Sucrose Metabolism and Accumulation in Sugarcane Systems

Sugarcane serves as the world’s foremost source of sucrose, underpinning both the global sugar industry and bioethanol production. In leaves, photosynthetically derived triose phosphates are channelled into sucrose biosynthesis via sequential activity of sucrose phosphate synthase (SPS) and sucrose phosphate phosphatase (SPP). The resulting sucrose is loaded into phloem vessels and translocated to stem internodes, where unloading, sink‐strength regulation and vacuolar storage determine final sucrose yield. Enzymes such as sucrose synthase (SuSy) and various invertase isoforms mediate reversible sucrose cleavage, linking carbohydrate reserves with cell wall biosynthesis and respiratory metabolism. Hormonal signals, notably ethylene and abscisic acid, integrate environmental cues with source–sink partitioning, while transcriptional and post‐transcriptional networks fine‐tune key regulators. Genotypic variation in gene expression, enzyme activities and transporter abundance underpins differences in sucrose content among cultivars. Advances in molecular breeding, genome‐wide association studies and gene‐editing strategies promise targeted enhancement of sucrose accumulation, with benefits extending to sustainable bioenergy, industrial feedstocks and improved agronomic performance under variable climates.

Research from Nature Portfolio

Ethylene‐mediated ripening treatments have been shown to boost sucrose accumulation by enhancing sink strength in maturing internodes. Hormonal profiling alongside transcriptome analysis revealed that ethylene triggers a cascade of hormone‐related transcriptional changes, upregulating cell wall‐bound and cytosolic invertases as well as ethylene‐responsive transcription factors. This hormonal interplay promotes sucrose retention and coordinates interactions between ethylene, abscisic acid, gibberellin and auxin pathways during ripening.

Transcriptomic comparisons of immature and mature internodes in genotypes differing in fibre content uncovered a suite of genes associated with carbohydrate metabolism. Although primarily focused on cellulose and lignin biosynthesis, the study highlighted upregulation of UDP‐glucose biosynthesis and sucrose conversion genes in high‐fibre lines, suggesting common regulatory nodes between sucrose partitioning and cell wall polymer assembly. These findings provide insight into carbon flux redistribution during stem maturation.

Sucrose Metabolism and Accumulation in Sugarcane Systems publication trend

The graph below shows the total number of articles in sucrose metabolism and accumulation in sugarcane systems across all publications each year (not limited to Nature Index journals).

Technical terms

Sucrose phosphate synthase (SPS): Enzyme catalysing the formation of sucrose-6-phosphate from UDP-glucose and fructose-6-phosphate, a key step in sucrose biosynthesis.

Sucrose synthase (SuSy): Enzyme that reversibly converts sucrose and UDP into UDP-glucose and fructose, linking sucrose metabolism with cell wall and starch biosynthesis.

Invertase: Enzyme family that hydrolyses sucrose into glucose and fructose, regulating sink strength and sucrose cleavage.

Source–sink relationship: Physiological framework describing the movement of photoassimilates from photosynthetic (source) tissues to storage or growth (sink) tissues.

Transcriptome: Full complement of RNA transcripts produced by a cell or tissue at a given developmental stage or environmental condition, used to analyse gene expression patterns.

References

1. Ethylene-mediated improvement in sucrose accumulation in ripening sugarcane involves increased sink strength. BMC Plant Biology (2019).
2. Ethylene-induced transcriptional and hormonal responses at the onset of sugarcane ripening. Scientific Reports (2017).
3. Transcriptome analysis highlights key differentially expressed genes involved in cellulose and lignin biosynthesis of sugarcane genotypes varying in fiber content. Scientific Reports (2018).
4. Sucrose metabolism analysis in a high sucrose sugarcane mutant clone at a mature stage in contrast to low sucrose parental clone through the transcriptomic approach. Chemical and Biological Technologies in Agriculture (2023).
5. Genetic association analysis in sugarcane (Saccharum spp.) for sucrose accumulation in humid environments in Colombia. BMC Plant Biology (2024).
6. Current perspectives on the regulatory mechanisms of sucrose accumulation in sugarcane. Heliyon (2024).
7. Carbon partitioning in sugarcane (Saccharum species). Frontiers in Plant Science (2013).