Search

Orchids produce millions of dust-like and reserveless tiny seeds per capsule and are unable to germinate on their own in nature. Orchid seeds have developed strategies to exploit seed germination-promoting orchid mycorrhizal fungi (sgOMFs) for acquisition of exogenous nutrients to fuel germination. Once colonized by sgOMFs, orchid seeds can digest intracellular sgOMF hyphae to acquire fungal nutrients, especially those for carbon nutrition. However, the underlying carbon delivery pathway from sgOMFs to orchid cells remains elusive. Clarification of the identities of fungally derived carbohydrates and the main molecular players responsible for the sgOMF-to-orchid carbon flow is of great significance for better understanding of symbiotic germination. To germinate in nature, orchid seeds strictly rely on seed germination-promoting orchid mycorrhizal fungi (sgOMFs) for provision of carbon nutrients. The underlying delivery pathway, however, remains elusive. We develop here a plausible model for sugar transport from sgOMFs to orchid embryonic cells to fuel germination. Orchids exploit sgOMFs to induce the formation of pelotons, elaborate intracellular hyphal coils in orchid embryos. The colonized orchid cells then obtain carbon nutrients by uptake from living hyphae and peloton lysis, primarily as glucose derived from fungal trehalose hydrolyzed by orchid-specific trehalases. The uptake of massive fungally derived glucose is likely to be mediated by two classes of membrane proteins, namely, sugars will eventually be exported transporters (SWEETs) and H+-hexose symporters. The proposed model serves as a launch pad for further research to better understand and improve orchid seed germination and conservation. [ABSTRACT FROM AUTHOR]

Background: Drought stress during flowering of maize (Zea mays L.) frequently results in decreased kernel setting, leading to grain yield depressions. Plasma membrane (PM) H+‐ATPase was identified as a key enzyme responsible for supply of assimilates to the developing maize kernels shortly after pollination. The activity of this enzyme was strongly inhibited under salt stress, pointing to an involvement in kernel abortion. Aims: This study aimed to determine whether also drought stress causes inhibition of PM H+‐ATPase in developing maize kernels shortly after pollination, leading to diminished hexose uptake and finally kernel abortion. The key questions are as follows: What are the limiting factors for grain yield production of maize plants facing drought? Are physiologically relevant parameters, quantified at flowering, reflected by yield determinants at maturity? Methods: Maize plants were cultivated using the container technique, and drought stress was imposed during 3 weeks bracketing flowering compared to well‐watered conditions throughout the entire growth period. The developing kernels were harvested 2 days after pollination, and PM vesicles were isolated and purified using two‐phase partitioning. Results: Water deficit caused a significant decrease in grain yield at maturity (−35%), which was determined by a reduced kernel number (−42%). Source limitation in the developing kernels under stress could be excluded. Acid invertase activity was unaffected by water deficit. Hexose availability was also no limiting factor for kernel setting and development. However, Vmax of in vitro hydrolytic activity of PM H+‐ATPase was significantly decreased in the developing maize kernels under drought stress and the maximal pH gradient at the PM was also significantly reduced. The observed inhibiting effects on PM H+‐ATPase were mainly of quantitative nature, as a lower number of proton pumps was present in the kernel PM. Qualitative changes of the enzyme (activation energy Ea, Michaelis constant Km) due to drought were not observed. Conclusions: The lower pH gradient probably decreased the proton‐driven transport of hexoses by carriers into the cytosol of the kernel cells, leading to kernel starvation and eventually contributing to kernel abortion. [ABSTRACT FROM AUTHOR]

Background: Dendrobium officinale Kimura et Migo, a renowned traditional Chinese orchid herb esteemed for its significant horticultural and medicinal value, thrives in adverse habitats and contends with various abiotic or biotic stresses. Acid invertases (AINV) are widely considered enzymes involved in regulating sucrose metabolism and have been revealed to participate in plant responses to environmental stress. Although members of AINV gene family have been identified and characterized in multiple plant genomes, detailed information regarding this gene family and its expression patterns remains unknown in D. officinale, despite their significance in polysaccharide biosynthesis. Results: This study systematically analyzed the D. officinale genome and identified four DoAINV genes, which were classified into two subfamilies based on subcellular prediction and phylogenetic analysis. Comparison of gene structures and conserved motifs in DoAINV genes indicated a high-level conservation during their evolution history. The conserved amino acids and domains of DoAINV proteins were identified as pivotal for their functional roles. Additionally, cis-elements associated with responses to abiotic and biotic stress were found to be the most prevalent motif in all DoAINV genes, indicating their responsiveness to stress. Furthermore, bioinformatics analysis of transcriptome data, validated by quantitative real-time reverse transcription PCR (qRT-PCR), revealed distinct organ-specific expression patterns of DoAINV genes across various tissues and in response to abiotic stress. Examination of soluble sugar content and interaction networks provided insights into stress release and sucrose metabolism. Conclusions: DoAINV genes are implicated in various activities including growth and development, stress response, and polysaccharide biosynthesis. These findings provide valuable insights into the AINV gene amily of D. officinale and will aid in further elucidating the functions of DoAINV genes. [ABSTRACT FROM AUTHOR]

The ecotoxicity of Ag particles of different size has been assessed by microbiological, biochemical, and phytotoxic indicators for the upper layer (0–20 cm) of ordinary chernozem (Haplic Chernozem) in a laboratory model experiment. The effect has been studied of nano- (10 and 100 nm) and microparticles (1000 nm) of Ag at concentrations of 1, 10, and 100 mg/kg on the biological parameters of ordinary chernozem 30 days after contamination: the activity of catalase, dehydrogenases, ferrireductase, urease, peroxidase, polyphenol oxidase, invertase, phosphatase, the total number of bacteria, the abundance of bacteria of Azotobacter genus, the number of germinated seeds and the length of radish roots. It was found that the ecotoxicity of Ag particles depended on their size: in most cases, Ag particles 10 nm in size had a stronger ecotoxic effect on the biological parameters than particles 100 and 1000 nm in size. There were no significant differences in the ecotoxicity of 100 and 1000 nm Ag particles. The difference in the effects of Ag particles of different sizes increased with increasing Ag concentration in the soil: the higher the Ag concentration was in the soil (from 1 to 100 mg/kg), the more pronounced the difference was in ecotoxicity between 10 nm Ag particles and 100 and 1000 nm Ag particles. Phytotoxic indicators were more sensitive to contamination by Ag nanoparticles at all concentrations studied (1, 10 and 100 mg/kg); the total number of bacteria, invertase and phosphatase activity at 10 and 100 mg/kg; the abundance of bacteria of Azotobacter genus and the activity of dehydrogenases at 100 mg/kg. It is advisable to use these indicators in biodiagnostics of the ecotoxicity of Ag nanoparticles. [ABSTRACT FROM AUTHOR]

