Sugar Accumulation Research Articles

Commercial processing of Oriental lilies affects bud opening and metabolic dynamics

Lilies are a high value cut flower typically producing 4–5 flowers per stem, but the opening of young buds of Oriental hybrid lilies is often affected in cut flowers. Commercial treatment includes harvesting of the stem when the oldest bud is closed and at turning colour, approximately 2 ds before it would open on the plant. Stems are then rehydrated, stored chilled for up to 72 h and transported dry. To understand the effect of commercial treatment onu the nutrient status metabolomes were compared throughout bud opening from different positions on the stem. At each developmental stage the metabolomic profile was affected by bud position and commercial treatment. Starch accumulated as long as buds remain closed; upon bud opening starch content declined. Reciprocally, sugar levels rose during flower opening and were affected by edge/ midrib location and commercial treatment. Glucose, fructose and sucrose levels remained higher in opened flowers still on the plant. AMY2 (amylase) transcript levels rose as did those of two sugar transporters (MST6 and SWEET7). Commercial processing therefore impacts on the metabolome and the ability to accumulate sugars in the opening flower bud. Commercial treatment delayed bud opening and the effect was dependent on the position of the bud on the stem. However, it had little impact on the rate of cell expansion during flower opening. Cell expansion in the different areas of the adaxial epidermis was unaffected by the commercial treatment. Furthermore, edge and adaxial tepal cells expanded faster during opening. Expression of cell expansion related genes (EXPA1 and LoPIP1) fell as flowers opened. This differential cell expansion in the tepal sectors could underpin the transition of a convex to a concave tepal shape during opening. In conclusion, commercial processing mainly affects the early stages of bud opening. Sugar and metabolite accumulation is compromised by commercial treatment, but this did not affect the capacity for cell expansion in the tepal. Furthermore, our data indicate that differential cell expansion in the different sectors of the tepals is important in lily flower opening, and that this is associated with starch breakdown and sugar accumulation.

Stress responsive ZmWRKY53 gene increases cold tolerance in rice.

Plant WRKY transcription factors are responsible for biotic and abiotic stresses and play an important role in enhancing their adaptability. The AtWRKY33 is a gene that functions in response to abiotic stresses such as low temperature, drought, salinity, etc. In this study, a recombinant vector YG8198-ZmWRKY53 carrying the ZmWRKY53, an interspecific homolog of the dicotyledonous AtWRKY33, was transferred to rice plants by Agrobacterium mediated transformation. The ectopic expression of the ZmWRKY53 in transgenic rice plants conferred cold tolerance with a higher accumulation of free proline and water-soluble sugars, an increase in chlorophyll content, a decrease in electrolyte leakage rate and MDA levels compared to control plants. This result suggests that ZmWRKY53 may confer cold tolerance in rice.

Soil Organic Matter and Total Nitrogen Reshaped Root-Associated Bacteria Community and Synergistic Change the Stress Resistance of Codonopsis pilosula.

The stress resistance of medicinal plants is essential to the accumulation of pharmacological active ingredients, but the regulation mechanism of biological factors and abiotic factors on medicinal plants is still unclear. To investigate the mechanism of soil nutrient and microecology on the stress resistance of C. pilosula, rhizosphere soil and roots were collected across the four seasons in Minxian, Gansu, and their physicochemical properties, as well as root-associated microorganisms, were examined. The results showed that the bacterial α-diversity indexes increased in the endosphere and rhizosphere from summer to autumn. At the same time, the community composition and function changed considerably. The stability of the endophytic bacterial community was higher than that rhizospheric bacteria, and the complexity of the endophytic bacterial community was lower than rhizospheric bacteria. Soil organic matter (OM), water content (WC), total potassium (TK), and total nitrogen (TN) have been identified as the key factors affecting bacterial community diversity and stress resistance of C. pilosula. WC, TN, and OM showed significant differences from summer to autumn (P < 0.5). Four key soil physiochemical factors changed significantly between seasons (P < 0.01). TN and OM change the stress resistance of C. pilosula mainly by changing the activity of antioxidant enzymes. Changes of OM and endophytic bacterial diversity affect the accumulation of soluble sugars to alter stress resistance. These four key soil physicochemical factors significantly influenced the diversity of endophytic bacteria. WC and OM were identified as the most important factors for endophytic and rhizospheric bacteria, respectively. This study provided the research basis for the scientific planting of C. pilosula.

