SLC7A11 negatively associates with mismatch repair gene expression and endows glioblastoma cells sensitive to radiation under low glucose conditions.

The cystine/glutamate antiporter xCT (SLC7A11) is frequently upregulated in many cancers, including glioblastoma (GBM). SLC7A11-mediated cystine taken up is reduced to cysteine, a precursor amino acid for glutathione synthesis and antioxidant cellular defense. However, little is known about the biological functions of SLC7A11 and its effect on therapeutic response in GBM. Here, we report that the expression of SLC7A11 is higher in GBM compared with normal brain tissue, but is negatively associated with tumor grades and positively impacts survival in the bioinformatic analysis of TCGA and CGGA database. Additionally, a negative association between SLC7A11 and mismatch repair (MMR) gene expression was identified by Pearson correlation analysis. In the GBM cells with glucose-limited culture conditions, overexpression of SLC7A11 significantly decreased MMR gene expression, including MLH1, MSH6, and EXO1. SLC7A11-overexpressed GBM cells demonstrated elevated double-strand break (DSB) levels and increased sensitivity to radiation treatment. Taken together, our work indicates that SLC7A11 might be a potential biomarker for predicting a better response to radiotherapy in GBM.

Selenium (Se) Does Not Reduce Cadmium (Cd) Uptake and Translocation in Rice (Oryza sativa L.) in Naturally Occurred Se-Rich Paddy Fields with a High Geological Background of Cd.

This study examined the selenium (Se) and cadmium (Cd) uptake by rice from soil and analyzed the relationship between Se and Cd in naturally occurred Se-rich paddy fields with a high geological background of Cd. Significant correlations were observed between soil Se and plant biomass Se, but not between soil Cd and plant biomass Cd. High concentrations of Cd were detected in rice plants and particularly in rice grains, suggesting potential health risks to human. Contrary to results from other previous studies, our results showed that high soil Se did not reduce Cd uptake by rice, although it decreased the availability of Cd in soil. Rather, soil Se and internal Se pool in rice were positively correlated to the transfer of Cd from root to straw. The effect of Se on the uptake and translocation of Cd in rice in field is therefore different from those in pot experiments.

[Effects of Biochar-loaded Ammonia Nitrogen on Soil Carbon Emissions, Enzyme Activity, and Microbial Communities].

The form of soil nitrogen input significantly affects soil CO2 emission. As a new form of nitrogen input, biochar-loaded ammonia nitrogen not only reduces the input of chemical nitrogen fertilizer in farmland but also reduces the cost of environmental treatment. It is of great significance to promote the zero growth of national chemical fertilizer, the prevention and control of farmland non-point source pollution, and the realization of the national goal of "carbon peak" and "carbon neutralization." Through an indoor culture experiment, the effects of different nitrogen input forms on soil carbon emission, enzyme activity, and microbial community were studied through four treatments:no fertilization (CK), single application of chemical nitrogen fertilizer (CF), biochar combined application of chemical nitrogen fertilizer (BF), and biochar-loaded ammonia nitrogen (BN). The results showed that compared with that in CF, BF significantly increased cumulative carbon emissions (66.24 %), whereas BN had no significant difference. It is worth noting that the cumulative carbon emissions were significantly reduced by 35.28 % compared with that in BF and BN. Compared with those in CF and BF, the activities of ß-glucosidase, peroxidase, and polyphenol oxidase treated with BN significantly increased by 20.25 % and 5.20 %, respectively. Compared with that in CF, the BF treatment increased microbial community richness and community diversity, whereas the BN treatment decreased microbial community richness. Compared with that in BF, the relative abundance of Proteobacteria decreased by 11.16 %, and the relative abundance of Actinobacteria and Bacteroidota increased by 8.12 % and 5.83 %, respectively, in which xylosidase activity was the most important soil factor affecting microbial community structure. The relative abundance of Chloroflexi was significantly correlated with cellobiose hydrolase activity, and the relative abundance of Gemmatimonadetes was significantly correlated with ß-glucosidase activity. There was a very significant correlation between the relative abundance of Proteobacteria and cumulative carbon emissions. To summarize, compared with those under biochar combined with chemical nitrogen fertilizer, biochar loaded with ammonia nitrogen significantly reduced cumulative carbon emissions, and its emission reduction effect was better. The results of this study will be beneficial to the landing of the national "double carbon strategy," the healthy development of the biological natural gas industry, the construction of the national green cultivation circular agriculture system, and the realization of the national zero growth strategy of chemical fertilizer.

[Effects of copper stress on the function of arbuscular mycorrhizal fungi community].

The functional differences of arbuscular mycorrhizal fungi (AMF) isolates from different sources have been extensively investigated in the last two decades. However, previous studies were mostly based on individual AMF species and the community level comparison was not addressed properly. Furthermore, many studies did not distinguish the difference between the effects of AMF source and community structure on their function, let alone concerned the significance of host plant. This study evaluated the effects of copper (Cu) stress on AMF community structure and compared the differences of AMF communities from Cu contaminated and uncontaminated substrates on performance of Zea mays through two short-term greenhouse pot culture experiments. The results showed that spore abundance and composition of AMF communities were changed dramatically under Cu stress compared with the control. The communities dominated by Rhizophagus intraradices and Claroideoglomus etunicatum from Cu contaminated soils conferred more benefits on Z. mays in terms of plant growth and physiological properties relative to that from control governed by Funneliformis mosseae.