Sucrose metabolism: regulatory mechanisms and pivotal roles in sugar sensing and plant development

New potential susceptibility factors contributing to tomato bacterial spot disease

The label-free shotgun proteomics analysis carried out in this study aimed to understand the molecular mechanisms that contribute towards tomato susceptibility to Xanthomonas euvesicatoria pv. perforans (Xep). To achieve this, comparative proteomics was performed on susceptible inoculated plants with the bacterium and the control group (saline solution) at 24 and 48 h after inoculation (hai). The results revealed that most of the identified proteins showed increased abundance in the infected group and were classified into different gene ontology groups. Eight of these proteins were related to susceptibility in other pathosystems, suggesting their potential involvement in the development of bacterial spot in tomato. Some of these proteins are involved in the negative regulation of salicylic acid, PR proteins and reactive oxygen species (ROS), as well as contributing to the acquisition of sugars by the pathogen. The results obtained in this study provided us with valuable information for understanding the molecular mechanisms that lead to tomato susceptibility to Xep and will help in developing tomato cultivars resistant to bacterial spot. SIGNIFICANCE: Our proteomic study of tomato plants during infection by Xep allowed for the identification of potential proteins that contribute to bacterial spot tomato disease development. These proteins can act in different ways to favor the pathogen, such as the negative modulation of phytohormones involved in plant defense, the inhibition of PR proteins and reactive oxygen species, as well as to collaborate in the acquisition of sugar for pathogen nutrition.

Multi-omics analysis combined with network pharmacology revealed the mechanisms of rutaecarpine in chronic atrophic gastritis

ETHNOPHARMACOLOGICAL RELEVANCE

Tetradium ruticarpum (A.Juss.) T.G.Hartley is a traditional Chinese medicine with a history of thousands of years, which plays an important role in the relief of gastric pain, indigestion, vomiting and diarrhea. Rutaecarpine (RUT) is one of the major active constituents of Tetradium ruticarpum (A.Juss.) T.G.Hartley with potential therapeutic activity in chronic atrophic gastritis (CAG). However, the mechanism of RUT to improve CAG is not well understood.

AIM OF THIS STUDY

This study aimed to evaluate the efficacy of RUT in treating CAG and its underlying mechanism.

MATERIALS AND METHODS

The CAG model of SD rats was established by induction with 0.1% ammonia and 20 mmol/L sodium deoxycholate solution, accompanied with irregular fasting cycle. The efficacy of RUT in treating CAG was assessed through pathological examination and serum biochemical indices including PP, IL-6, MTL, TNF-α, PG I, SS, PG II, IL-10 and GAS-17. Following this, network pharmacology, 16s rRNA sequencing, transcriptomics, and broadly targeted metabolomics were conducted to unravel the underlying mechanisms of RUT's action in CAG treatment. Ultimately, molecular docking, western blotting, and immunohistochemistry were employed to validate the critical targets and pathways involved in RUT's therapeutic approach for CAG.

RESULTS

RUT significantly improved body weight, gastric juice pH and gastric histologic injury in CAG rats. The results of serum biochemical indices showed that RUT significantly inhibited the expression levels of SS, GAS-17, IL-6 and TNF-α, and increased the levels of MTL, PP, PGI, PGII and IL-10. In addition, RUT apparently increased the expression of mucosal barrier proteins such as ZO-1, E-cadherin and claudin-4 and occludin. Network pharmacology in combination with transcriptomics revealed that the MAPK signaling pathway was the most important pathway for RUT treatment of CAG. Further analysis suggested that by regulating linoleic acid metabolism, metabolic pathways, etc. mainly related to energy metabolism, RUT intervention effectively ameliorated gastric tissue metabolic disorders in CAG rats. The 16S rRNA gene-based microbiota analysis revealed that RUT altered the composition of the intestinal microbiota and decreased the relative abundance of unclassified_Muribaculaceae. PICRUST analysis suggested that the differential bacteria may be involved in energy metabolism pathway regulation for the improvement of CAG. A comprehensive analysis of the transcriptome and metabolome showed that the RUT improved the differential metabolites through the regulation of TGER2, CBR1 and CTPS1 targets.

CONCLUSION

These findings indicated that RUT's mechanism of action in treating CAG was related to modulating the gut microbiota, influencing energy metabolism, and inhibiting the MAPK signaling pathway. This provided new insights into how RUT exerts its therapeutic effects on CAG.

Xylan structural diversity, biosynthesis, and functional regulation in plants

Xylan is a vital component of plant cell walls, contributing to their structural integrity and flexibility through interactions with other polymers. Its structure varies among plant species, influencing the mechanical properties of cell walls. Xylan also has significant industrial potential, including in biofuels, biomaterials, food, and pharmaceuticals, due to its ability to be converted into valuable bioproducts. However, key aspects of xylan biosynthesis, regulation, and structural impact on plant growth and structures remain unclear. This review highlights current researches on xylan biosynthesis, modification, and applications, identifying critical gaps in knowledge. Meanwhile the review proposes new approaches to regulate xylan synthesis and understand its role in cell wall assembly and interactions with other polymers. Addressing these gaps could unlock the full industrial potential of xylan, leading to more sustainable applications.

Transcriptome and Metabolome Analyses Reveal the Regulatory Mechanism of TC1a in the Sucrose and Starch Synthesis Pathways in Arabidopsis thaliana

Tumor necrosis factor receptor-associated factor (TRAF) proteins, originally identified in mammals, have since been found in most plants. TRAF proteins in plants have been shown to be involved in cellular autophagy, immunity, drought resistance, and ABA induction. However, the role in regulating sucrose and starch metabolism has not been reported. In this study, we confirmed that TC1a can regulate sucrose and starch metabolism through gene editing, phenotypic observation, transcriptomics and metabolomics analyses. Initially, 200 and 81 TRAF proteins were identified in rapeseed (Brassica napus L.) and Arabidopsis thaliana, respectively, and divided into five classes. We found that overexpression of TC1a inhibited root length, plant height, flowering, and leaf development in A. thaliana. Additionally, 12 differentially expressed genes (DEGs) related to sucrose and starch metabolism pathways were identified in overexpressing and knockout plants, respectively. Six differentially accumulated metabolites (DAMs)-fructose, sucrose, glucose, trehalose, maltose, and 6-phosphate fructose-were identified using widely targeted metabolomics analysis. The results show that TC1a affects the growth and development of Arabidopsis, and induces the expression of sucrose and starch synthase and hydrolases, providing a foundation for further research into its molecular mechanisms.

Sucrose synthase: An enzyme with multiple roles in plant physiology

Sucrose synthase (SuS) is a key enzyme in the regulation of sucrose metabolism in plants and participates in the reversible reaction of sucrose conversion to uridine diphosphate-glucose and fructose. It plays an important role in promoting taproot development, starch synthesis, cellulose synthesis, improving plant nitrogen fixation capacity, sugar metabolism, and fruit and seed development. Recent studies have shown that SuS responds to abiotic stresses such as drought stress, cold stress and waterlogging stress, especially in waterlogging stress. This paper provides a comprehensive review on the basic properties, physiological functions, and signal transduction pathways of SuS, aiming to establish a theoretical foundation for its further research.

Impact of Pristine and Aged Tire Wear Particles on Ipomoea aquatica and Rhizospheric Microbial Communities: Insights from a Long-Term Exposure Study

Tire wear particles (TWPs), generated from tire abrasion, contribute significantly to environmental contamination. The toxicity of TWPs to organisms has raised significant concerns, yet their effects on terrestrial plants remain unclear. Here, we investigated the long-term impact of pristine and naturally aged TWPs on water spinach (Ipomoea aquatica) and its rhizospheric soil. The results indicated that natural aging reduced the toxicity of TWPs, as evidenced by decreased levels of polycyclic aromatic hydrocarbons (PAHs) in soil and TWPs themselves. Consequently, aged TWPs were found to enhance the plant growth and chlorophyll content, whereas pristine TWPs increased the plant stress. Furthermore, aged TWPs improved soil organic matter (SOM) and total organic carbon (TOC), thereby boosting the microbial enzymes involved in nitrogen cycling. Metabolomic analysis revealed that aged TWPs upregulated key pathways related to carbon and nitrogen metabolism, enhancing plant growth and stress responses. Additionally, rhizosphere bacterial diversity was higher under aged TWPs, favoring nutrient-cycling taxa such as Acidobacteriota and Nitrospirota. Pristine TWPs may lead to overproliferation of certain dominant species, thereby reducing microbial diversity in soil, which could ultimately compromise the soil health. These findings contribute to a deeper understanding of the mechanisms underlying TWP toxicity in plants and highlight the necessity for further research on the impact of aged TWPs across various plant species over different exposure durations for comprehensive risk assessment.

Genome-wide identification of SWEET gene family and the sugar transport function of three candidate genes during female flower bud induction stage of Juglans sigillata Dode

Sugar Will Eventually be Exported Transporter (SWEET) transports sugar to sink organs and regulates intercellular sugar transport to provide energy for plant growth and development. In this study, twenty-two SWEET genes were identified and distributed on eleven chromosomes. Phylogenetic tree analysis showed that these genes could be divided into four subfamilies. Metabolism and transcriptome analysis showed that sucrose and fructose were accumulated in female flower buds at physiological differentiation stage (PDS). The third branch of JsSWEET1 and the fourth branch of JsSWEET9 and JsSWEET17 were highly expressed in female flower buds at undifferentiated stage (UDS) and PDS, which promoted sugar accumulation in female flower bud differentiation, so these three candidate SWEET genes were considered to be involved in the accumulation of sugar in the flower bud differentiation of Juglans sigillata. The subcellular localization showed that all three candidate genes were located on the cell membrane, and JsSWEET17 was also expressed and functioned in the vacuolar membrane. Through overexpression in callus and silencing in female flower buds at UDS and PDS, it was found that JsSWEET1 positively regulated the accumulation of sucrose in female flower buds, and JsSWEET9 and JsSWEET17 are involved in the transport and accumulation of fructose during flower bud differentiation. These results could provide a comprehensive understanding of the JsSWEETs gene family and provide theoretical guidance for further study of the function of SWEET-induced sugar accumulation in plant flower development.