Tissue- and time-dependent metabolite profiles during early grain development under normal and high night-time temperature conditions

BackgroundWheat grain development in the first few days after pollination determines the number of endosperm cells that influence grain yield potential and is susceptible to various environmental conditions, including high night temperatures (HNTs). Flag leaves and seed-associated bracts (glumes, awn, palea, and lemma) provide nutrients to the developing seed. However, the specific metabolic roles of these tissues are uncertain, especially their dynamics at different developmental stages and the time in a day. Tissue- and time-dependent metabolite profiling may hint at the metabolic roles of tissues and the mechanisms of how HNTs affect daytime metabolic status in early grain development.ResultsThe metabolite profiles of flag leaf, bract, seed (embryo and endosperm), and entire spike were analyzed at 12:00 (day) and 23:00 (night) on 2, 4, and 6 days after fertilization under control and HNT conditions. The metabolite levels in flag leaves and bracts showed day/night oscillations, while their behaviors were distinct between the tissues. Some metabolites, such as sucrose, cellobiose, and succinic acid, showed contrasting oscillations in the two photosynthetic tissues. In contrast, seed metabolite levels differed due to the days after fertilization rather than the time in a day. The seed metabolite profile altered earlier in the HNT than in the control condition, likely associated with accelerated grain development caused by HNT. HNT also disrupted the day/night oscillation of sugar accumulation in flag leaves and bracts.ConclusionsThese results highlight distinct metabolic roles of flag leaves and bracts during wheat early seed development. The seed metabolite levels are related to the developmental stages. The early metabolic events in the seeds and the disruption of the day/night metabolic cycle in photosynthetic tissues may partly explain the adverse effects of HNT on grain yield.

Effects of artificial management on culm properties of Dendrocalamus brandisii.

The artificial cultivation and management were extensively carried out in Dendrocalamus brandisii stands. However, the influences of artificial management on the anatomical and chemical characteristics of the bamboo culms were unknown. In this study, the fiber morphology, chemical composition and sugar accumulation of the D. brandisii culms with management and without management were compared in order to determine the influences of artificial management on bamboo culms. The results indicated that artificial management had a significant influence on the fiber morphology, resulting in shorter fiber length, larger L/T ratio, and smaller W/Lu value. However, the management not only increased the contents of moisture, ash, SiO2, and extractive, but also increased the holocellulose contents and decreased the lignin contents, as compared to those without management. Moreover, the management significantly increased the endogenous carbohydrates storage in the culms so as to improve the shoot production. The bamboos under management conditions could still be utilized as a raw material for papermaking. This provided a theoretical basis for the artificial management of D. brandisii stands.

Hot Water Treatment Preserves Chinese Chestnut (Castanea mollissima Blume) Quality during Storage by Increasing Its Sugar Accumulation and ROS-Scavenging Ability