In this work, an acid invertase isolated from Lathyrus aphaca seedlings is purified, and its thermal properties are investigated. Acid invertase was purified through salt fractionation, CM-cellulose, and Ultrogel ACA-44 chromatography. Using SDS-PAGE, the consistency of the isolated enzyme was verified. The enzyme weighs 29 kDa at the molecular level. Acid invertase functions best at a pH of 3.0 and a temperature of 45 °C. Activation energy of 29.5 kJ mol−1 and K m and V max values of 0.5 mM and 119.7 µmol. min−1. mg−1 of protein was found for the isolated enzyme. It was shown that the mercaptide-forming agent p -chloromercuribenzoic acid (PCMB; 0.5 mM) and the enzyme's activity were both modestly increased by Ca2+, Mn2+, and Mg2+ ions but inhibited by Hg2+, Cd2+, and Pb2+ ions. At elevated temperatures, the invertase exhibited an increase in thermostability due to an increase in activation entropies (∆Sº) and a decrease in activation enthalpies (∆Hº). The interactions between 4 M urea and α-chymotrypsin were tetraphasic, causing periodic increases and decreases in invertase activity. It also suggests a potential explanation for acid-invertase thermal inactivation at high temperatures. This enzyme might be a catabolite-resistant invertase to produce high-gravity ethanol or fructose syrup. [Display omitted] • Acid invertase was purified from Lathyrus aphaca seedlings with molecular weight 29 kDa. • Acid invertase free in a solution of 5% (w/v) sucrose, pH 3.0, is stable up to 50 °C for a period of 4 h. • The K m and V max values for acid invertase was 0.5 mM and 119.7 µmol. min-1.mg−1 of protein. • The acid invertase is more stable and their energy of deactivation are 107 kJ/mol (25 kcal/mol), respectively. • The effects of α-chymotrypsin and 4 M urea were tetraphasic with periodic gain and loss of enzyme activity. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum) is the third most important food crop in the world. Potato tubers must be stored at cold temperatures to minimize sprouting and losses due to disease. However, cold temperatures strongly induce the expression of the potato vacuolar invertase gene (VInv) and cause reducing sugar accumulation. This process, referred to as "cold-induced sweetening," is a major postharvest problem for the potato industry. We discovered that the cold-induced expression of VInv is controlled by a 200 bp enhancer, VInvIn2En, located in its second intron. We identified several DNA motifs in VInvIn2En that bind transcription factors involved in the plant cold stress response. Mutation of these DNA motifs abolished VInvIn2En function as a transcriptional enhancer. We developed VInvIn2En deletion lines in both diploid and tetraploid potato using clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9 (Cas9)-mediated gene editing. VInv transcription in cold-stored tubers was significantly reduced in the deletion lines. Interestingly, the VInvIn2En sequence is highly conserved among distantly related Solanum species, including tomato (Solanum lycopersicum) and other non-tuber-bearing species. We conclude that the VInv gene and the VInvIn2En enhancer have adopted distinct roles in the cold stress response in tubers of tuber-bearing Solanum species. An intronic enhancer is responsible for cold-induced expression of the vacuolar invertase gene in potato. [ABSTRACT FROM AUTHOR]

Sugar beet molasses is a low-value byproduct from the sugar industry. It contains significant amounts of sucrose (approx. 50% (w/w)), which can be used for many different applications, for example, as feedstock for the production of fuel (as ethanol) and biobased chemicals such as 5-hydoxymethyl furfural (HMF). To produce platform chemicals, sucrose is hydrolyzed into its monomeric C6 sugars: glucose and fructose. When comparing the hydrolysis rates of molasses with a pure sucrose solution, the specific reaction rate is much slower (Qp/x,60min = 93 and 70 gprod L−1 h−1 gcell−1 for pure sucrose and crude molasses, respectively) at the same sucrose concentration (300 g/L) and process conditions. To clarify why molasses inhibits the enzymatic hydrolysis rate, the influence of its viscosity and inorganic and organic composition was investigated. Also, the effects of molasses and treated molasses on pure enzymes, invertase (from Saccharomyces cerevisiae, 0.05 mg/mL), compared with hydrolysis using whole cells of Baker's yeast (3 mg/mL), were tested. The results indicate an inhibitory effect of potassium (Qp/x,60min = 76 gprod L−1 h−1 gcell−1), generally at high salt concentrations (Qp/x,60min = 67 gprod L−1 h−1 gcell−1), which could be correlated to the solution's high salt concentrations and possibly the synergistic effects of different ions when applying concentrations that were four times that in the molasses. Also, the viscosity and sucrose purity seem to have an effect, where pure sucrose solutions and thick juice from the sugar mill yielded higher hydrolysis rates (Qp/x,60min = 97 gprod L−1 h−1 gcell−1) than molasses-type solutions with a higher viscosity (Qp/x,60min = 70–74 gprod L−1 h−1 gcell−1). Attempting to further understand the effects of different components on the invertase activity, an in silico investigation was performed, indicating that high salt concentrations affected the binding of sucrose to the active site of the enzyme, which can result in a lower reaction rate. This knowledge is important for future scale-up of the hydrolysis process, since reduced hydrolysis rates require larger volumes to provide a certain productivity, requiring larger process equipment and thereby higher investment costs. [ABSTRACT FROM AUTHOR]

Background and Aims Extrafloral nectaries are nectar-secreting structures present on vegetative parts of plants which provide indirect defences against herbivore attack. Extrafloral nectaries in Clerodendrum chinense are patelliform-shaped specialized trichomatous structures. However, a complete understanding of patelliform extrafloral nectaries in general, and of C. chinense in particular, has not yet been established to provide fundamental insight into the cellular physiological machinery involved in nectar biosynthesis and secretory processes. Methods We studied temporal changes in the morphological, anatomical and ultrastructural features in the architectures of extrafloral nectaries. We also compared metabolite profiles of extrafloral nectar, nectary tissue, non-nectary tissue and phloem sap. Further, both in situ histolocalization and normal in vitro activities of enzymes related to sugar metabolism were examined. Key Results Four distinct tissue regions in the nectar gland were revealed from histochemical characterization, among which the middle nectariferous tissue was found to be the metabolically active region, while the intermediate layer was found to be lipid-rich. Ultrastructural study showed the presence of a large number of mitochondria along with starch-bearing chloroplasts in the nectariferous region. However, starch depletion was noted with progressive maturation of nectaries. Metabolite analysis revealed compositional differences among nectar, phloem sap, nectary and non-nectary tissue. Invertase activity was higher in secretory stages and localized in nectariferous tissue and adjacent region. Conclusions Our study suggests extrafloral nectar secretion in C. chinense to be both eccrine and merocrine in nature. A distinct intermediate lipid-rich layer that separates the epidermis from nectary parenchyma was revealed, which possibly acts as a barrier to water flow in nectar. This study also revealed a distinction between nectar and phloem sap, and starch could act as a nectar precursor, as evidenced from enzymatic and ultrastructural studies. Thus, our findings on changing architecture of extrafloral nectaries with temporal secretion revealed a cell physiological process involved in nectar biosynthesis and secretion. [ABSTRACT FROM AUTHOR]

Strigolactones (SLs) were recently defined as a novel class of plant hormones that act as key regulators of diverse developmental processes and environmental responses. Much research has focused on SL biosynthesis and signaling in roots and shoots, but little is known about whether SLs are produced in early developing seeds and about their roles in ovule development after fertilization. This study revealed that the fertilized ovules and early developing pericarp in Xanthoceras sorbifolium produced minute amounts of two strigolactones: 5-deoxystrigol and strigol. Their content decreased in the plants with the addition of exogenous phosphate (Pi) compared to those without the Pi treatment. The exogenous application of an SL analog (GR24) and a specific inhibitor of SL biosynthesis (TIS108) affected early seed development and fruit set. In the Xanthoceras genome, we identified 69 potential homologs of genes involved in SL biological synthesis and signaling. Using RNA-seq to characterize the expression of these genes in the fertilized ovules, 37 genes were found to express differently in the fertilized ovules that were aborting compared to the normally developing ovules. A transcriptome analysis also revealed that in normally developing ovules after fertilization, 12 potential invertase genes were actively expressed. Hexoses (glucose and fructose) accumulated at high concentrations in normally developing ovules during syncytial endosperm development. In contrast, a low ratio of hexose and sucrose levels was detected in aborting ovules with a high strigolactone content. XsD14 virus-induced gene silencing (VIGS) increased the hexose content in fertilized ovules and induced the proliferation of endosperm free nuclei, thereby promoting early seed development and fruit set. We propose that the crosstalk between sugar and strigolactone signals may be an important part of a system that accurately regulates the abortion of ovules after fertilization. This study is useful for understanding the mechanisms underlying ovule abortion, which will serve as a guide for genetic or chemical approaches to promote seed yield in Xanthoceras. [ABSTRACT FROM AUTHOR]

