Implications of the rhizosphere microbiome on the success of invasive plants in semi-arid ecosystems

Abstract

Within the framework of the invasion by non-native plant species problem in soils from semi-arid Mediterranean areas, an assessment has been conducted using mass sequencing techniques to analyze how plant invasions affect the composition, structure, and functionality of the rhizosphere microbiome (arbuscular mycorrhizal fungi, saprophytic fungi, and bacteria). These studies have examined whether such effects vary with the edaphic properties of the invaded ecosystems, their biogeographical location, the successional stage of the invasion process, as well as the predicted conditions of climate change. Several mechanisms are proposed through which the rhizosphere microbiome, altered by the presence of non-native plants, may promote the invasion process. The following non-native plant species, categorized as invasive, have been studied: Carpobrotus edulis (L.) N.E. Br, Pennisetum setaceum (Forssk.) Chiov., Nicotiana glauca R.C. Graham y Mirabilis jalapa L.. The invasive species studied can alter the composition and structure of communities of bacteria and saprophytic fungi, promoting a microbiota with distinctive functional characteristics, particularly in terms of functions related to soil nutrient cycling and defense mechanisms against biotic and abiotic stress. It has also been found that invasive species can establish different mycorrhizal associations throughout the invasion process, which were specific to the invading host plant in the early stages of its establishment and could have contributed to the success of the invasion.