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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Water Management Research » Research » Publications at this Location » Publication #397802
Research Project: Improving Soil and Water Productivity and Quality in Irrigated Cropping Systems

Location: Water Management Research

Title: Can Hg content in crops be controlled by Se fertilization? A meta-analysis and outline of Hg sequestration mechanisms

Author
item CHEN, JIEFEI - Southwest University
item Banuelos, Gary
item SHANGYAN, HAO - Southwest University
item ZHOU, XINBIN - Southwest University

Submitted to: Science of the Total Environment
Publication Type: Review Article
Publication Acceptance Date: 3/15/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Mercury (Hg) is a highly toxic heavy metal entering the human body through the food chain after absorption by plants. Selenium (Se) has a high affinity for Hg, which can form inert HgSe complexes with Hg in soil and plants, thus reducing the bioavailability of Hg. According to the previous literature, no consensus has been reached on selenium’s effect on Hg accumulation in plants. In this paper, 947 sets of data from 29 literatures were analyzed by meta-analysis, and the effects of exogenous Se on Hg accumulation in plants were studied from three aspects: Se properties, Se/Hg properties and Hg properties. The main mechanisms of Se in reducing Hg accumulation in rice was clarified based upon the effects of exogenous Se on Hg in soil and plants as follows: (1) exogenous Se reduced the Hg accumulation in most plants, rice and other plants by 27.26%, 24.13% and 32.17%, respectively; (2) exogenous Se (VI) better inhibited plant Hg accumulation than exogenous Se (IV); (3) exogenous Se (0.5-4 mg/kg) was most effective for inhibiting Hg accumulation in plants. In all cases, inorganic Hg (IHg) was more inhibited than methylmercury (MeHg). In rice, exogenous Se significantly inhibited the absorption and transport of Hg from roots to shoots, and thereby significantly reduced the Hg content in grains. The main mechanism of Se reducing Hg accumulation in rice may be the reduction of both bioavailability of Hg in soil and reduced absorption of Hg by roots and the transport of Hg from root to shoots. Overall, this is of great significance because the data analyzed show Se reduces Hg intake from the human diet, which improves human health by producing both low-Hg and Se-rich crops.