Levels Of Soluble Sugars Research Articles

Highland barley ELNs and physiological responses to different concentrations of Cr (VI) stress.

This study is the first to use highland barley (HB) to study the toxic effects of Cr (VI) on seedlings and the response mechanism of HELNs to Cr (VI) stress. The outcomes indicated that the germination rate of HB seeds, plant height, root length, water content, and levels of proline (PRO) and soluble sugar in both leaves and roots were all impacted by varying concentrations of Cr (VI) treatments. Differential changes in the activities of antioxidant enzymes (SOD, POD, CAT) were observed in leaves and roots of HB. We also extracted HB-derived ELNs (HELNs) and characterized and sequenced HELNs. The average particle size of CK-HELNs was 79.0 nm, and the concentration of HELNs was 4.56 E+10 (particles/mL). As the concentration of Cr (VI) increased, the particle size of HELNs in HB seedlings also increased, while the concentration decreased. A total of 29 miRNA species were identified in CK-HELNs, Cr10-HELNs, and Cr40-HELNs. Out of these, 25 were newly predicted miRNAs, and the remaining four were known miRNAs. A total of 2 known miRNAs and 11 novel miRNAs were upregulated under different concentrations of Cr (VI) stress. 1 known and 5 novel miRNAs were downregulated under different concentrations of Cr (VI) stress. Enrichment of the GO and KEGG pathways revealed that the differential gene functions were mainly focused on binding and catalytic activities. This study reveals for the first time the changes of HELNs under different concentrations of Cr (VI) stress and the toxic effects of Cr (VI) on HB seedlings. This study provides a new perspective to explore the function and utilisation of ELNs.

The phenology of flowering in Spiranthes sinensis s.s.

The native Spiranthes sinensis s.s. of Taiwan is an emerging ornamental potted orchid. This study aims to understand the conditions for floral differentiation and life cycle to facilitate artificial cultivation and commercial production of S. sinensis. Every August, new leaves appeared from the dwarf stem, during which the old roots acted as a nutrient source, providing the energy needed for the initial foliation phase. In November, the apical bud enters the floral initiation. In January, the apical bud began to transform into the primary inflorescence of the plant, while the lateral bud apical meristem began to differentiate into floral meristem. The plant produced a main spike in February, followed by the lateral bud inflorescences; the plant bloomed from March to May. Changes in sugar and starch contents were associated with inflorescence development. A higher soluble sugar level was noted in the roots and stems from January to April at the time of anthesis. Starch began to accumulate in the roots from February to August. The growth cycle restarted in August every year with new shoot formation, with the roots providing the initial nutrients for shoot growth to restart a new growing cycle. The influence of temperature changes on inflorescence development and flowering is discussed.

Induction of Salt Stress Tolerance in Wheat Seeds by Parental Treatment with Salicylic Acid

Soil salinization is an important factor that limits crop production. The effects of spraying salicylic acid (SA) during the grain-filling stage on the salt tolerance of progeny seeds in wheat (Triticum aestivum L.) were investigated in this study. The results showed that spraying SA during the grain-filling stage significantly increased the grain weight and yield of wheat plants. Meanwhile, the seeds from the SA-treated plants showed a higher germination rate, length and dry mass of the coleoptile and radicle, and a lower mean germination time compared to the seeds of water-treated plants under the salt germination condition, indicating that SA pretreatment during the grain-filling stage could effectively improve the salt tolerance of progeny seeds in wheat. SA pretreatment significantly increased the activities of amylases and the respiration rate, accompanied by a decrease in starch content, and a higher accumulation in the level of soluble sugars and adenosine triphosphate (ATP) in the germinated seedlings compared to the water pretreatment under salt stress. In addition, SA pretreatment obviously alleviated the increase in malondialdehyde (MDA) content and the reactive oxygen species (ROS) release rate in seedlings by activating antioxidant enzymes (superoxide dismutase (SOD) and peroxidase (POD)) under salt stress. Moreover, the seedlings of the SA-treated plants showed lower Na+ and higher K+ contents compared to the seeds of water-treated plants under salt stress. The results of this study indicate that spraying SA during the grain-filling stage improves the capacity of offspring seeds to maintain osmotic and ion balance and redox homeostasis under salt stress, thereby conferring salt tolerance to the wheat seeds.

