Plants in their natural habitat frequently face different biotic and abiotic stresses, which lead to the production of reactive oxygen species (ROS) that can damage cell membranes, cause peroxidation and deterioration of macromolecules, and ultimately result in cell death. Superoxide dismutase (SOD), a class of metalloenzymes, is primarily found in living organisms and serves as the principal line of defense against ROS. The SOD gene family has not yet been characterized in any species of water lily from the genus Nymphaea. The present study aims to conduct a genome-wide study to discover SOD genes in four representative water lily species. In our present comparative study, we discovered 43 SOD genes in the genomes of four water lily species. The phylogenetic investigation results revealed that SOD genes from water lily and closely related plant species formed two distinct groups, as determined by their binding domains with high bootstrap values. Enzymatic ion-binding classified the SOD gene family into three groups, FeSOD, Cu/ZnSOD, and MnSOD. The analysis of gene structure indicated that the SOD gene family exhibited a relatively conserved organization of exons and introns, as well as motif configuration. Moreover, we discovered that the promoters of water lily SODs contained five phytohormones, four stress-responsive elements, and numerous light-responsive cis-elements. The predicted 3D protein structures revealed water lily SODs form conserved protein dimer signatures that were comparable to each other. Finally, the RT-qPCR gene expression analysis of nine NcSOD genes revealed their responsiveness to heat, saline, cold, cadmium chloride, and copper sulphate stress. These findings establish a basis for further investigation into the role of the SOD gene family in Nymphaea colorata and offer potential avenues for genetic enhancement of water lily aquaculture.

In flowering plants, fertilization is a complex process governed by precise communication between the male and female gametophytes. This review focuses on the roles of various female gametophyte cells—synergid, central, and egg cells—in facilitating pollen tube guidance and ensuring successful fertilization. Synergid cells play a crucial role in attracting the pollen tube, while the central cell influences the direction of pollen tube growth, and the egg cell is responsible for preventing polyspermy, ensuring correct fertilization. The review also examines the role of the pollen tube in this communication, highlighting the mechanisms involved in its growth regulation, including the importance of pollen tube receptors, signal transduction pathways, cell wall dynamics, and ion homeostasis. The Ca²⁺ concentration gradient is identified as a key factor in guiding pollen tube growth toward the ovule. Moreover, the review briefly compares these communication processes in angiosperms with those in non-flowering plants, such as mosses, ferns, and early gymnosperms, providing evolutionary insights into gametophytic signaling. Overall, this review synthesizes the current understanding of male–female gametophyte interactions and outlines future directions for research in plant reproductive biology.

Nuclear Factor Y (NF-Y) transcription factors are evolutionarily conserved regulators that bind the CCAAT box, playing central roles in horticultural plant growth and adaptation. This review summarizes recent progress on NF-Ys in horticultural plants, focusing on their molecular mechanisms in development and stress responses. For development, NF-Ys mediate phase transition, flowering regulation, embryogenesis, and organ development by integrating endogenous signals (gibberellic acid, GA; abscisic acid, ABA) and regulating downstream genes. For stress responses, they enhance tolerance to abiotic stresses (drought, salt, extreme temperatures) via regulating reactive oxygen species (ROS) scavenging, ABA biosynthesis, and stress networks, and mediate biotic stress resistance (e.g., pathogen infection) by activating defense pathways. This review also briefly covers species-specific genomic features (e.g., duplication-driven expansion) and structural traits (conserved core domains, variable termini) underpinning NF-Y specialization. Finally, it highlights key knowledge gaps (e.g., incomplete regulatory networks, limited translational application) and proposes future directions: deciphering NF-Y crosstalk, exploring combined stress responses, accelerating functional validation of uncharacterized NF-Y genes, and translating research into horticultural breeding. This work provides a holistic reference for understanding NF-Y function and improving horticultural plant yield, quality, and stress resilience.

GATA transcription factors are crucial for plant development and environmental responses, yet their roles in plant evolution and root nodule symbiosis are still not well understood. This study identified GATA genes across the genomes of 77 representative plant species, revealing that this gene family originated in Charophyta and significantly expanded in both gymnosperms and angiosperms. Phylogenetic analyses, along with examinations of conserved motifs and cis-regulatory elements in Glycine max and Arabidopsis, clearly demonstrated structural and functional divergence within the GATA family. Chromosomal mapping and synteny analysis indicated that GATA gene expansion in soybean primarily resulted from whole-genome duplication events. These genes also exhibit high conservation and signs of purifying selection in Glycine max, Lotus japonicus, and Medicago truncatula. Furthermore, by integrating phylogenetic and transcriptomic data from eight nitrogen-fixing legume species, several GATA genes were identified as strongly co-expressed with NIN1, suggesting their potential co-regulatory roles in nodule development and symbiosis. Collectively, this study offers a comprehensive overview of the evolutionary dynamics of the GATA gene family and highlights their potential involvement in root nodule symbiosis in legumes, thus providing a theoretical foundation for future mechanistic studies.

AGL6 genes are critical floral regulators in diverse angiosperms, yet their roles in legumes remain poorly understood. This study aimed to characterize GmAGL6 genes in soybean (Glycine max [L.] Merr. cv. Williams 82). We identified four homologs (GmAGL6a–d) featuring conserved MADS-box and K-box domains that cluster within the AGL6 lineage. Tissue-specific expression profiling revealed significant transcript enrichment during flower bud differentiation and maturation. Using CRISPR/Cas9, we generated quadruple knockout lines to evaluate gene function. Phenotypic analysis showed that, unlike the homeotic transformations typical of AGL6 loss in monocots, Gmagl6 quadruple mutants retained a standard papilionaceous floral structure without keel petal aberrations. However, the mutants did not show significant changes in floral height or width, but exhibited a significantly increased floral height-to-width ratio and smaller mature seeds, while vegetative architecture and podding capacity remained unaffected. These results suggest that GmAGL6 genes in soybean may function primarily in the regulation of floral proportion and seed development rather than floral organ identity. This research provides insights into the evolution of specialized legume flowers and suggests candidate genes for seed size improvement.

The fusion of keel petals is a defining trait of Papilionoideae flowers, contributing to floral architecture and promoting self-pollination but hindering hybridization in crops like soybean. Here, we investigated the cellular and molecular basis of keel petal fusion in Glycine max (L.) Merr. cv. Jack using anatomical and transcriptomic approaches. Microscopy revealed that keel petal fusion involves marginal cell reshaping and postgenital adhesion with defective cuticle continuity, consistent with fusion modes in other Papilionoideae species. Comparative transcriptome analysis between fused and unfused petal stages identified 23,328 differentially expressed genes, with lipid and cuticle metabolism genes showing coordinated downregulation during fusion. A set of 384 keel-enriched genes was identified, among which a previously uncharacterized gene, KPEG1 (Keel Preferential Expression Gene 1), was preferentially expressed in fused keel petals. Protein interaction network analysis revealed that KPEG1 co-expresses with epigenetics-related genes, suggesting a regulatory role in fusion through chromatin-mediated mechanisms. These findings uncover the cellular dynamics and transcriptional reprogramming underlying keel petal fusion in soybean and provide a candidate regulator for further functional studies.