were consistent with previously reported traits for grain filling rate, internodes, panicle and lodging resistance. Further, candidate genes were predicted for stable and major QTLs and were associated with plant development and adverse stress in the transition from vegetative stage to reproductive stage. This study provided potential genetic basis and new information for exploring barley stem morphology, and laid a foundation for map-based cloning and further fine mapping of these QTLs.

Improving effect of cordycepin on insulin synthesis and secretion in normal and oxidative-damaged INS-1 cells.

Diabetes mellitus (DM) has recently become one of the major diseases that have received attention. Cordycepin (molecular formula: C10H13N5O3), is one of the major bioactive components of Cordyceps militaris, decreases blood glucose levels. In this study, the effect and mechanism of cordycepin in normal and oxidative-damaged INS-1 cells were explored by using cell and molecular biology methods. Results showed that cordycepin could enhance insulin synthesis and secretion. The mechanism is possibly related to the elevated ATP content induced membrane depolarisation and increased Ca2+ concentration. At the genetic level, cordycepin upregulated the mRNA level of insulin, pancreatic duodenal homeobox factor-1 (PDX-1) and glucose transporter 1 (GLUT1). At the protein level, cordycepin promoted the expression of PDX-1, GLUT1, serine threonine kinase (Akt) and phosphorylated Akt (P-Akt). These effects may also contribute to the enhancement of insulin synthesis and secretion. Further analysis revealed that cordycepin protected against H2O2-induced damage on INS-1 cells and improved their viability and insulin synthesis/secretion. This effect should be attributed to the reduced intracellular reactive oxygen species (ROS), enhanced mitochondrial membrane potential (MMP), increased activity of superoxide dismutase (SOD) and upregulated genetic and protein expression of catalase (CAT), PDX-1, GLUT1 and P-Akt. In conclusion, cordycepin promotes insulin synthesis and secretion in normal islet ß cells and improves this function in oxidative-damaged islet ß cells. Given that islet ß cells are vulnerable to oxidative stress, the improving effect of cordycepin on the antioxidant capacity and insulin synthesis/secretion of INS-1 cells may be an important mechanism for its hypoglycaemic effect.

Assessment of soil quality for guided fertilization in 7 barley agro-ecological areas of China.

Soil quality is the basis for the development of sustainable agriculture and may be used for evaluating the sustainability of soil management practices. Soil quality status and integrated soil quality index (SQI) in sampled 97 farmlands distributed in 7 barley agro-ecological areas of China were analyzed by using 13 soil chemical parameters. The results showed six principal components totally explained 72% variability for the 13 parameters and identified 9 parameters (includes pH, NH4+-N, NO3--N, available P, available K, exchangeable Mg, DTPA-Fe, DTPA-Cu and Cl-) with high factor loading values as the minimum data set (MDS) for assessing soil quality. Average soil quality of all farmlands is moderate (SQI = 0.62). The SQI of barley farmlands in 7 agro-ecological areas showed the following order: Inner Mongolia Plateau (0.75 ± 0.02) > Yunnan-Kweichow Plateau (0.72 ± 0.06) > Qinghai-Tibet Plateau (0.63 ± 0.08) > Yangtze Plain (0.62 ± 0.10) > Huanghuai Region (0.58 ± 0.09) > Northeast China Plain (0.56 ± 0.07) > Xinjiang Province (0.54 ± 0.07). Total 29 out of 97 farmlands in 7 areas have low SQI level (< 0.55). Hence, these farmlands require urgent attention for soil quality improvement through modification of the soil parameters in the MDS.

[Effects of salvianolic acid B on cardiovascular endothelial cells and platelet activation in a rabbit model of ischemia-reperfusion].

OBJECTIVE: To investigate the effects of salvianolic acid B (SA-B) on cardiovascular endothelial cell function and platelet activation during myocardial ischemia-reperfusion in rabbits. METHODS: A total of 24 New Zealand white rabbits were randomly divided into sham-operated group, ischemia-reperfusion group (untreated group) and SA-B group. The hearts of rabbits in untreated group and SA-B group underwent half an hour of left anterior descending coronary artery (LADCA) occlusion via ligation technology, which was followed by 4 hours of reperfusion to prepared ischemia-reperfusion injury model in vivo. For sham-operated group, the animals were not subjected to occlusion of LADCA. In SA-B treatment group the rabbits were intravenously administered SA-B immediately after LADCA occlusion, and the other two groups were given normal saline in the same way instead of SA-B. The jugular vein bloods of animals were collected before LADCA ligation, half an hour after ligation and after 1-, 4-hour reperfusion, respectively. The content of plasma nitric oxide (NO) was determined by nitrate reductase process. Radioimmunoassay was applied to detect the endothelin (ET) content in plasma and the count of alpha-granule membrane protein-140 (GMP-140) on platelet surface to identify the activation of the platelet. RESULTS: No significant difference was observed before and after sham LADCA occlusion in sham-operated group in the contents of NO and ET in plasma (P>0.05), neither was the count of GMP-140 on platelet surface (P>0.05). The content of NO in plasma detected 0.5 h after LADCA occlusion was significantly decreased in untreated group compared with the sham-operated group at the corresponding time, and they were also much lower than that before LADCA occlusion in the sham-operated group (P<0.05). The plasma content of NO in untreated group showed a progressive decrease in response to the myocardial reperfusion. However, the content of ET in plasma and the count of GMP-140 on platelet surface were remarkably increased after myocardial ischemia as compared with those before LADCA ligation and those detected in sham-operated group (P<0.05). The content of ET and the count of GMP-140 in the untreated group were further increased corresponding to the aggressive reperfusion. The content of NO was significantly increased while the content of ET and the count of GMP-140 were both significantly decreased in SA-B group as compared with untreated group after 1- and 4-hour myocardial reperfusion, respectively (P<0.01). CONCLUSION: The results show that endothelial dysfunction and platelet activation occur during ischemia-reperfusion in rabbit hearts in vivo and SA-B protects cardiovascular endothelium cells against ischemia-reperfusion injury and inhibits the activation of platelet during myocardial ischemia and reperfusion.