An invasive plant experiences greater benefits of root morphology from enhancing nutrient competition associated with arbuscular mycorrhizae in karst soil than a native plant

Abstract

The Eupatorium adenophorum have widespread invaded the karst ecosystem of southwest China and threatened the regional native community stability. Arbuscular mycorrhizae (AM) plays an important role in promoting growth for host plants via root external mycelia. However, whether AM regulates plant root traits underlying competition between invasive and native species via mycorrhizal networks in karst habitats, remains unclear. An experiment was conducted in a microcosm composed of two planting compartments flanking a competition compartment. The invasive E. adenophorum and native Artemisia annua were each placed in one of the two planting compartments with or without Glomus etunicatum fungus. The nutrient access treatments included the competitive utilization (Cu), single utilization (Su) and non-utilization (Nu) by using different nylon meshes allowed or prevented mycelium passing to acquire nutrients from the competition compartment. Root traits and nutrients of the two species were analyzed. The results showed that AM fungi had differential effects on root traits and nutrients of E. adenophorum and A. annua seedlings, which increased dry weight, length, surface area, volume, tips and branching points in roots, specific root length and volume, root nitrogen (N) and phosphorus (P) contents under Cu, Su and Nu treatments. AM fungus was also associated with decreases in the average diameter for both species. Under the Cu treatment, E. adenophorum had significantly greater length, surface area, volume, tips and branching points of roots, specific root traits, and root N and P than A. annua. AM fungi changed root phenotypes and nutrient uptake for both invasive and native plant species via interconnected mycorrhizal networks. Overall, our results suggest that through mycorrhizal networks, the invasive plant experiences greater benefits than the native plant in the nutrient competition, which fosters root morphological developments in karst soil.

Indigenous Microorganisms Offset Arbuscular Mycorrhizal Fungi-Induced Plant Growth and Nutrient Acquisition Through Negatively Modulating the Genes of Phosphorus Transport and Nitrogen Assimilation

“…AM fungi can induce the expression of mycorrhiza-specific phosphate (Pi) transporters, such as StPT3 in potato and ZEAma and Pht1 and Pht6 in maize ( Javot et al, 2007 ), respectively. In addition, AM fungi can regulate root architecture ( Xia et al, 2020 ) and produce extensive mycelium for exploring rhizosphere scale ( Shen et al, 2020 ) to help plants absorb nutrients, which are the essential mechanisms for plants to adapt to some special habitat, such as karst habitat with nutrient deficiency owning to thin and barren soil layer ( Li et al, 2002 ). Conversely, the host plant provides sugars and lipids to the fungal partner, such as AM fungi ( Jiang et al, 2017 ; Rich et al, 2017 ).…”

Soil patch heterogeneity improves plant productivity and nutrients regulated by arbuscular mycorrhizal fungi

“…It was consistent with H1. The positive effects of AM colonization on plant growth performance and nutrient uptakes have been well reported, particularly in nutrient‐poor heterogeneous soils, as AM hyphae can help the root systems expand plants' absorption area to access soil resources (He et al, 2017; Xia, Wang, et al, 2020). For example, AM fungi promoted biomass production and N and P accumulations of pioneer herbs in nutrient‐deficient karst areas (He et al, 2017, 2019).…”

“…Extensive AM fungal root epitaxial hyphae are an important pathway for plants to obtain nutrients from soil patches compared with root foraging because the carbon cost of finer hyphae growth is often less than thicker root growth (Chen et al, 2018; Smith & David Read, 2008). Numerous studies have widely recognized AM fungi's positive role in promoting host plants' growth and nutrient acquisition, particularly in heterogeneous soil patches (Croft et al, 2012; Smith & David Read, 2008; Xia, Wang, et al, 2020). Specifically, AM fungal hyphae detect and respond to nutrient patches outside the rhizosphere in heterogeneous soils for additional resources (Shi et al, 2011).…”

Indigenous microorganisms offset the benefits of growth and nutrition regulated by inoculated arbuscular mycorrhizal fungi for four pioneer herbs in karst soil

“…AM fungi formed a symbiotic relationship with 80% of terrestrial plants [ 18 , 19 ], improve plant growth, nutrient accumulation [ 20 , 21 ], enhance drought stress tolerance [ 22 ] and maintain soil structure [ 23 ], e.g. Guo et al (2021) [ 24 ] proposed that AM fungi differently affected the competitive ability of Broussonetia papyrifera and Carpinus pubescens ; Xia et al (2020) [ 25 ] also showed that AM fungi increased nutrients of host plants by regulating the morphological development of karst plant roots. In addition, Shi et al (2015) [ 26 ] illustrated that AM fungi increased the biomass, N, and P content in shoots and roots of plants.…”