Search Results (39)

Low-light (LL) stress is a major abiotic limiting factor in protected cherry tomato production, adversely affecting vegetative growth, inducing oxidative damage, and disrupting fruit sugar metabolism. To clarify the regulatory role of exogenous abscisic acid (ABA) in mitigating LL stress, we examined the effects of varying ABA concentrations on plant growth, antioxidant capacity, and fruit sugar metabolism in cherry tomatoes under low-light conditions. A two-factor randomized complete block design, with two light regimes—normal light (NL, 100% natural sunlight) and low light (LL, 25% natural sunlight)—and three ABA concentrations (CK: 0 mg·L⁻¹, T1: 10 mg·L⁻¹, T2: 20 mg·L⁻¹). Fruits were sampled at three typical ripening stages (green mature, breaker, and red ripe) to evaluate vegetative and reproductive physiological responses. The results showed that exogenous ABA application effectively suppressed LL-induced excessive stem elongation and alleviated LL-caused reductions in stem diameter and biomass accumulation. ABA treatment significantly increased peroxidase (POD) activity and reduced malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) accumulation, thereby relieving LL-triggered oxidative damage. In addition, ABA regulated key sugar-metabolizing enzymes (soluble acid invertase (SAI), sucrose synthase (SS), sucrose phosphate synthase (SPS), and amylase (Amy)) and the transcript levels of related functional genes (HXK1, SPS, SS, AI), thereby mediating stage-dependent fruit sugar metabolism under LL stress. In conclusion, exogenous ABA effectively modulates vegetative growth, antioxidant homeostasis, and stage-specific fruit sugar metabolism, ultimately alleviating low-light stress damage in cherry tomato. Among the tested treatments, 20 mg·L⁻¹ ABA exhibited the most pronounced mitigation effects, which can be recommended as an optimal foliar application concentration for cherry tomato cultivation in low-light protected facilities. Full article

Seasonal drought constitutes a major abiotic stress limiting the growth and yield of pineapple, a globally important Crassulacean acid metabolism (CAM) crop. The sucrose catabolism mediated by cell wall invertase (CWIN) plays a vital role in regulating plant growth and development, as well as adaptive responses to abiotic stresses. Invertase inhibitors (INHs) serve as specific post-translational regulators that modulate CWIN enzymatic activity. However, the INH family has not been systematically characterized in pineapple, and its functional roles in mediating sucrose metabolism and drought resistance remain elusive. In this study, three AcINHs were identified from the pineapple genome, followed by comprehensive analyses of their gene structures, phylogenetic relationships, homology characteristics and protein structures. Structural analysis revealed that all AcINH members harbor conserved motifs 1, 2, 3, 5 and 9, whereas only AcINH3 possesses motif 7. Expression analysis showed that only AcINH3 was significantly transcriptionally induced by drought stress among all family members. Functional validation demonstrated that AcINH3 knockout markedly elevated CWIN activity in pineapple seedling leaves, facilitating hexose accumulation and promoting plant growth and development. Moreover, AcINH3-edited lines exhibited enhanced drought resistance, accompanied by increased accumulation of soluble sugars (sucrose, glucose, fructose), abscisic acid (ABA), and proline (PRO), reduced malondialdehyde (MDA) content, and enhanced peroxidase (POD) activity. Biochemical assays further verified a direct physical interaction between AcINH3 and AcCWIN1, which mediates sucrose metabolism and drought stress responses. Collectively, this study identifies a novel AcINH3–AcCWIN1 post-translational module that modulates sugar metabolism and drought tolerance in pineapple, providing critical mechanistic insights for CAM plants. Our findings highlight AcINH3 as a promising target for genome-editing breeding to enhance drought resistance in CAM crops. Full article

