Raffinose Family Research Articles

Gene isolation and expression analysis of galactinol synthase from proso millet (Panicum miliaceum L.)

Abstract Drought is the major devastating stress affecting plant growth and development. The plant develops some physiological and biochemical changes to withstand drought. The raffinose family of oligosaccharides (RFOs) are sugars that have a significant role in abiotic stress tolerance. Galactinol synthase (EC 2.4.1.123; GolS) initiates the primary step of the RFOs synthesis. Their accumulation implies a role for RFOs in abiotic stress adaptation. The galactinol synthase gene from proso millet was isolated and characterized. Full length proso millet galactinol synthase gene of size ~1,200 bp having 3 exons with 2 introns was isolated and predicted using bioinformatics tools. A high sequence similarity was observed at 97.2, 95.6, 91.8 and 85.4% with Panicum hallii, Panicum virgatum, Setaria italica and Zea mays mRNA, respectively. PmGolS gene expression pattern with respect to drought stress was evaluated in proso millet. PmGolS gene was highly expressed, 40.3 and 23.7-fold in vegetative and reproductive stages of drought-stressed plants respectively compared to control. It suggested that PmGolS gene has an active role in drought stress tolerance.

The Role of PLATZ6 in Raffinose Family Oligosaccharides Loading of Leaves via PLATZ Family Characterization in Cucumber

The plant AT protein and zinc-binding protein (PLATZ) genes, a novel cluster of plant-specific zinc-finger-dependent DNA-binding proteins, play a crucial role in regulating stress response and plant development. However, there has been little study focus on the role of the cucumber PLATZ family in assimilating loading in leaves. (1) In this study, a total of 12 PLATZ genes were identified from the cucumber genome. The cucumber PLATZ genes were clustered into five groups, and unevenly distributed on five chromosomes. A single pair of cucumber PLATZ genes underwent segmental duplication. (2) The results of genome-wide expression analysis suggested that the cucumber PLATZ genes were widely expressed in a wide range of cucumber tissues, with three PLATZ (PLATZ2, PLATZ6, and PLATZ12) genes exhibiting high expression in the vascular tissues of cucumber leaves. PLATZ2, PLATZ6, and PLATZ12 proteins were primarily located in cytomembrane and nucleus. (3) In VIGS-PLATZ6 plants, the expression of Galactinol synthase 1 (GolS1) and STACHYOSE SYNTHASE (STS), two genes involved in the synthesis of raffinose family oligosaccharides (RFOs) were observed to be decreased in cucumber leaves. In conclusion, the comprehensive analysis of the cucumber PLATZ family and the preliminary functional verification of PLATZ6 lay the foundation for the molecular and physiological functions of cucumber PLATZ genes.

Low molecular weight carbohydrates and abiotic stress tolerance in lentil (Lens culinaris Medikus): a review.

Lentil (Lens culinaris Medikus) is a nutrient-rich, cool-season food legume that is high in protein, prebiotic carbohydrates, vitamins, and minerals. It is a staple food in many parts of the world, but crop performance is threatened by climate change, where increased temperatures and less predictable precipitation can reduce yield and nutritional quality. One mechanism that many plant species use to mitigate heat and drought stress is the production of disaccharides, oligosaccharides and sugar alcohols, collectively referred to as low molecular weight carbohydrates (LMWCs). Recent evidence indicates that lentil may also employ this mechanism - especially raffinose family oligosaccharides and sugar alcohols - and that these may be suitable targets for genomic-assisted breeding to improve crop tolerance to heat and drought stress. While the genes responsible for LMWC biosynthesis in lentil have not been fully elucidated, single nucleotide polymorphisms and putative genes underlying biosynthesis of LMWCs have been identified. Yet, more work is needed to confirm gene identity, function, and response to abiotic stress. This review i) summarizes the diverse evidence for how LMWCs are utilized to improve abiotic stress tolerance, ii) highlights current knowledge of genes that control LMWC biosynthesis in lentil, and iii) explores how LMWCs can be targeted using diverse genomic resources and markers to accelerate lentil breeding efforts for improved stress tolerance.

