Exogenous Sugar Research Articles

The Different Concentrations of Applied Exogenous Sugars Widely Influence the Specificity, Significance and Physiological Relevance of Study Outcomings.

Plant growth and development are governed via signal networks that connect inputs from nutrient status, hormone signals, and environmental cues. Substantial researches have indicated a pivotal role of sugars as signalling molecules in plants that integrate external environmental cues and other nutrients with intrinsic developmental programmes regulated via multiple plant hormones. Therefore, plant growth and development are controlled through complication signalling networks. However, in many studies, to obtain more obviously experimental findings, excess concentrations of applied exogenous sugars have aggravated the complexity of this signalling networks. Once researchers underestimate this complexity, a series of contradictory or contrasting findings will be generated. More importantly, in terms of these contradictory findings, more contradictory study outcomings are derived. In this review, we carefully analyze some reports, and find that these reports have confused or neglected that the sugar-antagonism of ethylene signalling is specific or conditional. As a result, many contradictory conclusions are generated, which will in turn misdirect the scientific community.

Анализ отношений стабильных изотопов легких элементов в отдельных компонентах мёда

Honey possesses excellent sensory and nutritional properties, which makes it a valuable food ingredient. However, the same qualities make it one of the most often adulterated products in the world. Constant violations of processing technology threaten the beekeeping industry. In this regard, new authenticity criteria are a popular area of honey studies. The article introduces a method for establishing ratios of light stable isotopes in honey. The study featured 36 samples of honey of various geographical origins and botanical profiles, as well as five samples of sugar syrups from various raw materials. The quantitative profiles were obtained using a Delta Advantage V isotope mass spectrometer (USA – Germany) with additional Flash IRMS and Conflo IV modules. The experiment involved the ratios of stable carbon isotopes in honey δ13C (gross) and nitrogen δ15N in its protein fraction, as well as the values of δ13C, δ18O, and δ2H of ethanol isolated from fermented honey. The values of δ13C (gross) and δ13C of honey proteins made it possible to calculate the amount of added sugar of corn and cane origin. Exogenous sugars in the amounts of 6.5% and 18% cane sugar were detected in two samples. Isotope mass spectrometry was able to identify honey samples with exogenous sugars of C4-plant origin. However, the method failed to detect sugar-containing substances from C3-type plants. The δ18O index demonstrated some prospects as an identification criterion for sugars from C3-plants in honey. Nitrogen isotope ratios in honey proteins proved to be an efficient tool for determining honey authenticity and an additional criterion for identifying bee products. The research resulted in a patent (RU2809285C1) for a new method of determining exogenous sugar-containing substances in honey

Regulation of exogenous sugars on the biosynthesis of key secondary metabolites in Cyclocarya paliurus.

The biosynthesis and accumulation of secondary metabolites play a vital role in determining the quality of medicinal plants, with carbohydrate metabolism often influencing secondary metabolism. To understand the potential regulatory mechanism, exogenous sugars (sucrose, glucose/fructose) were applied to the leaves of Cyclocarya paliurus, a highly valued and multiple function tree species. The results showed that exogenous sugars enhanced the accumulation of soluble sugar and starch while increasing the enzyme activity related to carbohydrate metabolism. In addition, the plant height was increased by a mixture of exogenous mixed sugars, the addition of sucrose promoted the net photosynthetic rate, while all types of exogenous sugars facilitated the accumulation of flavonoids and terpenoids. Based on weighted gene co-expression network analysis (WGCNA), two key gene modules and four candidate transcription factors (TFs) related to carbohydrate metabolism and secondary metabolite biosynthesis were identified. A correlation analysis between transcriptome and metabolome data showed that exogenous sugar up-regulated the expression of key structural genes in the flavonoid and terpenoid biosynthetic pathway. The expression levels of the four candidate TFs, TIFY 10A, WRKY 7, EIL 3 and RF2a, were induced by exogenous sugar and were strongly correlated with the key structural genes, which enhanced the synthesis of specific secondary metabolites and some plant hormone signal pathways. Our results provide a comprehensive understanding of key factors in the quality formation of medicinal plants and a potential approach to improve the quality.

