Climate warming alters the soil microbial association network and role of keystone taxa in determining wheat quality in the field

The soil microbial community is an essential biotic component in plant-soil feedback processes that can alter plant fitness, growth, and reproduction. Further, they may exert an influence on plants by forming a microbial association network. Accordingly, pronounced changes in the soil microbial community induced by climate warming is vital when evaluating the future risks on plants posed by global climate change. Although the climate warming issue has gained much attention for its impact upon soil microbial communities, attempts to identify its effects on their network associations through plant growth stages, especially in agroecosystems, remains limited and generally understudied. Here, the effects of elevated temperature in association with wheat plant growth upon soil bacteria, fungi, and arbuscular mycorrhizal (AM) fungi were determined in a field experiment. Our results revealed the alpha diversity of soil bacteria (ACE and Chao values) decreased through plant growth stages, while the relative abundances of bacteria and fungi between seeding time and mature stage were revealed significantly distinct in the PCA analysis. The derived microbial association network showed that warming could enhance the complexity of the network and wheat planting might weaken it. We also found the wheat planting and warming could increase the number of keystone species. Furthermore, the keystone species had the strongest relationship with the grain mass and quality of wheat. These findings could provide a better understanding of plant-soil feedback dynamics in wheat crops, along with those in other similar agroecosystems in the future under global climate change.