Effects of cooking and market classes on nutritional and antioxidant properties of dry bean flours and soluble dietary fiber-rich fractions

Dry beans are a rich source of proteins, starch, dietary fiber, and phenolic compounds, thus exhibiting potential health benefits. Fractionating dry beans, especially soluble dietary fiber (SDF), could be considered a valuable functional food ingredient. This study investigated the effects of pinto and black dry bean market classes and atmospheric pressure cooking on the physicochemical attributes of dry bean flours and the extraction and characterization of SDF-rich fractions. Cooking significantly (p < 0.05) increased the dietary fiber content, altering the macronutrient profile. Raw flours exhibited higher levels of extractable phenols and antioxidant capacity, while cooked flours had more hydrolyzable phenols and associated antioxidant activities. Pinto beans were found to have higher levels of slowly digestible starch (23.76%) and resistant starch (5.24%) compared to black beans (20.63% and 3.22%, respectively). The SDF-rich fraction from cooked flours showed a reduced residual protein content and included pectic polysaccharides, hemicelluloses, and raffinose family oligosaccharides (RFOs), with cooking affecting their molecular weight distribution. These fractions demonstrated shear-thinning behavior and temperature-dependent viscosity. The study highlights the significant influence of market class and cooking process on the nutritional and antioxidant properties of dry beans, suggesting their potential contributions to dietary health.

Removal of raffinose and stachyose from soy-based beverages using soluble and immobilized MelA α-D-galactosidase from Lactiplantibacillus plantarum WCFS1

The hydrolysis of α-galactose-carbohydrates in soy-based beverages using the enzyme MelA α-D-galactosidase (Lp_3485) from Lactiplantibacillus plantarum WCFS1 is presented. MelA is a highly unstable trimeric enzyme whose activity and stability are strongly dependent on the dilution and polarity of the reaction medium. Considering this, the enzyme was immobilized and stabilized using different immobilization protocols. Post-immobilization techniques consisting of cross-linking with different polyfunctional polymers were used. The optimal derivative was used to hydrolyse different oligosaccharides of the raffinose family (raffinose and stachyose) present in soy drink preparations. Remarkably, MelA showed specific activity and high hydrolytic efficiency towards RFOs in soy-based beverages at a relatively low temperature (20 °C). Therefore, these results suggest that this enzyme could be preferentially used in the early stage of soybean processing to remove RFOs from soy-based beverages and soy-derived products, thereby improving their nutritional value.

Determinants of raffinose family oligosaccharide use in Bacteroides species.

The gut microbiome is important in health and disease. The diverse and densely populated environment of the gut makes competition for resources fierce. Hence, it is important to study the strategies employed by microbes for resource usage. Raffinose family oligosaccharides are abundant in plants and are a major source of nutrition for the microbiota in the colon since they remain undigested by the host. Here, we study how the model commensal organism, Bacteroides thetaiotaomicron utilizes raffinose family oligosaccharides. This work highlights how an important member of the microbiota uses an abundant dietary resource.

Virus-Induced galactinol-sucrose galactosyltransferase 2 Silencing Delays Tomato Fruit Ripening.

Tomato fruit ripening is an elaborate genetic trait correlating with significant changes at physiological and biochemical levels. Sugar metabolism plays an important role in this highly orchestrated process and ultimately determines the quality and nutritional value of fruit. However, the mode of molecular regulation is not well understood. Galactinoal-sucrose galactosyltransferase (GSGT), a key enzyme in the biosynthesis of raffinose family oligosaccharides (RFOs), can transfer the galactose unit from 1-α-D-galactosyl-myo-inositol to sucrose and yield raffinose, or catalyze the reverse reaction. In the present study, the expression of SlGSGT2 was decreased by Potato Virus X (PVX)-mediated gene silencing, which led to an unripe phenotype in tomato fruit. The physiological and biochemical changes induced by SlGSGT2 silencing suggested that the process of fruit ripening was delayed as well. SlGSGT2 silencing also led to significant changes in gene expression levels associated with ethylene production, pigment accumulation, and ripening-associated transcription factors (TFs). In addition, the interaction between SlGSGT2 and SlSPL-CNR indicated a possible regulatory mechanism via ripening-related TFs. These findings would contribute to illustrating the biological functions of GSGT2 in tomato fruit ripening and quality forming.