Evaluation of [68Ga]Ga-DOTA-AeK as a Potential Imaging Tool for PET Imaging of Cell Wall Synthesis in Bacterial Infections.

The ability of bacteria to recycle exogenous amino acid-based peptides and amino sugars for peptidoglycan biosynthesis was extensively investigated using optical imaging. In particular, fluorescent AeK-NBD was effectively utilized to study the peptidoglycan recycling pathway in Gram-negative bacteria. Based on these promising results, we were inspired to develop the radioactive AeK conjugate [68Ga]Ga-DOTA-AeK for the in vivo localization of bacterial infection using PET/CT. An easy-to-implement radiolabeling procedure for DOTA-AeK with [68Ga]GaCI3 followed by solid-phase purification was successfully established to obtain [68Ga]Ga-DOTA-AeK with a radiochemical purity of ≥95%. [68Ga]Ga-DOTA-AeK showed good stability over time with less protein binding under physiological conditions. The bacterial incorporation of [68Ga]Ga-DOTA-AeK and its fluorescent Aek-NBD analog were investigated in live and heat-killed Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Unfortunately, no conclusive in vitro intracellular uptake of [68Ga]Ga-DOTA-AeK was observed for E. coli or S. aureus live and heat-killed bacterial strains (p > 0.05). In contrast, AeK-NBD showed significantly higher intracellular incorporation in live bacteria compared to the heat-killed control (p < 0.05). Preliminary biodistribution studies of [68Ga]Ga-DOTA-AeK in a dual-model of chronic infection and inflammation revealed limited localization at the infection site with non-specific accumulation in response to inflammatory markers. Finally, our study demonstrates proof that the intracellular incorporation of AeK is necessary for successful bacteria-specific imaging using PET/CT. Therefore, Ga-68 was not a suitable radioisotope for tracing the bacterial uptake of AeK tripeptide, as it required chelation with a bulky metal chelator such as DOTA, which may have limited its active membrane transportation. An alternative for optimization is to explore diverse chemical structures of AeK that would allow for radiolabeling with 18F or 11C.

Sweet Immunity in Action: Unlocking Stem Reserves to Improve Yield and Quality. A Potential Key Role for Jasmonic Acid.

Common agronomic practices such as stem topping, side branch removal, and girdling can induce wound priming, mediated by jasmonic acid (JA). Low light conditions during greenhouse tomato production make the leaves more sensitive to the application of exogenous sugar, which is perceived as a "danger" in accordance with the concept of "Sweet Immunity". Consequently, source-sink balances are altered, leading to the remobilization of stem starch reserves and enabling the redirection of more carbon toward developing fruits, thereby increasing tomato yield and fruit quality. Similarities are drawn with the mobilization of fructans following defoliation of fodder grasses (wounding) and the remobilization of fructan and starch reserves under terminal drought and heat stress in wheat and rice (microwounding, cellular leakage). A central role for JA signaling is evident in all of these processes, closely intertwining with sugar signaling pathways. Therefore, JA signaling, associated with wounding and sugar priming events, offers numerous opportunities to alter source-sink balances across a broader spectrum of agricultural and horticultural crops, for instance, through the exogenous application of JA and fructans or a combination. This may entail reconfiguring and reversing phloem connections, potentially leading to an enhanced yield and product quality. Such processes may also disengage the growth-defense trade-off in plants.

Application of Spatial Offset Raman Spectroscopy (SORS) and Machine Learning for Sugar Syrup Adulteration Detection in UK Honey.