Heat treatment is a widely used physical technology for postharvest fruit and crops. The Chinese chestnut cultivar “Kuili” has high sugar and amylose contents, and is popular among people. However, the chestnut quality decreases quickly after harvest. In order to maintain the chestnuts’ quality during storage, this study explores five hot water treatments for chestnuts: T1 (control, no treatment), T2 (50 °C), T3 (65 °C), T4 (75 °C), and T5 (90 °C) for 45 min. T1 was dried at ambient temperature, while the other heat treatments were dried at 30 °C for 30 min. After treatment, chestnuts were placed in plastic trays, covered with a 15 μm thick PVC film, and stored at 4 °C with 70% relative humidity; they remained in the same air for 120 days. Results indicated that T3 and T4 showed slight color changes while maintaining shell and kernel firmness, and their weight loss was reduced (+5–8%), as well as their decay rate (limited to within 20%). The T3, T4, and T5 treatments (from days 60 to 120) decreased their pest survival rates to &lt;2%. Additionally, heat treatments facilitated the accumulation of total soluble sugar and increased the expression of sugar biosynthesis-related genes. Meanwhile, T3 and T4 delayed starch reduction (they maintained relatively higher contents, from 288 to ~320 mg g−1 DW) and altered some starch biosynthesis genes. Furthermore, T2, T3, and T4 exhibited higher antioxidant activity and lower hydrogen peroxide (H2O2) and superoxide anions (O2−) contents than T1. At the end of storage, the scores of T3 and T4 treatments were 55.1 and 52.3, and they ranked first and second among the five treatments, respectively. Therefore, these findings provide valuable insights for controlling postharvest losses in chestnuts.

Integrated metabolomics and transcriptomics reveal that HhERF9 positively regulates salt tolerance in Hibiscus hamabo Siebold & Zuccarini

Hibiscus hamabo Siebold & Zuccarini is one of the few semi-mangrove plants in the genus Hibiscus that can survive in saline-alkali soil and flooded land, but the mechanism underlying its adaptation to salt soil remains unknown. Here, to uncover this unsolved mystery, we characterized the changes in the accumulation of specific metabolites under salt stress in H. hamabo by integrating physiological, metabolic, and transcriptomic data, and found that osmotic adjustment and abscisic acid (ABA) is highly associated with the salt stress response. Further, a weighted gene co-expression network analysis was performed on the root transcriptome data, which identified three key candidate transcription factors responsive to salt stress. Among them, the expression HhERF9 was significantly upregulated under salt stress and ABA treatment and was involved in regulating the expression of genes related to the salt stress response. Further research indicated that HhERF9 enhances the accumulation of proline and soluble sugars by regulating the expression of genes such as NHX2 and P5CS. These findings provide a reference for improving H. hamabo through targeted genetic engineering and lay a theoretical foundation for its future promotion and cultivation in saline-alkali areas.

Drought Protective Effects of Exogenous ABA and Kinetin on Lettuce: Sugar Content, Antioxidant Enzyme Activity, and Productivity.

Drought is an environmental stressor that significantly impacts plant growth and development. Comprehending the complexity of drought stress and water utilization in the context of plant growth and development holds significant importance for sustainable agriculture. The aim of this study was to evaluate the effect of exogenously applied phytohormones on lettuce (Lactuca sativa L.) sugar content profiles and antioxidant enzyme activity and productivity. Lettuce plants were grown under normal and drought conditions in a growth chamber with a photoperiod of 14/10 h (day/night). Kinetin and abscisic acid were applied separately and in combinations when the second leaf was fully expanded. The results showed that sugar accumulation and productivity of the pretreated plants under drought were significantly higher than the controls. The perspective offered by this work showed that growth-related and stress-related phytohormones significantly influenced plant sugar metabolism, metabolic profiles, and productivity, thus enabling the control of yield and quality.

Effect of Phosphorus Fertilizer on Morpho-physiological, and Biochemical Traits of Bambara Groundnut (Vigna subterranea (L.) Verdc.) Plants Under Water Deficit