Enzymatic activity of soils is the most important diagnostic indicator of the ecological state of soils affected by various types of anthropogenic impact. The aim of the study was to evaluate the enzymatic activity of ordinary chernozem (Haplic Chernozem) contaminated with Ag, Bi, Te, and Tl. Ten enzymes (catalase, dehydrogenase, peroxidase, polyphenol oxidase, ascorbate oxidase, ferrireductase, protease, phosphatase, invertase, and urease) were analyzed. According to the degree of inhibition of enzymes, heavy metals formed the following sequence: Tl > Ag > Bi > Te. With an increase in the concentration of heavy metals, the toxic effect on the activity of enzymes increased. The oxidoreductases showed greater sensitivity to Ag, Bi, Te, and Tl contamination than hydrolases. Among oxidoreductases, the highest sensitivity was found for ferrireductase, and the lowest one for ascorbate oxidase. According to the activity of enzymes of the hydrolase class, invertase was the most sensitive, and urease was the least sensitive. When contaminated with Ag, Bi, and Te, invertase had the highest informative value, and when contaminated with Tl, urease and polyphenol oxidase were the most informative. Among the enzymes of the oxidoreductase class, the highest information value was found for peroxidase, and the lowest one for ascorbate oxidase. Among the enzymes of the hydrolase class, invertase was the most sensitive, and phosphatase was the least sensitive. The results of the study can be used to assess the ecological state of soils contaminated with Ag, Bi, Te and Tl. [ABSTRACT FROM AUTHOR]

The results of studying the effect of fires on biological properties of cinnamonic soils of xerophytic forests (Skeletic Leptic Cambisol) of the Utrish State Nature Reserve, Krasnodar krai (crown fire of 2020), and burozem of mesophytic forests (Haplic Cambisol (Loamic)) of the Khamyshinsk forestry, Republic of Adygea (ground fire of 2018) are presented. Changes in the soil reaction, in the organic carbon content, and in the activity of enzymes: catalase, urease, phosphatase, and invertase involved in the cycle of carbon, phosphorus, and nitrogen have been studied. The reaction of enzymes to pyrogenic effects depends on the enzyme kind and the soil type. The factor analysis was also performed. The activity of catalase and invertase decreases by 47% on average for two soil types in the 0–3-cm-thick layer, while the reaction of phosphatase and urease depends on the soil type. Two years after the fire, the phosphatase activity in the surface layer of post-pyrogenic cinnamonic soils approached the control values; and the urease activity regenerated more slowly as compared to other enzymes. Four years after the fire, the values of urease activity in the 0–3-cm-thick layer of the post-pyrogenic acid burozem, on the contrary, approached the control values. An increase in pH by 30% on average and a decrease in the Corg content by 12% on average were also recorded for both two soil types. The mean activity of all the studied enzymes in the 3–10-cm-thick layer increased in cinnamonic soils and, on the contrary, decreased in acid burozem. The factor analysis showed a relationship between the soil reaction, the organic carbon content, and the activity of enzymes, and the strength and nature of relationships differed depending on the soil type. The results obtained testify to the effect of soil properties on the response of enzymatic activity to the pyrogenic impact. [ABSTRACT FROM AUTHOR]

Carbohydrates and gamma-amino butyric acid (GABA) have not been studied under the stress of stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) in wheat. Wheat cultivars PBW725 (resistant) and HD2967 (susceptible) were compared at 1, 2 and 4 d of GABA, Pst, and GABA + Pst sprayed to 30-d of seedling growth. Starch was hydrolyzed, and levels of sugars and proteins improved over time of infection in PBW725 however HD2967 improved under GABA + Pst. Proline increased while GABA decreased over the time of infection in HD2967. Progressive increase of diamine oxidase and glutamate decarboxylase was seen in PBW725 during infection. Protease levels became low at 4 d of infection but improved under GABA + Pst in HD2967. Protein carbonyls increased in HD2967 only under Pst but decreased under GABA + Pst. Results concluded that GABA is an essential regulator of carbohydrates under stripe rust. Sustained response over time of infection may be important for resistance. [ABSTRACT FROM AUTHOR]

Key message: Sucrose invertase activity is positively related to osmotic and salt stress resistance in peanut. Sucrose invertases (INVs) have important functions in plant growth and response to environmental stresses. However, their biological roles in peanut are still not fully revealed. In this research, we identified 42 AhINV genes in the peanut genome. They were highly conserved and clustered into three groups with 24 segmental duplication events occurred under purifying selection. Transcriptional expression analysis exhibited that they were all ubiquitously expressed, and most of them were up-regulated by osmotic and salt stresses, with AhINV09, AhINV23 and AhINV19 showed the most significant up-regulation. Further physiochemical analysis showed that the resistance of peanut to osmotic and salt stress was positively related to the high sugar content and sucrose invertase activity. Our results provided fundamental information on the structure and evolutionary relationship of INV gene family in peanut and gave theoretical guideline for further functional study of AhINV genes in response to abiotic stress. [ABSTRACT FROM AUTHOR]

The food enzyme β‐fructofuranosidase (β‐d‐fructofuranoside fructohydrolase; EC 3.2.1.26) is produced with the non‐genetically modified Saccharomyces cerevisiae strain NCYC R693 by Kerry Ingredients & Flavours Ltd. The production strain meets the requirements for the qualified presumption of safety (QPS) approach. The food enzyme is intended to be used in four food manufacturing processes. The dietary exposure to the food enzyme–total organic solids (TOS) was estimated to be up to 2.485 mg TOS/kg body weight per day in European populations. As the production strain qualifies for the QPS approach of safety assessment and no issue of concern arising from the production process of the food enzyme were identified, the Panel considered that no toxicological studies other than the assessment of allergenicity were necessary. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and one match with a tomato allergen was found. The Panel considered that the risk of allergic reactions upon dietary exposure to this food enzyme, particularly in individuals sensitised to tomato, cannot be excluded. However, the likelihood of allergic reactions is expected not to exceed the likelihood of allergic reactions to tomato. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use. [ABSTRACT FROM AUTHOR]

Sugar beet factories employ long-term storage of sugar beet roots to extend the processing campaign in Egypt. Changes in the chemical composition of sugar beet roots during storage, driven by invertase enzyme activity, impact the crystallization process in sugar production. This study aimed to monitor invertase activity in sugar beet roots harvested at 180, 195 and, 210 days of cultivation, applying different storage conditions for 1, 10, 20, and 30 days. Additionally, the study explored the influence of invertase activity on reducing sugars content in sugar beet roots. Results indicated that covered storage conditions exhibited the lowest invertase activity compared to open air and room storage conditions. Moreover, reducing sugars content was affected by invertase enzyme activity. Storage conditions displayed the lowest inverted sugars content across all tested sugar beet root varieties. Thus, the study suggests that long-term storage with covered conditions is suitable for extending the processing campaign, emphasizing the importance of considering inverted sugars concentration. [ABSTRACT FROM AUTHOR]

AbstractEkINV and BsINV are two invertases from Enterobacter kobei and Bacillus subtillis, respectively. The two enzymes were produced extracellularly at pH 3.0 and former at 45 °C while latter at 25 °C. The Km values were observed to be 1.7 mol/L (EkINV) and 1.9 mol/L (BsINV). Purification and characterization analysis revealed trimer structure EkINV having subunit molecular mass as 87.14, 42.98 and 29.0 kDa. Unlike, BsINV was monomer with molecular mass of 55.1 kDa. The invertases beside hydrolytic activity exhibited transfructolysation which is used in preparation of low calorie Ready To Serve mango juice and muffins. [ABSTRACT FROM AUTHOR]

