The APETALA2/ethylene response factor (AP2/ERF) family of transcription factors (TFs) is one of the largest and most important TF families in plants. This family plays a crucial role in regulating growth, development, and responses to both biotic and abiotic stresses. This study provides a comprehensive overview of the structure, classification, and distribution of AP2/ERF TFs in various plant species, with particular emphasis on their roles in responses to biotic stress. These findings provide valuable insights for future research on AP2/ERF TFs and their potential applications in crop improvement through molecular breeding.

Sugarcane, a C₄ plant, provides most of the world’s sugar, and a substantial amount of renewable bioenergy, due to its unique sugar-accumulating and feedstock properties. Brazil, India, China, and Thailand are the four largest sugarcane producers worldwide, and the crop has the potential to be grown in arid and semi-arid regions if its stress tolerance can be improved. Modern sugarcane cultivars which exhibit a greater extent of polyploidy and agronomically important traits, such as high sugar concentration, biomass production, and stress tolerance, are regulated by complex mechanisms. Molecular techniques have revolutionized our understanding of the interactions between genes, proteins, and metabolites, and have aided in the identification of the key regulators of diverse traits. This review discusses various molecular techniques for dissecting the mechanisms underlying the sugarcane response to biotic and abiotic stresses. The comprehensive characterization of sugarcane’s response to various stresses will provide targets and resources for sugarcane crop improvement.

Sugarcane is the most important sugar crop, contributing ≥80% to total sugar production around the world. Spodoptera frugiperda is one of the main pests of sugarcane, potentially causing severe yield and sugar loss. The identification of key defense factors against S. frugiperda herbivory can provide targets for improving sugarcane resistance to insect pests by molecular breeding. In this work, we used one of the main sugarcane pests, S. frugiperda, as the tested insect to attack sugarcane. Integrated transcriptome and metabolomic analyses were performed to explore the changes in gene expression and metabolic processes that occurred in sugarcane leaf after continuous herbivory by S. frugiperda larvae for 72 h. The transcriptome analysis demonstrated that sugarcane pest herbivory enhanced several herbivory-induced responses, including carbohydrate metabolism, secondary metabolites and amino acid metabolism, plant hormone signaling transduction, pathogen responses, and transcription factors. Further metabolome analysis verified the inducement of specific metabolites of amino acids and secondary metabolites by insect herbivory. Finally, association analysis of the transcriptome and metabolome by the Pearson correlation coefficient method brought into focus the target defense genes against insect herbivory in sugarcane. These genes include amidase and lipoxygenase in amino acid metabolism, peroxidase in phenylpropanoid biosynthesis, and pathogenesis-related protein 1 in plant hormone signal transduction. A putative regulatory model was proposed to illustrate the sugarcane defense mechanism against insect attack. This work will accelerate the dissection of the mechanism underlying insect herbivory in sugarcane and provide targets for improving sugarcane variety resistance to insect herbivory by molecular breeding.

High sugar content is the primary objective in sugarcane (Saccharum spp. hybrids) breeding. Plant microRNA 164 (miR164) plays pivotal roles in plant development and stress responses through the post-transcriptional regulation of its target genes. NAC transcription factors play a crucial role in various plant physiological processes. However, their role in sugar metabolism remains uncharacterized. Our previous work revealed the potential role of the shy-miR164 and a sugarcane NAC transcription factor (ScNAC) in sugar metabolism based on multiomics analysis. In this study, shy-miR164 and ScNAC exhibited an inverse regulatory relationship in sugarcane. Subsequent RLM-RACE and dual-luciferase assays confirmed that shy-miR164 regulates ScNAC expression through direct cleavage of its mRNA. Knockdown of miR164 using short tandem target mimic technology significantly enhanced sugar content in tomato (Solanum lycopersicum L.) fruits, whereas the opposite effect was observed in miR164-overexpressing plants, indicating its involvement in sugar metabolism. Furthermore, heterologous expression of ScNAC in tomato also enhanced fruit sugar content. Taken together, these findings reveal a previously unexplored role of shy-miR164 in sugar metabolism through the direct cleavage of its target gene ScNAC. This work advances our understanding of the mechanisms underlying sugar metabolism and provides candidate targets for improved sugar production in sugarcane through biotechnology.

Chilo sacchariphagus Bojer is an important sugarcane pest globally. Along with genetic modification strategies, the sterile insect technique (SIT) has gained more attention as an environment-friendly method for pest control. The identification of key genes associated with sex determination and differentiation will provide important basic information for this control strategy. As such, the transcriptome sequencing of female and male adults was conducted in order to understand the sex-biased gene expression and molecular basis of sex determination and differentiation in this species. A total of 60,429 unigenes were obtained; among them, 34,847 genes were annotated. Furthermore, 11,121 deferentially expressed genes (DEGs) were identified, of which 8986 were male-biased and 2135 were female-biased genes. The male-biased genes were enriched for carbon metabolism, peptidase activity and transmembrane transport, while the female-biased genes were enriched for the cell cycle, DNA replication, and the MAPK signaling pathway. In addition, 102 genes related to sex-determination and differentiation were identified, including the protein toll, ejaculatory bulb-specific protein, fruitless, transformer-2, sex-lethal, beta-Catenin, sox, gata4, beta-tubulin, cytosol aminopeptidase, seminal fluid, and wnt4. Furthermore, transcription factors such as myb, bhlh and homeobox were also found to be potentially related to sex determination and differentiation in this species. Our data provide new insights into the genetic elements associated with sex determination and differentiation in Chilo sacchariphagus, and identified potential candidate genes to develop pest-control strategies.

Improving nitrogen use efficiency (NUE) is essential for sustainable sugarcane production. Breeding high-NUE varieties enables high yields under low nitrogen (N) input, and identifying NUE-related genes is a critical step for molecular breeding. In this study, we compared two sugarcane genotypes, AS108 (high NUE) and GT11 (low NUE), under normal N (NN) and low N (LN) conditions. AS108 maintained significantly higher biomass, nitrogen content, and NUE under nitrogen limitation. Integrative analyses of enzyme activity, gene expression, and correlation networks indicated that its superior performance results from coordinated, organ-specific enhancement of nitrogen transport and assimilation. AS108 displayed consistently higher Glutamine synthetasec (GS) and glutamate synthase (GOGAT) activities, earlier and stronger induction of high-affinity transporters NRT2 and NRT2.2, and dynamic network reorganization under low nitrogen conditions. Network analysis identified NRT2/NRT2.2 as central hubs coupling nitrate uptake with GS/GOGAT-mediated assimilation. Notably, key nitrate transporter genes peaked 30–60 days earlier in AS108, highlighting the importance of temporal coordination. Together, these findings define a systems-level mechanism in which early-activated nitrate transport drives downstream assimilation to sustain growth under nitrogen limitation, providing molecular targets for breeding high NUE sugarcane cultivars.