Honey authentication is a complex process which traditionally requires costly and time-consuming analytical techniques not readily available to the producers. This study aimed to develop non-invasive sensor methods coupled with a multivariate data analysis to detect the type and percentage of exogenous sugar adulteration in UK honeys. Through-container spatial offset Raman spectroscopy (SORS) was employed on 17 different types of natural honeys produced in the UK over a season. These samples were then spiked with rice and sugar beet syrups at the levels of 10%, 20%, 30%, and 50% w/w. The data acquired were used to construct prediction models for 14 types of honey with similar Raman fingerprints using different algorithms, namely PLS-DA, XGBoost, and Random Forest, with the aim to detect the level of adulteration per type of sugar syrup. The best-performing algorithm for classification was Random Forest, with only 1% of the pure honeys misclassified as adulterated and <3.5% of adulterated honey samples misclassified as pure. Random Forest was further employed to create a classification model which successfully classified samples according to the type of adulterant (rice or sugar beet) and the adulteration level. In addition, SORS spectra were collected from 27 samples of heather honey (24 Calluna vulgaris and 3 Erica cinerea) produced in the UK and corresponding subsamples spiked with high fructose sugar cane syrup, and an exploratory data analysis with PCA and a classification with Random Forest were performed, both showing clear separation between the pure and adulterated samples at medium (40%) and high (60%) adulteration levels and a 90% success at low adulteration levels (20%). The results of this study demonstrate the potential of SORS in combination with machine learning to be applied for the authentication of honey samples and the detection of exogenous sugars in the form of sugar syrups. A major advantage of the SORS technique is that it is a rapid, non-invasive method deployable in the field with potential application at all stages of the supply chain.

Improve Cannabis sativa micropropagation through increasing air change rate in photoautotrophic and traditional tissue culture

Micropropagation is essential for pathogen-free plant materials. However, the conventional in-vitro micropropagation approach poses challenges for optimal growth and development. This study enhances Cannabis sativa micropropagation by implementing a photoautotrophic tissue culture with increased air change rates. This method relies exclusively on photosynthesis for carbohydrate synthesis, eliminating the need for exogenous sugar supplementation. To overcome the limitations of conventional in vitro culture, the photoautotrophic culture requires higher air exchange in the vessel to supply CO2 for photosynthesis. The research evaluates the effects of varying air change rates, comparing conventional tissue culture (TC) with photoautotrophic micropropagation (PAM). Nodal explants, each with 3–4 fully expanded leaves, were transferred to PAM or TC media in Magenta boxes, undergoing four distinct air change rate treatments: 0.5 (control), 4.1, 7.9, and 14.5 air change per hour. Magenta boxes were placed under controlled chamber conditions, including a photosynthetic photon flux density of 100 µmol·m−2·s−1, 18-hour photoperiod, 25 °C temperature, 70 % relative humidity, and CO2 concentration of 553 µmol·mol−1; data were collected after a 28-day period. Increasing the air change rate in TC (from 0.5 to 7.9 h−1) and PAM (from 0.5 to 14.5 h−1) resulted in a significant 25.1 % and 146.6 % increase in shoot dry mass, respectively. The number of axillary buds per plant exhibited a linear increase response to increasing air change rates only under PAM; as well as a significant difference between PAM (11.5) and TC (8.3) under an air change rate of 7.9 h−1. Particularly advantageous for PAM was simultaneous root growth, escalating from 5.2 to 44.3 mg as the air change rate rose from 0.5 to 14.5 h−1. Implementing the photoautotrophic culture practice not only accelerated Cannabis micropropagation but also maintained outcomes comparable to traditional sugar-based tissue culture, contributing to cost-effective cultivation practices in the Cannabis and tissue culture industries.

