The overexpression of ascorbate peroxidase 2 (APX2) gene improves drought tolerance in maize

Maize, a primary global food crop, is crucial for food security. In recent years, climatic and other abiotic stresses have led to frequent global droughts. Ascorbate peroxidase (APX) plays a vital role in the ascorbate-glutathione cycle. Under drought stress, APX effectively scavenges reactive oxygen species (ROS) produced by plants and maintains the normal growth and development of organisms. This study successfully amplified APX-related genes, and the ZmAPX2 gene was screened using expression analysis. pCAMBIA3301-ZmAPX2-Bar and pCXB053-ZmAPX2-Bar plant expression vectors were constructed and transformed into the maize inbred line H120. Drought tolerance of plants was analyzed by phenotypic characteristics, physiological and biochemical indices in T₂ generation positive maize seedlings as well as agronomic traits at maturity. Results indicate that boosting APX2 gene expression enhances maize drought resistance by reducing ROS content. This research underpins the exploration of new drought-tolerant maize germplasm and resistance mechanisms.

The online version contains supplementary material available at 10.1007/s11032-025-01548-2.