Aims: To evaluate the effect of water deficit (WD) and P-fertilizer on the growth and biochemical composition of Bambara groundnut. Study Design: The experimental design was a randomized complete block with three factors: landraces (L1, L2, and L3), single superphosphate doses (0, 20, 40, 60, 100 mg P2O5.kg-1), and watering regime (90% (control), 60%, and 30% of field capacity (FC)). Place and Duration of Study: Department of Plant Biology, Faculty of Science, University of Yaounde I for three months. Methodology: The seedlings (radicle at 2 mm) were sown in the polyethylene pots filled with substrate with the appropriate P-doses. The plants were grown for up to four weeks under normal watering level (90%_FC). Four weeks after sowing (WAS), the WD was applied by stopping irrigation and maintaining the desired FC. At harvest (8WAS), growth, physiological and biochemical parameters were evaluated. Results: P-fertilizer significantly improved growth and biochemical composition under WD or none. The plant height increased from 20.3% from 0 to 100 mg P2O5 at 30%_FC to L2 at the 8th week. At 90%_FC, the doses 20, 40, 60, 100 mg increased sugars content by 52.6, 59.4, 64.6, and 90.4%, respectively, compared to 0 mg at L3. Proline content at 30%_FC was twice (2.5) that of 90%_FC at L2. Increased accumulation of sugars, proline, and amino acids in leaves was recorded at the severe level of WD. Conclusion: P-fertilizer mitigated the adverse effect of WD on the growth and biochemical composition of Bambara groundnut. A sufficient P-supply (60 mg P2O5.kg-1) was recommended to help Bambara groundnut plants tolerate WD. L1 and L3 appear to be more tolerant than L2 and can be recommended to farmers. As the adaptation mechanisms of these landraces to WD are different, it would be advisable to evaluate their performance in the field to better assess their behavior.

Brown planthoppers manipulate rice sugar transporters to benefit their own feeding

The feeding of piercing-sucking insect herbivores often elicits changes in their host plants that benefit the insect.1 In addition to thwarting a host's defense responses, these phloem-feeding insects may manipulate source-sink signaling so as to increase resources consumed.2,3 To date, the molecular mechanisms underlying herbivore-induced resource reallocation remain less investigated. Brown planthopper (BPH), an important rice pest, feeds on the phloem and oviposits into leaf sheaths. BPH herbivory increases sugar accumulations 5-fold in the phloem sap of leaf sheaths and concurrently induces the expression of two clade III SWEET genes, SWEET13 and SWEET14, in leaf tissues, but not in leaf sheaths of attacked rice plants. Mutations of both genes by genome editing attenuate resistance to BPH without alterations of known chemical and physical defense responses. Moreover, BPH-elicited sugar levels in the phloem sap were significantly reduced in sweet13/14 mutants, which is likely to attenuate BPH feeding behavior on sweet13/14 mutants. In one of the two field seasons tested, the sweet13/14 mutants showed comparable yield to wild types, and in the other season, the mutants demonstrated stronger BPH resistance. These preliminary results suggested that the mutations in these SWEET transporters could enhance BPH resistance without yield penalties. Given that sweet13/14 mutants also exhibit resistance to bacterial blight pathogen, Xanthomonas oryzae pv. oryzae, these SWEET genes could serve as excellent molecular targets for the breeding of resistant rice cultivars.

Effects of GA3 Treatments on Fruit Vascular Structure and Water Transport of Grape

ABSTRACT Exogenous gibberellic acid was applied to regulate fruit growth of grapes to acquire high quality seedless berries. The vascular bundles provide the pathway of water and nutrient transport into the fruit and play an important role in berry growth and sugar accumulation. Therefore, changes in berry size and quality are closely related to the structure and function of the vascular tissue. In this study, 10-year-old “Shine Muscat” grape vines were treated with GA3 in grapevine production. Based on previous research and experimental environmental conditions, four treatments were applied: elongating cluster（5 mg L−1 GA3 on Apr. 28）+ seedless（25 mg L−1 GA3 on May. 24）+ expanding（50 mg L−1 GA3 on Jun. 7） (T1), seedless（25 mg L−1 GA3 on May. 24）+ expanding（50 mg L−1 GA3 on Jun. 7） (T2), expanding（50 mg L−1 GA3 on Jun. 7） (T3) and water (CK). Compared to CK, all fruits treated with GA3 had greater berry size. In addition, GA3 treated grapes had greater vascular bundle areas, including the areas of both phloem and xylem, as well as a greater number of vessels compared to control fruit. During the first rapid growth stage, water transport into the grape was rapid and did not differ among treatments. During veraison, the water transport rate among the four treatments differed, and the rank of speed was T2>T3>CK>T1. Therefore, we found that GA3 treatment can significantly promote the differentiation of vascular tissues and improve water transport capacity and phloem sugar unloading; T2 promoted the development of vascular bundles, enhanced water transport speed and phloem sugar unloading of fruit after veraison, and increased berry size.

