Compared to conventional, ecological intensive management promotes beneficial proteolytic soil microbial communities for agro-ecosystem functioning under climate change-induced rain regimes

Projected climate change and rainfall variability will affect soil microbial communities, biogeochemical cycling and agriculture. Nitrogen (N) is the most limiting nutrient in agroecosystems and its cycling and availability is highly dependent on microbial driven processes. In agroecosystems, hydrolysis of organic nitrogen (N) is an important step in controlling soil N availability. We analyzed the effect of management (ecological intensive vs. conventional intensive) on N-cycling processes and involved microbial communities under climate change-induced rain regimes. Terrestrial model ecosystems originating from agroecosystems across Europe were subjected to four different rain regimes for 263 days. Using structural equation modelling we identified direct impacts of rain regimes on N-cycling processes, whereas N-related microbial communities were more resistant. In addition to rain regimes, management indirectly affected N-cycling processes via modifications of N-related microbial community composition. Ecological intensive management promoted a beneficial N-related microbial community composition involved in N-cycling processes under climate change-induced rain regimes. Exploratory analyses identified phosphorus-associated litter properties as possible drivers for the observed management effects on N-related microbial community composition. This work provides novel insights into mechanisms controlling agro-ecosystem functioning under climate change

Sex modulates the interactive effect of the serotonin transporter gene polymorphism and childhood adversity on hippocampal volume.

Item does not contain fulltextThe common genetic variation of the serotonin transporter-linked polymorphic region (5-HTTLPR) has been related to depressive symptoms, in particular after stressful life events. Although it has been investigated in the past, results suggesting that the 5-HTTLPR genotype also affects hippocampal volume are often inconsistent and it remains unclear to what extent reduced hippocampal volume is influenced by the effect of stressful life events and 5-HTTLPR genotype. Moreover, sex, which is known to affect the prevalence of depression substantially, has not been taken into account when trying to disentangle the interactive effect of common genetic variation and environmental stressors on the hippocampus. We investigated this potentially relevant three-way interaction using an automatic magnetic resonance imaging (MRI)-based segmentation of the hippocampus in 357 healthy individuals. We determined the 5-HTTLPR genotype as a biallelic locus and childhood adversity (CA) using a standard questionnaire. An interaction for hippocampal volume was found between the factors sex, genotype, and severe CA (p=0.010) as well as an interaction between genotype and severe CA (p=0.007) in men only. Post hoc tests revealed that only male S'-allele carriers with severe CA had smaller hippocampi (p=0.002). Interestingly, there was no main effect of genotype in men, while female S'-allele carriers had smaller hippocampi than L'L' carriers (p=0.023). Our results indicate that sex modulates the interactive effect of the 5-HTTLPR genotype and CA on hippocampal volume. While the S'-allele is associated with hippocampal volume independent of CA in women, men only have smaller hippocampi if they carry the risk allele and experienced severe CA.1 juli 201