Effects of arbuscular mycorrhizal fungi inoculation on arsenic accumulationby tobacco (Nicotiana tabacum L.)

A pot experiment was conducted to study the e ects of arbuscular mycorrhizal (AM) fungi (from contaminated or uncontaminatedsoils) on arsenic (As) uptake of tobacco (Nicotiana tabacum L.) in As-contaminated soil. Mycorrhizal colonization rate, dry weight,As and P uptake by plants, concentrations of water-extractable As and As fractions were determined. A low mycorrhizal colonizationrate (< 25%) was detected. Our research indicated that AM fungi isolated from polluted soils were no more e ective than those fromunpolluted soils when grown in symbiosis with tobacco. No significant di erences were observed in roots and stalks dry weights amongall treatments. Leaves and total plant dry weights were much higher in Glomus versiforme treatment than that in control treatment. Ascontents in roots and stalks from mycorrhizal treatments were much lower than that from control treatment. Total plant As contentexhibited the same trend. P concentrations in tobacco were not a ected by colonization, nor were stalks, leaves and total plant Pcontents. Roots P contents were remarkably lower in HN treatments than in other treatments. Meanwhile, decreased soil pH and lowerwater-extractable As concentrations and higher levels of As fraction bound to well-crystallized hydrous oxides of Fe and Al were foundin mycorrhizal treatments than in controls. The protective e ect of mycorrhiza against plant As uptake may be associated with changesin As solubility mediated by changing soil pH. These results indicated that under As stress, proper mechanisms employed by AM fungican protect tobacco against As uptake. Results confirmed that AM fungi can play an important role in food quality and safety.