Root-to-shoot signaling positively mediates source-sink relation in late growth stages in diploid and tetraploid wheat

Non-hydraulic root source signaling (nHRS) is a unique positive response to soil drying in the regulation of plant growth and development. However, it is unclear how the nHRS mediates the tradeoff between source and sink at the late growth stages and its adaptive mechanisms in primitive wheat. To address this issue, a root-splitting design was made by inserting solid partition in the middle of the pot culture to induce the occurrence of nHRS using four wheat cultivars (MO1 and MO4, diploid; DM22 and DM31, tetraploid) as materials. Three water treatments were designed as 1) both halves watered (CK), 2) holistic root system watered then droughted (FS), 3) one-half of the root system watered and half droughted (PS). FS and PS were designed to compare the role of the full root system and split root system to induce nHRS. Leaves samples were collected during booting and anthesis to compare the role of nHRS at both growth stages. The data indicated that under PS treatment, ABA concentration was significantly higher than FS and CK, demonstrating the induction of nHRS in split root design and nHRS decreased cytokinin (ZR) levels, particularly in the PS treatment. Soluble sugar and proline accumulation were higher in the anthesis stage as compared to the booting stage. POD activity was higher at anthesis, while CAT was higher at the booting stage. Increased ABA (nHRS) correlated with source-sink relationships and metabolic rate (i.e., leaf) connecting other stress signals. Biomass density showed superior resource acquisition and utilization capabilities in both FS and PS treatment as compared to CK in all plants. Our findings indicate that nHRS-induced alterations in phytohormones and their effect on source-sink relations were allied with the growth stages in primitive wheat.

Re-watering solution facilitates seed germination and seedling growth of Carex schmidtii: Implication for species re-introduction in degraded semi-arid wetlands

Water deficiency threatens the health and function of wetlands in semi-arid areas. Optimum re-watering is an effective method for close-to-natural restoration to mitigate wetland degradation. Although the ecological importance of optimal re-watering as a nature-based solution for promoting wetland plant growth has been widely recognized, the response mechanisms of seed germination and seedling growth to re-watering are still poorly understood despite their decisive impact on plant life history. To fill this gap, this study compared the characteristics of seed germination and seedling growth in Carex schmidtii under initial water content with three levels (30%, 50%, and 70%) and five re-watering treatments (maintained at constant water content and re-watering to 100% on 7th, 14th, 21st, and 28th day). Moreover, the degree of reserve mobilization during four germination stages (seed suckering, sprouting, 20% germination, and seedling growth) was investigated. The results showed that water deficiency and re-watering treatments significantly affected C. schmidtii seed germination, seedling growth, and reserve mobilization. Compared with the other treatments, 50% moisture content and re-watering to 100% on the 14th day (50%-RT3) treatment significantly improved germination traits (germination rate, daily germination rate, germination index, and vigor index) and seedling growth characteristics (shoot length, root length, shoot biomass, root biomass, and total biomass). Furthermore, the degree of mobilization of starch, soluble protein, fat, and soluble sugar accumulation in C. schmidtii seeds under 50%-RT3 was higher than that in the other treatments. The structural equation model showed that the characteristics of seed germination and seedling growth of C. schmidtii were directly related to water deficiency and re-watering treatments, whereas reserve mobilization indirectly affected seed germination and seedling growth. These findings demonstrated that water deficiency and re-watering treatments have a crucial regulatory effect on seed germination and seedling growth of wetland plant species through a dual mechanism. This study provides information for the formulation of an optimum re-watering strategy for wetland vegetation restoration in semi-arid areas of the world.

