White hyacinth bean polysaccharide ameliorates diabetes via microbiota-gut-brain axis in type 2 diabetes mellitus rats.

Gut played a potent role in onset and progression of metabolic disorders, presenting an exciting direction for diabetes prevention. Here, the anti-diabetic effects of White hyacinth bean polysaccharides (WHBP) were observed, including the reduction of blood glucose levels and improvement of intestinal impairment in type 2 diabetes mellitus (T2DM) rats. Further data concerning intestinal protection suggested that WHBP restored intestinal barrier, as evidenced by inhibition of intestinal pathological damage, up-regulation of Zonula occluden-1 expression and manipulation of the redox system in T2DM rats. Moreover, WHBP-mediated anti-diabetic effects were in parallel with the adjustment of changes in gut microbiota composition of T2DM rats. Meanwhile, hypersecretion of corticotropin-releasing hormone, adrenocorticotropic hormone, and corticosterone levels, which were critical coordinators of the hypothalamic-pituitary-adrenal (HPA) axis, were suppressed in T2DM rats exposed to WHBP, indicating that WHBP-mediated health benefits were referring to regulate brain feedback in reduction of HPA axis. Concomitantly, further suggested and expanded on gut-brain communication by data of microbial metabolites short-chain fatty acids, mediators of gut-brain interactions, were remarkably raised in cecum contents of T2DM rats subjected to WHBP. Collectively, WHBP performed anti-diabetic effects were associated with control of microbiota-gut-brain axis implicated in intestinal barrier, HPA axis, gut microbiota and their metabolites.

Individual and combined effects of herbicide prometryn and nitrate enrichment at environmentally relevant concentrations on photosynthesis, oxidative stress, and endosymbiont community diversity of coral Acropora hyacinthus.

Nitrogen pollution and pesticides such as photosystem II (PSII) inhibitor herbicides have several detrimental impacts on coral reefs, including breakdown of the symbiosis between host corals and photosynthetic symbionts. Although nitrogen and PSII herbicide pollution separately cause coral bleaching, the combined effects of these stressors at environmentally relevant concentrations on corals have not been assessed. Here, we report the combined effects of nitrate enrichment and PSII herbicide (prometryn) exposure on photosynthesis, oxidative status and endosymbiont community diversity of the reef-building coral Acropora hyacinthus. Coral fragments were exposed in a mesocosm system to nitrate enrichment (9 µmol/L) and two prometryn concentrations (1 and 5 µg/L). The results showed that sustained prometryn exposure in combination with nitrate enrichment stress had significant detrimental impacts on photosynthetic apparatus [the maximum quantum efficiency of photosystem II (Fv/Fm), nonphotochemical quenching (NPQ) and oxidative status in the short term. Nevertheless, the adaptive mechanism of corals allowed the normal physiological state to be recovered following 1 µg/L prometryn and 9 µmol/L nitrate enrichment individual exposure. Moreover, exposure for 9 days was insufficient to trigger a shift in Symbiodiniaceae community. Most importantly, the negative impact of exposure to the combined environmental concentrations of 1 µg/L prometryn and 9 µmol/L nitrate enrichment was found to be significantly greater on the Fv/Fm, quantum yield of non-regulated energy dissipation [Y(NO)], NPQ, and oxidative status of corals compared to the impact of individual stressors. Our results show that interactions between prometryn stress and nitrate enrichment have a synergistic impact on the photosynthetic and oxidative stress responses of corals. This study provides valuable insights into combined effects of nitrate enrichment and PSII herbicides pollution for coral's physiology. Environmental concentrations of PSII herbicides may be more harmful to photosystems and antioxidant systems of corals under nitrate enrichment stress. Thus, future research and management of seawater quality stressors should consider combined impacts on corals rather than just the impacts of individual stressors alone.

Integrating Multi-Omics Analysis Reveals the Regulatory Mechanisms of White-Violet Mutant Flowers in Grape Hyacinth (Muscari latifolium).