Exogenous nitrogen and carbon can affect plant cell walls, which are composed of structural carbon. Sucrose synthase (SUS), invertase (INV), hexokinase (HXK), phosphoglucomutase (PGM), and UDP-glucose pyrophosphorylase (UGP) are the key enzymes of sucrose metabolism involved in cell wall synthesis. To understand whether these genes are regulated by carbon and nitrogen to participate in structural carbon biosynthesis, we performed genome-wide identification, analyzed their expression patterns under different carbon and nitrogen treatments, and conducted preliminary functional verification. Different concentrations of nitrogen and carbon were applied to poplar (Populus trichocarpa Torr. and Gray), which caused changes in cellulose, lignin, and hemicellulose contents. In poplar, 6 SUSs, 20 INVs, 6 HXKs, 4 PGMs, and 2 UGPs were identified. Moreover, the physicochemical properties, collinearity, and tissue specificity were analyzed. The correlation analysis showed that the expression levels of PtrSUS3/5, PtrNINV1/2/3/5/12, PtrCWINV3, PtrVINV2, PtrHXK5/6, PtrPGM1/2, and PtrUGP1 were positively correlated with the cellulose content. Meanwhile, the knockout of PtrNINV12 significantly reduced the cellulose content. This study could lay the foundation for revealing the functions of SUSs, INVs, HXKs, PGMs, and UGPs, which affected structural carbon synthesis regulated by nitrogen and carbon, proving that PtrNINV12 is involved in cell wall synthesis. [ABSTRACT FROM AUTHOR]

The enzymatic approach is a highly effective and the major scientific method to eliminating bitter components in citrus-derived products nowadays. Microbial production of limonin invertase stands out due to its pivotal role in the removal of the bitter substance, limonin. The optimization of fermentation parameters and the study of scale-up fermentation are imperative for product commercialization. In this study, we focused on optimizing stirring speed, fermentation temperature, and initial pH to enhance the growth and limonin invertase production by the Aspergillus tabin strain UA13 in a 5-l stirred-tank bioreactor. Our results revealed the following optimal parameters are: a stirring speed of 300 rpm, a fermentation temperature of 35°C and a pH 5.0. Under these optimized conditions, the limonin invertase activity reached its peak at 63.38 U ml−1, representing a 1.67-fold increase compared to the unoptimized conditions (38.10 U ml−1), while also reducing the fermentation duration by 12 h. Furthermore, our research demonstrated that limonin invertase effectively hydrolyze limonin in grapefruit juice, reducing its content from 13.28 to 2.14 μg ml−1, as determined by HPLC, resulting in a 6.21-fold reduction of the bitter substance. [ABSTRACT FROM AUTHOR]

Sugarcane (Saccharum spp. hybrid) is the chief source of sugar and biofuel globally and is prominent among cash crops. Sucrose is the main required product in sugarcane, and many studies have been performed to understand the phenomena of sucrose synthesis, metabolism, and accumulation in sugarcane. However, none of the studies concluded that a single gene is responsible for the sucrose content. Instead, a complex mechanism consisting of several genes, such as sucrose phosphate synthase genes (SPS1, SPS2, SPS4, SPS5), sucrose synthase genes (SuSy1, SuSy2, SuSy4), invertase genes (INV, CWIN, NIN1, CINV2), and phytohormone, trehalose, transcription factor (TF), protein kinase, and sugar transporter genes are working spatiotemporally in sugarcane. Currently, omics approaches like transcriptomics, proteomics, and metabolomics are also being used to explore the sugar metabolism in sugarcane, but integrated transcriptomic, proteomic, and metabolomic studies have been less reported. The results obtained from the integrated analysis of transcriptomics, proteomics, and metabolomics are more reliable because the strong gene expression, received in the form of abundant mRNA, does not guarantee the plentiful existence of associated proteins or their particular activity in the target cells or tissues, which discloses the restraint of single interpretation and stresses the significance of the integrated analysis of transcriptomics, proteomics, and metabolomics. This review highlights different genes and molecules contributing to sugar metabolism at different stages and the significance of omics approaches in explaining sucrose metabolism, especially sucrose accumulation in sugarcane. It is also a vital source of knowledge for sugarcane breeders, particularly associated with sucrose content improvement and bioethanol energy production. [ABSTRACT FROM AUTHOR]

In this work, we established an efficient process for the production of itaconate from the regionally sourced industrial side-stream molasses using Ustilago cynodontis and Ustilago maydis. While being relatively cheap and more environmentally friendly than refined sugars, there are some major challenges to overcome when working with molasses. Some of those challenges are a high nitrogen load, unknown impurities in the feedstock, and high amounts of ill-favoured carbon sources, such as sucrose or lactate. We could show that the activity of the sucrose-hydrolysing enzyme invertase plays a crucial role in the efficiency of the process and that the fructose utilisation differs between the two strains used in this work. Thus, with a higher invertase activity, the ability to convert fructose into the desired product itaconate, and an overall higher tolerance towards undesired substances in molasses, U. maydis is better equipped for the process on the alternative feedstock molasses than U. cynodontis. The established process with U. maydis reached competitive yields of up to 0.38 g g−1 and a titre of more than 37 g L−1. This shows that an efficient and cost-effective itaconate production process is generally feasible using U. maydis, which has the potential to greatly increase the sustainability of industrial itaconate production. • Itaconate production from molasses with engineered Ustilago sp. • High invertase activity for sucrose hydrolysis is key to process efficiency • U. maydis shows superior sucrose conversion and raw material tolerance compared to U. cynodontis. • Fed-batch process with molasses achieves competitive itaconate yields and titres [ABSTRACT FROM AUTHOR]

The growing global market for industrial enzymes has led to a constant search for efficient, cost-effective methods for their production. This study reports the production of invertase using inexpensive and readily available agro-materials. Starch-digesting enzymes extracted from malted unkilned sorghum were used to hydrolyze cassava starch supplemented with 2% whole soybean. The production of intracellular invertase by Saccharomyces cerevisiae OL629078.1 in cassava-soybean and yeast sucrose broth was compared. The purification and characterization of invertase produced using the low-cost medium were also reported. The results showed that there was a 4.1-fold increase in the units of invertase produced in cassava-soybean medium (318.605 U/mg) compared to yeast sucrose broth medium (77.6 U/mg). The invertase produced was purified by chromatographic methods up to 5.53-fold with a recovery of 62.6%. Estimation of the molecular weight with gel filtration indicated a molecular weight of 118 kDa. The enzyme demonstrated its maximum activity at 50 °C and there was no decrease in its activity following a 1-h incubation at this temperature. At a pH of 5.0, the enzyme demonstrated optimal activity and it maintained over 60% of its activity in the acid range (pH 3–6). The Michalis-Menten constants Km and Vmax of intracellular invertase were 5.85 ± 1.715 mM and 6.472 ± 2.099 U/mg, respectively. These results suggest that Saccharomyces cerevisiae grown on cassava-soybean is a viable, cost-effective alternative for commercial invertase production, which can be explored for biotechnological processes. [ABSTRACT FROM AUTHOR]

Black rot disease, caused by Ceratocystis fimbriata Ellis & Halsted, severely affects both plant growth and post-harvest storage of sweet potatoes. Invertase (INV) enzymes play essential roles in hydrolyzing sucrose into glucose and fructose and participate in the regulation of plant defense responses. However, little is known about the functions of INV in the growth and responses to black rot disease in sweet potato. In this study, we identified and characterized an INV-like gene, named IbINV, from sweet potato. IbINV contained a pectin methylesterase-conserved domain. IbINV transcripts were most abundant in the stem and were significantly induced in response to C. fimbriata, salicylic acid, and jasmonic acid treatments. Overexpressing IbINV in sweet potato (OEV plants) led to vigorous growth and high resistance to black rot disease, while the down-regulation of IbINV by RNA interference (RiV plants) resulted in reduced plant growth and high sensitivity to black rot disease. Furthermore, OEV plants contained a decreased sucrose content and increased hexoses content, which might be responsible for the increased INV activities; not surprisingly, RiV plants showed the opposite effects. Taken together, these results indicate that IbINV positively regulates plant growth and black rot disease resistance in sweet potato, mainly by modulating sugar metabolism. [ABSTRACT FROM AUTHOR]

