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.

Improvement of sugarcane is hampered due to its narrow genetic base, and the difficulty in synchronizing flowering further hinders the exploitation of the genetic potential of available germplasm resources. Therefore, the continuous evaluation and optimization of flowering control and induction techniques are vital for sugarcane improvement. In view of this, the review was conducted to investigate the current understanding of photoperiodic and lighting treatment effects on sugarcane flowering and its genetic regulation. Photoperiod facilities have made a significant contribution to flowering control in sugarcane; however, inductive photoperiods are still unknown for some genotypes, and some intended crosses are still impossible to produce because of unresponsive varieties. The effectiveness of lower red/far-red ratios in promoting sugarcane flowering has been widely understood. Furthermore, there is vast potential for utilizing blue, red, and far-red light wavelengths in the flowering control of sugarcane. In this context, light-emitting diodes (LEDs) remain efficient sources of light. Therefore, the combined use of photoperiod regimes with different light wavelengths and optimization of such treatment combinations might help to control and induce flowering in sugarcane parental clones. In sugarcane, FLOWERING LOCUS T (ScFT) orthologues from ScFT1 to ScFT13 have been identified, and interestingly, ScFT3 has evidently been identified as a floral inducer in sugarcane. However, independent assessments of different FT-like gene family members are recommended to comprehensively understand their role in the regulation of flowering. Similarly, we believe this review provides substantial information that is vital for the manipulation of flowering and exploitation of germplasm resources in sugarcane breeding.

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.

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.