Fuente: PubMed "plant biotechnology" Int J Biol Macromol. 2025 Dec 13:149669. doi: 10.1016/j.ijbiomac.2025.149669. Online ahead of print.ABSTRACTArsenic (AsIII) and cadmium (CdII) are among the most toxic environmental pollutants that frequently co-occur in contaminated soils, due to industrial and agricultural activities. While their individual toxic effects are well-documented, their combined effects remain poorly understood. The present study deals with UV-Vis-NIR spectroscopy-based interaction studies of AsIII, CdII and AsIII + CdII, independently with plant genomic DNA under aqueous conditions. While the DNA spectral pattern at 260 nm remained unchanged with AsIII or CdII, significant hyperchromic shift was observed under AsIII + CdII, suggesting a synergistic response in terms of base pair unstacking and helix destabilization. The cleavage pattern obtained with restriction enzyme HindIII revealed that DNA accessibility under AsIII + CdII was significantly different than AsIII and CdII and comparable to those of control, indicating either the competitive binding or AsIII + CdII complexation. The AsIII + CdII interaction was further supported by bimodal DNA surface-charge distribution. The post-germination phenotyping highlighted antagonistic growth responses under AsIII + CdII, wherein the whole seedling biomass in the model plant Arabidopsis thaliana was comparable to those of AsIII-alone, while maximal growth reduction was seen under CdII treatment. Interestingly, the accumulation of total As and Cd remained unchanged, suggesting that AsIII and CdII interaction did not affect their uptake potential by the plants. Further, the AsIII + CdII growth antagonism was limited to only 1:1 ratio till 50 μM concentration, beyond which the co-exposure led to synergistic toxicity. Taken together, the study provided evidence about 'effect modification' under AsIII + CdII in terms of altered DNA interaction and weakened accessibility, thereby explaining AsIII + CdII antagonism in plants.PMID:41397594 | DOI:10.1016/j.ijbiomac.2025.149669