Foliar Application of Nettle and Japanese Knotweed Extracts on Vitis vinifera: Consequences for Plant Physiology, Biochemical Parameters, and Yield

Climate change is expected to affect grapevine physiology, berry quality, and yield in the Douro Demarcated Region (DDR). In this study, nettle (NE) and Japanese knotweed (JKE) extracts were tested to verify their biostimulant effect on the physiological and biochemical parameters of grapevine leaves and in vine yields. In fact, some parameters were improved after foliar application of the plant extracts, namely the photosynthetic activity and consequently, the levels of photosynthetic pigments (Clb), starch, and total soluble sugars. We also observed a reduction in lipid peroxidation, which could play a crucial role in protecting cell membranes from oxidative damage induced by the climatic conditions prevalent in this region. Therefore, we confirmed that the foliar application of plant extracts, along with the enhancement of secondary metabolites and the upregulation of plant defense genes, as previously reported, resulted in the enhancement of grapevine physiology, while also increasing the yield at harvest. In the future, these plant extracts could serve as a vital tool for winegrowers in mitigating the effects of expected changes in climatic conditions.

Enhancing Pelargonium graveolens L’Hér. (geranium) growth using Zn–Al and Mg–Al LDH nanomaterials: a biochemical approach

The approaches of nanoparticles (NPs) usage have been successfully applied to increase the growth and biological activity of aromatic and medicinal plants. In this context, we studied the effects of zinc–aluminum layered double hydroxide (Zn–Al LDH) and magnesium–Al LDH (Mg–Al LDH) NPs on geranium plants. Both LDH NPs were synthesized using the co-precipitation technique and characterized with SEM, FTIR, XRD, and Zeta potential. Using the spray method, Zn–Al LDH and Mg–Al LDH NPs (10 ppm) were used in a factorial experiment with a fully randomized design. Applying LDH NPs increased Mg and Zn content, which boosted plant growth, photosynthetic pigments, and soluble sugar levels. The administration of both LDH NPs results in a constant increase in secondary metabolites such as essential oils (EOs). Monoterpenes such as geraniol (32.7%) and β-citronellol (29.18%) were found to be the main components of the EO. Geranium plants treated with Mg–Al LDH NPs exhibited the highest levels of polyphenols (44.5%), flavonoids (33.5%), and total antioxidant capacity (31.7%). Additionally, LDH NPs had a favorable effect on antioxidant enzyme activity including catalase and peroxidase activities. Overall, Zn–Al LDH and Mg–Al LDH NPs foliar application acted as an elicitor to enhance growth and bioactive metabolite accumulation in geranium plants. Despite these promising results, several challenges remain for the broader application of LDH NPs in agriculture.Graphical abstract

Chitosan induced cold tolerance in Kobresia pygmaea by regulating photosynthesis, antioxidant performance, and chloroplast ultrastructure.

Cold stress is the primary factor that limits the growth and development of Kobresia pygmaea in the Tibetan Plateau, China. Chitosan (CTS) has been recognized for its ability to enhance agricultural production and tolerance to stress. This study examined the effect of treating seedlings under cold stress with chitosan. The results demonstrated that cold stress inhibited the growth of seedlings and adversely affected the photosynthetic capacity [net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), maximum efficiency of photosystem II (Fv/Fm), quantum yield of photosystem II (φ PSII ), electron transport rate (ETR), and non-light-induced non-photochemical fluorescence quenching Y(NPQ)] and destroyed PSII and the chloroplast structure. Under regular temperatures, low concentrations of CTS (0.005% and 0.01%) inhibited the soluble protein content, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) activity, and photosynthetic capacity. However, the application of 0.015% CTS increased the levels of soluble sugar, fructose, and protein, as well as those of the levels of ions, such as iron and magnesium, chlorophyll, photosynthetic capacity, and the activities of Rubisco, superoxide dismutase, and phenylalanine amino-lyase (PAL). Under cold stress, treatment with CTS decreased the contents of starch and sucrose; improved the contents of fructose, soluble protein, and antioxidants, such as ascorbic acid and glutathione; and enhanced the photosynthesis capacity and the activities of Rubisco, chitinase, and PAL. Exogenous CTS accelerated the development of the vascular bundle, mitigated the damage to chloroplast structure induced by cold, and promoted the formation of well-organized thylakoids and grana lamellae. Additionally, CTS upregulated the expression of genes related to cold tolerance in K. pygmaea, such as KpBSK2/KpERF/KpDRE326. These findings indicate that CTS enhances the cold tolerance in K. pygmaea by improving development of the vascular bundle, increasing the accumulation of solutes and antioxidants, regulating the transformation of carbohydrates, repairing the chloroplast structure, and maintaining the photosynthetic capacity and Rubisco activity.

