Effect of Increasing CO_2 on the Stratospheric Level of CO and O_3

Production and destruction processes of carbon monoxide (CO) and ozone (O3) are examined in the light of increasing amount of atmospheric carbon dioxide (CO2). It is found that doubling of CO2 will increase the stratospheric concentration of CO and will have positive effect on O3 concentration.

Effects of elevated CO_2 levels on root morphological traits and Cd uptakes of two Lolium species under Cd stress

This study was conducted to investigate the combined effects of elevated CO2 levels and cadmium (Cd) on the root morphological traits and Cd accumulation in Lolium multiflorum Lam.and Lolium perenne L.exposed to two CO2 levels (360 and 1000 μl/L) and three Cd levels (0,4,and 16 mg/L) under hydroponic conditions.The results show that elevated levels of CO2 increased shoot biomass more,compared to root biomass,but decreased Cd concentrations in all plant tissues.Cd exposure caused toxicity to both Lolium species,as shown by the restrictions of the root morphological parameters including root length,surface area,volume,and tip numbers.These parameters were significantly higher under elevated levels of CO2 than under ambient CO2,especially for the number of fine roots.The increases in magnitudes of those parameters triggered by elevated levels of CO2 under Cd stress were more than those under non-Cd stress,suggesting an ameliorated Cd stress under elevated levels of CO2.The total Cd uptake per pot,calculated on the basis of biomass,was significantly greater under elevated levels of CO2 than under ambient CO2.Ameliorated Cd toxicity,decreased Cd concentration,and altered root morphological traits in both Lolium species under elevated levels of CO2 may have implications in food safety and phytoremediation.

Transcriptome responses to elevated CO2 level and Wolbachia-lniecWon stress in Hylyphantes graminicola (Araneae: Linyphiidae)

Hybyphantes graminicola is a resident spider species found in maize and cotton fields and is an important biological control agent of various pests.Previous studies have demonstrated that stress from elevated CO2 and Wolbachia infection can strongly affect spider species.Thus,based on CO2 levels(400 ppm,current atmospheric CO2 concentration and 800 ppm,high CO2 concentration)and Wolbachia status(Wolbachia-infected,W^+and Wolbachia-uninfected,W^-),we divided H.graminicola individuals into four treatment groups:W^-400 ppm,W^-800 ppm,W^+400 ppm,and W^+800 ppm.To investigate the effects of elevated CO2 levels(W^-400 vs W^-800),Wolbachia infection(W^-400 vs W^+400),and the interactions between these two factors(W^-400 Vs W^+800),high-throughput transcriptome sequencing was employed to characterize the de novo transcriptome of the spiders and identify stress-related differentially expressed genes(DEGs).De novo assembly of complementary DNA sequences generated 86688 unigenes,23938 of which were annotated in public databases.A total of 84,21,and 157 DEGs were found among W^-400vs W^-800,W^-400 vs W^+400,and W^-400vs W^+800,respectively.Functional enrichment analysis revealed that metabolic processes,signaling,and catalytic activity were significantly affected by elevated CO2 levels and Wolbachia infection.Our findings suggest that the impact of elevated CO2 levels and Wolbachia infection on the H.graminicola transcriptome was,to a large extent,on genes involved in metabolic processes.This study is the first description of transcriptome changes in response to elevated CO2 levels and WoIbachia infection in spiders.