Genotype-specific water-use strategies in wild-type and bar-transgenic Arabidopsis thaliana under continuous graphene...

Graphene oxide (GO) exposure presents new opportunities for enhancing plant water management, but its interactions with diverse genetic backgrounds remain poorly understood. Specifically, the impact of GO exposure on genetically modified (GM) crops, which are currently cultivated worldwide, remains largely unstudied. We treated wild-type (WT) and bar-GM Arabidopsis thaliana with 0.75 and 1.5 mg-C/L GO throughout their life cycles. GO promoted growth in both genotypes, with GM plants achieving 1.43 times greater fresh weight and 1.69 times higher root weight than WT under the same conditions, demonstrating improved water-use efficiency. WT plants overactivated vascular transport, characterized by elongated root hairs, enlarged xylem vessels, and enhanced abscisic acid-mediated stomatal control-resulting in localized hypoxia. In contrast, GM plants fine-tuned apoplastic water pathways through controlled cell wall loosening and increased antioxidant capacity, thereby maintaining an optimal water-oxygen balance and minimizing wound-like stress. Intrinsic cell-wall-integrity signaling, shaped by each plant's genetic features, governs the different water-uptake strategies seen in WT versus GM plants. Whole-genome and targeted bisulfite analyses confirmed stable bar inheritance and hypermethylation of the bar coding region. The altered methylation in cell-wall genes suggested transgenerational epigenetic modulation of GO exposure. Collectively, our findings demonstrate that genotype-tailored GO exposure can precisely modulate plant hydraulics, paving the way for sustainable, water-efficient crop production.