Overexpression of a transcription factor MdWRKY126 altered soluble sugar accumulation in apple and tomato fruit

The compositions and contents of soluble sugars highly determine the flavor and quality of flshy fruits. In the present study, we found that the overexpression of transcription factor MdWRKY126 localized on the nucleus enhanced sucrose concentration while decreased fructose and glucose concentration in transgenic apple calli and ripening tomato fruits. To comprehensively understand the effects of the MdWRKY126 on the content of various soluble sugars in apple and tomato fruits, enzyme activities and related essential genes associated with the sugar metabolism and transportation pathway in MdWRKY126-overrexpressed apple and tomato lines were analyzed. The results indicated that the overexpression of MdWRKY126 upregulated sucrose phosphate synthase (SPS) activity and the gene expression levels of SPS and sucrose transporter SUT, which was conducive to a large accumulation of sucrose in fruit cells. Meanwhile, MdWRKY126 overexpression downregulated the activity of enzymes involved in sucrose decomposition including cell wall invertase (CWINV), sucrose synthase (SUSY) and the corresponding gene expressions, as well as inhibited the expression levels of hexose transporter (HTs) and tonoplast sugar transporter (TSTs) that transport hexose into vacuoles, resulting in a reduced hexose level in apple calli and tomato fruit. These findings enrich our understanding of the metabolism and regulation of soluble sugars in apple fruits.

Abscisic acid controls sugar accumulation essential to strawberry fruit ripening via the FaRIPK1-FaTCP7-FaSTP13/FaSPT module.

Strawberry is considered as a model plant for studying the ripening of abscisic acid (ABA)-regulated non-climacteric fruits, a process in which sugar plays a fundamental role, while how ABA regulates sugar accumulation remains unclear. This study provides a direct line of physiological, biochemical, and molecular evidence that ABA signaling regulates sugar accumulation via the FaRIPK1-FaTCP7-FaSTP13/FaSPT signaling pathway. Herein, FaRIPK1, a red-initial protein kinase 1 previously identified in strawberry fruit, not only interacted with the transcription factor FaTCP7 (TEOSINTE BRANCHEN 1, CYCLOIDEA, and PCF) but also phosphorylated the critical Ser89 and Thr93 sites of FaTCP7, which negatively regulated strawberry fruit ripening, as evidenced by the transient overexpression (OE) and virus-induced gene silencing transgenic system. Furthermore, the DAP-seq experiments revealed that FvTCP7 bound the motif "GTGGNNCCCNC" in the promoters of two sugar transporter genes, FaSTP13 (sugar transport protein 13) and FaSPT (sugar phosphate/phosphate translocator), inhibiting their transcription activities as determined by the electrophoretic mobility shift assay, yeast one-hybrid, and dual-luciferase reporter assays. The downregulated FaSTP13 and FaSPT transcripts in the FaTCP7-OE fruit resulted in a reduction in soluble sugar content. Consistently, theyeast absorption test revealed that the two transporters had hexose transport activity. Especially, the phosphorylation-inhibited binding of FaTCP7 to the promoters of FaSTP13 and FaSPT could result in the release of their transcriptional activities. In addition, the phosphomimetic form FaTCP7S89D or FaTCP7T93D could rescue the phenotype of FaTCP7-OE fruits. Importantly, exogenous ABA treatment enhanced the FaRIPK1-FaTCP7 interaction. Overall, we found direct evidence that ABA signaling controls sugar accumulation during strawberry fruit ripening via the "FaRIPK1-FaTCP7-FaSTP13/FaSPT" module.

Overexpression of VaBAM3 from Vitis amurensis enhances seedling cold tolerance by promoting soluble sugar accumulation and reactive oxygen scavenging.