Exogenous application of sucrose promotes the repartitioning of anthocyanin and proanthocyanidin in ‘Cabernet Sauvignon’ grapevine berries

Sugar and its metabolism play a critical role in fruit quality and determine the accumulation characteristics of secondary metabolites. In this study, the dynamic changes in anthocyanin and proanthocyanidin (PA) accumulation during exogenous sugar application were investigated throughout the grape ripening stage, and the underlying biosynthesis mechanism was monitored. Results showed that exogenous sucrose and N-acetyl-d-glucosamine (hexokinase inhibitor, HI) promoted grape berry ripening. Exogenous application of sucrose and HI significantly increased the levels of soluble sugars and anthocyanins, while significantly decreased the levels of acids and PAs in grape berries. Exogenous sucrose and HI activated the transcription of the VvSPS, VvAI and VvNI genes but inhibited the transcription of VvHXK gene to alter sugar metabolism. Notably, the accumulation of anthocyanin compounds, particularly peonidin derivatives, significantly increased in the sucrose- and HI-treated berries by upregulating the transcription of anthocyanin biosynthesis genes, including VvCHS2, VvF3′H, VvDFR, VvLDOX, and VvUFGT, whereas the accumulation of PA units, such as (‒)-epicatechin, (+)-gallocatechin, and (‒)-epigallocatechin, was repressed by downregulating the transcription of the VvLAR2 and VvANR genes, which boosted anthocyanin and PA reprogramming. These results provide preliminary information on how to modulate the biosynthesis and accumulation of anthocyanins and PAs in grape berries by the exogenous application of sucrose and thus, to modify berry composition.

Exogenous abscisic acid and sugar induce a cascade of ripening events associated with anthocyanin accumulation in cultured Pinot Noir grape berries.

Fruit quality is dependent on various factors including flavour, texture and colour. These factors are determined by the ripening process, either climacteric or non-climacteric. In grape berry, which is non-climacteric, the process is signalled by a complex set of hormone changes. Abscisic acid (ABA) is one of the key hormones involved in ripening, while sugar availability also plays a significant role in certain ripening aspects such as anthocyanin production. To understand the relative influence of hormone and sugar signalling in situ can prove problematic due to the physiological and environmental (abiotic and biotic) factors at play in vineyards. Here we report on the use of in vitro detached berry culture to investigate the comparative significance of ABA and sugar in the regulation of Pinot noir berry anthocyanin production under controlled conditions. Using a factorial experimental design, pre-véraison berries were cultured on media with various concentrations of sucrose and ABA. After 15 days of in vitro culture, the berries were analysed for changes in metabolites, hormones and gene expression. Results illustrated a stimulatory effect of sucrose and ABA on enhancing berry colour and a corresponding increase in anthocyanins. Increased ABA concentration was able to boost anthocyanin production in berries when sucrose supply was low. The sucrose and ABA effects on berry anthocyanins were primarily manifested through the up-regulation of transcription factors and other genes in the phenylpropanoid pathway, while in other parts of the pathway a down-regulation of key proanthocyanindin transcription factors and genes corresponded to sharp reduction in berry proanthocyanidins, irrespective of sucrose supply. Similarly, increased ABA was correlated with a significant reduction in berry malic acid and associated regulatory genes. These findings suggest a predominance of berry ABA over berry sugar in coordinating the physiological and genetic regulation of anthocyanins and proanthocyanins in Pinot noir grape berries.

Vacuolar Sugar Transporter TMT2 Plays Crucial Roles in Germination and Seedling Development in Arabidopsis

Vacuolar sugar transporters transport sugar across the tonoplast, are major players in maintaining sugar homeostasis, and therefore play vital roles in plant growth, development, and biomass yield. In this study, we analyzed the physiological roles of the tonoplast monosaccharide transporter 2 (TMT2) in Arabidopsis. In contrast to the wild type (WT) that produced uniform seedlings, the tmt2 mutant produced three types of offspring: un-germinated seeds (UnG), seedlings that cannot form true leaves (tmt2-S), and seedlings that develop normally (tmt2-L). Sucrose, glucose, and fructose can substantially, but not completely, rescue the abnormal phenotypes of the tmt2 mutant. Abnormal cotyledon development, arrested true leaf development, and abnormal development of shoot apical meristem (SAM) were observed in tmt2-S seedlings. Cotyledons from the WT and tmt2-L seedlings restored the growth of tmt2-S seedlings through micrografting. Moreover, exogenous sugar sustained normal growth of tmt2-S seedlings with cotyledon removed. Finally, we found that the TMT2 deficiency resulted in growth defects, most likely via changing auxin signaling, target of rapamycin (TOR) pathways, and cellular nutrients. This study unveiled the essential functions of TMT2 for seed germination and initial seedling development, ensuring cotyledon function and mobilizing sugars from cotyledons to seedlings. It also expanded the current knowledge on sugar metabolism and signaling. These findings have fundamental implications for enhancing plant biomass production or seed yield in future agriculture.