Inulinases are enzymes of great interest in the food industry, especially due to their application in the synthesis of fructose and fructo-oligosaccharides. Moreover, some inulinases (I) also present invertase activity (S), making them useful for sucrose hydrolysis processes. In the present study, the production of inulinase by Aspergillus niger URM5741 was evaluated and optimized using two statistical approaches. First, the composition of the cultivation medium was determined through a simplex centroid mixture design, followed by the selection of optimal fermentation conditions using the Box–Behnken design. Based on these experimental designs, the maximum activities of inulinase (16.68 U mL−1) and invertase (27.80 U mL−1) were achieved using a mixture of wheat, soy, and oat brans (5 g), along with 2.5% inulin and 40% moisture. The inulinase exhibited optimum temperature and pH of 60 °C and 4.0, respectively, displayed a high affinity for both substrates, as evidenced by very-low Michaelis constant values (1.07–1.54 mM). A relative thermostability was observed at 55–60 °C as indicated by half-lives values (I: 169.06–137.27 min; S: 173.29–141.52 min) and D-values (I: 561.61–456.00 min; S: 575.65–470.11 min) which were further confirmed by the high activation energy (123.01 and 143.29 kJ mol−1). The enzyme demonstrated favorable results in terms of inulin and sucrose hydrolysis, being a maximum release of reducing sugars of 6.04 and 15.80 g L−1, respectively. These results indicate that the sequential statistical approach proved to be beneficial to produce inulinase by A. niger URM5741, with the obtained enzyme considered promising for long-term industrial applications. [ABSTRACT FROM AUTHOR]

Invertase, an industrially significant glycoenzyme, was purified from baker's yeast using poly (2-Hydroxyethyl methacrylate) [PHema-Pba] cryogels functionalized with boronic acid. At subzero temperatures, PHema-Pba cryogels were synthesized and characterized using swelling tests, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The surface area of the PHema-Pba cryogels was 14 m2/g with a swelling ratio of 88.3% and macroporosity of 72%. The interconnected macropores of PHema-Pba cryogels were shown via scanning electron microscopy. Invertase binding capacity of PHema-Pba cryogel was evaluated by binding studies in different pH, temperature, and interaction time conditions and the maximum Invertase binding of PHema-Pba cryogel was found as 15.2 mg/g. and 23.7 fold Invertase purification was achieved from baker's yeast using PHema-Pba cryogels. The results show that PHema-Pba cryogels have high Invertase binding capacity and may be used as an alternative method for enzyme purification via boronate affinity systems. [ABSTRACT FROM AUTHOR]

Bud dormancy enables deciduous fruit trees to endure unfavorable conditions during winter, and considerably impacts growth and reproduction in spring. We investigated acid invertase activities during dormancy release until bud break under natural (orchard) conditions in two consecutive years. Our aim was to relate the activity patterns to the developmental progression and to air temperature, which is a major factor influencing the developmental processes at that stage. The enzyme assays were performed on extracts from leaf buds of the cultivar Idared, sampled from early March to April in the years 2020 and 2021. The air temperature was continually monitored during the observation periods. cwINV activity showed a trend of slight increase at the earlier developmental stages and sharply increased during bud break in both years. cwINV is known to contribute to organ sink strength. Its up-regulation may, therefore, be related to the increasing developmental demand for carbohydrates in apple leaf buds during dormancy release until bud break. vacINV activity was relatively constant at the earlier stages and also showed a pronounced increase in activity during bud break in both years. However, in both years, we observed drops in vacINV activity following cold spells. vacINV activity has been associated with growth via cell elongation through the regulation of cell turgor and may, thus, be involved in bud break. Therefore, we suggest that the down-regulation of vacINV activity as a consequence of cold spells might contribute to a delay in bud break to protect young leaf tissues from exposure to cold stress conditions. [ABSTRACT FROM AUTHOR]

The growing global market for industrial enzymes has led to a constant search for efficient, cost-effective methods for their production. This study reports the production of invertase using inexpensive and readily available agro-materials. Starch-digesting enzymes extracted from malted unkilned sorghum were used to hydrolyze cassava starch supplemented with 2% whole soybean. The production of intracellular invertase by Saccharomyces cerevisiae OL629078.1 in cassava-soybean and yeast sucrose broth was compared. The purification and characterization of invertase produced using the low-cost medium were also reported. The results showed that there was a 4.1-fold increase in the units of invertase produced in cassava-soybean medium (318.605 U/mg) compared to yeast sucrose broth medium (77.6 U/mg). The invertase produced was purified by chromatographic methods up to 5.53-fold with a recovery of 62.6%. Estimation of the molecular weight with gel filtration indicated a molecular weight of 118 kDa. The enzyme demonstrated its maximum activity at 50 °C and there was no decrease in its activity following a 1-h incubation at this temperature. At a pH of 5.0, the enzyme demonstrated optimal activity and it maintained over 60% of its activity in the acid range (pH 3–6). The Michalis-Menten constants Km and Vmax of intracellular invertase were 5.85 ± 1.715 mM and 6.472 ± 2.099 U/mg, respectively. These results suggest that Saccharomyces cerevisiae grown on cassava-soybean is a viable, cost-effective alternative for commercial invertase production, which can be explored for biotechnological processes. [ABSTRACT FROM AUTHOR]

Invertase is the key enzyme involved in several crucial biological processes by hydrolyzing sucrose for production of glucose and fructose. Invertase plays important roles in the fields of food, pharmacy, cosmetics, biofuels, and agriculture. Detection of invertase activity is urgently necessary for scientific research and industrial processes. Herein, a continuous fluorometric method was developed for real-time detection of invertase activity. 8-Isoquinolinylboronic acid responded to fructose by formation of a fluorescent complex in turn-on manner, and served as a fluorescent sensor to selectively recognize fructose in ternary enzymatic mixture containing sucrose and glucose. The limit of detection (LOD) for fructose was 0.07 mM. Progress curve for fructose production was established by directly and continuously monitoring the fluorescence for invertase reaction with sucrose as substrate. Initial velocity was obtained to characterize invertase activity. LOD for invertase assay was 0.10 U·mL−1. Km and υmax for invertase were determined as 7.70 mM and 0.86 mM·min−1, respectively. Copper ion was demonstrated to inhibit the invertase activity with IC50 of 33.61 mM. Applicability in high-throughput screening for inhibitor was demonstrated. The proposed method allows for real-time, simple, and rapidly monitoring the invertase activity. It has a broad range of potential applications for kinetics and screening inhibitor. [ABSTRACT FROM AUTHOR]

Invertases and their inhibitors play important roles in sucrose metabolism, growth and development, signal transduction, and biotic and abiotic stress tolerance in many plant species. However, in cucumber, both the gene members and functions of invertase and its inhibitor families remain largely unclear. In this study, in comparison with the orthologues of Citrullus lanatus (watermelon), Cucumis melo (melon), and Arabidopsis thaliana (Arabidopsis), 12 invertase genes and 12 invertase inhibitor genes were identified from the genome of Cucumis sativus (cucumber). Among them, the 12 invertase genes were classified as 4 cell wall invertases, 6 cytoplasmic invertases, and 2 vacuolar invertases. Most invertase genes were conserved in cucumber, melon, and watermelon, with several duplicate genes in melon and watermelon. Transcriptome analysis distinguished these genes into various expression patterns, which included genes CsaV3_2G025540 and CsaV3_2G007220, which were significantly expressed in different tissues, organs, and development stages, and genes CsaV3_7G034730 and CsaV3_5G005910, which might be involved in biotic and abiotic stress. Six genes were further validated in cucumber based on quantitative real-time PCR (qRT–PCR), and three of them showed consistent expression patterns as revealed in the transcriptome. These results provide important information for further studies on the physiological functions of cucumber invertases (CSINVs) and their inhibitors (CSINHs). [ABSTRACT FROM AUTHOR]