It is widely recognized that microbial inoculants (MI) and bio-organic fertilizers (BOFs) containing beneficial microorganisms can play an important role in improving orchard soil properties and enhancing fruit quality. However, insufficient data regarding the relevant fruit quality effects hindered the supplementary MI and BOFs in kiwifruit cultivation. Using conventional fertilization management as the control, this study investigated the impacts of supplementary applications of MI and BOFs at two gradient dosages on the harvest-time quality and cold storage characteristics of ‘Puyu’ yellow-fleshed kiwifruit. Regarding leaf physiological indices and soil pH, MI-3.0 and BOF-20 treatments significantly elevated total chlorophyll content at 60 days after flowering (DAF) (the fruit expansion stage). Leaf nitrogen (N), phosphorus (P) and potassium (K) contents declined gradually during fruit development, while MI-2.0 and BOF-10 treatments markedly promoted leaf P accumulation at 20–100 DAF. Additionally, the MI-2.0 treatment significantly reduced 20–40 cm subsoil pH, which is favorable for kiwifruit plants that prefer acidic and slightly acidic conditions. On the other hand, appropriate doses of MI and BOF treatments exerted a significant effect on improving the quality of kiwifruit at the ripening stage. These effects were mainly manifested in the increased single fruit weight, firmness, dry matter content and total soluble solids (TSSs) of kiwifruit following MI-3.0 and BOF-20 treatments. Furthermore, MI-3.0 and BOF-10 notably elevated the fructose and glucose contents in both flesh and core, as well as sucrose and ascorbic acid (AsA) contents in the flesh; MI-2.0 and BOF treatments significantly increased citric and malic acids in the core and quinic acid in the flesh. During cold storage, the BOF-20 treatment not only delayed the occurrence of the ethylene peak by 20 d and significantly reduced its peak value, but also alleviated the decline in total acid content at the middle storage stage (20–40 d). Additionally, MI-2.0 and BOF-20 treatments effectively delayed kiwifruit softening at the early storage stage (0–10 d), and MI treatments maintained a high AsA content in the core during 10–20 d of cold storage. MI and BOF fertilization treatments had little effect on the dynamic change trends of sucrose synthase (SuS), sucrose phosphate synthase (SPS) and acid invertase (AI) in kiwifruit during cold storage, only exerting significant effects at specific time points. In conclusion, supplementary applications of MI and BOFs could improve kiwifruit quality at the harvest stage by positively regulating the accumulation of dry matter, soluble sugars and organic acid contents, and also have the potential to enhance the storage performance of kiwifruit. These findings provide a scientific basis for establishing an effective fertilization regime for kiwifruit. Full article

Shade stress is a crucial constraint on asparagus growth in intercropping and dense-planting systems. However, the physiological and molecular mechanisms linking shading intensity to sugar metabolism remain insufficiently understood. Herein, integrating newly generated physiological data with a targeted re-analysis of previously published omics datasets, we elucidated sugar metabolism responses in asparagus stems under different shading intensities (0%, 35%, 55%, and 75%). Moderate shading (55%) was associated with higher sucrose and fructose contents, together with increased activities of key sucrose metabolism enzymes, including sucrose synthase (SUS), soluble acid invertase (S-AI), and sucrose phosphate synthase (SPS), accompanied by differential changes in antioxidant enzyme activities (SOD, CAT and POD). Metabolomic analysis revealed a shift in carbon allocation under 55% shading, characterized by the accumulation of nucleotide sugars such as UDP-galactose and GDP-L-fucose. Transcriptomic analysis further indicated the enrichment of glycolysis/gluconeogenesis pathways under this shading condition, along with the upregulation of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) genes. Collectively, rather than merely confirming known shading responses, these findings provide new empirical evidence that asparagus stems actively reprogram their energy homeostasis and invoke alternative carbon partitioning pathways specifically at a 55% shading threshold. Full article

Disorders in soybean seed-filling can lead to wrinkled seeds, affecting yield and quality. Previous studies have demonstrated that some soybean cultivars from Jiamusi, Heilongjiang Province (cold-temperate continental monsoon, ~3.5 °C mean annual temperature, ~530 mm precipitation) exhibit seed-filling disorders when cultivated in Shenyang, Liaoning Province (mid-temperate semi-humid continental monsoon, ~8.3 °C, ~610 mm). However, the causes and regulatory mechanisms remain unclear. In this study, Henong 76 (a soybean cultivar with seeds less prone to wrinkling) and Heihe 43 (a soybean cultivar with seeds prone to wrinkling) were used as experimental materials. They were sown simultaneously in Jiamusi and Shenyang, respectively, to explore the causes of seed-filling disorders in Heihe 43. The results indicated that there were significant differences in the contents of soluble sugars and starch, as well as in the activities of sucrose synthase and invertase, between the seeds of Henong 76 and Heihe 43 grown in Shenyang. However, no significant differences were found between them in Jiamusi. Transcriptomic and metabolomic analyses suggested that genes related to controlling starch hydrolysis (isoamylase, α-amylase, and glycogen phosphorylase) and sucrose synthesis and decomposition (sucrose synthase, invertase, glucose-6-phosphate isomerase, and phosphoglucomutase) in Heihe 43 were upregulated in Shenyang. In contrast, genes regulating plant hormone signal transduction (auxin, gibberellin, abscisic acid, and cytokinin) were generally downregulated. These changes led to differences in metabolites, resulting in the occurrence of seed-filling disorders. Furthermore, we analyzed the climatic conditions of the two cultivars during the soybean seed-filling period. The results indicated that high temperature might be the primary meteorological factor contributing to the occurrence of seed-filling disorders. All results indicated that the insufficient accumulation of sugars in seeds due to exposure to high temperatures during the seed-filling period is the primary cause of the prone-to-wrinkling phenomenon of the Heihe 43 cultivar under the ecological conditions of Shenyang. Full article