Grape hyacinth (Muscari spp.) is a famous bulbous blue flower; however, few bicolor varieties are available in the market. Therefore, the discovery of bicolor varieties and understanding of their mechanisms are crucial to the breeding of new varieties. In this study, we report a significant bicolor mutant with white upper and violet lower portions, with both parts belonging to a single raceme. Ionomics showed that pH and metal element contents were not responsible for the bicolor formation. Targeted metabolomics illustrated that the content of the 24 color-related compounds was significantly lower in the upper part than that in the lower part. Moreover, full-length transcriptomics combined with second-generation transcriptomics revealed 12,237 differentially expressed genes in which anthocyanin synthesis gene expression of the upper part was noted to be significantly lower than that of the lower part. Transcription factor differential expression analysis was used to describe the presence of a pair of MaMYB113a/b sequences, with low levels of expression in the upper part and high expression in the lower part. Furthermore, tobacco transformation confirmed that overexpression of MaMYB113a/b can promote anthocyanin accumulation in tobacco leaves. Accordingly, the differential expression of MaMYB113a/b contributes the formation of a bicolor mutant in Muscari latifolium.

Investigation of the phytochemical composition and remedial effects of southern grape hyacinth (Muscari neglectum Guss. ex Ten.) plant extract against carbon tetrachloride-induced oxidative stress in rats.

We aimed to determine the phytochemical contents of the aerial part M. neglectum aerial part (MAP) and M. neglectum bulb (MB) ethanolic extract of Muscari neglectum and to investigate their protective effects on gastric damage induced by carbon tetrachloride (CCl4) in rats. After the toxicity testing, 42 female Wistar albino rats were divided into 7 groups, Control, MAP, MB, CCl4, CCl4 + MAP, CCl4 + MB, and CCl4 + Silymarin groups. At the end of the experiment, the serum biochemical parameters, antioxidant defense enzymes, and malondialdehyde (MDA) contents in the stomach tissue were evaluated to determine the antioxidant role of the M. neglectum extracts. According to the gas chromatography-mass spectroscopy, fatty acid analysis, octadecadienoic, and 9,12,15 octadecatrienoic fatty acids were found as major fatty acids in the MAP, whereas 9,12 octadecadienoic and octadecanoic acids were the major fatty acids in the MB. According to the liquid chromatography-tandem mass spectrometry, quinic acid, fumaric acid, gentisic acid, caffeic acid, kaempferol, and apigenin were found in the MAP, while quinic acid, fumaric acid, caffeic acid, and kaempferol were found in the MB. The total phenolic and flavonoid contents in the extract were determined in the MAP and MB. The MAP and MB extracts generally caused a statistically significant decrease in the MDA content and increase in the antioxidant parameters in the stomach tissue. It was concluded that MAP and MB extracts may have antioxidant and gastric protective effects due to the phytochemical content of M. neglectum.HighlightsAccording to LC-MS/MS results, quinic acid, fumaric acid, chemferol, apigenin, and caffeic acid were determined as major compounds in M. neglectum extracts.According to GC-MS results, octadecadienoic, octadecatrienoic, and octadecanoic methyl esters were the major fatty acids of the M. neglectum extracts.The M. neglectum extracts regulated the levels of stomach damage and biochemical parameters.The M. neglectum extracts extract might have pharmaceutical-nutritional potential.

Comparison of pennywort and hyacinth in the development of membraned sediment plant microbial fuel cell for waste treatment.