Zinc Oxide Nanoparticle-Mediated Root Metabolic Reprogramming for Arsenic Tolerance in Soybean

Arsenate (AsV) is absorbed and accumulated by plants, which can affect their physiological activities, disrupt gene expression, alter metabolite content, and influence growth. Despite the potential of zinc oxide nanoparticles (ZnONPs) to mitigate the adverse effects of arsenic stress in plants, the underlying mechanisms of ZnONPs-mediated detoxification of AsV, as well as the specific metabolites and metabolic pathways involved, remain largely unexplored. In this study, we demonstrated root metabolomic profiling of soybean germinating seedlings subjected to 25 μmol L-1 arsenate (Na2HAsO4) and ZnONPs at concentrations of 25 μmol L-1 (ZnO25) and 50 μmol L-1 (ZnO50). The objective of this study was to examine the effects on soybean root metabolomics under AsV toxicity. Metabolomic analysis indicated that 453, 501, and 460 metabolites were significantly regulated in response to AsV, ZnO25, and ZnO50 treatments, respectively, compared to the control. Pathway analysis of the differentially regulated metabolites (DRMs) revealed that the tricarboxylic acid (TCA) cycle, glutathione metabolism, proline and aldarate metabolism, and arginine and proline metabolism were the most statistically enriched pathways in ZnONPs-supplemented plants. These findings suggest that ZnONPs enhance the tolerance response to AsV. Collectively, our results support the hypothesis that ZnONPs fertilization could be a potential strategy for improving soybean crop resilience under AsV stress.

The changes in sugar content and the selection of key genes at different developmental stages of 'Katy' and 'Kuijin' apricots

'Katy' and 'Kuijin' apricots are the main cultivated varieties in Shandong province. The flavor of the fruit is mainly determined by sugars and acids, with soluble sugar components serving as important nutritional elements in fruits as well as crucial indicators of fruit sweetness and flavor quality. However, little is known about the changes in soluble sugar content, especially sucrose content, and the sucrose metabolism mechanism during the entire fruit growth and development process of 'Katy' and 'Kuijin' apricots. In this study, we first detected the changes in sucrose, fructose, and glucose content at nine fruit development stages of 'Katy' and 'Kuijin' apricots, and found that the stage of rapid accumulation of sucrose and fructose was from 56 days after full bloom (DAF) to 63 DAF. Therefore, we identified the key gene PaSS1 of sucrose synthase through transcriptome data screening, and further analyzed the function of the PaSS1 gene in fruit sucrose metabolism process using virus-induced gene silencing (VIGS) technology. Silencing the PaSS1 gene reduced the breakdown activity of sucrose synthase, increasing sucrose content while decreasing glucose and fructose content, delaying fruit coloring and ripening, indicating that the PaSS1 gene may regulate the ripening of apricot fruits. This study provides a theoretical basis for further research on the molecular mechanism of the PaSS1 gene in apricot fruit ripening process.

Regulatory network analysis reveals gene-metabolite relationships in pear fruit treated with methyl jasmonate

The economic value of pear is determined by its intrinsic qualities, which are influenced by metabolites produced during the ripening process. Methyl jasmonate (MeJA), a hormone, plays an important role in plant metabolism. To date, few studies have investigated the molecular mechanism underlying the changes in metabolic pathways related to the internal quality of pear fruit after MeJA treatment. In this study, ultrahigh-performance liquid chromatography‒Q Exactive Orbitrap mass spectrometry (UHPLC‒QE‒MS) was used to determine the changes in metabolite contents in pear after MeJA treatment. MeJA treatment primarily activated carbohydrate metabolism and amino acid metabolism pathways. Through combined analysis of UHPLC‒QE‒MS data and whole-transcriptome data, the abovementioned pathways and each metabolite were analysed separately, and competitive endogenous RNA (ceRNA) and microRNA-transcription factor-target (miRNA-TF-target) regulatory networks were constructed. The core nodes of three genes (PEA, Pbr022732.1; GAA, Pbr035655.1; and miR8033-x) and two genes (SDS, Pbr031708.1; and novel-m6796-3p) were associated with the carbohydrate metabolism and amino acid metabolism pathways, respectively. The core mRNA nodes TCONS_00048038 and Pbr019584.1, the core miRNA node miR4993-x, the core lncRNA node TCONS_0004356, the core circRNA node novel_circ_001967 and the core transcription factor node TSO1 (Pbr025407.1) were identified via separate metabolite analyses. These findings elucidate the changes in metabolites related to fruit quality in 'Nanguo' pear and the relationships between the metabolites and genes, reveal the molecular mechanism underlying the response of MeJA treatment in pear fruit, and provide a theoretical basis for improving the internal quality of 'Nanguo' pear.

Sustained carbon import supports sugar accumulation and anthocyanin biosynthesis during fruit development and ripening in blueberry (Vaccinium ashei)

Fruit ripening is a highly coordinated process involving molecular and biochemical changes that collectively determine fruit quality. The underlying metabolic programs and their transitions leading to fruit ripening remain largely under-characterized in blueberry (Vaccinium sp.), which exhibits atypical climacteric behavior. In this study, we focused on sugar, acid and anthocyanin metabolism in two rabbiteye blueberry cultivars, Premier and Powderblue, during fruit development and ripening. Concentrations of the three major sugars, sucrose (Suc), glucose (Glc), and fructose (Fru) increased steadily during fruit development leading up to ripening, and increased dramatically by around 2-fold in 'Premier' and 2- to 3-fold in 'Powderblue' during the final stage of fruit ripening. Starch concentration was very low throughout fruit development in both cultivars indicating that it does not serve the role of a major transitory carbon (C) storage form in blueberry fruit. Together, these patterns indicate continued import of C, likely in the form of Suc, throughout blueberry fruit development. Concentrations of the predominant acids, malate and quinate, decreased during ripening, and may contribute to increased shikimate biosynthesis which, in-turn, allows for downstream phenylpropanoid metabolism leading to anthocyanin synthesis. Consistently, anthocyanin concentrations were highest in fully ripened blue fruit. Weighted gene co-expression network analysis (WGCNA) was performed using a 'Powderblue' fruit ripening transcriptome and targeted fruit metabolite concentration data. A 'dark turquoise' module positively correlated with sugars and anthocyanins, and negatively correlated with acids (malate, quinate), was identified. Gene Ontology (GO) enrichment analysis of this module identified transcripts related to sugar, acid, and phenylpropanoid metabolism pathways. Among these, increased transcript abundance of a VACUOLAR INVERTASE during ripening was consistent with sugar storage in the vacuole. In general, transcript abundance of the glycolysis pathway genes was upregulated during ripening. The transcript abundance of PHOSPHOENOLPYRUVATE (PEP) CARBOXYKINASE increased during fruit ripening and was negatively correlated with malate concentration, suggesting increased malate conversion to PEP, which supports anthocyanin production during fruit ripening. This was further supported by the co-upregulation of several anthocyanin biosynthesis-related genes. Together, this study provides insights into important metabolic programs, and their underlying gene expression patterns during fruit development and ripening in blueberry.

An Analysis of the Mechanism About CO2 Enrichment Promoting Carbohydrate Metabolism in Cucumber (Cucumis sativus L.) Leaves

Elevated CO2 can affect the synthesis and distribution of photosynthetic assimilates. However, the carbohydrate metabolism molecular mechanism of cucumber leaves in response to CO2 enrichment is unclear. Therefore, it is of great significance to investigate the key functional regulatory genes in cucumber. In this study, the growth of cucumber leaves under different CO2 conditions was compared. The results showed that under CO2 enrichment, leaf area increased, the number of mesophyll cells increased, stomata enlarged, and more starch grains accumulated in the chloroplasts. Compared with the control, the starch and soluble sugar content of leaves were maximally increased by 194.1% and 55.94%, respectively; the activities of fructose-1,6-bisphosphatase (FBPase), ADPG pyrophosphorylase (AGPase), starch synthase (SSS), sucrose phosphate synthase (SPS), sucrose synthase (SS) and invertase (Inv) were maximally increased by 36.91%, 66.13%, 33.18%, 21.7%, 54.11%, and 46.01%, respectively. Through transcriptome analysis, a total of 1,582 differential expressed genes (DEGs) were identified, in which the starch and sucrose metabolism pathway was significantly enriched, and 23 genes of carbon metabolism were screened. Through metabolome analysis, a total of 22 differential accumulation metabolites (DAMs) were identified. Moreover, D-glucose and D(+)-glucose were significantly accumulated, showing upregulation 2.4-fold and 2.6-fold, respectively. Through combined analysis of transcriptome and metabolome, it was revealed that seven genes were highly related to D-glucose, and Csa6G153460 (AGPase), Csa5G612840 (β-glucosidase), and Csa4G420150 (4-α-glucanotransferase) were significantly correlated to the carbohydrate regulatory network. Furthermore, the mechanism of CO2 enrichment that promotes carbohydrate metabolism in leaves at the molecular level was revealed. This mechanism advances the development of the cell wall and leaf morphology by activating the expression of key genes and improving enzyme activity.

