Mycorrhizal Symbiosis in Plant Growth and Stress Adaptation: From Genes to Ecosystems

Abstract

Plant roots associate with diverse microbes (including bacteria, fungi, archaea, protists, and viruses) collectively called the rhizosphere microbiome. Among them, mycorrhizal fungi colonize host roots and improve their access to nutrients, usually phosphorus and nitrogen. In exchange, plants deliver photosynthetic carbon to the colonizing fungi. This nutrient exchange affects key soil processes, the carbon cycle, and plant health and therefore has a strong influence on the plant and microbe ecosystems. The framework of nutrient exchange and regulation between host plant and arbuscular mycorrhizal fungi has recently been established. The local and systemic regulation of mycorrhizal symbiosis by plant nutrient status and the autoregulation of mycorrhizae are strategies by which plants maintain a stabilizing free-market symbiosis. A better understanding of the synergistic effects between mycorrhizal fungi and mycorrhizosphere microorganisms is an essential precondition for their use as biofertilizers and bioprotectors for sustainable agriculture and forestry management. Expected final online publication date for the Annual Review of Plant Biology, Volume 74 is May 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Trade‐offs in rooting strategy dimensions along an edaphic gradient in a grassland ecosystem

“…Much remains unknown concerning mycorrhizal‐related traits (Chagnon et al., 2013; Chaudhary et al., 2022), which can vary across environments and evolutionary lineages of both fungi and plants (Koch et al., 2017; Mensah et al., 2015; Shi et al., 2023; Wipf et al., 2019). Our measurements of AMF colonisation provided insights on the abundance of AMF interacting with roots (Barceló et al., 2020; Bell et al., 2021).…”

Alone as effective as together: AMF and Trichoderma inoculation boost maize performance but differentially shape soil and rhizosphere microbiota

“…[5%] and Fusarium [2%]) are classified as tentative organic matter degraders (Põlme et al, 2020). Since AMF cannot degrade organic compounds (as suggested by Shi et al, 2023), including lignin, this association with putative saprotrophs may indicate a dependency on other soil microorganisms for nutrient scavenging. To our knowledge, this is the first report of the fungal community composition associated with an AMF inoculant.…”

At the core of the endomycorrhizal symbioses: intracellular fungal structures in orchid and arbuscular mycorrhiza

“…Several plant genes encoding putative membrane transporters are upregulated both in OrM and in AM, and transfer of nutrients to the plant is thought to occur across the interface lined by the invaginated plant plasma membrane that surrounds fungal pelotons or arbuscules, respectively (Smith & Read, 2008). Nutrient transport to the host plant has been extensively investigated in the arbuscules formed by the Arum ‐type AM, thought to be the major site where mineral nutrients are exchanged for photosynthesis‐derived carbon (Wipf et al ., 2019; Shi et al ., 2023). Upregulation of specific plant transporters in arbuscule‐containing cells indicates that macronutrients are transferred mainly in inorganic forms, namely phosphate (Javot et al ., 2007), ammonium (Govindarajulu et al ., 2005; Guether et al ., 2009b), and sulfate (Casieri et al ., 2012; Giovannetti et al ., 2014).…”