Membraned Sediment Plant Microbial Fuel cells (SPMFCs) are appealing bioelectrochemical systems that generate power from organic compounds in sediment through exoelectrogen decomposition and are used to treat wastewater. This research was designed to develop a single-chambered sediment plant microbial fuel cell using two membrane electrodes; one carbon plate cathode and one anode. Wastewater and sediment mixture was sampled from Rawalpindi, Pakistan, and bacterial isolation was performed by serial dilution. Five strains were selected on the basis of morphology and growth-promoting characteristics. The selected strains were identified by 16s rRNA sequencing and designated as A (Geobacter sulfurreducens OP527025), B (Shawanella putrefaciens OP522353), C (Bacillus subtilus OP522349), D (Azospirillum humicireducens OP527050) and E (Pseudomonas putida OP526951). Consortium of five strains was developed. Two aquatic plants pennyworts (Hydrocotyle umbellate), and Hyacinth (Eichhornia crassipes) were used in the SPMFCs along with consortium. A maximum voltage of 1120mv was observed in SPMFCs treated with the consortium and water hyacinth, which was followed by 543.3 mv of SPMFCs treated with water pennyworts. Physicochemical analysis of wastewater showed a remarkable reduction of 74.5%, 71%, and 76% in nitrate, phosphate, and sulphate content of wastewater treated with microbes and water hyacinth. The heavy metal analysis showed a reduction of Zn (99.8%), Mg (99.9%), and Ni (98.4%) in SPMFCs treated with the consortium and water hyacinth. Mebraned SPMFCs showed an increase of 30% and 20% in shoot and root length of water hyacinth. A remarkable increase of 25%, 18%, and 12% were recorded in chlorophyll content, membrane stability index and relative water content of water hyacinth in SPMFCs treated with consortium compared to untreated cells. Osmolyte content had shown significant increase of 25% with consortium treated water hyacinth plant as compared to untreated one. An increase of 15%, 20% and 12% was noted in superoxide dismutase (SOD), peroxidase dismutase (POD) and catalase content of consortium treated water hyacinth as compared to control one. The present research gave insight into the potential of sediment plant microbial fuel cells along with aquatic plants for treatment of wastewater. This could be a effective method for removal of hazrdaous substances from wastewater and alternative approach for voltage production.

The R2R3MYB transcription factors MaMYBF and MaMYB1 regulate flavonoid biosynthesis in grape hyacinth.

R2R3 MYBs play vital roles in the regulation of flavonoid biosynthesis. However, the regulatory network of R2R3 MYBs in flavonoid biosynthesis is not fully understood in grape hyacinth (Muscari spp.). Here, we identified two R2R3 MYBs, MaMYBF and MaMYB1, as potential regulators of flavonol and anthocyanin biosynthesis, respectively. MaMYBF and MaMYB1 expression was elevated during flower development and was light-induced, and the expression patterns were related to those of the flavonoid structural genes MaFLS and MaDFR, respectively. The BiFC assay verified that MaMYB1 interacts with MabHLH1, but MaMYBF does not. A dual luciferase assay revealed that MaMYBF alone strongly activated pMaFLS, and its activation was attenuated at reduced doses of MaMYBF in the presence of MabHLH1, MaMybA, and MaMYB1. MaDFR transcription mediated by MaMybA and MabHLH1 was inhibited by MaMYB1. Moreover, overexpression of MaMYBF and MaMYB1 in tobacco reduced flower pigmentation and repressed the expression of flavonoid pathway key structural genes. Therefore, MaMYBF regulates the flavonol pathway independently of cofactors. Whereas MaMYB1 regulates anthocyanin biosynthesis by binding to MabHLH1 and disrupting the MaMybA-bHLH complex in grape hyacinth. Our results offer new insights into the intricate regulatory network of flavonoids in grape hyacinth involving the regulation of both flavonol and anthocyanin.

Persistence of phenotypic responses to short-term heat stress in the tabletop coral Acropora hyacinthus.