Similar chilling response of dormant buds in potato tuber and woody perennials

Bud dormancy is a survival strategy that plants have developed in their native habitats. It helps them endure harsh seasonal changes by temporarily halting growth and activity until conditions become more favorable. Research has primarily focused on bud dormancy in tree species and the ability to halt growth in vegetative tissues, particularly in meristems. Various plant species, such as potato, have developed specialized storage organs, enabling them to become dormant during their yearly growth cycle. Deciduous trees and potato tubers exhibit a similar type of bud endodormancy, where the bud meristem will not initiate growth, even under favorable environmental conditions. Chilling accumulation activates C-repeat/dehydration responsive element binding (DREB) factors (CBFs) transcription factors that modify the expression of dormancy-associated genes. Chilling conditions shorten the duration of endodormancy by influencing plant hormones and sugar metabolism, which affect the timing and rate of bud growth. Sugar metabolism and signaling pathways can interact with abscisic acid, affecting the symplastic connection of dormant buds. This review explores how chilling affects endodormancy duration and explores the similarity of the chilling response of dormant buds in potato tubers and woody perennials.

Comparative analysis of the physiological and transcriptomic profiles reveals alfalfa drought resistance mechanisms

BACKGROUND

Drought stress is a major limiting factor that affects forage yields, and understanding the drought resistance mechanism of plants is crucial for improving crop yields in arid areas. Alfalfa (Medicago sativa L.) is the most important legume plant, mainly planted in arid and semi-arid areas. However, the adaptability of alfalfa to drought stress and its physiological and molecular mechanisms of drought resistance remains unclear.

RESULTS

In this study, we analyzed the physiological and transcriptome responses of alfalfa cultivars with different drought resistances (drought-sensitive Gannong No. 3 (G3), drought-resistant Gannong No. 8 (G8), and strong drought-resistant Longdong (LD)) under drought stress at 0, 6, 12, and 24 h. LD had higher catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activities and a higher soluble protein content, lower malondialdehyde (MDA) content, a lower O2·- production rate, and a lower H2O2 content than G8 and G3 (P < 0.05). The functional enrichment analysis, temporal expression pattern analysis, and weighted gene co-expression network analysis (WGCNA) of the differentially expressed genes (DEGs) showed phenylpropanoid biosynthesis, flavonoid biosynthesis, starch and sucrose metabolism, glycolysis/gluconeogenesis, glutathione metabolism, and biosynthesis of amino acid responses to drought stress in alfalfa. The differential expression of genes during phenylpropanoid biosynthesis, starch and sucrose metabolism, and the glutathione metabolism pathway was further studied, and it was speculated that PAL, COMT, 4CL, CCR, CAD, HXK, INV, SUS, WAXY, AGP, GST, and APX1 played important roles in the alfalfa drought stress response.

CONCLUSIONS

The aim of this study was to enhance alfalfa drought resistance by overexpressing positively regulated genes and knocking out negatively regulated genes, providing genetic resources for the subsequent molecular-assisted breeding of drought-resistant alfalfa crops.

Identification of key gene networks controlling organic acid and sugar metabolism during star fruit (Averrhoa carambola) development

The sugar and organic acid content significantly impacts the flavor quality of star fruit, and it undergoes dynamic changes during development. However, the metabolic network and molecular mechanisms governing the formation of sugar and organic acid in star fruit remain unclear. In this study, 23 of 743 components were detected by metabonomic analysis. The highest metabolites contents were organic acids and derivatives. The highest sugar content in the fruit was fructose and glucose, followed by sucrose, which proved that A. carambola is a hexose accumulation type fruit. Genome identification preliminarily screened 141 genes related to glucose metabolism and 67 genes related to acid metabolism. A total of 7,881 unigenes were found in transcriptome data, 6,124 differentially expressed genes were screened, with more up-regulated than down-regulated genes. Transcriptome and metabolome association analysis screened seven core candidate genes related to glucose metabolism and 17 core genes highly related to organic acid pathway, and eight differentially expressed sugar and acid genes were selected for qRT-PCR verification. In addition, 29 bHLHs and eight bZIPs transcription factors were predicted in the glucose metabolism pathway, and 23 MYBs, nine C2H2s transcription factors and one GRAS transcription factor was predicted in the acid metabolism pathway, and transcription factors have both positive and negative regulatory effects on sugar and acid structure genes. This study increased our understanding of A. carambola fruit flavor and provided basic information for further exploring the ornamental and edible values of star fruit.

Brewer's Spent Grain-Cellulose-Coated Copper Electrode-Based Extended Gate Field-Effect Transistor for Nonenzymatic Glucose Detection toward Diagnosis of Diabetes Mellitus

The demand for environmentally friendly, reliable, and cost-effective electrodes for glucose sensor technology has become a major research area in the paradigm shift toward green electronics. In this regard, cellulose has emerged as a promising flexible biopolymer solution with unique properties such as biocompatibility, biodegradability, nontoxicity, renewability, and sustainability. Because of their large surface area and porous structure, fibrous cellulose substrates quickly adsorb and disperse analytes at detection sites. This work focuses on utilizing glyoxal-treated cellulose (derived from brewer's spent grain (BSG)) for the fabrication of extended gate field-effect transistor (EGFET)-based glucose sensors. This investigation extends to the utilization of BSG-cellulose for glucose detection in biomimicking electrolytes (phosphate buffer saline) to facilitate glucose detection in human blood samples. The fabricated electrode demonstrates a linear range of glucose detection from 1 to 13.5 mM with a Langmuir adsorption coefficient (K) of 0.102. Also, its selectivity toward glucose over interfering molecules such as sucrose, fructose, ascorbic acid, and uric acid under physiological conditions has been demonstrated. This cellulose-based EGFET electrode exhibits a sensitivity of 6.5 μA mM-1 cm-2 with a limit of detection (LOD) of 0.135 mM. Computational studies by density functional theory calculations confirmed the higher binding affinity of glucose molecules with glyoxal-modified cellulose (-0.95 eV) than with pristine cellulose (-0.46 eV). Here, the novelty lies in the fabrication of electrodes with biodegradable catalysts and their integration into the EGFET configuration.

Screening Germplasms and Detecting Quantitative Trait Loci for High Sucrose Content in Soybean

Sucrose is a desirable component of processed soybean foods and animal feed, and thus, its content is used as an important characteristic for assessing the quality of soybean seeds. However, few studies have focused on the quantitative trait loci (QTLs) associated with sucrose regulation in soybean seeds. This study aims to measure the sucrose content of 1014 soybean accessions and identify genes related to high sucrose levels using QTL analysis. Colorimetric analysis based on the enzymatic reaction of invertase (INV) and glucose oxidase (GOD) was employed to test the germplasms. A total of six high-sucrose genetic resources (IT186230, IT195321, IT263138, IT263276, IT263286, and IT276521) and two low-sucrose genetic resources (IT025668 and IT274054) were identified. Two F2:3 populations, IT186230 × IT025668 and Ilmi × IT186230, were then established from these germplasms. QTL analysis identified four QTLs (qSUC6.1, qSUC11.1, qSUC15.1, and qSUC17.1), explaining 7.3-27.6% of the phenotypic variation in the sugar content. Twenty candidate genes were found at the four QTLs. Notably, Glyma.17G152300, located in the qSUC17.1 QTL region, exhibited a 17-fold higher gene expression in the high-sucrose germplasm IT186230 compared to the control germplasm Ilmi, confirming its role as a major gene regulating the sucrose content in soybean. These results may assist in marker-assisted selection for breeding programs that aim to develop soybean lines with a higher sucrose content.

Simultaneous knockout of cytosolic and plastidial disproportionating enzymes disrupts grain setting and filling in rice

Rice (Oryza sativa) plants contain plastidial and cytosolic disproportionating enzymes (DPE1 and DPE2). Our previous studies showed that DPE2 acts on maltose, the major product of starch degradation in pollens, releasing one glucose to fuel pollen tube growth and fertilization, whereas DPE1 participates in endosperm starch synthesis by transferring maltooligosyl groups from amylose to amylopectin, and removing excess short maltooligosaccharides. However, little is known about their integrated function. Here, we report that the coordinated actions of DPE1 and DPE2 contribute to grain setting and filling in rice. The dpe1dpe2 mutants could not be isolated from the progeny of heterozygous parental plants but were obtained via anther culture. Unlike that reported in Arabidopsis (Arabidopsis thaliana) and potato (Solanum tuberosum), the dpe1dpe2 rice plants grew normally but only yielded a small number of empty, unfilled seeds. In the dpe1dpe2 seeds, nutrient accumulation was substantially reduced, and dorsal vascular bundles were also severely malnourished. Zymogram analyses showed that changes in the activities of the major starch-synthesizing enzymes matched well with various endosperm phenotypes of mutant seeds. Mechanistically, DPE1 deficiency allowed normal starch mobilization in leaves and pollens but affected starch synthesis in endosperm, while DPE2 deficiency blocked starch degradation, resulting in substantially decreased levels of the sugars available for pollen tube growth and grain filling. Overall, our results demonstrate the great potential of DPE1-DPE2 as an important regulatory module to realize higher crop yields and present a promising target for regulating nutrient accumulation in cereal crop endosperm.

