Methane and nitrous oxide emission characteristics of high-yielding rice field.

As representative varieties of the four phases of the super rice breeding project in China, Lianyoupei 9 (LYP9), Y Liangyou 1 (YLY1), Y Liangyou 2 (YLY2), and Y Liangyou 900 (YLY900) achieved higher yield under optimal cultivation techniques. However, the impact of these high-yield rice varieties on greenhouse gas (GHG) emissions under high-yield cultivation management practices remains poorly understood. In this study, we conducted field experiments to investigate CH4 and N2O emissions from paddies containing four elite rice varieties, managed with field drying at the ineffective tillering stage and alternate wet/dry irrigation at the grain-filling stage. The plants were fertilised with nitrogen (N) at three different rates. The results showed that CH4 emission was highest at the tillering stage. N2O emission flux was dramatically increased by field drying at the ineffective tillering stage, and with the rate of N application. Rice variety was among the most important factors affecting CH4 emission and global warming potential (GWP). N2O emission was mainly related to N application rate rather than rice variety. YLY2 achieved higher yield than LYP9, YLY1, and YLY900, and lower GHG emission than YLY900. Our results indicate that rice variety should be considered as a key factor to reduce GHG emissions from rice paddies under high-yield cultivation practices. Based on its high yield and low GHG emission at the study site, YLY2 may be an optimal rice variety.

CD147 modulates autophagy through the PI3K/Akt/mTOR pathway in human prostate cancer PC-3 cells.

The multifunctional glycoprotein cluster of differentiation (CD)147 is highly expressed on the cell surface of the majority of cancer cells, and promotes tumor invasion, metastasis and growth. However, the role of CD147 in autophagy has not yet been explored in prostrate cancer cells. In the present study, prostate cancer PC-3 cells were cultured under starvation conditions, and the expression level of CD147 gradually increased. Therefore, RNA interference was used to inhibit CD147 expression, in order to investigate the biological role of this glycoprotein in autophagy progression. Autophagic activity was monitored by the changes in green fluorescent protein-light chain 3 (GFP-LC3) location and the expression of the autophagy-associated protein LC3-II. It was found that downregulation of CD147 significantly promoted GFP-LC3 puncta formation and the expression of LC3-II. Furthermore, the levels of phosphorylated serine/threonine protein kinase B (p-Akt) and phosphorylated mammalian target of rapamycin (p-mTOR) were significantly decreased, and the level of LC3-II was inversely associated with levels of p-Akt and p-mTOR in cells with downregulated expression of CD147. The results of a trypan blue exclusion assay revealed that starvation-induced cell death was increased in PC-3/shCD147 cells compared with control PC-3/Scramble cells (37.7±6.4 vs. 21.7±5.5%). Together, these results indicate that CD147 may be important in the inhibition of autophagy via the PI3K/Akt/mTOR pathway, which prevents cell death from unrestrained autophagy.