Physiological Indices of Five Hybrid Larch Seedlings Under Low-Temperature Stress

Larch is a cold-temperate tree species native to the northern hemisphere and tolerant to low temperatures. It is one of the most significant timber species in Northeast China. This study examined growth changes in hybrid larch seedlings from five lines to explore the physiological responses of these seedlings to low-temperature stress. Using 8-month-old hybrids of larch seedlings, we subjected the plants to cold stress at 4 °C and freezing stress at −20 °C over three periods of 6, 12, and 24 h, and treatment at 25 °C was used as a control. Results showed that significant correlations were found among the growth indicators, with larch line 1306 having the lowest incremental growth indicators, the largest root-to-crown ratio, and better cold tolerance than the other larch lines. The levels of soluble sugars (SSs), soluble proteins (SPs), malondialdehyde (MDA), and relative electrolyte leakage (REC) increased significantly in all lines under low-temperature stress. The activities of superoxide dismutase (SOD) and catalase (CAT) showed variation over time. Significant correlations were found between MDA and REL, SS, SR, Pro, CAT, and SOD in most of the lines; no significant correlation was found between MDA and the other indices in lines 1301 and 1309; and significant correlations were found between most of the physiological indices in line 1306.

Transcriptome profiling uncovers differentially expressed genes linked to nutritional quality in vegetable soybean.

Vegetative soybean (maodou or edamame) serves as a nutrient-rich food source with significant potential for mitigating global nutritional deficiencies. This study undertook a thorough examination of the nutritional profiles and transcriptomic landscapes of six soybean cultivars, including three common cultivars (Heinong551, Heinong562, and Heinong63) and three fresh maodou cultivars (Heinong527, HeinongXS4, and HeinongXS5). Nutrient analysis of the seeds disclosed notable differences in the levels of protein, fat, soluble sugars, vitamin E, calcium, potassium, magnesium, manganese, iron, and zinc across the cultivars. Through comparative transcriptome profiling and RNA sequencing, distinct variations in differentially expressed genes (DEGs) were identified between fresh and traditional maodou cultivars. Functional enrichment analyses underscored the involvement of DEGs in critical biological processes, such as nutrient biosynthesis, seed development, and stress responses. Additionally, association studies demonstrated robust correlations between specific DEG expression patterns and seed nutrient compositions across the different cultivars. Sankey diagrams illustrated that DEGs are strongly linked with seed quality traits, revealing potential molecular determinants that govern variations in nutritional content. The identified DEGs and their relationships with nutritional profiles offer valuable insights for breeding programs focused on developing cultivars with improved nutritional quality, tailored to specific dietary needs or industrial applications.

Effects of pretreatment in a temporary immersion bioreactor on organogenesis efficacy of <i>Lilium candidum</i> L. bulbscales

Our experiment was conducted in two stages, i.e., pretreatment (first stage) and regeneration (second stage). The first stage was carried out in a liquid Murashige and Skoog basal medium (5 µM BAP and 0.05 µM NAA) in a bioreactor with a RITA temporary immersion system under the light of a fluorescent lamp. Explants (bulbscales) were immersed in the medium once a day for 15 minutes (RITA 1×15) or three times a day for 1 (RITA 3×1), 5 (RITA 3×5), and 15 minutes (RITA 3×15) for one to six weeks. For regeneration, the explants were transferred onto a solid medium of the same composition for another six weeks. The bulbscales not exposed to the liquid medium were used as a control. Biomass weight, biomass growth index, number and percentage of dry matter of bulblets, and the content of soluble sugars in the bulblets and in the liquid medium were examined. The bulblets were formed in all combinations from the third week of the culture, and their number increased in the RITA 3×15 combination for both the first and the second stages of the experiment. After the longest, 6-week pretreatment, more bulblets were obtained than in the control. Their fresh weight after six weeks of regeneration was positively associated with extended pretreatment time. This was in contrast with the dry weight of the bulblets, which decreased in the second stage of the experiment along with the extension of its first stage. Prolonged contact of the explants with the liquid medium during the pretreatment resulted in a higher content of soluble sugars in the bulblets at both stages of the experiment. The content of soluble sugars in the liquid medium decreased over time in all tested combinations. After six weeks of bioreactor culture, the lowest level of soluble sugars was observed in the RITA 3×15 combination.

