Effects of soil pH on the growth, soil nutrients and rhizosphere microbiome of weed Ageratina adenophora

Ageratina adenophora is a major invasive species in many countries worldwide. Understanding the mechanism of the influence of soil pH on its growth will help to improve our understanding of its invasion mechanism and to develop effective control measures for A. adenophora. In this study, a pot experiment was performed to study the effects of acidic (pH 5.5) to alkaline (pH 9.0) soils on the growth of A. adenophora, the availability of soil nutrients, the photosynthesis and antioxidant enzyme activities of its leaves, and the diversity, composition and interaction of its rhizosphere microbiome. We found that A. adenophora has a strong pH tolerance. After growing in acid and alkaline soils for 180 days, its fresh and dry weights of the aboveground and underground parts, plant heights and root lengths did not differ from those growing in neutral (pH 7.2) pH soil. The initial soil pH and pH change due to rhizosphere process of A. adenophora did not substantially affected the concentrations and availabilities of N, P and K in the rhizosphere soil of A. adenophora, and the photosynthesis and antioxidant enzyme activities in the leaves of A. adenophora. A. adenophora responded successfully to pH stress by reducing the diversity, changing the composition and importance of the key microorganisms, maintaining balanced cooperation/competition relationships among the key microbial genera, and improving the stability of the prokaryotic communities of its rhizosphere microbiome.