LcINH1 as an inhibitor of cell wall invertase LcCWIN5 regulates early seed development in Litchi chinensis Sonn

Sugar signal mediated by Cell wall invertase (CWIN) plays a central role in seed development. In higher plants, invertase inhibitors (INHs) suppress CWIN activities at a post-translational level. In Litchi chinensis cultivar 'Nuomici', impaired CWIN expression is associated with seed abortion. Here, the expression of LcINH1 was significantly higher in the funicle of seed-aborting cultivar 'Nuomici' than big-seeded cultivar 'Heiye'. Promoter analyses found LcINH1 contained a 404 bp repeat fragment with an endosperm regulatory element of Skn-1_motif. LcINH1 and LcCWIN2/5 were located in plasma membrane. LcINH1 was able to interact with LcCWIN5, but not with LcCWIN2. In vitro enzyme activity assay demonstrated that LcINH1 could inhibit CWIN activity. Silencing LcINH1 in 'Nuomici' resulted in normal seed development, paralleled increased CWIN activities and glucose levels. Transcriptome analysis identified 1079 differentially expressed genes (DEGs) in LcINH1-silenced fruits. KEGG analysis showed significant enrichment of DEGs in pathways related to transporters and plant hormone signal transduction. Weighted gene co-expression network analysis indicated that the turquoise module was highly correlated with fructose content, and LcSWEET3b was closely associated with early seed development. These findings suggest that LcINH1 regulate LcCWIN5 activity at the post-translational level to alter sucrose metabolism, thereby affecting early seed development in litchi.

Harnessing de novo transcriptome sequencing to identify and characterize genes regulating carbohydrate biosynthesis pathways in Salvia guaranitica L

Introduction

Carbohydrate compounds serve multifaceted roles, from energy sources to stress protectants, found across diverse organisms including bacteria, fungi, and plants. Despite this broad importance, the molecular genetic framework underlying carbohydrate biosynthesis pathways, such as starch, sucrose, and glycolysis/gluconeogenesis in Salvia guaranitica, remains largely unexplored.

Methods

In this study, the Illumina-HiSeq 2500 platform was used to sequence the transcripts of S. guaranitica leaves, generating approximately 8.2 Gb of raw data. After filtering and removing adapter sequences, 38 million reads comprising 210 million high-quality nucleotide bases were obtained. De novo assembly resulted in 75,100 unigenes, which were annotated to establish a comprehensive database for investigating starch, sucrose, and glycolysis biosynthesis. Functional analyses of glucose-6-phosphate isomerase (SgGPI), trehalose-6-phosphate synthase/phosphatase (SgT6PS), and sucrose synthase (SgSUS) were performed using transgenic Arabidopsis thaliana.

Results

Among the unigenes, 410 were identified as putatively involved in these metabolic pathways, including 175 related to glycolysis/gluconeogenesis and 235 to starch and sucrose biosynthesis. Overexpression of SgGPI, SgT6PS, and SgSUS in transgenic A. thaliana enhanced leaf area, accelerated flower formation, and promoted overall growth compared to wild-type plants.

Discussion

These findings lay a foundation for understanding the roles of starch, sucrose, and glycolysis biosynthesis genes in S. guaranitica, offering insights into future metabolic engineering strategies for enhancing the production of valuable carbohydrate compounds in S. guaranitica or other plants.

Arbuscular mycorrhizal fungi alter carbon metabolism and invertase genes expressions of Populus simonii × P. nigra under drought stress

Arbuscular mycorrhizal fungi (AMF) play a crucial role in regulating the allocation of carbon between source and sink tissues in plants and in regulating their stress responses by changing the sucrose biosynthesis, transportation, and catabolism in plants. Invertase, a key enzyme for plant development, participates in the response of plants to drought stress by regulating sucrose metabolism. However, the detailed mechanisms by which INV genes respond to drought stress in mycorrhizal plants remain unclear. This study examined the sugar content, enzyme activity, and expression profiles of INV genes of Populus simonii × P. nigra (PsnINVs) under two inoculation treatments (inoculation or non-inoculation) and two water conditions (well-watered or drought stress). Results showed that under drought stress, AMF up-regulated the expressions of PsnA/NINV1, PsnA/NINV2, PsnA/NINV3, and PsnA/NINV5 in leaves, which may be related to the enhancement of photosynthetic capacity. Additionally, AMF up-regulated the expressions of PsnA/NINV6, PsnA/NINV10, and PsnA/NINV12 in leaves, which may be related to enhancing osmotic regulation ability and drought tolerance.

Exploring the role of 28-homobrassinolide in regulation of temperature induced clastogenic aberrations and sugar metabolism of Brassica juncea L

The present research primarily focuses on Brassica juncea's physiological and cytological responses to low and high temperature stress at 4 °C and 44 °C respectively, along with elucidating the protective role of 28-Homobrassinolide (28-homoBL). Cytological investigations performed in floral buds of Brassica juncea L. under temperature (24, 4, 44 °C) stress conditions depict the presence of some abnormalities associated with cytomixis such as chromosome stickiness or agglutination, pycnotic nature of chromatin, irregularities in spindle formation, disoriented chromatins, and non-synchronous chromatin material condensation in Brassicaceae family that subsisted at diploid level (2n = 36). Spindle abnormalities produce various size pollen grains such as sporads micronuclei at some stages of microsporogenesis, polyads, triads, dyads that irrupted the productiveness of pollen grains. Furthermore, sugars play an imperative role in protecting plants under stress besides being energy sources. Therefore, the present study revealed accumulation of total soluble sugars (TSS), with 28-homoBL treatment which pinpoints protective role of 28-homoBL under temperature stress. Sugar profiling was done by using high-performance liquid chromatography (HPLC) which helped in analyzing different sugars both quantitatively and qualitatively under 28-homoBL and temperature stress conditions. The results indicate that the 28-homoBL treatment substantially enhances plant tolerance to heat stress, as evident by higher mitotic indices, fewer chromosomal abnormalities, and significantly more sugar accumulation. The findings of the study acknowledge the potential of 28-homoBL in inducing temperature stress tolerance in B. juncea along with improving the metabolic stability thereby implying application of 28-homoBL in crop strengthening under variable temperature conditions.

Multi-layer molecular analysis reveals distinctive metabolomic and transcriptomic profiles of different sweet corn varieties

In plants, sugar metabolism involves a complex interplay of genetic, molecular and environmental factors. To better understand the molecular mechanisms underlying these processes, we utilized a multi-layered approach that integrated transcriptomic and metabolomic datasets generated from multiple different varieties of sweet corn. Through this analysis, we found 2533 genes that were differentially expressed in the immature kernel tissues of sweet corn, including genes involved in transcriptional regulation, sugar metabolism, primary metabolism, and other processes associated with adaptability of sweet corn. We also detected 31 differential metabolites among the three types of sweet corn. Utilizing an integrated approach encompassing transcriptomics and eGWAS, we elucidated the transcriptional regulatory patterns governing these differential metabolites. Specifically, we delved into the transcriptional modulation of malate- and ubiquitin-associated genes across a range of sweet corn varieties, shedding new light on the molecular mechanisms underlying their regulation. This study provides a framework for future research aimed at improving the current understanding of sugar metabolism and regulatory gene networks in sweet corn, which could ultimately lead to the development of novel strategies for crop improvement.

Unveiling the molecular dynamics of low temperature preservation in postharvest lotus seeds: a transcriptomic perspective

BACKGROUND

Postharvest quality deterioration poses a significant challenge to the commercial value of fresh lotus seeds. Low temperature storage is widely employed as the primary method for preserving postharvest lotus seeds during storage and transportation.

RESULTS

This approach effectively extends the storage life of lotus seeds, resulting in distinct physiological changes compared to room temperature storage, including a notable reduction in starch, protein, H2O2, and MDA content. Here, we conducted RNA-sequencing to generate global transcriptome profiles of postharvest lotus seeds stored under room or low temperature conditions. Principal component analysis (PCA) revealed that gene expression in postharvest lotus seeds demonstrated less variability during low temperature storage in comparison to room temperature storage. A total of 14,547 differentially expressed genes (DEGs) associated with various biological processes such as starch and sucrose metabolism, energy metabolism, and plant hormone signaling response were identified. Notably, the expression levels of DEGs involved in ABA signaling were significantly suppressed in contrast to room temperature storage. Additionally, nine weighted gene co-expression network analysis (WGCNA)-based gene molecular modules were identified, providing insights into the co-expression relationship of genes during postharvest storage.

CONCLUSION

Our findings illuminate transcriptional differences in postharvest lotus seeds between room and low temperature storage, offering crucial insights into the molecular mechanisms of low temperature preservation in lotus seeds.

A neutral invertase controls cell division besides hydrolysis of sucrose for nutrition during germination and seed setting in rice

Sucrose is the transport form of carbohydrate in plants serving as signal molecule besides nutrition, but the signaling is elusive. Here, neutral invertase 8 (OsNIN8) mutated at G461R into OsNIN8m, which increased its charge and hydrophobicity, decreased hydrolysis of sucrose to 13% and firmer binding to sucrose than the wildtype. This caused downstream metabolites and energy accumulation forming overnutrition. Paradoxically, division of subinitials in longitudinal cell lineages was only about 15 times but more than 100 times in wildtype, resulting in short radicle. Further, mutation of OsNIN8 into deficiency of hydrolysis but maintenance of sucrose binding allowed cell division until ran out of energy showing the association but not hydrolysis gave the signal. Chemically, sucrose binding to OsNIN8 was exothermic but to OsNIN8m was endothermic. Therefore, OsNIN8m lost the signal function owing to change of thermodynamic state. So, OsNIN8 sensed sucrose for cell division besides hydrolyzed sucrose.