Understanding the Significance of Raffinose Family Oligosaccharides in Seed Physiology

Seed vigour and longevity are pivotal agronomic traits with profound implications for crop yield, food security, and the global economy. Seed longevity, often defined by the duration of seed viability, is crucial for effective gene bank management, influencing seed regeneration cycles and ensuring the long-term conservation of plant genetic resources. The inevitable process of seed deterioration, driven by a complex network of biochemical reactions, leads to altered metabolism and damage to critical cellular components such as membranes, DNA, mitochondria, proteins, and the antioxidative defence system. In recent research, Raffinose family oligosaccharides (RFOs) have emerged as key contributors to enhancing seed vigour and longevity. These sugars perform multiple functions in plants, including tolerance to abiotic and biotic stresses, regulation of seed germination, and maintenance of desiccation tolerance, all of which are essential for overall seed health. Studies suggest that RFOs significantly bolster seed vigour and longevity through mechanisms such as cytoplasmic vitrification, water replacement, and osmoprotection in dried seeds. These oligosaccharides are particularly abundant in the seeds of leguminous crops and are also found in roots and specialized storage organs. The glassy state formed by RFOs is vital for protecting cells from oxidative damage caused by reactive oxygen species (ROS), enhancing the stability of enzymes, and preventing deleterious conformational changes in proteins. Furthermore, delaying the degradation of RFOs has been shown to inhibit premature germination, underscoring their critical role in early seedling development and successful crop establishment.

Redesigning soybean with improved oil and meal traits.

Soybean seed oil and meal composition traits can be combined without interference to provide additional value to the crop. Soybean [Glycine max (L.) Merr.] is an important crop worldwide; its overall value comes from seed oil and high protein meal. The development of soybean varieties with allele combinations for improved oil and meal quality is expected to provide a compositional value bundle for soybean. The high oleic and low linolenic acid seed oil trait (HOLL; > 70% oleic and < 3% linolenic acid) is targeted to optimize the health and functional properties of soybean oil. For soybean meal, metabolizable energy is improved by altering the carbohydrate profile with increased sucrose and decreased anti-nutritional factors, raffinose family of oligosaccharides (RFOs). Previous research identified four variant alleles of fatty acid desaturase (FAD) genes and two raffinose synthase (RS) genes necessary for the HOLL trait in soybean oil and Low or Ultra-Low (UL) RFO traits in soybean meal, respectively. We employed a molecular marker-assisted breeding approach to combine six alleles conferring the desired soybean oil and meal value traits. Eight environment field trials were conducted with twenty-four soybean lines to evaluate phenotypic interactions among the variant alleles of FAD and RS genes. The results indicated that the four FAD gene alleles conditioned the HOLL fatty acid profile of the seed oil regardless of the allele status of the RS genes. Independent of the allele combination of the FAD genes, soybean with two variant alleles of the RS genes had the desired RFO trait in the seeds. The results confirm the feasibility of soybean variety development with this unique combination of oil and meal traits.

Source leaves are regulated by sink strengths through non-coding RNAs and alternative polyadenylation in cucumber (Cucumis sativus L.)

