Hao et al. 2024 — Meta-analysis: arbuscular mycorrhizal fungi effects on arsenic in food crops
This meta-analysis synthesizes evidence from 76 publications on whether arbuscular mycorrhizal fungi (AMF) inoculation reduces arsenic (As) accumulation in food crops, particularly grain. The strategic relevance of AMF to food safety is that these root-colonizing fungi can alter phosphate (and hence arsenate, the phosphate analogue) transport in plants. The analysis covers shoot As, root As, and critically, grain As concentrations, providing a quantitative estimate of the magnitude of AMF-mediated As reduction achievable in agricultural practice.
Key numbers
- Meta-analysis scope: 76 publications, covering multiple food crop species (rice predominant, also wheat, soybean, maize)
- Overall As reduction in plant tissue: 19.3% mean reduction in total shoot/plant As under AMF inoculation vs. non-inoculated controls
- Grain As reduction: 34.1% mean reduction in grain As under AMF inoculation; this is the food-safety relevant metric
- Rice (Oryza sativa): largest evidence base; AMF effects on grain iAs not separately analyzed (total As reported in most primary studies)
- Mechanism: AMF colonization downregulates plant phosphate/arsenate transporters (particularly OsNIP2;1, OsPT family); simultaneously, AMF hyphae can immobilize As in rhizosphere
- Effect size heterogeneity: significant variation across studies; outcome dependent on soil As concentration, AMF species, crop variety, and soil type
- Publication: Frontiers in Plant Science; DOI: 10.3389/fpls.2024.1327649; CC BY license
- Study design: randomized pot/field experiments in primary studies; effect sizes calculated as Hedges’ d or log response ratio (lnRR)
Methods (brief)
Systematic literature search through PubMed, Web of Science, Google Scholar; inclusion criteria: primary studies with measurable As concentrations in plant material with and without AMF; meta-analysis using random-effects model; publication bias assessed by Begg’s and Egger’s tests; forest plots and funnel plots reported.
Implications
Certification: AMF inoculation is a documented agronomic mitigation lever for arsenic in grain crops, with a mean 34% reduction in grain As. This is a magnitude-order finding for the wiki’s mitigation pages. The effect is primarily in the agronomic/soil-biology intervention category, not a post-harvest processing lever.
Courses: Illustrates AMF-plant-arsenic interaction; useful for supply chain and agronomic lever module.
App: Grain arsenic contamination profiles reflect field conditions; AMF status is a grower-level variable not visible in ingredient labeling, but this meta-analysis establishes the theoretical reduction achievable.
Microbiome: AMF are root-associated fungi, not gut microbiome; not directly relevant to the wiki’s gut microbiome pages.