The dwarf & pale leaf mutation reduces chloroplast numbers, resulting in sugar depletion that inhibits leaf growth of maize seedlings

Plant growth is ultimately driven by cell division and expansion, but how these processes are regulated to mediate a wide range of genotypic variation in organ size is still poorly understood. To address this, we screened an EMS maize mutant population to identify a new EMS maize dwarf mutant with small, pale-yellow leaves (dpl). The mutation was mapped to a region of 11.58 Mb at the 3’ end of chromosome 7. We identified Zm00001d022394 as a potential causal gene for the dpl phenotype, encoding a pentatricopeptide repeat-containing (PPR) family protein involved in chloroplast gene expression and function, explaining the pale color of dpl. Mature dpl leaves are thinner and shorter due to a reduced number of cells of approximately normal length. The chloroplasts of dpl are reduced in size and number, correlating with a decreased chlorophyll content, however chloroplast ultrastructure was not affected. Consistent with the reduced chlorophyll content photosynthetic rate of dpl were reduced by 50 % and a 30 reduction of Fv/Fm suggests photoinhibition. As a consequence, soluble and insoluble sugar levels are severely reduced throughout the leaf growth zone. At the cell level reduced cell division rates and size of the division zone, explain the reduced leaf elongation rate (LER). The growth of dpl leaves can be restored by supplying growing leaves with sucrose through their cut tips, which also restores sucrose levels in the division zone of maize leaf, demonstrating that limited sugar availability explains the reduced growth phenotype. Inversely, we phenocopied the mutant growth phenotype by inhibiting photosynthetic electron transport in wild type plants with DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea). Our study of dpl provides a functional link between inhibition of photosynthesis, soluble sugar flux to the leaf growth zone, the regulation of cell division and whole leaf growth.

Screening of saline-alkali tolerant microorganisms and their promoting effects on rice growth under saline-alkali stress

Soil salinization poses a global challenge, and cultivating rice on saline-alkali lands is a recognized strategy for exploiting and ameliorating these challenging environments, however, the yield and quality of rice are significantly lower compared to cultivation on non-saline lands. This study focused on the utilization of saline-alkali tolerant plant-growth-promoting microorganisms (PGPRs) and organic matter. Four PGPR strains were identified and subsequently fermented and propagated, and then combined in equal proportions and mixed with cow manure compost to prepare a PGPR amendment. This amendment was applied to rice cultivated in pots under saline-alkali stress. Agronomic traits were monitored at various growth stages to assess the amendment's impact on rice development. The results showed that under moderate saline-alkali stress, PGPR amendments significantly improved the physicochemical indicators of rice. Compared with the control group, rice plant height, root length and chlorophyll content increased by 113.56%, 43.19% and 95.43%, respectively. The antioxidant enzyme increased by 39.86%, and the levels of soluble sugars and proteins increased by 20.91% and 27.28%, respectively. Notably, rice under moderate saline-alkali stress showed greater improvements in response to the amendment compared to rice under mild stress conditions. These findings suggest that the amendments effectively mitigate the adverse effects of saline-alkali stress on rice growth, thereby offering a viable strategy for enhancing crop productivity in affected areas.

