Formation of Common Mycorrhizal Networks Significantly Affects Plant Biomass and Soil Properties of the Neighboring Plants under Various Nitrogen Levels

Abstract

Common mycorrhizal networks (CMNs) allow the transfer of nutrients between plants, influencing the growth of the neighboring plants and soil properties. Cleistogene squarrosa (C. squarrosa) is one of the most common grass species in the steppe ecosystem of Inner Mongolia, where nitrogen (N) is often a key limiting nutrient for plant growth, but little is known about whether CMNs exist between neighboring individuals of C. squarrosa or play any roles in the N acquisition of the C. squarrosa population. In this study, two C. squarrosa individuals, one as a donor plant and the other as a recipient plant, were planted in separate compartments in a partitioned root-box. Adjacent compartments were separated by 37 µm nylon mesh, in which mycorrhizal hyphae can go through but not roots. The donor plant was inoculated with arbuscular mycorrhizal (AM) fungi, and their hyphae potentially passed through nylon mesh to colonize the roots of the recipient plant, resulting in the establishment of CMNs. The formation of CMNs was verified by microscopic examination and 15 N tracer techniques. Moreover, different levels of N fertilization (N0 = 0, N1 = 7.06, N2 = 14.15, N3 = 21.19 mg/kg) were applied to evaluate the CMNs' functioning under different soil nutrient conditions. Our results showed that when C. squarrosa-C. squarrosa was the association, the extraradical mycelium transferred the 15 N in the range of 45-55% at different N levels. Moreover, AM fungal colonization of the recipient plant by the extraradical hyphae from the donor plant significantly increased the plant biomass and the chlorophyll content in the recipient plant. The extraradical hyphae released the highest content of glomalin-related soil protein into the rhizosphere upon N2 treatment, and a significant positive correlation was found between hyphal length and glomalin-related soil proteins (GRSPs). GRSPs and soil organic carbon (SOC) were significantly correlated with mean weight diameter (MWD) and helped in the aggregation of soil particles, resulting in improved soil structure. In short, the formation of CMNs in this root-box experiment supposes the existence of CMNs in the typical steppe plants, and CMNs-mediated N transfer and root colonization increased the plant growth and soil properties of the recipient plant.

Alleviation of cadmium and lead stress by A‐mycorrhizal fungi and rock phosphate on maize (Zea mays L.) growth under calcareous soil conditions

“…These results are in agreement with Abdelhameed and Metwally (2019) and Muneer et al. (2020). The beneficial impact of AMF on maize plant growth may be due to intensifying root growth, particularly fine roots with small radius (Abou El Seoud, 2008), developing depletion area nearby the plant rhizosphere depending on the hyphae of AMF (Abou El Seoud et al., 2020; Singh and Prabha, 2020), the mycorrhizal hyphae with fine radius can enter to the soil pore space tight to plant roots (Hammer et al., 2014), and transfer nutrients to the plant, as P (Rajtor & Piotrowska‐Seget, 2016; Smith, Jakobsen, Grønlund, & Smith, 2011), excreting organic compounds (Moe, 2013), increasing root exudation (Singh and Prabha, 2020), and phosphatase enzymes (Abdelhameed & Metwally, 2019; Chen et al., 2019; Sato et al., 2019).…”

Response of Fungal Diversity, Community Composition, and Functions to Nutrients Management in Red Soil

“…FUNGuild, the functional analysis of fungal communities, revealed that nutrient management practices increased the relative abundance of symbiotroph (e.g., endophyte, arbuscular mycorrhizal, and ectomycorrhizal fungi), whereas they decreased the relative abundance of plant pathotrophic fungi (e.g., plant-pathogen) compared with FFP. Generally, symbiotrophic fungi, in general, are highly helpful for the fitness, nutrition, and sustainability of most crops [ 85 , 86 , 87 ]. Pathotrophic fungi obtain nutrients by invading host cells.…”

Integrated Nutrient Management Significantly Improves Pomelo (Citrus grandis) Root Growth and Nutrients Uptake under Acidic Soil of Southern China

“…Recently, more emphasis has been given to the balanced fertilization strategy by reducing the usage of mineral fertilizers to improve crop quality, production, and uptake of nutrients [9]. The mineral fertilizers, especially nitrogen, phosphorus, and potassium, are essential for plant nutrition [10][11][12] and crop productivity [13,14]. However, an inappropriate or extensive application of fertilizers leads to severe problems of soil acidification [7,15], soil and water pollution [16,17], and greenhouse gas emissions [18,19].…”