Luyao Wang

Drought stress is a major abiotic factor that adversely affects plant growth, development, and crop productivity. Lipoxygenases (LOXs) are key enzymes in the jasmonic acid (JA) biosynthetic pathway and play crucial roles in plant responses to environmental stresses. In this study, the ZmLOX2 gene was cloned from maize (Zea mays L.), and was found to encode a chloroplast-localized 13-lipoxygenase (13-LOX) protein. Expression analysis revealed that ZmLOX2 was predominantly expressed in leaves and was strongly induced under osmotic stress conditions. Compared with wild-type plants, transgenic Arabidopsis thaliana overexpressing ZmLOX2 exhibited significantly higher survival rates, enhanced growth performance, and improved root development under water deficit conditions. Physiological and biochemical analyses showed that the overexpression lines displayed higher activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), accompanied by significantly reduced malondialdehyde (MDA) content and reactive oxygen species (ROS) accumulation. Further investigation demonstrated that the expression levels of JA biosynthesis- and signaling-related genes, including ALLENE OXIDE SYNTHASE (AtAOS), 12-OXOPHYTODIENOATE REDUCTASE 3 (AtOPR3), MYC DOMAIN PROTEIN 2 (AtMYC2), and JASMONATE ZIM-DOMAIN 1 (AtJAZ1), were markedly upregulated in the transgenic lines. Protein–protein interaction analysis suggested that ZmLOX2 may interact with ALLENE OXIDE SYNTHASE 1 (AOS1), HYDROPEROXIDE LYASE 1 (HPL1), and ALPHA-DIOXYGENASE 1 (DOX1). Collectively, these results suggest that ZmLOX2 may contribute to plant adaptation to water limitation by regulating responses associated with JA, enhancing antioxidant defense, and maintaining ROS homeostasis.

Sucrose phosphate synthase (SPS) is a key rate-limiting enzyme that regulates carbon partitioning and stress tolerance in plants. In this study, we systematically characterized the SPS gene family in maize (Zea mays L.) and identified key members and their interaction networks involved in drought responses. A total of seven ZmSPS genes were identified through genome-wide bioinformatics analyses. Motif composition, gene structure, phylogenetic relationships, and synteny analyses indicated that the ZmSPS gene family is highly conserved among monocot species. Promoter analysis revealed that the upstream regions of ZmSPS genes are enriched with multiple stress responsive cis-acting elements. Drought stress treatments combined with quantitative real-time PCR (RT-qPCR) analyses showed that the expression of ZmSPS3 was significantly upregulated with increasing stress duration. Furthermore, yeast two-hybrid assays demonstrated that ZmSPS3 physically interacts with protein kinases and F-box proteins. These interactions suggest a potential involvement of ZmSPS3 in post-translational modification and protein stability regulation during osmotic stress. As a potential candidate gene responsive to drought, ZmSPS3 provides a preliminary basis for understanding the complex drought-response networks in maize.

Background: Fatty acyl–ACP thioesterase (FAT) genes regulate fatty acid composition and content, yet the FAT family in maize has not been systematically characterized. Methods: Ten ZmFAT genes were identified from the maize genome and analyzed for gene structure, protein properties, phylogeny, collinearity, cis-acting elements, and predicted interactions. Transcriptome and qRT–PCR data were used to assess expression patterns during seed development. Results: The ten ZmFAT genes were grouped into two subfamilies (three ZmFATA and seven ZmFATB genes). Two pairs of collinear genes were detected within maize and one pair between maize and rice. Promoter analysis revealed light- and development-responsive elements. Two genes were functionally annotated in fatty acid biosynthesis, while five proteins exhibited interactions and 14 miRNAs were predicted to regulate ZmFAT genes. Expression analysis showed that ZmFATA1/2 and ZmFATB4/6/7 maintained high expression in both upper and lower seed parts, and qRT–PCR confirmed their gradual upregulation during seed development. Conclusion: This study provides the first comprehensive characterization of the maize ZmFAT family, offering insights into fatty acid metabolism and valuable genetic resources for improving maize oil composition.

Background/Objectives: Abiotic stresses impose significant constraints on crop growth, development, and yield. However, the comprehensive characterization of the maize (Zea mays) lipoxygenase (LOX) gene family under stress conditions remains limited. LOXs play vital roles in plant stress responses by mediating lipid oxidation and signaling pathways. Methods: In this study, 13 ZmLOX genes were identified in maize and characterized to explore their functions under abiotic stresses. Results: Phylogenetics revealed that ZmLOX genes share evolutionary origins with LOX genes in Arabidopsis and rice. Promoter analysis identified cis-acting elements associated with growth, light response, hormone signaling, and stress response, indicating their diverse biological roles. Gene Ontology (GO) and KEGG enrichment analyses showed that ZmLOX genes are involved in jasmonic acid metabolism, lipid signaling, and photosynthetic processes, while protein–protein interaction (PPI) analysis positioned ZmLOX proteins as central hubs in stress-related regulatory networks. Differential expression and qRT-PCR analyses revealed stress-specific (including heat, drought, salt, and cold) expression patterns, with ZmLOX2 and ZmLOX13 showing key roles in drought and cold tolerance, respectively. Conclusions: These findings provide new insights into the regulatory functions of ZmLOX genes, offering potential targets for enhancing maize resilience to abiotic stresses and improving agricultural productivity.