Perspective: Transcriptomics of Cryopreserved Cells

Cryopreservation is a well-known strategy to conserve genetic resources at ultra-low temperature. However, there is still limited knowledge on the cellular processes and molecular adjustments that allow cells to withstand the multiple stresses to which they are exposed during cryopreservation. To evaluate these processes, transcriptomics, the sub-discipline of omics that simultaneously examines mRNA transcripts formed by transcription from the genome, has been recently used. This article reviews recent scientific studies which use the basic principles of cryopreservation practices together with transcriptomics approaches, within the conceptual framework of cryobiomics. Moreover, the connections between factors that may be useful to optimize and validate approaches for mammalian or plant cell cryopreservation are also assessed. Transcriptomic applications are mainly performed with methods such as reverse transcriptase polymerase chain reaction (RT-PCR), simultaneous polymerase chain reaction (real-time PCR), northern blot, microarray/biochip and gene expression analysis (SAGE). Transcriptomic technologies allow a global view of gene expression profiles of different mammalian or plant cell types to be obtained before and after cryopreservation under multiple stress conditions. For these processes, small amounts of RNA enable efficient transcriptomics analysis. Transcriptomic analysis of cryopreserved mammalian and plant cells provides a conceptual way to identify the genes and their relative alterations in transcriptional abundances together with non-coding RNAs involved in important pathways related to cell viability and proliferation during and after cryopreservation. Moreover, it greatly contributes to understanding of non-fatal cryodamage and related developmental disorders in cryopreserved mammalian oocytes and sperm. In addition, single cell transcriptomics has the potential to non-invasely monitor immune actions and to diagnose the stage of the inflammatory process in kidney. Finally, qRT-PCR and RNA-seq studies have also revealed that some transcription factors are effective at inducing cold tolerance in many plants by elevating the levels of soluble sugars, proline and unsaturated fatty acids in cells. Hence transcriptomics studies may also aid investigations of the main mechanisms behind the so-called 'cryo-recalcitrance' that is observed mostly in plant cells.

Ecophysiological Trade-Off Strategies of Three Gramineous Crops in Response to Root Extracts of Phytolacca americana.

The invasive Phytolacca americana L. poses a significant threat to local agroforestry ecosystems due to its allelopathic toxicity. However, the ecophysiological response mechanisms of crops to allelochemicals remain unclear. This study investigated the seedling growth, physiological, and biochemical responses of three gramineous crops to the root extracts of P. americana and identified potential allelochemicals of the invader. The germination and seedling growth of three crops were inhibited by extracts differently, with high-concentration extracts causing more severe inhibition on seedling roots in hydroponic (>57%) than soil culture experiments (>18%). This inhibition may be related to representative secondary metabolites such as fatty acyls, alkaloids, and phenols. Despite the significant inhibition of high-concentration extracts on seedling growth, the levels of soluble sugar, soluble protein, and antioxidant enzymes increased synergistically. Under allelopathic stress, three species enhanced antioxidant enzyme activities and metabolite contents at the cost of reducing their shoot, root biomass, and root/shoot ratio. This may be an ecophysiological growth-defense strategy to bolster their resistance to allelopathy. Interestingly, transgenic rice exhibited greater sensitivity to allelochemicals than wild-type rice, resulting in more pronounced growth inhibition and increased levels of most metabolites and antioxidant enzymes. This study highlights the adaptive strategies of three gramineous crops to the allelopathy of invasive P. americana.

Impact of Heat Wave on the Plant Architecture of Field Grown Jatropha curcas Accession

Heatwave is one of the common phenomena in the arid and semi-arid regions which greatly hinders crop productivity. Jatropha curcas, which is well known for its medicinal and seed biodiesel uses, is one of the crops that are negatively affected by high temperatures. Therefore, this study was aimed at monitoring the effect of a heat wave on the plant architecture of Jatropha curcas plants grown in the south east of Botswana, a semi-arid region. The field experiment was conducted in 2016 (2016/2017) and 2017 (2017/2018) cropping season using plants that were established in 2011. Data on changes in leaf numbers, changes in leaf areas, photosynthetic rates, leaf temperatures, and soluble sugar levels were measured over the spring, summer, and autumn seasons of 2016 and 2017. In 2016, the general trend of the above measured parameters was that they peaked in summer and declined in autumn. However, in the summer of 2017, the accessions were hit by a heat wave, which depressed the photosynthetic rates, concomitantly decreasing leaf numbers, leaf areas, and leaf area indices. This reduction continued into the autumn of 2017. The plant architecture of the J. curcas accessions differed in the two years, indicating that the accessions responded differently under heat waves. The observations made as the plants recovered was that immediately below the apex, 2–3 leafed lateral shoots developed, which would normally be evident much lower down the stem. This suggests that the effect of the heat wave thus appeared to have impacted the plant architecture in the autumn. Soluble sugar levels were also higher in the autumn leaves of 2017 than in the autumn leaves of 2016.

