Transcriptomics and Ionomics Reveal Arsenic Transport and Detoxification Pathways in Wheat (Triticum aestivum) Genotypes

Arsenic (As) is a toxic contaminant of global concern as it poses risks to public health when consumed through cereals, including wheat. However, the relationship between the ionomic and transcriptomic responses to As in wheat to decipher As detoxification is poorly understood. The present study delivers a comprehensive report on transcriptomics level regulations integrated with ionomic data, and morphological traits to highlight growth impacts, As transport, and As detoxification. Four Wheat genotypes were exposed to arsenate treatments (0, 100, 200, and 400 mg/L) in a hydroponic experiment for 30 days. Growth traits, chlorophyll index, total nitrogen index, secondary metabolites, and elemental concentration were determined. Based on the findings, two genotypes (BARANI-70 and NARC-2009) were selected for a second hydroponic experiment (control vs 200 mg/L), and transcriptomics analysis was carried out on the roots. The As treatment resulted in significant differences in root As, copper (Cu), and manganese (Mn), and shoot As and selenium (Se) concentrations between the control plants and treated plants. A total of 2263 DEGs and 2148 DEGs were identified in the roots of BARANI-70 and NARC-2009 (p ≤ 0.01, log2FC ± 1), respectively, when the control plants and treated plants were analysed. Gene ontology revealed significant upregulation of glutathione metabolism (glutathione-S-transferase) in both genotypes under As treatment, while the MAPK signalling pathway was negatively regulated in both genotypes in response to the As treatment. The integration of ionomics and transcriptomics provided a deeper understanding of the molecular pathways of As detoxification in wheat.