Kyoho grapes are rich in nutrients, yet their susceptibility to spoilage poses a significant challenge for postharvest preservation. While light treatment can improve fruit quality and carbohydrate metabolism in postharvest grapes, the potential benefits of combining light treatment with modified atmosphere packaging (MAP) remain unexplored. A preservation method that combined red and blue light treatments with MAP has been developed to enhance postharvest fruit quality and carbohydrate metabolism in Kyoho grapes. Our study showed that this combined treatment significantly increased postharvest fruit hardness, as well as total soluble solids (TSS) and fruiting pedicel water content. It also improved the activities of superoxide dismutase (SOD) and phenylalanine ammonialyase (PAL) and increased the antioxidant, anti-browning capacity. This composite treatment slowed down sucrose decomposition by regulating the activities of key enzymes of carbohydrate metabolism (sucrose synthase (SS), sucrose phosphate synthase (SPS), neutral invertase (NI) and acid invertase (AI)). After 60 days of storage, the glucose, fructose, and sucrose contents of the RP group increased by 13.4%, 30.2%, and 18.1%, respectively, compared to the CK group (p < 0.05). In summary, light combined with modified atmosphere packaging significantly improved the physicochemical properties and sugar metabolism of postharvest grapes. The results indicated that the optimal treatment condition was continuous red-light irradiation combined with MAP. The hardness, TSS content, VC content and glucose content of Kyoho grapes in this treatment group were the best in all treatment groups. Full article

NaCl stress is one of the most serious forms of salt stress. Prohexadione–calcium (EA) is a plant growth regulator, and gibberellin (GA) is a plant hormone that regulates various plant developmental processes. In this experiment, Guanghong 3 and Huang Huazhan served as experimental rice (Overza sativa L.) varieties to study the effects of EA and GA on the growth of rice seedlings. The results revealed that NaCl treatment significantly inhibited plant growth and destroyed the balance of the carbon metabolism. The inhibition effect of NaCl stress on the growth and physiological metabolism of rice seedlings was alleviated by EA and GA, but the effects of EA and GA were slightly different. Compared with the NaCl treatment, the EA and GA treatments significantly increased the net photosynthetic rate, stem base width, and dry matter accumulation but had opposite effects on the plant height, with the GA treatment significantly increasing the plant height of rice seedlings. The EA treatment was superior to the GA treatment in improving the metabolic pathway efficiency of sucrose and starch in the leaves of rice seedlings. The soluble sugar content, sucrose content, fructose content, sucrose synthase activity, sucrose phosphate synthase activity, α-amylase activity, β-amylase activity, and starch phosphorylase activity increased with increasing NaCl stress time, and the changes in the starch content and acid invertase activity were the opposite. The max/min values were reached on the 13th day of NaCl stress. Full article

Chlorine (Cl) is an essential nutrient for higher plants, playing a critical role in their growth and development. However, excessive Cl application can be detrimental, leading to its limited use in controlled-environment agriculture. Recently, Cl has been recognized as a beneficial macronutrient, yet studies investigating its impact on plant growth and fruit quality remain scarce. In this study, we determined the optimal Cl concentration in nutrient solutions through a series of cultivation experiments. A comparative analysis of Cl treatments at 1, 2, and 3 mM revealed that 3 mM Cl⁻ significantly enhanced chlorophyll content, biomass accumulation, and yield. Furthermore, we examined the effects of 3 mM Cl⁻ (supplied as 1.5 mM CaCl₂ and 3 mM KCl) on leaf photosynthesis, chlorophyll fluorescence, and fruit sugar metabolism. The results demonstrated that Cl⁻ treatments enhanced the activity of Photosystem I (PS I) and Photosystem II (PS II), leading to a 25.53% and 28.37% increase in the net photosynthetic rate, respectively. Additionally, Cl⁻ application resulted in a 12.3% to 16.5% increase in soluble sugar content in mature tomato fruits. During fruit development, Cl⁻ treatments promoted the accumulation of glucose, fructose, and sucrose, thereby enhancing fruit sweetness and overall quality. The observed increase in glucose and fructose levels was attributed to the stimulation of invertase activity. Specifically, acidic invertase (AI) activity increased by 61.6% and 62.6% at the green ripening stage, while neutral invertase (NI) activity was elevated by 56.2% and 32.8% in the CaCl₂ and KCl treatments, respectively, at fruit maturity. Furthermore, sucrose synthase (SS-I) activity was significantly upregulated by 1.5- and 1.4-fold at fruit maturity, while sucrose phosphate synthase (SPS) activity increased by 76.4% to 77.8% during the green ripening stage. These findings provide novel insights into the role of Cl⁻ in tomato growth and metabolism, offering potential strategies for optimizing fertilization practices in protected horticulture. Full article

