Li, Q. X. | Search bioRxiv

bioRxiv2026

Single-cell RNA sequencing uncovers cell-type-specific reprogramming of water-channel and cell-wall genes in PFOA uptake by lettuce root tips

Per- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants that accumulate in edible crops, posing threats to food safety and human health. Breeding varieties with reduced PFAS accumulation offers a promising mitigation strategy, yet the underlying cellular mechanisms remain elusive. Here, we integrated short- and long-read single-cell RNA sequencing to generate a high-resolution transcriptomic atlas of lettuce (Lactuca sativa L.) root tips, comparing varieties with contrasting perfluorooctanoic acid (PFOA) accumulation capacities. Our analyses uncovered a synergistic mechanism underlying PFOA uptake: up-regulation of aquaporin genes in epidermal and xylem cells, coupled with down-regulation of cell-wall biosynthesis genes specifically in epidermal and xylem. Furthermore, we identified distinct RNA isoforms-including variants with altered coding potential-that may contribute to PFOA transport and deposition through structural modulation of the encoded proteins. This study represents the first application of single-cell sequencing to elucidate the cellular and molecular basis of crop responses to PFOA, providing new insights into pollutant-crop interactions and informing strategies for sustainable agriculture and food safety.

plant biology↗

bioRxiv2022

Benzopyrene biodegradation by multiple and individual mesophilic bacteria in axenic conditions and in soil samples

Thus far, only a handful of bacterial strains that can independently degrade and utilize benzo[a]pyrene (BaP) as the sole carbon source have been isolated and characterized. Here, three new bacterial strains, JBZ1A, JBZ2B, and JBZ5E, were isolated from contaminated soil and, using 16S rRNA sequencing, were identified as Bradyrhizobium japonicum, Micrococcus luteus, and Bacillus cereus, respectively. The growth ability of each individual strain and a consortium of all strains in the presence of BaP (4-400 {micro}mol{middle dot}l-1, pH 7, 37{degrees}C) was identified by the doubling time (dt). The results illustrated that dt decreased with increasing BaP concentrations for individual strain and the consortium. The optimum growth conditions of the consortium were 37{degrees}C, 0.5% NaCl (w/v), and pH 7. Under these conditions, the degradation rate was 1.06 {micro}mol{middle dot}l-1{middle dot}day-1, whereas that of individual strains ranged 0.9-0.38 {micro}mol{middle dot}l-1{middle dot}day-1. B. cereus had the strongest contribution to the consortiums activity, with a degradation rate of 0.9 {micro}mol{middle dot}l-1{middle dot}day-1. The consortium could also remove BaP spiked with soil, but at a lower rate (0.01 {micro}mol.l-1.day-1). High-performance liquid chromatography-high-resolution tandem mass spectrometry permitted the detection of the metabolites of these strains, and a biodegradation pathway has been proposed.

microbiology↗