FTIR-ATR detection method for emerging C3-plants-derivated adulterants in honey: Beet, dates, and carob syrups

The European Union Publications Office has recently presented a report on the European Union's coordinated action with the Joint Research Centre to determine certain fraudulent practices in the honey sector, in which it has been indicated that 74% of the samples analyzed, imported from China, and 93% of the samples analyzed, imported from Turkey, the two largest honey producers worldwide, presented at least one indicator of exogenous sugar or suspicion of being adulterated. This situation has revealed the critical state of the problem of honey adulteration worldwide and the need to develop analytical techniques for its detection. Even though the adulteration of honey is carried out in a general way with sweetened syrups derived from C4 plants, recent studies have indicated the emerging use of syrups derived from C3 plants for the adulteration of honey. This kind of adulteration makes it impossible to analyze its detection using official analysis techniques. In this work, we have developed a fast, simple, and economical method based on the Fourier transform infrared spectroscopy technique, with attenuated total reflectance, for the qualitative, quantitative, and simultaneous determination of beetroot, date, and carob syrups, derived from of C3 plants; whose available bibliography is very scarce and analytically not very conclusive for its use by the authorities. The proposed method has been based on the establishment of the spectral differences between honey and the mentioned syrups at eight different points in the spectral region between 1200 and 900 cm−1 of the mid-infrared, characteristic of the vibrational modes of carbohydrates in honey, which allows the pre-discrimination of the presence or absence of the syrups studied, and their subsequent quantification, with precision levels lower than 2.0% of the relative standard deviation and relative errors lower than 2.0% (m/m).

Functional analysis of MdSUT2.1, a plasma membrane sucrose transporter from apple

Sugar content is a determinant of apple (Malus×domestica Borkh.) sweetness. However, the molecular mechanism underlying sucrose accumulation in apple fruit remains elusive. Herein, the role of the sucrose transporter MdSUT2.1 in the regulation of sucrose accumulation in apple was reported. The MdSUT2.1 gene encodes a protein with 612 amino acid residues that could be localized at the plasma membrane when expressed in tobacco leaf protoplasts. MdSUT2.1 was highly expressed in fruit and was positively correlated with sucrose accumulation during apple fruit development. Moreover, the sucrose transport activity of MdSUT2.1 was validated by complementary growth assays in a yeast mutant. MdSUT2.1 overexpression in apple and tomato resulted in significant increases in sucrose, fructose, and glucose contents compared to WT. Further analysis revealed that the expression levels of sugar metabolism- and transport-related genes SUSYs, NINVs, FRKs, HXKs, and TSTs increased in apple and tomato with MdSUT2.1 overexpression compared to WT. Finally, unlike the tonoplast sugar transporters MdTST1 and MdTST2, the promoter of MdSUT2.1 was not inducible by exogenous sugars. These findings provide valuable insights into the molecular mechanism underlying sugar accumulation in apple.

Sugar infusion into trees: A novel method to study tree carbon relations and its regulations.