Foliar fertilization, an effective strategy for enhancing crop yields, is relatively uncommon in bamboo cultivation. To investigate the impact of potassium fertilizer applied directly to bamboo leaves, we applied K₂CO₃ on the fresh leaves of 1-year-old Neosinocalamus affinis culms. The results indicated that potassium fertilization significantly promoted leaf growth and development, evidenced by thicker leaf and epidermal and mesophyll cells and increased areas of bulliform and fusoid cells. Additionally, the chlorophyll content rose, while the moisture levels declined. Notably, the soluble sugar, starch, and non-structural carbohydrate (NSC) contents in the leaves also increased. Further analysis of the sugar metabolism revealed that the exogenous potassium application boosted the activities of key enzymes involved in sucrose metabolism, including soluble acid convertase (SAI), cell wall invertase (CWI), sucrose synthase (SuSy), and sucrose phosphate synthetase (SPS). The foliar application of K₂CO₃ also promoted starch synthesis in the leaves by elevating the activities of ADPG pyrophosphorylase (AGPase), soluble starch synthase (SSS), and granular-bound starch synthase (GBSS), while simultaneously diminishing the activities of starch phosphorylase (STP), α-amylase, and β-amylase. Moreover, the targeted application of K₂CO₃ significantly reduced the contents of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) and significantly enhanced the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), thereby improving the stress resistance of bamboo leaves. This study suggested that the foliar application of potassium fertilizer promoted leaf growth, enhanced bamboo’s sugar metabolism and storage, and increased the stress resistance of bamboo leaves. Full article

This study investigated the optimal strategies for improving sugar biosynthesis in mango fruits. Randomized block design was used for experimental treatments. The mango cultivar “Renong-1” was sprayed with five green plant growth regulators, including solutions of SBP (sucrose-based polymers, a new highly efficient and eco-friendly plant growth regulator), SPM (sucrose + potassium dihydrogen phosphate + microelement fertilizer), TPM (taurine + potassium dihydrogen phosphate + microelement fertilize), PFA (potassium fulvic acid), and SOP (seaweed oligosaccharide peptide) at different fruit development stages. Indicators, such as soluble solid content, soluble sugar and starch contents, and activities of 11 enzymes associated with sugar metabolism in physiologically mature and in full ripening fruits were evaluated. The results showed that SBP solution diluted 100-fold exerted the strongest effect on the soluble sugar content and sweetness value of “Renong-1” mango fruits. Based on the linear regression analysis, a significant negative correlation was observed between the activity of acid invertase and the perceived sweetness of physiologically mature fruits, while the activities of other enzymes were significantly negatively correlated with the perceived sweetness of full ripening fruits. According to multiple regression (by lars function in R) and other comprehensive analysis, A1B3 (spraying SBP solution one time in the young fruit stage) was selected as the optimal treatment combination for enhancing “Renong-1” mango perceived sweetness, followed by A1B2 (spraying SBP solution for the first time in the young fruit stage and the second time at medium maturity) as the alternative treatment combination. Full article