Greywater irrigation of pepper plants: Possible application and its impact on soil and plant growth

AbstractGreywater reuse may be considered a water source that can compensate for water scarcity. Reusing treated greywater on fields instead of disposing of it would be more environmentally friendly. The objective of this study was to investigate the physiological response of pepper plants to the application of both untreated and treated greywater. The greywater obtained from Al‐Huson University College was treated with zeolite filters before being used for plant irrigation in the experiments. The electrical conductivity (EC), total dissolved solids (TDSs) and chemical oxygen demand (COD) of greywater were all higher than those of tap water by 44%, 68% and 509%, respectively. The results demonstrated that plants irrigated with tap water and treated with greywater presented greater fruit and biological productivity than did those irrigated with untreated greywater. The use of treated greywater led to a notable 8.3% increase in overall chlorophyll levels. Irrigation of pepper plants with untreated greywater led to a 33% increase in electrolyte leakage. The plants irrigated with greywater presented the highest levels of proline and total soluble sugars. Compared with those in all the other water treatments, the plants irrigated with greywater presented significantly greater magnesium and salt concentrations. Typically, treated greywater has the most significant impact on agricultural productivity.

Effects of alkaline salt stress on growth, physiological properties and medicinal components of clonal Glechoma longituba (Nakai) Kupr.

BackgroundGlechoma longituba, recognized as a medicinal plant, provides valuable pharmaceutical raw materials for treating various diseases. Saline-alkali stress may effectively enhance the medicinal quality of G. longituba by promoting the synthesis of secondary metabolites. To investigate the changes in the primary medicinal components of G. longituba under saline-alkali stress and improve the quality of medicinal materials, Na2CO3 was applied to induce short-term stress under different conditions and the biomass, physiologically active substances and primary medicinal components of G. longituba were measured in this study.ResultsUnder alkaline salt stress, the activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) were elevated in G. longituba, accompanied by increased accumulation of proline (Pro) and malondialdehyde (MDA). Furthermore, analysis of the medicinal constituents revealed that G. longituba produced the highest levels of soluble sugars, flavonoids, ursolic acid, and oleanolic acid under 0.6% Na2CO3 stress for 48 h, 0.2% Na2CO3 stress for 72 h, 0.4% Na2CO3 stress for 12 h, and 0.4% Na2CO3 stress for 8 h, respectively.ConclusionsShort-term Na2CO3 stress enhances the synthesis of medicinal components in G. longituba. By manipulating stress conditions, the production of various medicinal substances could be optimized. This approach may serve as a basis for the targeted cultivation of G. longituba, offering potential applications in the treatment of diverse diseases.

Yield, cell structure and physiological and biochemical characteristics of rapeseed under waterlogging stress

Rapeseed (Brassica napus L.) is a major oilseed crop in the middle and lower reaches of the Yangtze River in China. However, it is susceptible to waterlogging stress. This study aimed to investigate the physiological characteristics, cellular changes, and gene expression patterns of rapeseed under waterlogging stress, with the goal of providing a foundation for breeding waterlogging-tolerant rapeseed. The results revealed that waterlogging-tolerant rapeseed exhibited higher levels of soluble sugars and antioxidant enzyme activity, particularly in the roots. Conversely, waterlogging-sensitive rapeseed displayed greater changes in malondialdehyde, proline, and hydrogen peroxide levels. Cellular observations showed that after experiencing waterlogging stress, the intercellular space of rapeseed leaf cells expanded, leading to disintegration of mitochondria and chloroplasts. Moreover, the area of the root xylem increased, the number of vessels grew, and there were signs of mitochondrial disintegration and vacuole shrinkage, with more pronounced changes observed in waterlogging-sensitive rapeseed. Furthermore, significant differences were found in the transcription levels of genes related to anaerobic respiration and flavonoid biosynthesis, and different varieties demonstrated varied responses to waterlogging stress. In conclusion, there are differences in the response of different varieties to waterlogging stress at the levels of morphology, physiological characteristics, cell structure, and gene transcription. Waterlogging-tolerant rapeseed responds to waterlogging stress by regulating its antioxidant defense system. This study provides valuable insights for the development of waterlogging-tolerant rapeseed varieties.

Anti-echinococcal effect of metformin in advanced experimental cystic echinococcosis: reprogrammed intermediary carbon metabolism in the parasite.

