Abstract
There is an increasing need to develop high-yielding, disease-resistant crops and reduce fertilizer usage. Combining disease resistance with efficient nutrient assimilation through improved associations with symbiotic microorganisms would help to address this. Arbuscular mycorrhizal fungi (AMF) form symbiotic relationships with most terrestrial plants, resulting in nutritional benefits and the enhancement of stress tolerance and disease resistance. Despite these advantages, arbuscular mycorrhizal (AM) interactions are not normally directly considered in plant breeding. Much of our understanding of the mechanisms of AM symbiosis comes from model plants, which typically exhibit positive growth responses. However, applying this knowledge to crops has not been straightforward. In many crop plants, phosphate uptake and growth responses in AM-colonized plants are variable, with AM plants exhibiting sometimes zero or negative growth responses and lower levels of phosphate acquisition. Host plants must also balance the ability to host AMF with the ability to resist pathogens. Advances in understanding the plant immune system have revealed similarities between pathogen infection and AM colonization that may lead to trade-offs between symbiosis and disease resistance. This review considers the potential trade-offs between AM colonization, agronomic traits and disease resistance and highlights the need for translational research to apply fundamental knowledge to crop improvement.
Highlights
Arbuscular mycorrhizal (AM) symbioses are formed between the majority of land plants and members of the ancient and diverse phylum of fungi, the Glomeromycota [1,2]
The negative relationship between MP and direct pathway (DP) may explain arbuscular mycorrhizal (AM)-induced depressions in plant growth which have often been attributed to fungal “cheats”, i.e., Arbuscular mycorrhizal fungi (AMF) species that do not provide adequate phosphate in exchange for host plant carbon [108,109]
Phylogenomic studies have shown an MLO family member to be conserved for AM symbiosis [136]. These findings suggest that MLO is shared by the symbiont-response and powdery mildew infection pathways (Figure 2)
Summary
Arbuscular mycorrhizal (AM) symbioses are formed between the majority of land plants and members of the ancient and diverse phylum of fungi, the Glomeromycota [1,2] This relationship supplies water and nutrients, phosphate [3] and nitrogen (ammonium) [4] and other metals and salts including zinc [5,6], to the host plant. Extends beyond the depletion zone (grey), accessing a greater arbuscular mycorrhizal fungi (AMF) extends beyond the depletion zone (grey), accessing a greater area of of soil soil for for phosphate phosphate uptake. Benefits of AM symbiosis include improved tolerances to many abiotic (mainly salt and drought) [28,29] and biotic stresses (mainly soil-borne pathogens) [30,31] (Table 1; Figure 1). Heluta [91], Phytophthora palmivora
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
