Identification and characterisation of cold stress-related proteins in Oryza rufipogon at the seedling stage using label-free quantitative proteomic analysis.

In this study, label-free quantitative proteomics were used to study cold stress-related proteins in Dongxiang wild rice (Oryza rufipogon Griff., DWR) and cold sensitive cultivated rice 'Xieqingzao B'(Oryza sativa L. ssp. indica cv., XB). The results demonstrated the presence of 101 and 216 differentially expressed proteins (DEPs) were detected in DWR and XB, respectively, after cold stress. Bioinformatics analysis showed that DWR and XB differed significantly in their ability to scavenge reactive oxygen species (ROS) and regulate energy metabolism. Of the 101 DEPs of DWR, 46 DEPs related to differential expressed genes were also detected by transcriptome analysis. And 13 out of 101 DEPs were located in previous cold related quantitative trait loci (QTL). Quantitative real-time PCR analysis indicated that protein expression and transcription patterns were not similar in XB and DWR. Protein-protein interaction (PPI) network was constituted using the DEPs of DWR and XB, and the following three centre proteins were identified: Q8H3I3, Q9LDN2, and Q2QXR8. Next, we selected a centre protein and two of the 37 DEPs with high levels of differential expression (fold change ≥ 2) were used for cloning and prokaryotic expression. We found that Q5Z9Q8 could significantly improve the cold tolerance of Escherichia coli.

Unlocking the potential antioxidant and anti-inflammatory activities of Rhododendron molle G. Don.

Rhododendron molle G. Don is an important traditional Chinese medicinal plant, which has been applied to treat some inflammatory diseases. In the present study, ethanol extracts of R. molle flower (RFE) and leaf (RLE) were used for phytochemical, antioxidant and anti-inflammatory analysis. The antioxidant activity was investigated using the free radicals of 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical (OH-)-scavenging activity, super oxide anion radical (O2.-)-scavenging activity and iron reducing power (FRAP). Production of nitric oxide (NO) was an indicator to evaluate the anti-inflammatory activity. The results showed that compared with RFE, RLE was more active against DPPH (56.66%), FRAP (51.29%) and hydroxyl radical (OH-) (69.66%) at 100µg/mL. In the same time, RLE and RFE had significant anti-inflammatory activity which could reduce nitrite production from 8.76µM to 5.08µM and 6.01µM, respectively. In addition, GC-MS analysis showed that 43 compounds were identified in R. molle. Among them, 11 compounds had antioxidant and 5 compounds had anti-inflammatory effect. Results showed that ethanol extracts of R. molle have significant antioxidant and anti-inflammatory activity. These results would be helpful for further investigation on the anti-inflammatory mechanism of R. molle.