Unveiling the latitudinal dependency of global patterns in soil prokaryotic gene content

Prokaryotic genomic traits offer insights into their functional roles, evolutionary processes, and ecological interactions, but global patterns in soil microbial genomes remain poorly understood. In this study, we examined 6436 metagenome-assembled genomes (MAGs) from global soil environments to explore the driving factors of prokaryotic gene content. Through random forest analysis, we found that, among numerous potential influencing factors such as climate, soil physicochemical properties, and human activities, geographic latitude was the primary factor affecting prokaryotic gene content. Our results showed a marked decrease in gene content from the tropics to the poles, with polar MAGs containing 10.4 % and 13.3 % fewer genes than those in tropical and temperate zones, respectively. This decline correlates with shifts in key metabolic processes, such as nitrogen fixation and energy conversion. Furthermore, we assessed interspecies metabolic interactions using Metabolic Resource Overlap (MRO) and Metabolic Interaction Potential (MIP) metrics. Our analysis revealed significantly lower MRO in high-latitude microbial communities, yet comparable MIP values to those in lower latitudes, indicating that reduced competition may contribute to genomic streamlining. These findings highlight the significant influence of latitude and interspecies interactions on microbial genomic characteristics, advancing our comprehension of microbial ecological adaptations.