Sugar sensing in C4 source leaves: a gap that needs to be filled

Plant growth depends on sugar production and export by photosynthesizing source leaves and sugar allocation and import by sink tissues (grains, roots, stems, and young leaves). Photosynthesis and sink demand are tightly coordinated through metabolic (substrate, allosteric) feedback and signalling (sugar, hormones) mechanisms. Sugar signalling integrates sugar production with plant development and environmental cues. In C3 plants (e.g. wheat and rice), it is well documented that sugar accumulation in source leaves, due to source-sink imbalance, negatively feeds back on photosynthesis and plant productivity. However, we have a limited understanding about the molecular mechanisms underlying those feedback regulations, especially in C4 plants (e.g. maize, sorghum, and sugarcane). Recent work with the C4 model plant Setaria viridis suggested that C4 leaves have different sugar sensing thresholds and behaviours relative to C3 counterparts. Addressing this research priority is critical because improving crop yield requires a better understanding of how plants coordinate source activity with sink demand. Here we review the literature, present a model of action for sugar sensing in C4 source leaves, and suggest ways forward.

Perturbation of tonoplast sucrose transport alters carbohydrate utilization for seasonal growth and defense metabolism in coppiced poplar

Nonstructural carbohydrate reserves of stems and roots underpin overall tree fitness and productivity under short-rotation management practices such as coppicing for bioenergy. While sucrose and starch comprise the predominant stem carbohydrate reserves of Populus, utilization for fitness and agricultural productivity is understood primarily in terms of starch turnover. The tonoplast sucrose transport protein SUT4 modulates sucrose export from source leaves to distant sinks during photoautotrophic growth, but the possibility of its involvement in remobilizing carbohydrates from storage organs during heterotrophic growth has not been explored. Here, we used PtaSUT4-knockout mutants of Populus tremula × P. alba (INRA 717-1B4) in winter (cool) and summer (warm) glasshouse coppicing experiments to assess SUT4 involvement in reserve utilization. Conditions preceding and supporting summer sprouting were considered favorable for growth, while those preceding and supporting cool temperature sprouting were suboptimal akin to conditions associated with coppicing as generally practiced. Epicormic bud emergence was delayed in sut4 mutants following lower temperature 'winter' but not summer coppicing. Winter xylem hexose increases were observed in control but not in sut4 stumps after coppicing. The magnitude of starch and sucrose reserve depletion was similar in control and sut4 stumps during the winter and did not explain the sprouting and xylem hexose differences. However, winter maintenance costs appeared higher in sut4 based partly on Krebs cycle intermediate levels. In control plants, bark accrual of abundant defense metabolites, including salicinoids and condensed tannins, was higher in summer than in winter, but this increase of summer defense allocations was attenuated in sut4 mutants. Temperature-sensitive trade-offs between growth and other priorities may therefore depend on SUT4 in Populus.

Sugar import mediated by sugar transporters and cell wall invertases for seed development in Camellia oleifera

Seed development and yield depend on the transport and supply of sugar. However, an insufficient supply of nutrients from maternal tissues to embryos results in seed abortion and yield reduction in Camellia oleifera. In this study, we systematically examined the route and regulatory mechanisms of sugar import into developing C. oleifera seeds using a combination of histological observations, transcriptome profiling, and functional analysis. Labelling with the tracer carboxyfluorescein revealed a symplasmic route in the integument and an apoplasmic route for postphloem transport at the maternal-filial interface. Enzymatic activity and histological observation showed that at early stages [180-220 days after pollination (DAP)] of embryo differentiation, the high hexose/sucrose ratio was primarily mediated by acid invertases, and the micropylar endosperm/suspensor provides a channel for sugar import. Through Camellia genomic profiling, we identified three plasma membrane-localized proteins including CoSWEET1b, CoSWEET15, and CoSUT2 and one tonoplast-localized protein CoSWEET2a in seeds and verified their ability to transport various sugars via transformation in yeast mutants and calli. In situ hybridization and profiling of glycometabolism-related enzymes further demonstrated that CoSWEET15 functions as a micropylar endosperm-specific gene, together with the cell wall acid invertase CoCWIN9, to support early embryo development, while CoSWEET1b, CoSWEET2a, and CoSUT2 function at transfer cells and chalazal nucellus coupled with CoCWIN9 and CoCWIN11 responsible for sugar entry in bulk into the filial tissue. Collectively, our findings provide the first comprehensive evidence of the molecular regulation of sugar import into and within C. oleifera seeds and provide a new target for manipulating seed development.

Sucrose-Phosphate Synthase and Sucrose Synthase contribute to refoliation in ryegrass, a grassland fructan-accumulating species

The perennity of grassland species such as Lolium perenne greatly depends on their ability to regrow after cutting or grazing. Refoliation largely relies on the mobilization of fructans in the remaining tissues and on the associated sucrose synthesis and transport towards the basal leaf meristems. However, nothing is known yet about the sucrose synthesis pathway. Sucrose Phosphate Synthase (SPS) and Sucrose Synthase (SuS) activities, together with their transcripts, were monitored during the first hours after defoliation along the leaf axis of mature leaf sheaths and elongating leaf bases (ELB) where the leaf meristems are located. In leaf sheaths, which undergo a sink-source transition, fructan and sucrose contents declined while SPS and SuS activities increased, along with the expression of LpSPSA, LpSPSD.2, LpSuS1, LpSuS2, and LpSuS4. In ELB, which continue to act as a strong carbon sink, SPS and SuS activities increased to varying degrees while the expression of all the LpSPS and LpSuS genes decreased after defoliation. SPS and SuS both contribute to refoliation but are regulated differently depending on the source or sink status of the tissues. Together with fructan metabolism, they represent key determinants of ryegrass perennity and, more generally, of grassland sustainability.

Termostable and effective immobilized invertase for sucrose determination in fruit juices

In this study, immobilization of invertase enzyme was performed on a previously synthesized and characterized poly(N-vinylpyrrolidone-co-butylacrylate-co-N hydroxymethylacrylamide) terpolymer membranes by covalent bonding method. Glutaraldehyde(GA) was used as the crosslinker and Bovine Serum Albumin(BSA) was used as the binding agent. Optimum pH, temperature, amount of polymer, substrate concentration, amount of BSA and amount of GA values were determined for both free and immobilized enzyme. Optimum pH and temperature values were found as pH = 5.0, T = 55 °C, pH = 7.0 and T = 80 °C for free and immobilized enzyme, respectively. In particular, the optimum temperature of 80 °C for the immobilized enzyme provides its potential to be used commercially. The kinetic parameters of the free enzyme and the immobilized enzyme were determined using the well known Lineweaver-Burk method. The Vmax values for free (13.4 μM/min) and immobilized enzyme (12.2 μM/min) were found as close to each other, while the Km value of the immobilized enzyme (8.33 mM) was much lower than that of the free enzyme (29.41 mM). In reuse studies conducted with peach and orange juices, it was determined that the immobilized enzyme retained approximately 90% of its activity even after 30 reuses within 1 month.

Transcriptomic analysis provides insights into the molecular mechanism of melatonin-mediated cadmium tolerance in Medicago sativa L

Cadmium (Cd), a toxic element, often makes a serious threat to plant growth and development. Previous studies found that melatonin (Mel) reduced Cd accumulation and reestablished the redox balance to alleviate Cd stress in Medicago sativa L., however, the complex molecular mechanisms are still elusive. Here, comparative transcriptome analysis and biochemical experiments were conducted to explore the molecular mechanisms of Mel in enhancing Cd tolerance. Results showed that 7237 differentially expressed genes (DEGs) were regulated by Mel pretreatment to Cd stress compared to the control condition in roots of Medicago sativa L. Besides, in comparison with Cd stress alone, Mel upregulated 1081 DEGs, and downregulated 1085 DEGs. These DEGs were mainly involved in the transcription and translation of genes and folding, sorting and degradation of proteins, carbohydrate metabolism, and hormone signal network. Application of Mel regulated the expression of several genes encoding ribosomal protein and E3 ubiquitin-protein ligase involved in folding, sorting and degradation of proteins. Moreover, transcriptomic analyse suggested that Mel might regulate the expression of genes encoding pectin lyase, UDP-glucose dehydrogenase, sucrose-phosphate synthase, hexokinase-1, and protein phosphorylation in the sugar metabolism. Therefore, these could promote sucrose accumulation and subsequently alleviate the Cd damage. In conclusion, above findings provided the mining of important genes and molecular basis of Mel in mitigating Cd tolerance and genetic cultivation of Medicago sativa L.

Regional Variability in Sugar and Amino Acid Content of U.S. Soybeans and the Impact of Autoclaving on Reducing Sugars and Free Lysine

Exploring the sugar and amino acid content variability and the influence of thermal processing on these in soybeans can help optimize their utilization in animal feed. This study examined 209 samples harvested in 2020 and 55 samples harvested in 2021 from across the U.S. to assess their sugar variability and amino acid variability. Harvest regions included the East Corn Belt, West Corn Belt, Mid-South, East Coast, and the Southeast of the U.S. In addition to the sugar and amino acid contents, protein, oil, and seed size were also analyzed. Samples from 2021 were evaluated for their sugar and amino acid contents before and after autoclaving the seeds at 105-110 °C for 15 min. For the samples harvested in 2020, sucrose (4.45 g 100 g-1) and stachyose (1.34 g 100 g-1) were the most prevalent sugars. For the samples harvested in 2021, L-arginine (9.82 g 100 g-1), leucine (5.29 g 100 g-1), and glutamate (4.90 g 100 g-1) were the most prevalent amino acids. Heat treatment resulted in an 8.47%, 20.88%, 11.18%, and 1.46% median loss of free lysine, sucrose, glucose, and fructose. This study's insights into the variability in sugar and amino acid content and the heat-induced changes in the nutritional composition of soybeans provide a reference for improving soybean quality assessment and optimizing its use in animal feed formulations in the U.S.

