Currently, the agricultural sector is one of the most affected by climate change, and the main challenge facing researchers is to find environmentally friendly and sustainable methods to cope with these issues. Plasma activated water (PAW) is considered a potential sustainable tool for improving plant tolerance to abiotic stress. Maize is regarded as one of the most important crops worldwide and plays a crucial role in global food security, especially in areas with harsh conditions. This study aimed to investigate potential structural changes of the leaf sheaths of two maize (Z. mays L.) landraces, SVGB-718 and SVGB-11742, grown in pots in a greenhouse for 28 days under two temperature regimes (normal, 22 °C; low, 4–9 °C for 7 days followed by 7 days of recovery) and irrigated with untreated water or PAW. Transverse sections of the leaf sheaths were analyzed after double staining with iodine green and ruthenium red. In all variants, the sheaths showed closed collateral vascular bundles scattered in the ground parenchyma, and no qualitative structural changes attributable to the treatments were detected. The only apparent difference was a visually more intense ruthenium red staining of the ground parenchyma in plants exposed to low temperature, regardless of the irrigation water. Because this stain binds acidic polysaccharides in general, and not only pectins, this observation may indicate a cold-related change in cell wall composition, which remains to be tested. No distinct histo-anatomical changes associated with PAW were detected by light microscopy in either accession.