Many carbon-related physiological questions in plants such as carbon (C) limitation or starvation have not yet been resolved thoroughly due to the lack of suitable experimental methodology. As a first step towards resolving these problems, we conducted infusion experiments with bonsai trees (Ficus microcarpa) and young maple trees (Acer pseudoplatanus) in greenhouse, and with adult Scots pine trees (Pinus sylvestris) in the field, that were "fed" with 13C-labelled glucose either through the phloem or the xylem. We then traced the 13C-signal in plant organic matter and respiration to test whether trees can take up and metabolize exogenous sugars infused. Ten weeks after infusion started, xylem but not phloem infusion significantly increased the δ13C values in both aboveground and belowground tissues of the bonsai trees in the greenhouse, whereas xylem infusion significantly increased xylem δ13C values and phloem infusion significantly increased phloem δ13C values of the adult pines in the field experiment, compared to the corresponding controls. The respiration measurement experiment with young maple trees showed significantly increased δ13C-values in shoot respired CO2 at the time of four weeks after xylem infusion started. Our results clearly indicate that trees do translocate and metabolize exogenous sugars infused, and because the phloem layer is too thin, and thus xylem infusion can be better operated than phloem infusion. This tree infusion method developed here opens up new avenues and has great potential to be used for research on the whole plant C balance and its regulation in response to environmental factors and extreme stress conditions.

Effects of pretreatment with a combination of ultrasound and γ-aminobutyric acid on polyphenol metabolites and metabolic pathways in mung bean sprouts.

Polyphenols play an important role in human nutrition, therefore, how to improve its content with innovative approach is important, and understanding the metabolic pathys is necessary. Mung beans are rich in polyphenols, which made them have physiological functions such as hypoglycemia, antioxidant, and hypotension. However, the content of polyphenols in natural mung bean is relatively low, and it needs to be increased. The methods of increasing polyphenol content in grains and beans by enrichment include physical stress, such as ultrasonic stress, hypoxia stress and ultraviolet radiation, and single exogenous substance stress, such as exogenous amino acids, exogenous sugars. But, the enrichment of polyphenols using exogenous substances in combination with physical stress is less applied. Therefore, this study innovated the use of exogenous γ-aminobutyric acid (GABA) combined with ultrasonic stress to enrich mung bean sprouts polyphenols and enhance their content. The metabolic pathways of the enrichment process were also analyzed to provide a reference for studies related to the enrichment of polyphenols. Mung bean seeds were pretreated with a combination of ultrasound and GABA under different conditions. Single-factor test and response surface methodology were used for optimizing pretreatment conditions of mung bean. Effects of combined pretreatments on the polyphenols content and antioxidant activity of sprouted mung beans were investigated. Additionally, metabolites were identified, and metabolic pathways were analyzed using non-targeted metabolomics techniques. Optimal conditions of mung bean pretreatment were found to be 370 W for ultrasound power, 40 min for ultrasonication time, 10 mmol/L for GABA concentration, and 8 h for the soaking duration. Under these conditions, the predicted polyphenol content was found to be 4.52 mg GAE/g DW. The pretreatment of mung beans with a combination of ultrasound and exogenous GABA resulted in mung bean sprouts with enhanced polyphenol content and antioxidant activity compared to mung beans germinated without pretreatment. A significant increase in the content of six polyphenols [Genistein, (-)-Epigallocatechin, Epicatechin, Nobiletin, Naringenin, Biochanin A] in the pretreated and germinated mung beans was found, and six metabolic pathways (flavonoid biosynthesis, isoflavones biosynthesis, biosynthesis of phenylpropanoids, anthocyanin biosynthesis, biosynthesis of secondary metabolites, and metabolic pathways) were significantly activated. The obtained results suggest that a combination of ultrasound and exogenous GABA treatment can be used to produce mung bean sprouts with enriched polyphenols content and enhanced antioxidant activity.

A Plate Growth Assay to Quantify Embryonic Root Development of Zea mays.