Honeybee products are highly valued food products in the nutrition and medicine.This work aims to determine physicochemical parameters of polyfloral and sunflower honey, which are produced in Bulgaria. Twelve sunflower and 17 polyfloral honey samples were used in this study. The parameters color, water content, electrical conductivity, specific optical rotation, pH, proline, invertase, diastase, hydroxymethylfurfural (HMF) were analyzed. Bulgarian sunflower and polyfloral honeys were characterized by main physicochemical parameters and compared to products from other countries. The color correlates with the electrical conductivity and diastase correlates with invertase in the sunflower honey. The results of the present study indicated that Bulgarian sunflower and polyfloral honey are known for its good quality since the criteria that were closely correlated with the honey’s quality were measured. [ABSTRACT FROM AUTHOR]

Fructooligosaccharides (FOS) are prebiotics of interest to the food industry. These compounds can be produced through the transfructosylation reaction by the enzyme fructofuranosidase. This enzyme is widely produced by fungi in a medium rich in sugar. Therefore, in this work, the main objectives were production, purification, biochemical characterization of a novel fructofuranosidase enzyme by Penicillium citreonigrum URM 4459 and synthesize and evaluate the antibacterial potential of fructooligosaccharides. With respect to sucrose hydrolysis, the optimal pH was 5.5, the apparent Km for purified FFase was 3.8 mM, the molecular mass was 43.0 kDa, estimated by gel filtration on Superdex increase G75 controlled by AKTA Avant 25 and confirmed by 10% SDS-PAGE under denaturing condition. Also, the isoelectric point was 4.9. The fractions obtained with enzymatic activities, both stable at acidic pH and high temperatures, as well as being able to produce FOS. Regarding antibacterial activity, the FOS produced in this study showed better results than commercial FOS and other carbon sources. Thus, this work presents relevant data for the use of P. citreonigum to produce fructofuranosidase and consequently FOS and can be used in the food and pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Late spring cold (LSC) occurred in the reproductive period of wheat impairs spike and floret differentiation during the reproductive period, when young spikelets are very cold-sensitive. However, under LSC, the responses of wheat spikelets at various positions, leaves, and stems and the interactions between them at physiological levels remain unclear. In the present study, two-year treatments at terminal spikelet stage under two temperatures (2 °C, °2 °C) and durations (1, 2, and 3 days) were imposed in an artificial climate chamber to compare the effects of LSC on grain number and yield in the wheat cultivars Yannong 19 (YN19, cold-tolerant) and Xinmai 26 (XM26, cold-sensitive). The night temperature regimes were designed to reproduce natural temperature variation. LSC delayed plant growth and inhibited spike and floret differentiation, leading to high yield losses in both cultivars. LSC reduced dry matter accumulation (DMA, g) in spikes, stems, and leaves, reducing the DMA ratios of the spike to leaf and spike to stem. Plant cell wall invertase (CWINV) activity increased in upper and basal spikelets in YN19, whereas CWINV increased in middle spikelets in XM26. Under LSC, soluble sugar and glucose were transported and distributed mainly in upper and basal spikelets for glume and rachis development, so that spike development was relatively complete in YN19, whereas the upper and basal spikelets were severely damaged and most of the glumes in middle spikelets were relatively completely developed in XM26, resulting in pollen abortion mainly in upper and basal spikelets. The development of glumes and rachides was influenced and grain number per spike was decreased after LSC, with kernels present mainly in middle spikelets. Overall, reduced total DMA and dry matter partitioning to spikes under LSC results in poor spikelet development, leading to high losses of grain yield. [ABSTRACT FROM AUTHOR]

Fusarium crown rot (FCR) and sharp eyespot (SE) are serious soil‐borne diseases in wheat and its relatives that have been reported to cause wheat yield losses in many areas. In this study, the expression of a cell wall invertase gene, TaCWI‐B1, was identified to be associated with FCR resistance through a combination of bulk segregant RNA sequencing and genome resequencing in a recombinant inbred line population. Two bi‐parental populations were developed to further verify TaCWI‐B1 association with FCR resistance. Overexpression lines and ethyl methanesulfonate (EMS) mutants revealed TaCWI‐B1 positively regulating FCR resistance. Determination of cell wall thickness and components showed that the TaCWI‐B1‐overexpression lines exhibited considerably increased thickness and pectin and cellulose contents. Furthermore, we found that TaCWI‐B1 directly interacted with an alpha‐galactosidase (TaGAL). EMS mutants showed that TaGAL negatively modulated FCR resistance. The expression of TaGAL is negatively correlated with TaCWI‐B1 levels, thus may reduce mannan degradation in the cell wall, consequently leading to thickening of the cell wall. Additionally, TaCWI‐B1‐overexpression lines and TaGAL mutants showed higher resistance to SE; however, TaCWI‐B1 mutants were more susceptible to SE than controls. This study provides insights into a FCR and SE resistance gene to combat soil‐borne diseases in common wheat. [ABSTRACT FROM AUTHOR]

Endodormancy (ED) is a crucial stage in the life cycle of many perennial plants. ED release requires accumulating a certain amount of cold exposure, measured as chilling units. However, the mechanism governing the effect of chilling on ED duration is poorly understood. We used the potato tuber model to investigate the response to chilling as associated with ED release. We measured the accumulation of specific sugars during and after chilling, defined as sugar units. We discovered that ED duration correlated better with sugar units accumulation than chilling units. A logistic function was developed based on sugar units measurements to predict ED duration. Knockout or overexpression of the vacuolar invertase gene (StVInv) unexpectedly modified sugar units levels and extended or shortened ED, respectively. Silencing the energy sensor SNF1‐related protein kinase 1, induced higher sugar units accumulation and shorter ED. Sugar units accumulation induced by chilling or transgenic lines reduced plasmodesmal (PD) closure in the dormant bud meristem. Chilling or knockout of abscisic acid (ABA) 8′‐hydroxylase induced ABA accumulation, in parallel to sweetening, and antagonistically promoted PD closure. Our results suggest that chilling induce sugar units and ABA accumulation, resulting in antagonistic signals for symplastic connection of the dormant bud. Summary statement: Endodormancy (ED) duration of potato tuber correlates better with soluble sugars accumulation (sugar units) than chilling units. Chilling induces sugar units and ABA accumulation, resulting in antagonistic signals for symplastic connection of the dormant bud, determining ED duration. [ABSTRACT FROM AUTHOR]

Puccinia triticina (Pt) is an important pathogen of wheat. While breeding programmes develop resistant wheat cultivars to mitigate the effects of such rust-causing pathogens, the emergence of new rust races with wider virulence mandates the implementation of other control strategies. Our study investigated whether acidic pH conditions affected selected Carbohydrate-Active Enzymes (CAZymes) in Pt-inoculated Thatcher + Lr9 (IR) wheat compared to those found in the Thatcher (IS) wheat. The β-glucosidase and amyloglucosidase activity levels significantly increased in IR compared to the control from 1 to 14 days post-inoculation (dpi). In contrast, activity levels of invertase did not change in the IR wheat relative to the control at 1 and 7 dpi, but were significantly reduced in the IR plants at 14 dpi. The IS had higher activity of all three hexose-producing enzymes under acidic conditions. These enzyme activities could be increased in the IS to produce hexose sugars required by Pt to develop and advance infection. The phenotypic analysis supported this view because leaf rust disease symptoms were only visible in the IS plants. For cell wall loosening-related enzymes, the IR displayed higher activity of exoglucanase, xylanase and peroxidase enzymes compared to IS. The liquid chromatography–mass spectrometry analysis showed IR had higher concentrations of complex oligosaccharides compared to the IS. Thus, we concluded that the higher exoglucanase, xylanase and peroxidase activity could be involved in cell wall loosening under acidic conditions, while oligosaccharides could be building-blocks for synthesizing cell wall barriers that apprehend Pt growth in inoculated Thatcher + Lr9. [ABSTRACT FROM AUTHOR]