Transcriptomic Profiling of Sugarcane White Leaf (SCWL) Canes during Maturation Phase

Sugarcane white leaf (SCWL) disease, caused by Candidatus Phytoplasma sacchari, results in the most damage to sugarcane plantations. Some SCWL canes can grow unnoticed through the maturation phase, subsequently resulting in an overall low sugar yield, or they can be used accidentally as seed canes. In this work, 12-month-old SCWL and asymptomatic canes growing in the same field were investigated. An abundance of phytoplasma in SCWL canes affected growth and sugar content as well as alterations of transcriptomic profiles corresponding to several pathways that responded to the infection. Suppression of photosynthesis, porphyrin and chlorophyll metabolism, coupled with an increase in the expression of chlorophyllase, contributed to the reduction in chlorophyll levels and photosynthesis. Blockage of sucrose transport plausibly occurred due to the expression of sugar transporters in leaves but suppression in stalks, resulting in low sugar content in canes. Increased expression of genes associated with MAPK cascades, plant hormone signaling transduction, callose plug formation, the phenylpropanoid pathway, and calcium cascades positively promoted defense mechanisms against phytoplasma colonization by an accumulation of lignin and calcium in response to plant immunity. Significant downregulation of CPK plausibly results in a reduction in antioxidant enzymes and likely facilitates pathogen invasion, while expression of sesquiterpene biosynthesis possibly attracts the insect vectors for transmission, thereby enabling the spread of phytoplasma. Moreover, downregulation of flavonoid biosynthesis potentially intensifies the symptoms of SCWL upon challenge by phytoplasma. These SCWL sugarcane transcriptomic profiles describe the first comprehensive sugarcane-phytoplasma interaction during the harvesting stage. Understanding molecular mechanisms will allow for sustainable management and the prevention of SCWL disease-a crucial benefit to the sugar industry.

Understanding the Saffron Corm Development-Insights into Histological and Metabolic Aspects

The reproduction of Crocus sativus L., a sterile triploid plant, is carried out exclusively through corms, whose size determines the saffron yield. The development of daughter corms (DC) is supported by photoassimilates supplied by the leaves as well as by the mother corms (MC). While biomass partitioning during DC development is well studied, growth dynamics in terms of cell number and size, the involved meristems, as well as carbohydrate partition and allocation, are not yet fully understood. We conducted a comprehensive study into saffron corm growth dynamics at the macroscopic and microscopic levels. Variations in carbohydrate content and enzymatic activities related to sucrose metabolism in sources and sinks were measured. Two key meristems were identified. One is involved in vascular connections between DC and MC. The other is a thickening meristem responsible for DC enlargement. This research explains how the previously described phases of corm growth correlate with variations in cell division, enlargement dynamics, and carbohydrate partitioning among organs. Results also elucidated that the end of DC growth relates to a significant drop in MC root biomass, limiting the water supply for the DC growth, and establishing the onset of leaf wilting. The lack of starch accumulation in aged leaf cells is noteworthy, as is the accumulation of lipids. We hypothesize a signaling role of sugars in DC growth initiation, stop, and leaf aging. Finally, we established a predominant role of sucrose synthase as a sucrolytic enzyme in the maintenance of the high flux of carbon for starch synthesis in DC. Together, the obtained results pave the way for the definition of strategies leading to better control of saffron corm development.

The roles of non-structural carbohydrates in fruiting: a review focusing on mango (Mangifera indica)

Reproductive development of fruiting trees, including mango (Mangifera indica L.), is limited by non-structural carbohydrates. Competition for sugars increases with cropping, and consequently, vegetative growth and replenishment of starch reserves may reduce with high yields, resulting in interannual production variability. While the effect of crop load on photosynthesis and the distribution of starch within the mango tree has been studied, the contribution of starch and sugars to different phases of reproductive development requires attention. This review focuses on mango and examines the roles of non-structural carbohydrates in fruiting trees to clarify the repercussions of crop load on reproductive development. Starch buffers the plant's carbon availability to regulate supply with demand, while sugars provide a direct resource for carbon translocation. Sugar signalling and interactions with phytohormones play a crucial role in flowering, fruit set, growth, ripening and retention, as well as regulating starch, sugar and secondary metabolites in fruit. The balance between the leaf and fruit biomass affects the availability and contributions of starch and sugars to fruiting. Crop load impacts photosynthesis and interactions between sources and sinks. As a result, the onset and rate of reproductive processes are affected, with repercussions for fruit size, composition, and the inter-annual bearing pattern.

Auxin regulates bulbil initiation by mediating sucrose metabolism in Lilium lancifolium

Lily bulbils, which serve as advantageous axillary organs for vegetative propagation, have not been extensively studied in terms of the mechanism of bulbil initiation. The functions of auxin and sucrose metabolism have been implicated in axillary organ development, but their relationship in regulating bulbil initiation remains unclear. In this study, exogenous indole-3-acetic acid (IAA) treatment increased the endogenous auxin levels at leaf axils and significantly decreased bulbil number, whereas treatment with the auxin polar transport inhibitor N-1-naphthylphthalamic acid (NPA), which resulted in a low auxin concentration at leaf axils, stimulated bulbil initiation and increased bulbil number. A low level of auxin caused by NPA spraying or silencing of auxin biosynthesis genes YUCCA FLAVIN MONOOXYGENASE-LIKE 6 (LlYUC6) and TRYPTOPHAN AMINOTRANSFERASERELATED 1 (LlTAR1) facilitated sucrose metabolism by activating the expression of SUCROSE SYNTHASES 1 (LlSusy1) and CELL WALL INVERTASE 2 (LlCWIN2), resulting in enhanced bulbil initiation. Silencing LlSusy1 or LlCWIN2 hindered bulbil initiation. Moreover, the transcription factor BASIC HELIX-LOOP-HELIX 35 (LlbHLH35) directly bound the promoter of LlSusy1, but not the promoter of LlCWIN2, and activated its transcription in response to the auxin content, bridging the gap between auxin and sucrose metabolism. In conclusion, our results reveal that an LlbHLH35-LlSusy1 module mediates auxin-regulated sucrose metabolism during bulbil initiation.

Integrative omics studies revealed synergistic link between sucrose metabolic isogenes and carbohydrates in poplar roots infected by Fusarium wilt

Advances in carbohydrate metabolism prompted its essential role in defense priming and sweet immunity during plant-pathogen interactions. Nevertheless, upstream responding enzymes in the sucrose metabolic pathway and associated carbohydrate derivatives underlying fungal pathogen challenges remain to be deciphered in Populus, a model tree species. In silico deduction of genomic features, including phylogenies, exon/intron distributions, cis-regulatory elements, and chromosomal localization, identified 59 enzyme genes (11 families) in the Populus genome. Spatiotemporal expression of the transcriptome and the quantitative real-time PCR revealed a minuscule number of isogenes that were predominantly expressed in roots. Upon the pathogenic Fusarium solani (Fs) exposure, dynamic changes in the transcriptomics atlas and experimental evaluation verified Susy (PtSusy2 and 3), CWI (PtCWI3), VI (PtVI2), HK (PtHK6), FK (PtFK6), and UGPase (PtUGP2) families, displaying promotions in their expressions at 48 and 72 h of post-inoculation (hpi). Using the gas chromatography-mass spectrometry (GC-MS)-based non-targeted metabolomics combined with a high-performance ion chromatography system (HPICS), approximately 307 metabolites (13 categories) were annotated that led to the quantification of 46 carbohydrates, showing marked changes between three compared groups. By contrast, some sugars (e.g., sorbitol, L-arabitol, trehalose, and galacturonic acid) exhibited a higher accumulation at 72 hpi than 0 hpi, while levels of α-lactose and glucose decreased, facilitating them as potential signaling molecules. The systematic overview of multi-omics approaches to dissect the effects of Fs infection provides theoretical cues for understanding defense immunity depending on fine-tuned Suc metabolic gene clusters and synergistically linked carbohydrate pools in trees.

Transcriptome Profiling Reveals Molecular Responses to Salt Stress in Common Vetch (Vicia sativa L.)

Common vetch (Vicia sativa L.) is an important annual diploid leguminous forage. In the present study, transcriptomic profiling in common vetch in response to salt stress was conducted using a salt-tolerant line (460) and a salt-sensitive line (429). The common responses in common vetch and the specific responses associated with salt tolerance in 460 were analyzed. Several KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways, including plant hormone and MAPK (mitogen-activated protein kinase) signaling, galactose metabolism, and phenylpropanoid phenylpropane biosynthesis, were enriched in both lines, though some differentially expressed genes (DEGs) showed distinct expression patterns. The roots in 460 showed higher levels of lignin than in 429. α-linolenic acid metabolism, carotenoid biosynthesis, the photosynthesis-antenna pathway, and starch and sucrose metabolism pathways were specifically enriched in salt-tolerant line 460, with higher levels of accumulated soluble sugars in the leaves. In addition, higher transcript levels of genes involved in ion homeostasis and reactive oxygen species (ROS) scavenging were observed in 460 than in 429 in response to salt stress. The transcriptomic analysis in common vetch in response to salt stress provides useful clues for further investigations on salt tolerance mechanism in the future.