Widespread mapping of coral thermal resilience is essential for developing effective management strategies and requires replicable and rapid multi-location assays of heat resistance and recovery. One- or two-day short-term heat stress experiments have been previously employed to assess heat resistance, followed by single assays of bleaching condition. We tested the reliability of short-term heat stress resistance, and linked resistance and recovery assays, by monitoring the phenotypic response of fragments from 101 Acropora hyacinthus colonies located in Palau (Micronesia) to short-term heat stress. Following short-term heat stress, bleaching and mortality were recorded after 16 hours, daily for seven days, and after one and two months of recovery. To follow corals over time, we utilized a qualitative, non-destructive visual bleaching score metric that correlated with standard symbiont retention assays. The bleaching state of coral fragments 16 hours post-heat stress was highly indicative of their state over the next 7 days, suggesting that symbiont population sizes within corals may quickly stabilize post-heat stress. Bleaching 16 hours post-heat stress predicted likelihood of mortality over the subsequent 3-5 days, after which there was little additional mortality. Together, bleaching and mortality suggested that rapid assays of the phenotypic response following short-term heat stress were good metrics of the total heat treatment effect. Additionally, our data confirm geographic patterns of intraspecific variation in Palau and show that bleaching severity among colonies was highly correlated with mortality over the first week post-stress. We found high survival (98%) and visible recovery (100%) two months after heat stress among coral fragments that survived the first week post-stress. These findings help simplify rapid, widespread surveys of heat sensitivity in Acropora hyacinthus by showing that standardized short-term experiments can be confidently assayed after 16 hours, and that bleaching sensitivity may be linked to subsequent survival using experimental assessments.

Growth model analysis of wild hyacinth macaw (Anodorhynchus hyacinthinus) nestlings based on long-term monitoring in the Brazilian Pantanal.

Studies on the breeding of vulnerable and endangered bird species are hindered by low numbers of individuals, inaccessible location of nests, unfavourable environmental conditions, and complex behavioural patterns. In addition, intraspecific variation may emerge only following long-term, systematic observations of little-known patterns and processes. Here, data collected over 30 years were used to determine growth model of hyacinth macaw (Anodorhynchus hyacinthinus) chicks in the Pantanal biome of Brazil. During this period, the speed of growth and body mass of chicks varied widely. Four growth models were tested: logistic, Gompertz, Richards, and cubic polynomial. They were fitted using three biometric measurements: body mass, total length, and tail length. The best-fitting growth curves were identified using Akaike's information criterion. The best models were the cubic polynomial for body mass, Richards for total length, and Gompertz for tail length. We confirmed the occurrence of dwarf individuals, whose body mass, total length, and tail length were 20%, 22%, and 70% smaller, respectively, than in the overall population. The dwarfs remain small in size after having fledged and are easily identified as adults. We discuss the importance of long-term studies to identify windows of opportunity for further research that will help in the conservation of endangered macaw species.

Two B-Box Proteins, MaBBX20 and MaBBX51, Coordinate Light-Induced Anthocyanin Biosynthesis in Grape Hyacinth.

Floral colour is an important agronomic trait that influences the commercial value of ornamental plants. Anthocyanins are a class of flavonoids and confer diverse colours, and elucidating the molecular mechanisms that regulate their pigmentation could facilitate artificial manipulation of flower colour in ornamental plants. Here, we investigated the regulatory mechanism of light-induced anthocyanin biosynthesis during flower colouration in grape hyacinth (Muscari spp.). We studied the function of two B-box proteins, MaBBX20 and MaBBX51. The qPCR revealed that MaBBX20 and MaBBX51 were associated with light-induced anthocyanin biosynthesis. Both MaBBX20 and MaBBX51 are transcript factors and are specifically localised in the nucleus. Besides, overexpression of MaBBX20 in tobacco slightly increased the anthocyanin content of the petals, but reduced in MaBBX51 overexpression lines. The yeast one-hybrid assays indicated that MaBBX20 and MaBBX51 did not directly bind to the MaMybA or MaDFR promoters, but MaHY5 did. The BiFC assay revealed that MaBBX20 and MaBBX51 physically interact with MaHY5. A dual luciferase assay further confirmed that the MaBBX20-MaHY5 complex can strongly activate the MaMybA and MaDFR transcription in tobacco. Moreover, MaBBX51 hampered MaBBX20-MaHY5 complex formation and repressed MaMybA and MaDFR transcription by physically interacting with MaHY5 and MaBBX20. Overall, the results suggest that MaBBX20 positively regulates light-induced anthocyanin biosynthesis in grape hyacinth, whereas MaBBX51 is a negative regulator.

