Publisher: China Science Daily

Date: April 11, 2025

Recent research led by Professor Wei Weihui and Xiang Lei's team at Jinan University has unveiled, for the first time, the mechanisms by which microorganisms derived from seeds influence the absorption and accumulation of organic pollutants in crops. The study highlighted that low molecular weight organic acids secreted by plant roots are crucial in driving the vertical transfer effects of these microorganisms, playing a significant regulatory role in the crop's uptake of antibiotics. The findings were published in the journal Microbiome.

(Screenshot of the paper)

Background:

The accumulation of antibiotics in crops poses a serious threat to human health. However, the specific mechanisms and effects of microorganisms on the uptake and accumulation of these pollutants remain largely unstudied. This research investigates how seed-borne microbiota in roots impacts the accumulation of ciprofloxacin (CIP) in two varieties of choy sum through amplicon sequencing, statistical analyses, and validation of key bacterial species via isolation and co-culturing with plants.

Results:

The study found that Bacillaceae (primarily Bacillus species) were specifically enriched in the roots of a high-antibiotic accumulator variety (HAV) through vertical transmission activated by maleic acid derived from root exudates. The relative abundance of Bacillaceae in HAV roots was found to be 9.2 to 27.7 times higher than that in the low-antibiotic accumulating variety (LAV). This enrichment supported the formation of a beneficial bacterial community through deterministic processes. The microbiota in HAV not only stimulated antioxidative activities and reduced membrane lipid peroxidation by secreting indoleacetic acid and siderophores but also promoted increased root biomass, significantly enhancing the variety's tolerance to and absorption of CIP. Consequently, the plant-microbial interactions unique to HAV led to a 1.6- to 3.2-fold increase in CIP accumulation in shoots compared to LAV.

Conclusions:

This research underscores the vital role of seed-borne microbiota in influencing the uptake and accumulation of antibiotics in crops, providing new insights into the accumulation of organic pollutants in plants with an emphasis on plant-microbial interactions. Given that antibiotics are prevalent pollutants entering the environment from agricultural and healthcare applications, their detection in farmland soils and subsequent absorption by crops presents risks to agricultural safety and public health. Identifying and cultivating crop varieties that exhibit low pollutant accumulation is a critical strategy for ensuring the safe utilization of polluted soil.

The research team, supported by significant projects such as the National Natural Science Foundation of China, was the first to successfully screen and identify low accumulation varieties (LAVs) of ciprofloxacin in typical leafy vegetable crops, including cabbage within the Pearl River Delta environment. The study provides preliminary insights into the physiological, biochemical, and molecular mechanisms behind these low-accumulation varieties, emphasizing the vital yet previously unclear role of microorganisms in pollutant absorption by crops.

For more extensive information, the related paper can be accessed at: https://doi.org/10.1186/s40168-025-02073-2.