The SlGRAS9-SlZHD17 transcriptional cascade regulates chlorophyll and carbohydrate metabolism contributing to fruit quality traits in tomato

Some essential components of fleshy fruits are dependent on photosynthetic activity and carbohydrate metabolism. Nevertheless, the regulatory mechanisms linking chlorophyll and carbohydrate metabolism remain partially understood. Here, we uncovered the role of SlGRAS9 and SlZHD17 transcription factors in controlling chlorophyll and carbohydrate accumulation in tomato fruit. Knockout or knockdown of SlGRAS9 or SlZHD17 resulted in marked increase in chlorophyll content, reprogrammed chloroplast biogenesis and enhanced accumulation of starch and soluble sugars. Combined genome-wide transcriptomic profiling and promoter-binding experiments unveiled a complex mechanism in which the SlGRAS9/SlZHD17 regulatory module modulates the expression of chloroplast and sugar metabolism either via a sequential transcriptional cascade or through binding of both TFs to the same gene promoters, or, alternatively, via parallel pathways where each of the TFs act on different target genes. For instance, the regulation of SlAGPaseS1 and SlSUS1 is mediated by SlZHD17 whereas that of SlVI and SlGLK1 occurs only through SlGRAS9 without the intervention of SlZHD17. Both SlGRAS9 and SlZHD17 can also directly bind the promoter of SlPOR-B to regulate its expression. Taken together, our findings uncover two important regulators acting synergistically to manipulate chlorophyll and carbohydrate accumulation and provide new potential breeding targets for improving fruit quality in fleshy fruits.

Effects of Root-Root Interactions on the Physiological Characteristics of Haloxylon ammodendron Seedlings

The root traits and response strategies of plants play crucial roles in mediating interactions between plant root systems. Current research on the role of root exudates as underground chemical signals mediating these interactions has focused mainly on crops, with less attention given to desert plants in arid regions. In this study, we focused on the typical desert plant Haloxylon ammodendron and conducted a pot experiment using three root isolation methods (plastic film separation, nylon mesh separation, and no separation). We found that (1) as the degree of isolation increased, plant biomass significantly increased (p < 0.05), while root organic carbon content exhibited the opposite trend; (2) soil electrical conductivity (EC), soil total nitrogen (STN), soil total phosphorus (STP), and soil organic carbon (SOC) were significantly greater in the plastic film and nylon mesh separation treatments than in the no separation treatment (p < 0.05), and the abundance of Proteobacteria and Actinobacteriota was significantly greater in the plastic film separation treatment than in the no separation treatment (p < 0.05); (3) both plastic film and nylon mesh separations increased the secretion of alkaloids derived from tryptophan and phenylalanine in the plant root system compared with that in the no separation treatment; and (4) Pseudomonas, Proteobacteria, sesquiterpenes, triterpenes, and coumarins showed positive correlations, while both pseudomonas and proteobacteria were significantly positively correlated with soil EC, STN, STP, and SOC (p < 0.05). Aurachin D was negatively correlated with Gemmatimonadota and Proteobacteria, and both were significantly correlated with soil pH, EC, STN, STP, and SOC. The present study revealed strong negative interactions between the root systems of H. ammodendron seedlings, in which sesquiterpenoids, triterpenoids, coumarins, and alkaloids released by the roots played an important role in the subterranean competitive relationship. This study provides a deeper understanding of intraspecific interactions in the desert plant H. ammodendron and offers some guidance for future cultivation of this species in the northwestern region of China.

Assessing the Chemical Composition, Antioxidant and enzyme Inhibitory Effects of Pentapleura subulifera and Cyclotrichium glabrescens Extracts

The Lamiaceae family, encompassing diverse plant species, holds significant value in food, medicine, and cosmetics. Within this family, Pentapleura subulifera and Cyclotrichium glabrescens, relatively unexplored species, were investigated for their chemical composition, antioxidant capacity, and enzyme-inhibiting effects. The chemical composition of hexane, methanolic, and aqueous extracts from P. subulifera and C. glabrescens were analyzed using LC-ESI-MS/MS and the non-polar hexane fraction was investigated via GC-MS. The antioxidant potential of the extracts was determined through radical scavenging, reducing power and metal chelating assays. Additionally, inhibitory activity against six enzymes - acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, amylase, and glucosidase - was examined. The aqueous extract of P. subulifera and the methanolic extract of C. glabrescens exhibited elevated phenolic content at 129.47 mg gallic acid equivalent (GAE)/g and 55.97 mg GAE/g, respectively. Chemical profiling of the constituents of the two plant species resulted in the identification of a total of twenty compounds. The majority of which belonged to flavonoids and quinic acid derivatives, primarily concentrated in the methanol and aqueous extracts. Among all antioxidant assays, the aqueous extracts of P. subulifera demonstrated superior antioxidant activity, with the highest recorded activity of 404.93 mg trolox equivalent (TE)/g in the cupric reducing antioxidant capacity (CUPRAC) test. Meanwhile, the hexane extract of C. glabrescens exhibited the highest AChE inhibitory activity at 2.71 mg galanthamine equivalent (GALAE)/g, followed by the methanol extract of P. subulifera at 2.41 mg GALAE/g. These findings unequivocally establish the notable antioxidant and enzyme inhibitory activity of P. subulifera and C. glabrescens extracts, underscoring their potential as a source of valuable natural antioxidants.

Cyclic variable temperature conditioning induces the rapid sweetening of sweet potato tuberous roots by regulating the sucrose metabolism

This study aimed to investigate the influence of cyclic variable temperature conditioning (CVTC) on the rapid sweetening of sweet potato tuberous roots, as assessed through the analysis of sugar metabolism-related compounds and enzyme activities of tubers during storage. The results showed that CVTC effectively preserved the quality of sweet potato tuberous roots, leading to a significant elevation in soluble solids and soluble sugars. The CVTC group displayed sucrose and fructose levels that were 1.72 and 1.46 times higher, respectively, compared to the control group at the 8 d. Additionally, after storage, the activities of β-amylase, sucrose phosphate synthase (SPS), and sucrose synthase (SS) in the CVTC group were increased by 19.85 %, 60.74 %, and 82.48 %, respectively. Conversely, acid convertase (AI) activity showed inhibition of 64.72 %. In conclusion, implementing CVTC enhanced enzymatic activity in β-amylase, SPS, and SS, facilitating starch degradation and sucrose synthesis, which contributed to the overall improvement in the sweetness of sweet potato tubers.

Integrating metabolomics and high-throughput sequencing to investigate the effects of tire wear particles on mung bean plants and soil microbial communities

Tire wear particles (TWPs) generated by vehicle tires are ubiquitous in soil ecosystems, while their impact on soil biota remains poorly understood. In this study, we investigated the effects of TWPs (0.1%, 0.7%, and 1.5% of dry soil weight) on the growth and metabolism of mung bean (Vigna radiata) plants over 32 days in soil pots. We found that TWPs-treated soils had high levels of heavy metals and polycyclic aromatic hydrocarbons (PAHs). However, there was no significant impact of TWPs exposure on plant growth, suggesting that mung bean plants have a degree of tolerance to TWPs. Despite the lack of impact on plant growth, exposure to TWPs had significant effects on soil enzyme activities, with a decrease of over 50% in urease and dehydrogenase activity. Furthermore, TWPs exposure resulted in marked changes in the plant metabolite profile, including altered levels of sugars, carboxylic acids, and amino acids, indicating altered nitrogen and amino acid-related metabolic pathways. TWPs exposure also disrupted the rhizospheric and bulk soil microbiota, with a decrease in the abundance of bacterial (Blastococcus) and fungal (Chaetomium) genera involved in nitrogen cycles and suppressing plant diseases. In summary, our study provides new insights into the effects of TWPs on plants and soil, highlighting the potential ecological consequences of TWPs pollution in terrestrial ecosystems and underscoring the need for further research in this area.

Genome-Wide Identification and Expression Analysis of the SUT Family from Three Species of Sapindaceae Revealed Their Role in the Accumulation of Sugars in Fruits

Sapindaceae is an economically important family of Sapindales and includes many fruit crops. The dominant transport and storage form of photoassimilates in higher plants is sucrose. Sucrose transporter proteins play an irreplaceable role in the loading, transportation, unloading, and distribution of sucrose. A few SUT (sugar transporter) family genes have been identified and characterized in various plant species. In this study, 15, 15, and 10 genes were identified in litchi, longan, and rambutan, respectively, via genome-wide screening. These genes were divided into four subgroups based on phylogenetics. Gene duplication analysis suggested these genes underwent potent purifying selection and tandem duplications during evolution. The expression levels of SlSut01 and SlSut08 were significantly increased in the fruits of Sapindaceae members. The homologs of these two genes in longan and rambutan were also highly expressed in the fruits. The expression pattern of SUTs in three organs of the two varieties was also explored. Subcellular colocalization experiments revealed that the proteins encoded by both genes were present in the plasma membrane. This report provides data for the functional study of SUTs in litchi and provides a basis for screening sugar accumulation-related genes in fruits of Sapindaceae.

A SNP variation in the Sucrose synthase (SoSUS) gene associated with sugar-related traits in sugarcane

Background

Sugarcane (Saccharum spp.) is an economically significant crop for both the sugar and biofuel industries. Breeding sugarcane cultivars with high-performance agronomic traits is the most effective approach for meeting the rising demand for sugar and biofuels. Molecular markers associated with relevant agronomic traits could drastically reduce the time and resources required to develop new sugarcane varieties. Previous sugarcane candidate gene association analyses have found single nucleotide polymorphism (SNP) markers associated with sugar-related traits. This study aims to validate these associated SNP markers of six genes, including Lesion simulating disease 1 (LSD), Calreticulin (CALR), Sucrose synthase 1 (SUS1), DEAD-box ATP-dependent RNA helicase (RH), KANADI1 (KAN1), and Sodium/hydrogen exchanger 7 (NHX7), in a diverse population in 2-year and two-location evaluations.