Introduction: The implementation of an enzymatic technology capable of operating at high temperatures with a thermostability that allows the hydrolysis of concentrated sucrose solutions; it constitutes a novel alternative in the glucose production process. Objective: To carry out a comparative analysis of the methods of glucose production by acid and enzymatic hydrolysis of sucrose, considering the technology installed in the UEB Derivados Chiquitico Fabregat and the technological conception for the operation using the biocatalyst. Materials and Methods: Mass and energy balances were developed for the installed technology employing acid hydrolysis of sucrose. With the experimental results reported on the use of the thermostable invertase enzyme thermostable invertase enzyme, the kinetic study, the technological conception and the quantification of the currents involved were developed. With these results, a comparative analysis of the annual consumption for the hydrolysis stage and the products generated by both methods was carried out. Results and Discussion: A low output of acid glucose was obtained, while enzymatic hydrolysis evidenced a 1.83 times increase in production. The kinetic behavior of the biocatalyst was adjusted to a first order reaction. The technological design for the use of enzymatic hydrolysis included three bioreactors, a dissolving tank and a heat exchanger, which guarantee a favorable annual production balance. Conclusions: Under conditions of maximum utilization of the installed capacity, the high efficiency of enzymatic glucose and the substitution of aggressive substances guarantee the technical, economic and environmental feasibility of the process. [ABSTRACT FROM AUTHOR]

In order to improve the rearing of Coccinella septempunctata L. (Coleoptera: Coccinellidae), nutrients such as shrimp, pollen, honey, and lard were added to the basic artificial diet, and the effects of the artificial diet on biological parameters and digestive enzymes were evaluated. The results show that beetles feeding on the supplemented diet exhibited pupation, emergence, fecundity, and hatching rates that were 102.69%, 125.02%, 162.33%, and 119.90% of those supplied with the basic diet, respectively. The addition of shrimp and pollen to the basal diet improved protease, trypsin, chymotrypsin, and aminopeptidase activity in larvae and female adults. The addition of lard improved lipase activity in female adults, and the addition of honey improved invertase activity in adults of both sexes. This study provides guidance for improving the nutritional benefits of ladybug artificial diets. [ABSTRACT FROM AUTHOR]

Sugar is crucial for grape berry, whether used for fresh food or wine. However, berry enlargement treatment with forchlorfenuron (N-(2-chloro4-pyridyl)-N′-phenylurea) (CPPU, a synthetic cytokinin) and gibberellin (GA) always had adverse effects on sugar accumulation in some grape varieties, especially CPPU. Therefore exploring the molecular mechanisms behind these adverse effects could provide a foundation for improving or developing technology to mitigate the effects of CPPU/GA treatments for grape growers. In the present study, invertase (INV) family, the key gene controlling sugar accumulation, was identified and characterized on the latest annotated grape genome. Their express pattern, as well as invertase activity and sugar content, were analyzed during grape berry development under CPPU and GA3 treatment to explore the potential role of INV members under berry enlargement treatment in grapes. Eighteen INV genes were identified and divided into two sub-families: 10 neutral INV genes (Vv-A/N-INV1-10) and 8 acid INV genes containing 5 CWINV (VvCWINV1-5) and 3 VIN (VvVIN1-3). At the early development stage, both CPPU and GA3 treatment decreased the hexose level in berries of 'Pinot Noir' grape, whereas the activity of three types inverstase (soluble acid INV, insoluble acid INV, and neutral INV) increased. Correspondingly, most of INV members were up-regulated by GA3 /CPPU application at least one sampling time point during early berry development, including VvCWINV1, 2, 3, 4, 5, VvVIN1, 2, 3 and Vv-A/N-INV1, 2, 5, 6, 7, 8, 10. At maturity, the sugar content in CPPU-treated berries is still lower than that in the control. Soluble acid INV and neutral INV, rather than insoluble acid INV, presented lower activity in CPPU-treated berries. Meanwhile, several corresponding genes, such as VvVIN2 and Vv-A/N-INV2, 8, 10 in ripening berries were obviously down-regulated by CPPU treatment. These results suggested that most of INV members could be triggered by berry enlargement treatment during early berry development, whereas VvVINs and Vv-A/N-INVs, but not VvCWINVs, could be the limiting factor resulting in decreased sugar accumulation in CPPU-treated berries at maturity. In conclusion, this study identified the INV family on the latest annotated grape genome and selected several potential members involving in the limit of CPPU on final sugar accumulation in grape berry. These results provide candidate genes for further study of the molecular regulation of CPPU and GA on sugar accumulation in grape. [ABSTRACT FROM AUTHOR]

Low light stress seriously decreased wheat grain number through the formation of aborted spike during the reproductive period and induced new tiller regeneration to offset the loss of grain number. However, the mechanism by which plants coordinate spike aborted growth and the regeneration of new tillers remains unknown. To better understand this coordinated process, morphological, physiological and transcriptomic analyses were performed under low light stress at the young microspore stage. Our findings indicated that leaves exhausted most stored carbohydrates in 1 day of darkness. However, spike and uppermost internode (UI) were converted from sink to source, due to increased abscisic acid (ABA) content and decreased cytokinin content. During this process, genes encoding amylases, Sugars Will Eventually be Exported Transporters (SWEET) and sucrose transporters or sucrose carriers (SUT/SUC) were upregulated in spike and UI, which degraded starch into soluble sugars and loaded them into the phloem. Subsequently, soluble sugars were transported to tiller node (TN) where cytokinin and auxin content increased and ABA content decreased, followed by unloading into TN cells by upregulated cell wall invertase (CWINV) genes and highly expressed H+/hexose symporter genes. Finally, expansin genes integrated the sugar pathway and hormone pathway, and regulate the formation of new tillers directly. Summary Statement: Low light stress changed source–sink relationship by regulating the expression of sugar metabolism genes and sugar transport genes as well as hormone content in spike, uppermost internode and tiller node. Meanwhile, expansin genes integrated the sugar pathway and hormone pathway and regulated the formation of new tillers. [ABSTRACT FROM AUTHOR]

Abstract—In this study, we performed expression analysis of genes associated with cold-induced sweetening in potato tubers: vacuolar invertase (Pain-1), sucrose synthase (SUS4), and invertase inhibitor (InvInh2). Potato varieties Nikulinsky, Symfonia, and Nevsky were used. All three varieties were found to accumulate sugars at low temperatures; the maximum accumulation of reducing sugars was observed at 4°C. It was found that the expression pattern of genes associated with cold-induced sweetening differs depending on the variety and storage duration. The increased expression of vacuolar invertase and its inhibitor is more pronounced at the beginning of storage period, whereas the increased expression of sucrose synthase is more pronounced after 3 months of storage. At early storage periods, high expression of invertase and low expression of inhibitor is observed in the Dutch variety Symfonia, and vice versa in the Russian varieties Nikulinsky and Nevsky. The involvement of the studied genes in the process of cold-induced sweetening is discussed. [ABSTRACT FROM AUTHOR]

There is an ever-increasing demand for industrial enzyme, necessitating a constant search for its efficient producers. The isolation and characterization of invertase producer yeasts from natural palm wine is reported in this study. Yeasts were isolated from fresh palm wine obtained from Abagboro community Ile-Ife, Nigeria following standard methods. A total of six yeast strains were isolated from the palm wine. The strains were screened for their ability to produce invertase and the most efficient invertase producer was characterized and identified using phenotypic and molecular methods. Isolate C showed the highest invertase activity (34.15 µmole/ml/min), followed by isolate B (18.070 µmole/ml/min) and isolate A (14.385 µmole/ml/min). The identity of isolate C was confirmed by genotypic methods to be Saccharomyces cerevisiae (OL629078.1 accession number on NCBI database). The Saccharomyces cerevisiae strain fermented galactose, arabinose, maltose, glucose, sucrose and raffinose, grew in 50% and 60% glucose and at 25–35 °C. The newly isolated Saccharomyces cerevisiae strain is an efficient producer of invertase and can be exploited for commercial biosynthesis of the enzyme for use in biotechnological applications. [ABSTRACT FROM AUTHOR]