The main goal of this study was to investigate the effect of lead (Pb) at various concentrations, as an abiotic factor, and the cross-talk between Pb and pea aphid (Acyrthosiphon pisum (Harris)) (Hemiptera: Aphididae), as a biotic factor, on the defence responses of pea seedlings (Pisum sativum L. cv. Cysterski). The analysis of growth parameters for pea seedlings demonstrated that Pb at a low concentration, i.e., 0.025–0.0625 mM Pb(NO₃)₂, caused a hormesis effect, i.e., stimulation of seedling growth, whereas Pb at higher concentrations, i.e., 0.01–0.325 mM Pb(NO₃)₂, inhibited growth, which manifested as the inhibition of length and fresh biomass. The differences in the level of the main defence-related phytohormones, such as abscisic acid (ABA), jasmonic acid (JA) and salicylic acid (SA), and indole-3-acetic acid (IAA)—an auxin stimulating plant cell growth—depended on the dose of Pb, aphid infestation and direct contact of the stress factor with the organ. A high accumulation of soluble sugars in the organs of pea seedlings both at sublethal doses and hormetic doses at early experimental time points was observed. At 0 h and 24 h of the experiment, the hormetic doses of Pb significantly stimulated invertase activities, especially in the roots. Moreover, an increase was observed in the pisatin concentration in pea seedlings growing in the presence of different concentrations of Pb and in the case of cross-talk between Pb and A. pisum in relation to the control. Additionally, a significant induction of the expressions of isoflavone synthase (IFS) and 6α-hydroxymaackiain 3-O-methyltransferase (HMM) genes, which participate in the regulation of the pisatin biosynthesis pathway, in pea seedlings growing under the influence of sublethal 0.5 mM Pb(NO₃)₂ and hormetic 0.075 mM Pb(NO₃)₂ doses of Pb was noted. The obtained results showed that the response of P. sativum seedlings depends on the Pb dose applied, direct contact of the stress factor with the organ and the duration of contact. Full article

Burdock fructooligosaccharide (BFO) is fructose with a low polymerization degree, which could improve the immunity to pathogens, quality, and stress resistance of vegetables. Still, there are no studies on applying BFO in Chinese cabbage. In this study, the effects of exogenous BFO sprayed with different concentrations (0, 5, 10, 20, 30 g·L⁻¹) on the growth and soluble sugar content of Chinese cabbage seedlings were determined. The result showed that 10 g·L⁻¹ was the appropriate spraying concentration. Based on metabolome analysis, a total of 220 differentially accumulated metabolites (DAMs) were found, among which flavonoid metabolites, glucosinolate metabolites, and soluble sugar-related metabolites were the key metabolites involved in improving the quality of Chinese cabbage caused by BFO. Further combination analysis with transcriptome, trans-cinnamate 4-monooxygenase (CYP73A5), and chalcone synthase 1 (CHS1) were more closely associated with the DAMs of flavonoid biosynthesis. Sulfotransferases 18 (SOT18), Branched-chain amino acid amino transferases 6 (BCAT6), and cytochrome P450 monooxygenase (CYP83A1) were the key genes in glucosinolate biosynthesis. Hexokinase (HxK1), beta-glucosidase 8 (BGL08), invertase 3 (INV3), beta-glucosidase 3B (BGL3B), and sucrose phosphate synthase 1 (SPS1) were significantly upregulated, potentially playing crucial roles in the soluble sugar metabolism. In conclusion, these results provided an understanding of the effects of BFO on the expression of genes and the accumulation of metabolites related to quality formation in Chinese cabbage. Full article

The purpose of this study was to explore the carbon and nitrogen metabolism mechanisms of sand-cultivated cucumbers under different deficit irrigation–nitrogen management strategies and provide a theoretical basis for their greenhouse management. This study set up two factors, the deficit irrigation level and the nitrogen application rate, and conducted an experiment on deficit irrigation–nitrogen coupling of sand-cultivated cucumbers using a quadratic saturation D–optimal design. Seven treatments were set up in the experiment, to measure the soluble sugar and protein contents, as well as the activity of key enzymes for carbon and nitrogen metabolism at five different growth stages. The results indicate that the 80% irrigation with 623 kg N hm⁻² (IN4) treatment significantly improved the soluble sugar, protein, and actual leaf nitrogen contents of cucumber at the five different growth stages and, as a result, achieved higher sucrose synthase (SS) and sucrose phosphate synthase (SPS) activities in the cucumber leaves. Furthermore, such improvements were due to the reduction in oxidative damage of sand–cultivated cucumber at various growth stages. The IN4 and 89% irrigation with 1250 kg N hm⁻² (IN5) treatments significantly increased the activities of RuBisCO, catalase (CAT), peroxidise (POD), and superoxide dismutase (SOD) at various growth stages of sand-cultivated cucumber. The higher activities of glutamate dehydrogenase (GLDH), glutamate synthase (GOGAT), nitrate reductase (NR), glutamine synthase (GS), acid invertase enzyme (AIE), neutral invertase enzyme (NIE), and better antioxidative enzyme activities were recorded under the IN4 treatments at various growth stages, which effectively improve (69.6%) cucumber yield. The soil properties, carbon and nitrogen metabolism, and antioxidant metabolism were positively correlated with sand-cultivated cucumber yield in a greenhouse. We concluded that the IN4 treatment was the better deficit irrigation–nitrogen management strategy because it considerably improves carbon and nitrogen metabolism, antioxidant enzyme activities, and sand–cultivated cucumber yield in a greenhouse. Full article