Methods

After genotyping of seven targeted SNP markers was performed by PCR Allelic Competitive Extension (PACE) SNP genotyping, the association with sugar-related traits and important cane yield component traits was determined on a set of 159 sugarcane genotypes. The marker-trait relationships were validated and identified by both t-test analysis and an association analysis based on the general linear model.

Results

The mSoSUS1_SNPCh10.T/C and mSoKAN1_SNPCh7.T/C markers that were designed from the SUS1 and KAN1 genes, respectively, showed significant associations with different amounts of sugar-related traits and yield components. The mSoSUS1_SNPCh10.T/C marker was found to have more significant association with sugar-related traits, including pol, CCS, brix, fiber and sugar yield, with p values of 6.08 × 10-6 to 4.35 × 10-2, as well as some cane yield component traits with p values of 1.61 × 10-4 to 3.35 × 10-2. The significant association is consistent across four environments.

Conclusion

Sucrose synthase (SUS) is considered a crucial enzyme involved in sucrose metabolism. This marker is a high potential functional marker that may be used in sugarcane breeding programs to select superior sugarcane with good fiber and high sugar contents.

Transcriptome Analysis Reveals Fruit Quality Formation in Actinidia eriantha Benth

Actinidia chinensis Planch. is a fruit tree originating from China that is abundant in the wild. Actinidia eriantha Benth. is a type of A. chinensis that has emerged in recent years. The shape of A. eriantha is an elongated oval, and the skin is covered with dense, non-shedding milk-white hairs. The mature fruit has flesh that is bright green in colour, and the fruit has a strong flavour and a grass-like smell. It is appreciated for its rich nutrient content and unique flavour. Vitamin C, sugar, and organic acids are key factors in the quality and flavour composition of A. eriantha but have not yet been systematically analysed. Therefore, we sequenced the transcriptome of A. eriantha at three developmental stages and labelled them S1, S2, and S3, and comparisons of S1 vs. S2, S1 vs. S3, and S2 vs. S3 revealed 1218, 4019, and 3759 upregulated differentially expressed genes and 1823, 3415, and 2226 downregulated differentially expressed genes, respectively. Furthermore, the upregulated differentially expressed genes included 213 core genes, and Gene Ontology enrichment analysis showed that they were enriched in hormones, sugars, organic acids, and many organic metabolic pathways. The downregulated differentially expressed genes included 207 core genes, which were enriched in the light signalling pathway. We further constructed the metabolic pathways of sugars, organic acids, and vitamin C in A. eriantha and identified the genes involved in vitamin C, sugar, and organic acid synthesis in A. eriantha fruits at different stages. During fruit development, the vitamin C content decreased, the carbohydrate compound content increased, and the organic acid content decreased. The gene expression patterns were closely related to the accumulation patterns of vitamin C, sugars, and organic acids in A. eriantha. The above results lay the foundation for the accumulation of vitamin C, sugars, and organic acids in A. eriantha and for understanding flavour formation in A. eriantha.

Suppression of a hexokinase gene SlHXK1 in tomato affects fruit setting and seed quality

Hexokinase is considered to be the key molecule in sugar signaling and metabolism. Here, we reported that silencing SlHXK1 resulted in a decrease in flower number, increased rate of flower dropping, abnormal thickening of the anther wall, and reduced pollen and seed viability. An anatomical analysis revealed the loss of small cells and abnormal thickening of anther walls in SlHXK1-RNAi lines. Treatment with auxin and 1-methylcyclopropene inhibited flower dropping from the pedicel abscission zone. qRT-PCR analysis revealed that the effect of SlHXK1 on abscission was associated with the expression levels of genes related to key meristem, auxin, ethylene, cell wall metabolism and programmed cell death. Pollen germination and pollen staining experiments showed that pollen viability was significantly reduced in the SlHXK1-RNAi lines. Physiological and biochemical analyses showed that hexokinase activity and starch content were markedly decreased in the transgenic lines. The expression of genes related to tomato pollen development was also suppressed in the transgenic lines. Although the RNAi lines eventually produced some viable seeds, the yield and quality of the seeds was lower than that of wild-type plants. Yeast two-hybrid and bimolecular fluorescence complementation assays showed that SlHXK1 interacted with SlKINγ. Furthermore, SlPIF4 inhibited the transcriptional expression of SlHXK1. In conclusion, our results demonstrate that SlHXK1 may play important roles in pollen, anther, seed and the pedicel abscission zone by affecting starch accumulation or cell wall synthesis, as well as by regulating the number of the transcripts of genes that are involved in auxin, ethylene and cell wall degradation.

The subgenome Saccharum spontaneum contributes to sugar accumulation in sugarcane as revealed by full-length transcriptomic analysis

INTRODUCTION

Modern sugarcane cultivars (Saccharum spp. hybrids) derived from crosses between S. officinarum and S. spontaneum, with high-sugar traits and excellent stress tolerance inherited respectively. However, the contribution of the S. spontaneum subgenome to sucrose accumulation is still unclear.

OBJECTIVE

To compensate for the absence of a high-quality reference genome, a transcriptome analysis method is needed to analyze the molecular basis of differential sucrose accumulation in sugarcane hybrids and to find clues to the contribution of the S. spontaneum subgenome to sucrose accumulation.

METHODS

PacBio full-length sequencing was used to complement genome annotation, followed by the identification of differential genes between the high and low sugar groups using differential alternative splicing analysis and differential expression analysis. At the subgenomic level, the factors responsible for differential sucrose accumulation were investigated from the perspective of transcriptional and post-transcriptional regulation.

RESULTS

A full-length transcriptome annotated at the subgenomic level was provided, complemented by 263,378 allele-defined transcript isoforms and 139,405 alternative splicing (AS) events. Differential alternative splicing (DA) analysis and differential expression (DE) analysis identified differential genes between high and low sugar groups and explained differential sucrose accumulation factors by the KEGG pathways. In some gene models, different or even opposite expression patterns of alleles from the same gene were observed, reflecting the potential evolution of these alleles toward novel functions in polyploid sugarcane. Among DA and DE genes in the sucrose source-sink complex pathway, we found some alleles encoding sucrose accumulation-related enzymes derived from the S. spontaneum subgenome were differentially expressed or had DA events between the two contrasting sugarcane hybrids.

CONCLUSION

Full-length transcriptomes annotated at the subgenomic level could better characterize sugarcane hybrids, and the S. spontaneum subgenome was found to contribute to sucrose accumulation.

Leaf senescence attributes: the novel and emerging role of sugars as signaling molecules and the overlap of sugars and hormones signaling nodes

Sugars are the primary products of photosynthesis and play multiple roles in plants. Although sugars are usually considered to be the building blocks of energy storage and carbon transport molecules, they have also gradually come to be acknowledged as signaling molecules that can initiate senescence. Senescence is an active and essential process that occurs at the last developmental stage and corresponds to programmed degradation of: cells, tissues, organs, and entire organisms. It is a complex process involving: numerous biochemical changes, transporters, genes, and transcription factors. The process is controlled by multiple developmental signals, among which sugar signals are considered to play a vital role; however, the regulatory pathways involved are not fully understood. The dynamic mechanistic framework of sugar accumulation has an inconsistent effect on senescence through the sugar signaling pathway. Key metabolizing enzymes produce different sugar signals in response to the onset of senescence. Diverse sugar signal transduction pathways and a variety of sugar sensors are involved in controlling leaf senescence. This review highlights the processes underlying initiation of sugar signaling and crosstalk between sugars and hormones signal transduction pathways affecting leaf senescence. This summary of the state of current knowledge across different plants aids in filling knowledge gaps and raises key questions that remain to be answered with respect to regulation of leaf senescence by sugar signaling pathways.

Metabolite Changes in Soybean (Glycine max) Leaves during the Entire Growth Period

Although soybean (Glycine max) leaves generate building blocks to produce seeds, a comprehensive understanding of the metabolic changes in soybean leaves during the entire growth stages is limited. Here, we investigated the metabolite changes in soybean leaves from five cultivars among four vegetative (V) and eight reproductive (R) stages using metabolite profiling coupled with chemometrics. Principal component analysis (PCA) of all samples showed a clear separation by growth stage. The total amount of monosaccharides and organic acids for energy production were highly detected in the V stage samples, accumulating in concentrations 2.5 and 1.7 times higher than in the R stage samples, respectively. The results of partial least-squares-discriminant analysis (PLS-DA) revealed a clear separation from R1 to R5 by the first PLS, suggesting significant alterations in the metabolic networks up to R5. After flowering, the stage of seed formation, R5, was associated with lower levels of most amino acids and an accumulation of phytosterols. The negative correlation observed between amino acids and phytosterol levels suggests a sophisticated coordination between carbon and nitrogen metabolism in plant, ensuring and supporting optimal growth (r = -0.50085, P = 0.0001). In addition, R-stage samples had decreased monosaccharide levels, indicating redistribution to seeds and senescence-related metabolite changes. Thus, metabolite profiling coupled with chemometrics could be a useful tool for investigating alterations in metabolic networks during various plant growth and development stages. Furthermore, we observed variations in flavonoid contents among the different cultivars. The results could be a basis of further studies on the source-sink interactions in the plant system.