BackgroundThe yield of major crops is generally limited by sink capacity and source strength. Cucumber is a typical raffinose family oligosaccharides (RFOs)–transporting crop. Non-coding RNAs and alternative polyadenylation (APA) play important roles in the regulation of growth process in plants. However, their roles on the sink‒source regulation have not been demonstrated in RFOs–translocating species.ResultsHere, whole–transcriptome sequencing was applied to compare the leaves of cucumber under different sink strength, that is, no fruit-carrying leaves (NFNLs) and fruit-carrying leaves (FNLs) at 12th node from the bottom. The results show that 1101 differentially expressed (DE) mRNAs, 79 DE long non–coding RNAs (lncRNAs) and 23 DE miRNAs were identified, which were enriched in photosynthesis, energy production and conversion, plant hormone signal transduction, starch and carbohydrate metabolism and protein synthesis pathways. Potential co–expression networks like, DE lncRNAs–DE mRNAs/ DE miRNAs–DE mRNAs, and competing endogenous RNA (ceRNA) regulation models (DE lncRNAs–DE miRNAs–DE mRNAs) associated with sink‒source allocation, were constructed. Furthermore, 37 and 48 DE genes, which enriched in MAPK signaling and plant hormone signal transduction pathway, exist differentially APA, and SPS (CsaV3_2G033300), GBSS1 (CsaV3_5G001560), ERS1 (CsaV3_7G029600), PNO1 (CsaV3_3G003950) and Myb (CsaV3_3G022290) may be regulated by both ncRNAs and APA between FNLs and NFNLs, speculating that ncRNAs and APA are involved in the regulation of gene expression of cucumber sink‒source carbon partitioning.ConclusionsThese results reveal a comprehensive network among mRNAs, ncRNAs, and APA in cucumber sink–source relationships. Our findings also provide valuable information for further research on the molecular mechanism of ncRNA and APA to enhance cucumber yield.

Application of an α-galactosidase from Bacteroides fragilis on structural analysis of raffinose family oligosaccharides

Raffinose family oligosaccharides (RFOs) have diverse structures and exhibit various biological activities. When using RFOs as prebiotics, their structures need to be identified. If we first knew whether an RFO was classical or non-classical, structural identification would become much easier. Here, we cloned and expressed an α-galactosidase (BF0224) from Bacteroides fragilis which showed strict specificity for hydrolyzing α-Gal-(1 → 6)-Gal linkages in RFOs. BF0224 efficiently distinguished classical from non-classical RFOs by identifying the resulting hydrolyzed oligo- and mono-saccharides with HPAEC-PAD-MS. Using this strategy, we identified a non-classical RFO from Pseudostellaria heterophylla (Miquel) Pax with DP6 (termed PHO-6), as well as a classical RFO from Lycopus lucidus Turcz. with DP7 (termed LTO-7). To characterize these RFO structures, we employed four other commercial or reported α-galactosidases in combination with NMR and methylation analysis. Using this approach, we elucidated the accurate chemical structure of PHO-6 and LTO-7. Our study provides an efficient analytical approach to structurally analyze RFOs. This enzyme-based strategy also can be applied to structural analysis of other glycans.

Activity-based metaproteomics driven discovery and enzymological characterization of potential α-galactosidases in the mouse gut microbiome

The gut microbiota offers an extensive resource of enzymes, but many remain uncharacterized. To distinguish the activities of similar annotated proteins and mine the potentially applicable ones in the microbiome, we applied an effective Activity-Based Metaproteomics (ABMP) strategy using a specific activity-based probe (ABP) to screen the entire gut microbiome for directly discovering active enzymes and their potential applications, not for exploring host-microbiome interactions. By using an activity-based cyclophellitol aziridine probe specific to α-galactosidases (AGAL), we successfully identified and characterized several gut microbiota enzymes possessing AGAL activities. Cryo-electron microscopy analysis of a newly characterized enzyme (AGLA5) revealed the covalent binding conformations between the AGAL5 active site and the cyclophellitol aziridine ABP, which could provide insights into the enzyme’s catalytic mechanism. The four newly characterized AGALs have diverse potential activities, including raffinose family oligosaccharides (RFOs) hydrolysis and enzymatic blood group transformation. Collectively, we present a ABMP platform that facilitates gut microbiota AGALs discovery, biochemical activity annotations and potential industrial or biopharmaceutical applications.

