Overexpression of ZmPEBP Improves Drought Tolerance in Maize ( Zea mays <

ABSTRACT

Phosphatidylethanolamine‐binding proteins (PEBPs) play crucial roles in regulating plant responses to abiotic stress. In this study, we systematically investigated the maize PEBP gene family using transgenic technology and bioinformatics approaches. We identified the phylogenetic relationships of 25 PEBP genes in the maize genome and classified them into four subfamilies comprising five branches: MFT‐like, TFL1‐like, FT‐like‐1, FT‐like‐2 and PEBP‐like. Analysis of promoter cis‐regulatory elements revealed that ZmPEBP genes contain MYB‐binding sites associated with drought induction and response. Gene duplication and collinearity analyses identified 23 pairs of homologous PEBP genes between maize and rice, indicating that ZmPEBPs are closely related to OsPEBPs. Real‐time quantitative PCR results demonstrated that drought stress induced the differential expression of ZmZCN3, ZmZCN6, ZmZCN10, ZmZCN11, ZmPEBP, ZmZCN2, and ZmZCN17. Correlation analysis revealed that most PEBP genes exhibited expression patterns similar to those of the stress‐responsive transcription factors. Physiological and biochemical assessments revealed that compared with wild‐type plants, ZmPEBP‐overexpressing lines exhibited significantly higher germination rates, fresh weight and chlorophyll content, whereas malondialdehyde levels were significantly lower. In addition, the accumulation of reactive oxygen species, such as H ₂ O ₂ and O ₂ ⁻ , in the leaves decreased, resulting in enhanced drought tolerance. This study provides a comprehensive analysis of the maize ZmPEBP gene family, offering a theoretical foundation for the functional characterisation of drought tolerance within this gene family and guiding future research in this field.