Single and combined effect of tetracycline and polyethylene microplastics on two drought contrasting cultivars of Oryza sativa L. (Rice) under drought stress

Co-exposure of tetracycline (TC) and polyethylene microplastic (MP-PE) pollution might result in more intricate effects on rice growth and grain quality. In present study, two different rice cultivars of contrasting drought tolerance, Hanyou73 (H73, drought-resistant) and Quanyou280 (Q280, drought-sensitive) were grown on MP-PE and TC-contaminated soils under drought. It was found that drought stress had different influence on TC accumulation in the two rice cultivars. H73 accumulated more TC in leaves and grains without drought stress while Q280 accumulated more TC under drought stress. Furthermore, metabolomics results demonstrated that under drought stress, about 80 % of metabolites in H73 and 95 % in Q280 were down-regulated as compared to non-drought treatments. These findings provide insights into the effects of TC and MP-PE with and without drought stress on potential risks to rice growth and grain quality, which has implications on rice production and cultivar election under multiple-stress conditions.