Oligosaccharides from Stellaria dichotoma L. var. lanceolate bind to galectin-3 and ameliorate effects of colitis

Even though Stellaria dichotoma L. var. lanceolate (S. dichotoma) is a well-known medicinal plant in the family Caryophyllaceae, its oligosaccharides remain unexplored in terms of their potential as bioactive agents. Here, we isolated a mixture of oligosaccharides from S. dichotoma (Yield: 12 % w/w), that are primarily non-classical raffinose family oligosaccharides (RFOs). Nine major oligosaccharides were purified and identified from the mixture, including sucrose, raffinose, 1-planteose, lychnose, stellariose, along with four new non-classical RFOs. Two of the four new oligosaccharides are linear hexose pentamers with α-galactosyl extensions on their lychnose moieties, and the other two are branched hexose hexamers with α-galactosyl extensions on their stellariose groups. Their interactions with galectin-3 (Gal-3) revealed significant binding, with the terminal galactose providing enhanced affinity for the lectin. Notably, Gal-3 residues Arg144, His158, Asn160, Arg162, Asn174, Trp181, Glu184 and Arg186 coordinate with the lychnose. In vivo studies using the dextran sulfate sodium (DSS) mouse model for colitis demonstrated the ability of these carbohydrates in mitigating ulcerative colitis (UC). Overall, our study has provided structural information and potential applications of S. dichotoma oligosaccharides, also offers new approaches for the development of medicinal oligosaccharides.

Reduction of antinutrients and off-flavour in kidney bean flour by acidic and alkaline reactive extrusion

The presence of antinutrients and undesirable flavours in kidney bean flour poses challenges to consumer acceptance. Although extrusion can mitigate antinutrients to some extent, its impact on reducing beany flavour in bean flour remains underexplored. This study investigated the effects of injecting acetic acid or sodium carbonate solutions at three concentration levels (0.05, 0.1, 0.15 mol/L), in conjunction with three temperature profiles (40/60/80/80/90, 40/60/80/90/110, 50/70/90/110/130 °C) and two feed moisture levels (25, 30 %), on the removal of antinutrients (condensed tannins, trypsin inhibitor activity, phytic acid, raffinose family oligosaccharides) and reduction of volatile compounds that contribute to beany flavour in whole kidney bean flour. The results showed that all concentrations of acetic acid and sodium carbonate solutions effectively reduced condensed tannins compared to water, especially at 130 °C extrusion temperature. Introducing acetic acid and sodium carbonate solutions at a concentration of 0.15 mol/L led to 72 and 90 % reduction of total raffinose family oligosaccharide content, respectively, in contrast to the 17 % reduction observed with water alone. The incorporation of sodium carbonate solution reduced the total volatile compounds by 45–58 % as compared with water (23–33 %) and acetic acid (11–27 %). This reduction was primarily due to the reduction of aldehydes, alcohols, and aromatic hydrocarbons. These results indicate that injecting sodium carbonate solution during extrusion can effectively reduce antinutrients and beany flavour compounds in kidney bean flour.

From Genes to Stress Response: Genomic and Transcriptomic Data Suggest the Significance of the Inositol and Raffinose Family Oligosaccharide Pathways in Stylosanthes scabra, Adaptation to the Caatinga Environment.

S. scabra is an important forage and extremophilic plant native to the Brazilian Caatinga semiarid region. It has only recently been subjected to omics-based investigations, and the generated datasets offer insights into biotechnologically significant candidates yet to be thoroughly examined. INSs (inositol and its derivatives) and RFO (raffinose oligosaccharide family) pathways emerge as pivotal candidates, given their critical roles in plant physiology. The mentioned compounds have also been linked to negative impacts on the absorption of nutrients in mammals, affecting overall nutritional intake and metabolism. Therefore, studying these metabolic pathways is important not just for plants but also for animals who depend on them as part of their diet. INS and RFO pathways in S. scabra stood out for their abundance of identified loci and enzymes. The enzymes exhibited genomic redundancy, being encoded by multiple loci and various gene families. The phylogenomic analysis unveiled an expansion of the PIP5K and GolS gene families relative to the immediate S. scabra ancestor. These enzymes are crucial for synthesizing key secondary messengers and the RFO precursor, respectively. Transcriptional control of the studied pathways was associated with DOF-type, C2H2, and BCP1 transcription factors. Identification of biological processes related to INS and RFO metabolic routes in S. scabra highlighted their significance in responding to stressful conditions prevalent in the Caatinga environment. Finally, RNA-Seq and qPCR data revealed the relevant influence of genes of the INS and RFO pathways in the S. scabra response to water deprivation. Our study deciphers the genetics and transcriptomics of the INS and RFO in S. scabra, shedding light on their importance for a Caatinga-native plant and paving the way for future biotechnological applications in this species and beyond.