Salinity stress poses a significant threat to crop productivity worldwide, necessitating effective mitigation strategies. This study investigated the phytochemical composition and potential of grape seed extract (GSE) to mitigate salinity stress effects on faba bean plants. GC–MS analysis revealed several bioactive components in GSE, predominantly fatty acids. GSE was rich in essential nutrients and possessed a high antioxidant capacity. After 14 days of germination, GSE was applied as a foliar spray at different concentrations (0, 2, 4, 6, and 8 g/L) to mitigate the negative effects of salt stress (150 mM NaCl) on faba bean plants. Foliar application of 2–8 g/L GSE significantly enhanced growth parameters such as shoot length, root length, fresh weight, and dry weight of salt-stressed bean plants compared to the control. The Fv/Fm ratio, indicating photosynthetic activity, also improved with GSE treatment under salinity stress compared to the control. GSE effectively alleviated the oxidative stress induced by salinity, reducing malondialdehyde, hydrogen peroxide, praline, and glycine betaine levels. Total soluble proteins, amino acids, and sugars were enhanced in GSE-treated, salt-stressed plants. GSE treatment under salinity stress modulated the total antioxidant capacity, antioxidant responses, and enzyme activities such as peroxidase, ascorbate peroxidase, and polyphenol oxidase compared to salt-stressed plants. Gene expression analysis revealed GSE (6 g/L) upregulated photosynthesis (chlorophyll a/b-binding protein of LHCII type 1-like (Lhcb1) and ribulose bisphosphate carboxylase large chain-like (RbcL)) and carbohydrate metabolism (cell wall invertase I (CWINV1) genes) while downregulating stress response genes (ornithine aminotransferase (OAT) and ethylene-responsive transcription factor 1 (ERF1)) in salt-stressed bean plants. The study demonstrates GSE’s usefulness in mitigating salinity stress effects on bean plants by modulating growth, physiology, and gene expression patterns, highlighting its potential as a natural approach to enhance salt tolerance. Full article

Sugarcane is a significant primitive source of sugar and energy worldwide. The progress in enhancing the sugar content in sugarcane cultivars remains limited due to an insufficient understanding of specific genes related to sucrose production. The present investigation examined the enzyme activities, levels of reducing and non-reducing sugars, and transcript expression using RT-qPCR to assess the gene expression associated with sucrose metabolism in a high-sucrose sugarcane clone (GXB9) in comparison to a low-sucrose sister clone (B9). Sucrose phosphate synthase (SPS), sucrose phosphate phosphatase (SPP), sucrose synthase (SuSy), cell wall invertase (CWI), soluble acid invertase (SAI), and neutral invertase (NI) are essential enzymes involved in sucrose metabolism in sugarcane. The activities of these enzymes were comparatively quantified and analyzed in immature and maturing internodes of the high- and low-sucrose clones. The results showed that the higher-sucrose-accumulating clone had greater sucrose concentrations than the low-sucrose-accumulating clone; however, maturing internodes had higher sucrose levels than immature internodes in both clones. Hexose concentrations were higher in immature internodes than in maturing internodes for both clones. The SPS and SPP enzymes activities were higher in the high-sucrose-storing clone than in the low-sucrose clone. SuSy activity was higher in the low-sucrose clone than in the high-sucrose clone; further, the degree of SuSy activity was higher in immature internodes than in maturing internodes for both clones. The SPS gene expression was considerably higher in mature internodes of the high-sucrose clones than the low-sucrose clone. Conversely, the SuSy gene exhibited up-regulated expression in the low-sucrose clone. The enhanced expression of SPS in the high-sucrose clone compared to the low-sucrose clone suggests that SPS plays a major role in the increased accumulation of sucrose. These findings provide the opportunity to improve sugarcane cultivars by regulating the activity of genes related to sucrose metabolism using transgenic techniques. Full article