Murashige-Skoog medium solutions have been used in a variety of plant plate growth assays, yet most research uses Arabidopsis thaliana as the study organism. For larger seeds such as maize (Zea mays), most protocols employ a paper towel roll method for experiments, which often involves wrapping maize seedlings in wet, sterile germination paper. What the paper towel roll method lacks, however, is the ability to image the roots over time without risk of contamination. Here, we describe a sterile plate growth assay that contains Murashige-Skoog medium to grow seedlings starting two days after germination. This protocol uses a section of a paper towel roll method to achieve uniform germination of maize seedlings, which are sterilely transferred onto large acrylic plates for the duration of the experiment. The media can undergo modification to include an assortment of plant hormones, exogenous sugars, and other chemicals. The acrylic plates allow researchers to freely image the plate without disturbing the seedlings and control the environment in which the seedlings are grown, such as modifications in temperature and light. Additionally, the protocol is widely adaptable for use with other cereal crops. Key features • Builds upon plate growth methods routinely used for Arabidopsis seedlings but that are inadequate for maize. • Real-time photographic analysis of seedlings up to two weeks following germination. • Allows for testing of various growth conditions involving an assortment of additives and/or modification of environmental conditions. • Samples are able to be collected for genotype screening.

Sugar metabolism mediates temperature-dependent flowering induction in saffron (Crocus sativus L.)

Saffron, which comprises the stigma of the Crocus sativus flower, is an important culinary and medicinal product. Saffron productivity depends on its flower formation, which is regulated by temperature. Inappropriate temperatures at the flowering stages result in flower atrophy and reduced or no flowering. The effect of temperature on saffron flowering was investigated using morphological studies coupled with transcriptomics and metabolic studies of meristem-enriched tissue collected from corms stored and grown at two different temperatures [high (25°C) and low (8°C)] during flowering. Morphological and histological studies suggested that high temperature, during the resting phase of the saffron corm life cycle, promotes flowering, whereas low temperature suppresses it. Low temperatures suppress flowering by inhibiting flower induction. Transcriptome analysis during the flower induction stage indicated that sugar metabolism genes were differentially regulated at different temperatures. Genes coding for starch and sucrose metabolism were enriched and differentially regulated at 25°C vs 8°C. High temperature promoted starch breakdown and soluble sugar formation, whereas low temperature had a vice-versa effect. Further, we identified that low-temperature mediated suppression of flowering involves the downregulation of the floral integrator gene CsatFT3. Exogenous sugar feeding, mainly sucrose, can rescue the low-temperature suppression of flower induction via upregulation of the CsatFT3 gene. Overall the results suggest that environmental temperatures alter sugar metabolism, which mediates temperature-dependent flower induction in saffron corms via regulation of the FT3 gene. These findings will aid in identifying temperature driven molecular factors controlling flowering in saffron.

Energy status-promoted growth and development of Arabidopsis require copper deficiency response transcriptional regulator SPL7.

Copper (Cu) is a cofactor of around 300 Arabidopsis proteins, including photosynthetic and mitochondrial electron transfer chain enzymes critical for adenosine triphosphate (ATP) production and carbon fixation. Plant acclimation to Cu deficiency requires the transcription factor SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE7 (SPL7). We report that in the wild type (WT) and in the spl7-1 mutant, respiratory electron flux via Cu-dependent cytochrome c oxidase is unaffected under both normal and low-Cu cultivation conditions. Supplementing Cu-deficient medium with exogenous sugar stimulated growth of the WT, but not of spl7 mutants. Instead, these mutants accumulated carbohydrates, including the signaling sugar trehalose 6-phosphate, as well as ATP and NADH, even under normal Cu supply and without sugar supplementation. Delayed spl7-1 development was in agreement with its attenuated sugar responsiveness. Functional TARGET OF RAPAMYCIN and SNF1-RELATED KINASE1 signaling in spl7-1 argued against fundamental defects in these energy-signaling hubs. Sequencing of chromatin immunoprecipitates combined with transcriptome profiling identified direct targets of SPL7-mediated positive regulation, including Fe SUPEROXIDE DISMUTASE1 (FSD1), COPPER-DEFICIENCY-INDUCED TRANSCRIPTION FACTOR1 (CITF1), and the uncharacterized bHLH23 (CITF2), as well as an enriched upstream GTACTRC motif. In summary, transducing energy availability into growth and reproductive development requires the function of SPL7. Our results could help increase crop yields, especially on Cu-deficient soils.