ABA-receptor agonist iSB09 decreases soil water consumption and increases tomato CO2 assimilation and water use efficiency under drought stress

Climate change can alter precipitation patterns, disrupting the natural water cycle and generating drought periods that negatively impact crop yield or plant survival. Novel biotechnological approaches are being developed to face water deficits. Specifically, molecular knowledge of the plant hormone abscisic acid (ABA) can be harnessed to develop genetic and chemical approaches to cope with abiotic stress. ABA receptor agonists are promising molecules that activate ABA signaling on demand and show long-lasting effects, in contrast to the exogenous application of ABA, which has a short half-life. In this work, we studied the effect of the iSB09 agonist on tomato plants grown under drought stress or well-watered conditions. iSB09 treatment induced stomatal closure in tomato through activation of PYL1-like and PYL4-like ABA receptors. Additionally, RNA-seq analyses reveal coordinated upregulation by ABA or iSB09 of the genes encoding enzymes involved in the synthesis of the osmoprotective galactinol and raffinose family of oligosaccharides. Foliar spraying of iSB09 under drought conditions anticipated the regulation of transpiration, promoted drought avoidance and increased water use efficiency in tomato plants. Physiological analysis of agonist-treated plants reveals increased CO2 assimilation and effective quantum yield of the photosystem II under drought conditions in iSB09-treated plants compared to mock-treated. Faster regulation of transpiration at the start of the drought period was achieved by iSB09 treatment, and, as a result, water consumption was reduced compared to mock-treated plants. Overall, the agonist treatment mounts the genome-wide transcriptional response to stress and increases water use efficiency under drought conditions and plant protection.

Purification, characterisation and immobilisation of a protease‐resistant α‐galactosidase from Monascus purpureus and its application in removal of raffinose family oligosaccharides

SummaryIn this study, an α‐galactosidase (MPG) was produced by submerged fermentation from Monascus purpureus, a food‐grade fungus used for making red yeast rice. MPG was purified from intracellular extract which showed a subunit molecular mass of 95 kDa. MPG was optimally active at pH 4.0 and 50 °C and was stable between pH 3.5–8.0 and at temperatures up to 50 °C. The enzyme retained its activity in the presence of most of the metal ions except Cu2+ and Fe2+. MPG exhibited remarkable resistance to the proteases, pepsin, trypsin and proteinase K as well as to the sugars, galactose and sucrose. Moreover, it retained complete activity under simulated gastric conditions. The enzyme displayed specificity for the substrates, melibiose, raffinose and stachyose and was able to hydrolyze these oligosaccharides. It was effective in the removal of non‐digestible raffinose family oligosaccharides (RFOs) from soybeans, chickpeas and kidney beans. MPG was immobilised onto chitosan and the immobilised enzyme (iMPG) displayed higher optimal temperature (60 °C), better thermostability and substrate specificity as compared to MPG. iMPG was also capable of hydrolyzing RFOs in chickpeas and could be efficiently reused six times. In view of their superior properties, MPG and iMPG may have great prospects in the food and feed industries for the removal of RFOs from soy and other legumes.

Galactinol synthase 2 influences the metabolism of chlorophyll, carotenoids, and ethylene in tomato fruits.

