Elevated CO₂ affects the rhizosphere microbial community and the growth of two invader plant species differently in semiarid Mediterranean soils

Abstract

The rise in atmospheric CO 2 levels is foreseen to enhance the growth of exotic invasive plants and potentially alter the rhizosphere microbial community, which in turn could enhance the risk of colonization by such invaders. This response could be determined by the plant type and the features of invaded soil. The goal of this investigation was to compare the effects of elevated CO 2 on the rhizosphere bacterial and fungal communities of two invaders with distinct degrees of invasiveness, Nicotiana glauca and Mirabilis jalapa, by growing the plants in five different semiarid soils at ambient (410 ppm) or elevated (760 ppm) CO 2 . The changes in soil physicochemical, biochemical, and biological features mediated by the invaders were also evaluated.The effect of CO 2 supply on shoot dry biomass was only significant for N. glauca, the shoot and root biomass of plants grown under elevated CO 2 being approximately 53% and 14% greater, respectively, than those of the plants grown under ambient CO 2 . Elevated CO 2 only promoted shifts in the rhizosphere bacterial community composition and enhanced the bacterial functional potential related to nucleoside and nucleotide biosynthesis and N-cycling in N. glauca. Among the bacterial indicator species, the genera Sphingomonas, Stenotrophobacter, and Gaiella were more abundant in the rhizosphere of N. glauca plants grown under elevated CO 2 . This study demonstrates that the responses of aboveground and belowground biomass of invasive plants to CO 2 enrichment, as well as those of the composition and functioning of soil microbial communities, are dependent on their degree of invasiveness.

Effects of Pine Wilt Disease on Rhizosphere Microbiota and Fine Root Fungi: Insights into Enzyme Activity, Ectomycorrhizal Infection and Microbial Composition

“…Interestingly, the abundance of the ureolysis functional group in rhizosphere bacteria was positively correlated with Gaiella, known for its contribution to nutrient cycling, especially nitrogen decomposition [51]. The decrease in ureolysis in the rhizospheric diseased trees could have caused a reduction in soil CO2 amount, which may have led to a decrease in the abundance of Gaiella [52]. The rhizosphere of diseased hosts showed a higher abundance of fungal phylum Mortierellomycota and species M. humilis.…”

An Integrated Investigation of the Relationship between Two Soil Microbial Communities (Bacteria and Fungi) and Chrysanthemum Zawadskii (Herb.) Tzvel. Wilt Disease

“…These studies used CZHZ plantation soils to alter the physical and chemical properties that cause CWD. In recent years, we have come to realize that rhizosphere microbial communities (RMCs) play an important role in plant health and disease resistance [ 11 ]. The RMC composition of healthy chrysanthemums is stable and diverse, including a variety of fungi, bacteria, archaea, symbiotic bacteria, and probiotics.…”