More negative charges on roots enhanced manganese(II) uptake in leguminous and non‐leguminous poaceae crops

• Published in: Journal of the science of food and agriculture Vol. 103; no. 7; pp. 3531 - 3539
• Main Authors: Lu, Hai‐long, Nkoh, Jackson Nkoh, Xu, Ren‐kou, Dong, Ge, Li, Jiu‐yu
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.05.2023; John Wiley and Sons, Limited
• Subjects: Biological Transport; Calcium ions; Cations; Crops; Crops, Agricultural; Fabaceae; Functional groups; Hydroponics; Legumes; Magnesium; Manganese; Mn(II) chemical forms; Mn(II) sorption; Mn(II) uptake; negative charge; Plant Roots; Poaceae; Roots; Shoots; Soil; Soil solution; Streaming potential; Surface charge; Toxicity; Vegetables; Zeta potential; functional groups; Mn(II) sorption; Mn(II) chemical forms; Mn(II) uptake; plant roots; negative charge
• DOI: 10.1002/jsfa.12505
• ISSN: 0022-5142

BACKGROUND Manganese (Mn) is an essential micronutrient for plants, whereas excess Mn(II) in soils leads to its toxicity to crops. Mn(II) is adsorbed onto plant roots from soil solution and then absorbed by plants. Root charge characteristics should affect Mn(II) toxicity to crops and Mn(II) uptake by the roots of the crops. However, the differences in the effects of root surface charge on the uptake of Mn(II) among various crop species are not well understood. RESULTS The roots of nine legumes and six non‐legume poaceae were obtained by hydroponics and the streaming potential method and spectroscopic analysis were used to measure the zeta potentials and functional groups on the roots, respectively. The results indicate that the exchangeable Mn(II) adsorbed by plant roots was significantly positively correlated with the Mn(II) accumulated in plant shoots. Legume roots carried more negative charges and functional groups than non‐legume poaceae roots, which was responsible for the larger amounts of exchangeable Mn(II) on legume roots in 2 h and the Mn(II) accumulated in their shoots in 48 h. Coexisting cations, such as Ca2+ and Mg2+, were most effective in decreasing Mn(II) taken up by roots and accumulated in shoots than K+ and Na+. This was because Ca2+ and Mg2+ could compete with Mn(II) for active sites on plant roots more strongly compared to K+ and Na+. CONCLUSION The root surface charge and functional groups are two important factors influencing Mn(II) uptake by roots and accumulation in plant shoots. © 2023 Society of Chemical Industry.