Metformin, a safe biguanide derivative with antiproliferative properties, has shown antiparasitic efficacy against the Echinococcus larval stage. Hence, we assessed the efficacy of a dose of 250 mg kg-1 day-1 in experimental models of advanced CE, at 6 and 12 months post-infection with oral and intraperitoneal administration, respectively. At this high dose, metformin reached intracystic concentrations between 0.7 and 1.7 mM and triggered Eg-TOR inhibition through AMPK activation by AMP-independent and -dependent mechanisms, which are dependent on drug dose. Cystic metformin uptake was controlled by increased expression of organic cation transporters in the presence of the drug. In both experimental models, metformin reduced the weight of parasite cysts, altered the ultrastructural integrity of their germinal layers, and reduced the intracystic availability of glucose, limiting the cellular carbon and energy charge and the proliferative capacity of metacestodes. This glucose depletion in the parasite was associated with a slight increase in cystic uptake of 2-deoxiglucose and the transcriptional induction of GLUT genes in metacestodes. In this context, drastic glycogen consumption led to increased lactate production and altered intermediary metabolism in treated metacestodes. Specifically, the fraction of reducing soluble sugars decreased twofold, and the levels of non-reducing soluble sugars, such as sucrose and trehalose, were modified in both cystic fluid and germinal cells. Taken together, our findings highlight the relevance of metformin as a promising candidate for CE treatment and warrant further research to improve the therapeutic conditions of this chronic zoonosis in humans.

Increased sugar content impairs pollen fertility and reduces seed-setting in high-photosynthetic-efficiency rice

Crop yield depends on biomass, which is primarily associated with photosynthesis. We previously demonstrated that two photorespiratory bypasses, i.e., GOC (glycolate oxidase + oxalate oxidase + catalase) and GCGT (glycolate oxidase + catalase + glyoxylate carboligase + tartronic semialdehyde reductase), significantly increased photosynthesis, biomass, and grain yield, but decreased seed-setting rates in rice. This study explored the underlying mechanism of how elevated photosynthetic efficiency impacted the seed-setting. First, pollen germination assessed in vivo and in vitro, revealed a reduced germination rate in GCGT rice. Subsequent analysis found that photosynthates highly accumulated in the leaves and stems; sucrose and soluble sugar levels were increased but the starch level was reduced in the anthers. Uridine diphosphate glucose (UDP-Glc) was increased but uridine diphosphate galactose (UDP-Gal) was unaltered, thus causing an imbalance in the UDP-Glc/UDP-Gal ratio in GCGT anthers. Most anthers in GCGT plants had two locules in contrast to four in the wild-type (WT). Pollen tapetum was developmentally abnormal, and genes related to sucrose synthesis, transport, and tapetal programmed cell death (PCD) were upregulated, whereas those involved in starch synthesis and conversion were downregulated in GCGT anthers. Taken together, our results demonstrated that an increase in sugar content was the primary factor causing reduced seed-setting rates in high photosynthetic efficiency rice, during which metabolic disorder of sugars and UDP sugar imbalance in anthers lead to impaired pollen fertility.

High ecostoichiometric stability and accumulating SiO2 and NO3− as main physiological adaptive mechanisms for reed to adverse environments

Previous studies have shown that nutrients accumulation played important roles in resisting to stress resistance of plants. Our study examined the ecostoichiometric internal stability (EIS) of nutrients accumulation and, concomitantly identified the main resistant regulating substances and their contributions to stress resistance of reed (Gramineae) in arid desert areas. Plants (digging method) and soil samples (quartering method)) obtained from sand dune (SD), desert steppe (DP), interdune lowland (IL), saline meadow (SM) and wetland (W) habitats were brought back to the lab for nutrients analysis. Results indicated that soil nutrients differed obviously, while reed maintained relatively stable ratios of SiO2:N, N:K, and P:K when the eco-environments changed in different habitats. Furthermore, reed exhibits common adaptive characteristics by mainly accumulating large amounts of SiO2 (122.6–174.0 g/kg) and NO3− (166.1–216.6 g/kg), as well as moderate levels of soluble sugar (SS: 24.0–55.0 g/kg), which are mainly stored in leaves for stress resistance. The contribution of ions to stress resistance was 80.03%–91.15% (with SiO2 and NO3− accounting for 54.91%–63.10%), whereas the contribution of solutes was only 8.85%–19.97% (with SS contributing to 5.14%–10.91%) in different habitats. These findings suggest that maintaining relatively high EIS, while still accumulating SiO2 and NO3− as main physiological regulators might be an effective strategy for reed to positively respond to adverse habitats, which provide a strong theoretical basis and technical reference for searching useful methods for restoration and reconstruction of the degraded ecosystems in desert oasis regions.