Galactinol synthase (GolS), which catalyses the synthesis of galactinol, is the first critical enzyme in the biosynthesis of raffinose family oligosaccharides (RFOs) and contributes to plant growth and development, and resistance mechanisms. However, its role in fruit development remains largely unknown. In this study, we used CRISPR/Cas9 gene-editing technology in tomato (Solanum lycopersicum) to create the gols2 mutant showing uniformly green fruits without dark-green shoulders, and promoting fruit ripening. Analysis indicated that galactinol was undetectable in the ovaries and fruits of the mutant, and the accumulation of chlorophyll and chloroplast development was suppressed in the fruits. RNA-sequencing analysis showed that genes related to chlorophyll accumulation and chloroplast development were down-regulated, including PROTOCHLOROPHYLLIDE OXIDOREDUCTASE, GOLDEN 2-LIKE 2, and CHLOROPHYLL A/B-BINDING PROTEINS. In addition, early color transformation and ethylene release was prompted in the gols2 lines by regulation of the expression of genes involved in carotenoid and ethylene metabolism (e.g. PHYTOENE SYNTHASE 1, CAROTENE CIS-TRANS ISOMERASE, and 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACID SYNTHASE2/4) and fruit ripening (e.g. RIPENING INHIBITOR, NON-RIPENING, and APETALA2a). Our results provide evidence for the involvement of GolS2 in pigment and ethylene metabolism of tomato fruits.

CHARACTERIZATION OF GALACTINOL SYNTHASE (GOLS) GENES IN IPOMOEA TRILOBA AND I. TRIFIDA: AN APPROACH USING BIOINFORMATICS

Galactinol synthase (GolS - EC 2.4.1.123) is classified as a key enzyme that catalyzes the first step in the synthesis pathway of the raffinose family (RFOs). Although GolS genes have been characterized in several important species, their characterization in sweet potatoes has yet to be explored. Ipomoea trifida (Kunth) G. Don (2n = 2x = 30) is currently described as one of the closest ancestors of the sweet potato and considered an excellent crossbreeding species, allowing the introgression of important genes such as GolS. This study aimed to identify and characterize in silico the GolS genes in I. trifida and compare with I. triloba. We identified nine GolS genes, five in I. triloba and four in I. trifida. Our study encompassed various aspects, including gene structure analysis, motif identification, chromosomal distribution, synteny analysis, and gene expression. The presence of gene duplications and purifying selection were highlighted, suggesting the evolutionary significance of GolS genes in these species. Phylogenetic analysis categorized GolS proteins into three groups, potentially reflecting distinct functional roles. Furthermore, synteny analysis revealed orthologous relationships between GolS genes in the studied species and related plants, contributing to our understanding of their evolutionary history. In silico expression analysis across diverse tissues unveiled tissue-specific expression patterns, hinting at specialized roles for GolS genes in different plant organs. These findings contribute to the broader field of plant genetics, carbohydrate metabolism, and agriculture, offering opportunities for crop improvement and sustainable food production.

Variation of sugar compounds in Phoebe chekiangensis seeds during natural desiccation.

To investigate the role of sugar metabolism in desiccation-sensitive seeds, we performed a natural desiccation treatment on Phoebe chekiangensis seeds in a room and systematically analyzed the changes in seed germination, sugar compounds, malondialdehyde, and relative electrical conductivity during the seed desiccation. The results revealed that the initial moisture content of P. chekiangensis seed was very high (37.06%) and the seed was sensitive to desiccation, the germination percentage of the seed decreased to 5.33% when the seed was desiccated to 22.04% of moisture content, therefore, the seeds were considered recalcitrant. Based on the logistic model, we know that the moisture content of the seeds is 29.05% when the germination percentage drops to 50% and that it is desirable to keep the seed moisture content above 31.74% during ambient transportation. During seed desiccation, sucrose and trehalose contents exhibited increasing trends, and raffinose also increased during the late stage of desiccation, however, low levels of the non-reducing sugar accumulations may not prevent the loss of seed viability caused by desiccation. Glucose and fructose predominated among sugar compounds, and they showed a slight increase followed by a significant decrease. Their depletion may have contributed to the accumulation of sucrose and raffinose family oligosaccharides. Correlation analysis revealed a significant relationship between the accumulation of sucrose, trehalose, and soluble sugars, and the reduction in seed viability. Sucrose showed a significant negative correlation with glucose and fructose. Trehalose also exhibited the same pattern of correlation. These results provided additional data and theoretical support for understanding the mechanism of sugar metabolism in seed desiccation sensitivity.