【Objective】In order to provide the scientific basis for obstacles research and development, nutrient management and high-quality flue-cured tobacco production in regional tobacco planting soil, the characteristics of main obstacles to tobacco planting soil in 5 counties（cities, districts）of Baoshan city were analyzed.【Method】The samples of tobacco planting soil were collected from 72 villages in 24 towns in 5 counties of Baoshan city.Total of 12 indexes, including pH, organic matter（OM）, total N（TN）, total P（TP）, total K（TK）, alkaline N（AN）, available P（AP）, available K（AK）, soil bulk density（BD）, field water holding capacity（FC）, sucrase invertase（INV）and urease（URE）, were selected as the total data set（TDS）to construct the minimum data set（MDS）, and the soil quality index was calculated, and the main obstacle factors were analyzed by using the diagnosis model of obstacle factors.【Result】By K-S test, the 12 indexes complied with the normal distribution and were included in TDS. Six indexes including OM, TP, AN, AP, BD and INV were included in the MDS by principal component analysis.The MDS-SQI of soil quality index was positively correlated with TDS-SQI, and the MDS could represent the TDS to evaluate the soil quality in Baoshan tobacco planting area.The MDS-SQI soil quality indexes in Shidian county, Changning county, Longyang district, Longling county and Tengchong city were 0.681, 0.668, 0.665, 0.626 and 0.579, respectively.The obstacle degree analysis showed that the main obstacle factors were FC（average obstacle 0.251）, AN（average obstacle 0.196）, pH（average obstacle 0.142）and OM（average obstacle 0.110）.【Conclusion】The established MDS of soil quality assessment has certain representativeness and accuracy, which can be used to evaluate and diagnose soil quality and obstacles. [ABSTRACT FROM AUTHOR]

The catalytic action of invertase generates bilayer asymmetry that stabilises membrane curvature. The driving mechanism for the generation of membrane curvature by invertase is investigated using giant unilamellar vesicles (GUVs). The invertase cleaves the sucrose in the exterior compartment, thereby creating a sugar asymmetry across the bilayer membrane that is measured for GUV membranes consisting of the lipid Dioleoylphosphatidylcholine (DOPC). Finally, the advantage of this method to control membrane curvature and to stabilize multi‐sphere morphologies is demonstrated. The GUV system in the presence of invertase is beneficial as a tool to generate multiple on‐demand compartments with more extended stability after the enzymatic activity has established the asymmetry. [ABSTRACT FROM AUTHOR]

Invertases are ubiquitous enzymes that catalyze the unalterable cleavage of sucrose into glucose and fructose, and are crucially involved in plant growth, development and stress response. In this study, a total of 17 putative invertase genes, including 3 cell wall invertases, 3 vacuolar invertases, and 11 neutral invertases were identified in apple genome. Subcellular localization of MdNINV7 and MdNINV11 indicated that both invertases were located in the cytoplasm. Comprehensive analyses of physicochemical properties, chromosomal localization, genomic characterization, and gene evolution of MdINV family were conducted. Gene duplication revealed that whole-genome or segmental duplication and random duplication might have been the major driving force for MdINVs expansion. Selection index values, ω, showed strong evidence of positive selection signatures among the INV clusters. Gene expression analysis indicated that MdNINV1/3/6/7 members are crucially involved in fruit development and sugar accumulation. Similarly, expression profiles of MdCWINV1 , MdVINV1 , and MdNINV1/2/7/11 suggested their potential roles in response to cold stress. Furthermore, overexpression of MdNINV11 in apple calli at least in part promoted the expression of MdCBF1–5 and H 2 O 2 detoxification in response to cold. Overall, our results will be useful for understanding the functions of MdINVs in the regulation of apple fruit development and cold stress response. [ABSTRACT FROM AUTHOR]

A comprehensive assessment was carried out of the changes occurring during the darkening of the callus obtained from vegetative buds of 40-year-old Scots pine trees Pinus sylvestris L. Based on biometric assessment of callus (intensity of callus formation, proportion of light callus, callus mass) from 32 analyzed trees (16 genotypes represented by two clones), two genotypes with high callus-forming ability were singled out. Analysis of mitosis showed that, although the proportion of aberrant cells in the callus does not exceed the rate of spontaneous mutation for P. sylvestris, the range of violations at the stage of meta-, ana-, and telophase in the callus culture was wider compared to that in the seed progeny of the same pine trees. Darkening of the callus was accompanied by a decrease in sucrose metabolism in the cell (decrease in cytoplasmic, vacuolar invertase and sucrose synthase) and a significant decrease in peroxidase activity. At the same time, the activity of apoplast invertase was maintained at a constant level. The activity of superoxide dismutase, catalase, polyphenol oxidase, and phenylalanine ammonia lyase, on the contrary, was higher in dark callus. The possible use of the studied enzymes as biochemical markers of the transition to darkening callus pine crops is discussed. [ABSTRACT FROM AUTHOR]

In this study, the influences of long-term soil drought with three levels [soil-relative water content (SRWC) (75 ± 5)%, as the control; SRWC (55 ± 5)%, mild drought; SRWC (45 ± 5)%, severe drought] were investigated on sucrose-starch metabolism in sweet potato tuberous roots (TRs) by pot experiment. Compared to the control, drought stress increased soluble sugar and sucrose content by 4–60% and 9–75%, respectively, but reduced starch accumulation by 30–66% through decreasing the starch accumulate rate in TRs. In the drought-treated TRs, the inhibition of sucrose decomposition was attributed to the reduced activities of acid invertase (AI) and alkaline invertase (AKI) and the IbA-INV3 expression, rather than sucrose synthase (SuSy), consequently leading to the increased sucrose content in TRs. In addition, starch synthesis was inhibited mainly by reducing ADP-glucose pyrophosphorylase (AGPase), granular starch synthase (GBSS) and starch branching enzyme (SBE) activities in TRs under drought stress, and AGPase was the rate-limiting enzyme. Furthermore, soil drought remarkably up-regulated the IbSWEET11, IbSWEET605, and IbSUT4 expressions in Jishu 26 TRs, while it down-regulated or had no significant differences in Xushu 32 and Ningzishu 1 TRs. These results suggested that the sucrose-loading capability in Jishu 26 TRs were stronger than that in Xushu 32 and Ningzishu 1 TRs. Moreover, IbA-INV3, IbAGPS1, IbAGPS2, IbGBSSI and IbSBEII play important roles in different drought-tolerant cultivars under drought stress. [ABSTRACT FROM AUTHOR]

The food enzyme β‐fructofuranosidase (β‐d‐fructofuranoside fructohydrolase; EC 3.2.1.26) is produced with the non‐genetically modified Saccharomyces cerevisiae strain INV by DSM Food Specialties B.V. It is intended to be used in four food manufacturing processes: manufacture of specialty carbohydrates (invert sugar syrups), baking processes, production of sucrose‐based fermented beverages and confectionary processes. The dietary exposure to the food enzyme–total organic solids (TOS) was estimated to be up to 2.51 mg TOS/kg body weight (bw) per day in European populations. Toxicological studies were not considered necessary, given the qualified presumption of safety status of the production strain and the nature of the manufacturing process. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and one match with a tomato allergen was found. The Panel considered that, under the intended conditions of use, the risk of allergic reactions upon dietary exposure to this food enzyme, particularly in individuals sensitised to tomato, cannot be excluded. However, the likelihood of allergic reactions to the β‐fructofuranosidase from S. cerevisiae strain INV is expected not to exceed the likelihood of allergic reactions to tomato. As the prevalence of allergic reactions to tomato is low, also the likelihood of such reaction to occur to the food enzyme is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use. [ABSTRACT FROM AUTHOR]