Zhang et al. 2026 - AMF and calcium mitigation of arsenic stress in cotton seedlings

Zhang and colleagues tested whether arbuscular mycorrhizal fungi and exogenous calcium could reduce arsenate stress in cotton seedlings. This is mitigation and supply-chain agronomy evidence for cotton grown on arsenic-contaminated soil, not finished-product occurrence evidence for fabric or child-product rows. The paper supports the mitigation layer because the combined fungal and calcium treatment improved growth, root architecture, photosynthetic performance, osmotic regulation, antioxidant activity, and potassium/calcium balance under arsenate stress.

Key numbers

• Experimental design: 2 x 2 x 2 pot experiment crossing non-mycorrhizal vs. Funneliformis mosseae inoculated seedlings, 0 vs. 100 mg As(V)/kg dry soil, and 0 vs. 20 mmol/L exogenous CaCl2. The eight treatments had three replicates each, for 24 pots total.
• Arsenic stressor: sodium arsenate dodecahydrate was mixed into soil to reach 100 mg As5+/kg dry soil.
• Soil mixture before treatment: 50.52 g/kg organic matter, 83.35 mg/kg available potassium, 40.52 mg/kg available nitrogen, 8.17 mg/kg Olsen phosphorus, and pH 7.8.
• Mycorrhizal colonization: F. mosseae colonization rates were 74.35% under non-arsenic/no-calcium conditions, 78.02% under non-arsenic/calcium conditions, and 64.03% under arsenic stress with or without calcium.
• Under arsenic stress, AMF inoculation increased plant height by 28.05% without added calcium and 15.18% with added calcium.
• Under arsenic stress, AMF inoculation increased shoot dry weight by 26.64% without added calcium and 38.78% with added calcium.
• Under arsenic stress, AMF inoculation increased root dry weight by 53.57% without added calcium and 51.43% with added calcium.
• Under arsenic stress, calcium application increased plant height by 14.20% in non-mycorrhizal seedlings and 4.43% in mycorrhizal seedlings.
• Under arsenic stress, calcium application increased shoot dry weight by 12.83% in non-mycorrhizal seedlings and 23.64% in mycorrhizal seedlings.
• Under arsenic stress, calcium application increased root dry weight by 20.69% in non-mycorrhizal seedlings and 23.26% in mycorrhizal seedlings.
• Three-way ANOVA found significant As x AMF x Ca2+ interactions for plant height, shoot dry weight, root area, net photosynthetic rate, intercellular CO2 concentration, Fv/Fm, PhiPSII, soluble sugar in leaf and root, soluble protein in leaf and root, and several antioxidant or ion-balance endpoints.

Methods (brief)

Cotton seeds of the DaLing cotton 69 variety were grown in sterilized soil/sand/organic matter mixture under greenhouse conditions. AMF-inoculated pots received 30 g of F. mosseae inoculum 5 cm below the seeds, while non-AMF pots received a filtered microbial suspension to better match non-mycorrhizal microbial exposure. Arsenic was applied before planting as Na3AsO4 * 12H2O; calcium treatments received 20 mmol/L CaCl2 in Hoagland solution and later foliar CaCl2 applications.

The study measured mycorrhizal colonization, plant height, shoot and root dry weights, root morphology, photosynthetic gas exchange, chlorophyll fluorescence, osmotic regulators, antioxidant enzymes, malondialdehyde, and K+/Ca2+ status. It does not report finished cotton fiber arsenic concentrations, and the arsenic exposure is an experimental arsenate-spiked-soil stress model.

Implications

Certification: The source should not enter occurrence benchmark pools for textiles, fabric-contact products, or child durables. Its values are intervention/stress-response evidence for arsenic-contaminated cotton supply chains.

Courses: Useful case study for distinguishing an agronomic mitigation lever from product occurrence data. The same source can be relevant to HMTc risk controls without contributing concentration values to product thresholds.

App: Potential future supply-chain note for cotton-derived materials: AMF plus calcium is a candidate agronomic lever for arsenic-stressed cotton, but the study is greenhouse-scale and not a consumer-product test.

Microbiome: The relevant microbial system is plant-root mycorrhiza, not the human or product microbiome.

Wiki pages this source may touch

• agronomic
• remediation-evidence
• fabric-contact-products-other
• arsenic-inorganic
• arsenic

Verification notes

• DOI, title, authors, journal, year, license, arsenate dose, calcium dose, replicate count, and growth-response percentages were transcribed from the PDF.
• The auto-fetch filename mapped this source to walkers, but the paper is about cotton seedlings. The page routes it to cotton/fabric-contact supply-chain context rather than to walkers as a finished child-durable occurrence source.
• Arsenic was applied as arsenate, an inorganic arsenic species. The page therefore uses iAs in frontmatter and does not substitute the greenhouse arsenate-stress dose for total arsenic in finished cotton products.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.