Sugarcane, a vital cash crop, contributes significantly to the world’s sugar supply and raw materials for biofuel production, playing a significant role in the global sugar industry. However, sustainable productivity is severely hampered by biotic and abiotic stressors. Genetic engineering has been used to transfer useful genes into sugarcane plants to improve desirable traits and has emerged as a basic and applied research method to maintain growth and productivity under different adverse environmental conditions. However, the use of transgenic approaches remains contentious and requires rigorous experimental methods to address biosafety challenges. Clustered regularly interspaced short palindromic repeat (CRISPR) mediated genome editing technology is growing rapidly and may revolutionize sugarcane production. This review aims to explore innovative genetic engineering techniques and their successful application in developing sugarcane cultivars with enhanced resistance to biotic and abiotic stresses to produce superior sugarcane cultivars.

Background: The MAP Kinase cascade system is a conserved signaling mechanism essential for plant development, growth, and stress tolerance. Thus far, genes from the MAPK cascade have been identified in several plant species but remain uncharacterized in the polyploid Saccharum spp. Hybrid R570 genome. Results: This study identified 89 ScMAPK, 24 ScMAPKK, and 107 ScMAPKKK genes through genome-wide analysis. Phylogenetic classification revealed that four subgroups were present in each ScMAPK and ScMAPKK family, and three sub-families (ZIK-like, RAF-like, and MEKK-like) presented in the ScMAPKKK family. Conserved motif and gene structure analysis supported the evolutionary relationships of the three families inferred from the phylogenetic analysis. All of the ScMAPK, ScMAPKK and ScMAPKKK genes were mapped on four scaffolds (Scaffold_88/89/91/92) and nine chromosomes (1–8, 10). Collinearity and gene duplication analysis identified 169 pairs of allelic and non-allelic segmentally duplicated MAPK cascade genes, contributing to their expansion. Additionally, 13 putative ‘ss-miRNAs’ were predicted to target 87 MAPK cascade genes, with ‘ssp-miR168a’ alone regulating 45 genes. qRT-PCR analysis revealed differential gene expression under abiotic stressors. ScMAPK07, ScMAPK66, and ScRAF43 were down-regulated and acted as negative regulators. Conversely, ScMAPKK13, ScRAF10, and ScZIK18 were up-regulated at specific time points under drought, with ScZIK18 exhibiting strong defense. Under NaCl stress, most genes were down-regulated, except for slight increases in ScZIK18 and ScMAPKK13, suggesting a positive role in salt stress response. Under CaCl₂ stress, five genes were significantly down-regulated, while ScRAF43 remained unchanged, reflecting their negative roles in stress adaptation and resource conservation. Conclusion: This study provides insights into MAPK cascade gene evolution and function in sugarcane, highlighting distinct regulatory roles in abiotic stress responses. Interestingly, some genes acted as negative regulators, serving as a mechanism to balance stress responses and prevent overactivation. In contrast, others contributed to defense mechanisms, offering potential targets for stress resilience improvement. Clinical Trail Number: This study contains no clinical trials. Not applicable.

Sugarcane, a key cash crop in tropical and subtropical regions, is primarily cultivated for sucrose and bioethanol. However, Sugarcane Leaf Scald Disease, caused by the Gram-negative bacterium Xanthomonas albilineans, significantly threatens global sugarcane production. This review examines the disease cycle, epidemics, host–pathogen interactions, integrated management strategies, and future prospects for combating leaf scald. It highlights advancements in understanding pathogenicity, immune responses, and sustainable management of bacterial plant diseases to enhance control and prevention efforts. An analysis of GenBank data revealed 21 strains of X. albilineans, with some featuring complete genome maps and varying guanine-cytosine (GC) content. Advanced genomic tools, including clustered regularly interspaced short palindromic repeats (CRISPR), and molecular techniques, such as polymerase chain reaction (PCR), enable accurate pathogen detection and facilitate the identification of resistance genes, aiding breeding programs. Recent progress in whole-genome sequencing and reduced costs have enabled the assembly of multiple X. albilineans genomes, enhancing bioinformatics analysis. Despite these advancements, research on the global genetic diversity of X. albilineans remains limited. Addressing this gap is crucial for developing more sustainable strategies to manage leaf scald, ensuring stable sugarcane yields and supporting global production. Further studies will strengthen efforts to mitigate this significant agricultural challenge.