Screening For Potential Exopolysaccharide Producers From Lactobacillus spp Isolated From Locally Fermented Milk (Nono)

Exopolysaccharides (EPS) are exogenous bacterial sugar polymers with many applications in dairy, pharmaceutical and cosmetic industries, using it as thickeners, stabilizers and gelling agents. The study aimed to screen for potential exopolysaccharide producers from Lactobacillus spp. isolated from locally fermented milk (nono). Twenty-five nono Samples were collected from Wambai market, Kano. Lactic acid bacteria were isolated using de Man Ragosa and Sharpe Agar. Isolates were identified by API 50 CHL kit and web, and screened for EPS production in which the EPS was extracted and quantified using the phenol-sulphuric method. Next, the influence of carbon source (Glucose, Sucrose and Lactose) and concentrations on EPS were evaluated on some of the isolated strains. The functional groups of the EPS were confirmed using FTIR. The isolated Lactobacillus spp. were all Gram positive, catalase and oxidase negative, API identification yielded; Lactobacillus acidophilus 1, Lb. brevis 1, Lb. fermentum, Lb. paracasei ssp paracasei, Lb. acidophilus 3. Ten isolates yielded EPS in the range of 248.33mg/l - 07.83mg/l. The FTIR analysis of extracted EPS produced peaks around 3,300–881cm-1. Hence the study has brought to light the presence of potential EPS producing LAB in nono, which could be further exploited to harness their potential.

The effect of exogenous sugar supplementation on the dynamics of microRNA156 and SPL gene expression in apple (Malus × domestica Borkh.) in vitro cultures

ISHS I International Symposium on Reproductive Biology of Fruit Tree Species The effect of exogenous sugar supplementation on the dynamics of microRNA156 and SPL gene expression in apple (Malus × domestica Borkh.) in vitro cultures

Genome-wide identification of sugar transporter gene family in Brassicaceae crops and an expression analysis in the radish

BackgroundSugar not only is an important biomacromolecule that plays important roles in plant growth, development, and biotic and abiotic stress tolerance but also provides a skeleton for other macromolecules, such as proteins and nucleic acids. Sugar transporter proteins (STPs) play essential roles in plant sugar transport and ultimately affect the abovementioned life processes. However, the evolutionary dynamics of this important gene family in Brassicaceae crops are still largely unknown, and the functional differentiation of radish STP genes remains unclear.ResultsIn the present study, a comparative genomic study of STP genes in five representative Brassicaceae crops was conducted, and a total of 25, 25, 28, 36 and 49 STP genes were individually identified in Raphanus sativus (Rs), Brassica oleracea (Bo), B. rapa (Br), B. napus (Bn) and B. juncea (Bj), which were divided into four clades by phylogenetic analysis. The number of STP genes was no direct correlation with genome size and the total number of coding genes in Brassicaceae crops, and their physical and chemical properties showed no significant difference. Expression analysis showed that radish STP genes play vital roles not only in flower and seedpod development but also under heavy metal (cadmium, chromium and lead), NaCl and PEG-6000 stresses, Agrobacterium tumefaciens infection, and exogenous sugar treatment. RsSTP13.2 was significantly upregulated in the resistant radish cultivar by A. tumefaciens infection and induced by heavy metal, NaCl and PEG-6000 stress, indicating that it is involved in resistance to both biotic and abiotic stress in radish.ConclusionsThe present study provides insights into the evolutionary patterns of the STP gene family in Brassicaceae genomes and provides a theoretical basis for future functional analysis of STP genes in Brassicaceae crops.