The VaBAM3 cloned from Vitis amurensis can enhance the cold tolerance of overexpressed plants, but VaBAM3 knock out by CRISPR/Cas9 system weakened grape callus cold tolerance. In grape production, extreme cold conditions can seriously threaten plant survival and fruit quality. Regulation of starch content by β-amylase (BAM, EC: 3.2.1.2) contributes to cold tolerance in plants. In this study, we cloned the VaBAM3 gene from an extremely cold-tolerant grape, Vitis amurensis, and overexpressed it in tomato and Arabidopsis plants, as well as in grape callus for functional characterization. After exposure to cold stress, leaf wilting in the VaBAM3-overexpressing tomato plants was slightly less pronounced than that in wild-type tomato plants, and these plants were characterized by a significant accumulation of autophagosomes. Additionally, the VaBAM3-overexpressing Arabidopsis plants had a higher freezing tolerance than the wild-type counterparts. Under cold stress conditions, the activities of total amylase, BAM, peroxidase, superoxide dismutase, and catalase in VaBAM3-overexpressing plants were significantly higher than those in the corresponding wild-type plants. Furthermore, sucrose, glucose, and fructose contents in these lines were similarly significantly higher, whereas starch contents were reduced in comparison to the levels in the wild-type plants. Furthermore, we detected high CBF and COR gene expression levels in cold-stressed VaBAM3-overexpressing plants. Compared with those in VaBAM3-overexpressing grape callus, the aforementioned indicators tended to change in the opposite direction in grape callus with silenced VaBAM3. Collectively, our findings indicate that heterologous overexpression of VaBAM3 enhanced cold tolerance of plants by promoting the accumulation of soluble sugars and scavenging of excessive reactive oxygen species. These findings provide a theoretical basis for the cultivation of cold-resistant grape and support creation of germplasm resources for this purpose.

Comparative study on dynamic in vitro digestion characteristics of lotus seed starch-EGCG complex prepared by different processing methods

To study the effect of starch-polyphenol interaction induced by different processing methods on digestion characteristics, a dynamic in vitro human gastrointestinal system was employed to investigate the digestive characteristics of lotus seed starch–epigallocatechin gallate (EGCG) complex (LS–EGCG) prepared by different processing methods. Digestion altered crystal structure, particle size, morphology, pH, starch hydrolysis, and EGCG content. Processing broke physical barriers, reducing particle size by enzyme erosion. Enzymatic hydrolysis gradually exposed EGCG, indicated by green fluorescence. Heat and high pressure treatments enhanced starch dissolution, increasing sugar accumulation and hydrolysis. However, ultrasonic-microwave and high pressure microfluidization treatments formed dense structures, decreasing hydrolysis rates. Overall, the complex formed by high pressure microfluidization showed better enzyme resistance. The results provide a scientific basis for the development of food with quality and functional properties.

Unlocking the potential of Algerian lignocellulosic biomass: exploring indigenous microbial diversity for enhanced enzyme and sugar production.

Nowadays, natural resources like lignocellulosic biomass are gaining more and more attention. This study was conducted to analyse chemical composition of dried and ground samples (500μm) of various Algerian bioresources including alfa stems (AS), dry palms (DP), olive pomace (OP), pinecones (PC), and tomato waste (TW). AS exhibited the lowest lignin content (3.60 ± 0.60%), but the highest cellulose (58.30 ± 2.06%), and hemicellulose (20.00 ± 3.07%) levels. DP, OP, and PC had around 30% cellulose, and 10% hemicellulose. OP had the highest lignin content (29.00 ± 6.40%), while TW contained (15.70 ± 2.67% cellulose, 13.70 ± 0.002% hemicellulose, and 17.90 ± 4.00% lignin). Among 91 isolated microorganisms, nine were selected for cellulase, xylanase, and/or laccase production. The ability of Bacillus mojavensis to produce laccase and cellulase, as well as B. safensis to produce cellulase and xylanase, is being reported for the first time. In submerged conditions, TW was the most suitable substrate for enzyme production. In this conditions, T. versicolor K1 was the only strain able to produce laccase (4,170 ± 556 U/L). Additionally, Coniocheata hoffmannii P4 exhibited the highest cellulase activity (907.62 ± 26.22 U/L), and B. mojavensis Y3 the highest xylanase activity (612.73 ± 12.73 U/L). T. versicolor K1 culture showed reducing sugars accumulation of 18.87% compared to initial concentrations. Sucrose was the predominant sugar detected by HPLC analysis (13.44 ± 0.02g/L). Our findings suggest that T. versicolor K1 holds promise for laccase production, while TW represents a suitable substrate for sucrose production.