The improvement of sucrose yield in sugarcane is impeded by the crop’s complex polyploid genome and slow progress in breeding. To clarify how arginine (Arg) regulates sugar metabolism and identify key genes associated with sucrose transport and accumulation in sugarcane, a screening experiment was performed by spraying L-arginine hydrochloride on the leaves and leaf sheaths of three sugarcane varieties (YZ05-51, YZ08-1609, and YT93-159), which differ in growth vigor, leaf morphology and other phenotypic traits. YZ05-51 exhibited the most prominent sugar-increasing effect, and subsequent optimization experiments on its leaf sheaths revealed that 20 g/mu L-arginine hydrochloride at pH 7.0 was optimal, significantly enhancing stem sucrose content. Transcriptomic analysis revealed the upregulation of genes related to sucrose synthesis and transport, with candidate genes enriched in pathways such as starch-sucrose metabolism, glycolysis/gluconeogenesis, and ATP-binding cassette (ABC) transporters. Metabolomic analysis detected 32 sugar metabolites across three categories, of which 24 were differentially abundant (e.g., glucose, galactose, fructose, and mannose). Integrated multi-omics analysis identified key regulatory genes, including SBEs and TPS1 (sucrose synthesis and carbon flux regulation), RBSK, α-amylases, GH28 (starch breakdown, glycolysis, and sugar mobilization), ABC transporters, GTs, and TIM10/TIM12 (sucrose transporter). Collectively, these analyses demonstrate enhanced activity of genes and metabolites involved in sucrose synthesis/transport in leaf sheaths, accompanied by reduced synthesis of other monosaccharides and oligosaccharides. Vigorously metabolizing leaf sheaths is more conducive to sucrose transport. This study provides valuable insights into the molecular mechanisms underlying Arg-mediated sucrose accumulation specifically in the sugarcane YZ05-51 sugarcane, highlighting its critical regulatory roles.

Fructose-1,6-bisphosphatase (FBP) is a crucial regulatory enzyme in sucrose synthesis and photosynthetic carbon assimilation, functioning through two distinct isoforms: cytosolic FBP (cyFBP) and chloroplastic FBP (cpFBP). However, the identification and functional characterization of FBP genes in Saccharum remains limited. In this study, we conducted a systematic identification and comparative genomics analyses of FBPs in three Saccharum species. We further examined their expression patterns across leaf developmental zones, spatiotemporal profiles, and responses to diurnal rhythms and hormonal treatments. Our analysis identified 95 FBP genes, including 44 cyFBPs and 51 cpFBPs. Comparative analyses revealed significant divergence in physicochemical properties, gene structures, and motif compositions between the two isoforms. Expression profiling indicated that both cyFBPs and cpFBPs were predominantly expressed in leaves, particularly in maturing and mature zones. During diurnal cycles, their expression peaked around the night–day transition, with cpFBPs exhibiting earlier peaks than cyFBPs. FBP genes in Saccharum spontaneum displayed greater diurnal sensitivity than those in Saccharum officinarum. Hormonal treatments further revealed significant regulatory divergence in FBP genes, both between isoforms and across species. Notably, cyFBP_2 and cpFBP_2 members consistently exhibited higher expression levels across all datasets, suggesting their pivotal roles in sugarcane physiology. These findings not only identify potential target genes for enhancing sucrose accumulation, but also highlight the breeding value of S. spontaneum and S. officinarum in sugarcane breeding.

The spontaneous adventitious bud (SAB) mutant of sugarcane, which forms clustered buds on the stem, provides a unique system for elucidating the mechanisms underlying in vivo regeneration and plant meristem differentiation anomalies. The present study investigated the mechanism underlying SAB formation in the sugarcane mutant 'YZ2018-81' through an integrated approach combining histological analysis, endogenous hormone profiling, and RNA-sequencing. Histological analysis revealed that the adventitious buds originated from the dedifferentiating cortical parenchyma cells, following a developmental sequence of dedifferentiation, proliferation, callus-like protrusion formation, and bud differentiation. Further profiling of the endogenous hormones revealed significantly elevated levels of trans-zeatin (tZ) in the second internode below the shoot apical meristem (SAM) (the 2nd IN) and upper stem nodes (the sixth internode below the SAM, the 6th IN), respectively, abscisic acid (ABA), and auxin (IAA) but lower levels of isopentenyladenine (IP) and jasmonic acid (JA) in SAB than in CK, suggesting synergistic roles for tZ, IAA, and ABA in bud initiation, and the inhibitory role of JA in cell division. Meanwhile, elevated gibberellin (GA₃) in the 6th IN indicated its participate in promoting bud elongation in the SAB mutant. Transcriptome analysis identified 20,858 differentially expressed genes (DEGs) in the samples, including upregulated genes such as meristem development regulators (RS1, REL2, and DCL), hormone signaling components (ARFs and RRs), and regeneration factors (GRF10, PLT2, and CYCD2-2). These DEGs were enriched in "plant hormone signal transduction" and "MAPK signaling pathway". The heterologous overexpression of ScGRF10 in rice induced ectopic roots at stem nodes, confirming its involvement in ectopic organogenesis. Our work elucidates the cellular, hormonal, and transcriptional framework of in vivo bud regeneration in sugarcane. The mutant also serves as a novel model for monocot regeneration and valuable genetic resources for enhancing sugarcane biotechnology.