Superoxide Dismutase Premodulates Oxidative Stress in Plastids for Protection of Tobacco Plants from Cold Damage Ultrastructure Damage

ROS-dependent induction of oxidative damage can be used as a trigger initiating genetically determined non-specific protection in plant cells and tissues. Plants are potentially able to withstand various specific (toxic, osmotic) factors of abiotic effects, but do not have sufficient or specific sensitivity to form an adequate effective response. In this work, we demonstrate one of the possible approaches for successful cold acclimation through the formation of effective protection of photosynthetic structures due to the insertion of the heterologous FeSOD gene into the tobacco genome under the control of the constitutive promoter and equipped with a signal sequence targeting the protein to plastid. The increased enzymatic activity of superoxide dismutase in the plastid compartment of transgenic tobacco plants enables them to tolerate the oxidative factor of environmental stresses scavenging ROS. On the other hand, the cost of such resistance is quite high and, when grown under normal conditions, disturbs the arrangement of the intrachloroplastic subdomains leading to the modification of stromal thylakoids, probably significantly affecting the photosynthesis processes that regulate the efficiency of photosystem II. This is partially compensated for by the fact that, at the same time, under normal conditions, the production of peroxide induces the activation of ROS detoxification enzymes. However, a violation of a number of processes, such as the metabolism of accumulation, and utilization and transportation of sugars and starch, is significantly altered, which leads to a shift in metabolic chains. The expected step for further improvement of the applied technology could be both the use of inducible promoters in the expression cassette, and the addition of other genes encoding for hydrogen peroxide-scavenging enzymes in the genetic construct that are downstream in the metabolic chain.

Combined transcriptome and metabolome analyses reveal the effects of selenium on the growth and quality of Lilium lancifolium.

Lilium lancifolium Thunb (L. lancifolium) is an important medicinal and edible plant with outstanding functionality for selenium (Se) biofortification. However, the molecular response of L. lancifolium to exogenous Se has not been fully elucidated. In this study, the effects of different levels of Se on L. lancifolium growth and quality were explored by transcriptome, metabolome and biochemical analyses. The results showed that the total Se and organic Se content in L. lancifolium bulbs increased with increasing Se dosage (0-8.0 mmol/L). Moreover, Se stimulated the growth of L. lancifolium at low level (2.0 mmol/L) but showed an inhibitory effect at high levels (≥4.0 mmol/L). Metabolomic and biochemical analyses revealed that the bulb weight and the content of amino acid, soluble sugar, and soluble protein were significantly increased in the 2.0 mmol/L Se treatment compared with those in the control (0 mmol/L Se). Transcriptome and metabolome analyses revealed that the significant upregulation of the GPD1, GPAT and ADPRM genes promoted glycerophospholipid accumulation. Additionally, the significantly upregulated glyA and downregulated asnB, nadB, thrA and SAT genes coordinate to the regulation of amino acid biosynthesis. The significantly upregulated SUS, bgl B, BAM, and SGA1 genes were involved in soluble sugar accumulation under Se treatment. In summary, this study identified the optimal Se concentration (2.0 mmol/L), which significantly improved the growth and nutritional quality of L. lancifolium and contributed to understanding the combined effects of Se treatment on the expression of genes and the accumulation of metabolites in L. lancifolium bulbs.