Tampon Technology in Britain: Unilever's Project Hyacinth and the "7-Day War" Campaign," 1968-1980.

How much do we know about the historic relationship between the corporations that develop menstrual technologies and consumers? This case study adds to the growing literature on users of gendered technology, examining consumers' role in Unilever's ambitious but ultimately unsuccessful tampon project in the 1970s. Investigating the creation of the absorbent material Lyogel, Unilever's menstrual data collection, and the accompanying "7-Day War" marketing campaign, I demonstrate the link between technology, corporations, and consumers. Anonymous consumers gave Unilever information about their menstrual habits. This provided insight into the lived experience of menstruation and knowledge of menstrual technologies in an era when talking about this topic was taboo.

Preparation and characterization of hyacinth bean starch film incorporated with TiO2 nanoparticles and Mesona chinensis Benth polysaccharide.

Hyacinth bean starch (HBS) was used to prepare nanocomposite films with the reinforcement agent of nanotitanium oxide (TiO2-N) and Mesona chinensis Benth polysaccharide (MCP). The effects of TiO2-N and MCP on the moisture combination, rheological properties of film-forming solutions (FFS) and physiochemical properties of films were investigated. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) revealed that HBS, TiO2-N and MCP had good compatibility, while no novel absorption peak in FTIR spectra, and characteristic peaks of TiO2-N were found in XRD patterns of composite films. Contact angle of HBS/TiO2-N/M3 film increased from 65.6° to 90.9°, which illustrated that TiO2-N and MCP effectively enhanced hydrophobicity of films. TiO2-N and MCP positively affected anti-UV light ability of HBS films by resisting most of invisible light. Furthermore, stable and compact network structures were formed by the synergistic effect of TiO2-N and MCP, thereby elongation to break was increased from 17.123% to 28.603% significantly, and heat resistance was enhanced clearly. This study prepared a nanocomposite HBS-based films based TiO2-N and MCP, which had guiding significance for development of functional films and combination of polysaccharides and metallic oxide.

High-Quality Complete Genome Resource of Plant-Pathogenic Bacterium Dickeya solani IPO 2019, Isolated from Hyacinthus orientalis.

Dickeya solani is an emerging plant-pathogenic bacterium causing disease symptoms in a variety of agriculturally relevant crop species worldwide. To date, a number of D. solani genomes have been sequenced and characterized; the great majority of these genomes have, however, come from D. solani strains isolated from potato (Solanum tuberosum L.) and not from other plant hosts. Herewith, we present the first complete, high-quality genome of D. solani IPO 2019 (LMG 25990), isolated from the ornamental plant Hyacinthus orientalis. The genome of D. solani IPO 2019 consists of one chromosome of 4,919,542 bp, with a GC content of 56.2% and no plasmids. The genome contains 4,502 annotated features, 22 ribosomal RNA genes, 73 transfer RNA genes, and one CRISPR. We believe that the information on this high-quality, complete, closed genome of D. solani strain isolated from a host plant different from potato (i.e. hyacinth) will provide resources for comparative genomic studies and for analyses targeting adaptation and ecological fitness mechanisms present in Dickeya solani species.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Isolation and functional diversity of Bowman-Birk type serine proteinase inhibitors from Hyacinthus orientalis.

Bowman-Birk inhibitors (BBIs) are plant-derived serine proteinase inhibitors. Endogenously, they function as defense molecules against pathogens and insects, but they also have been explored for applications in cancer treatment and inflammatory disorders. Here, we isolated 15 novel BBIs from the bulb of Hyacinthus orientalis (termed HOSPIs). These isoinhibitors consisted of two or three chains, respectively, that are linked by disulfides bonds based on proposed cleavage sites in the canonical BBI reactive site loop. They strongly inhibited trypsin (Ki = 0.22-167 nM) and α-chymotrypsin (Ki = 19-1200 nM). Notably, HOSPI-B4 contains a six-residue reactive loop, which appears to be the smallest such motif discovered in BBIs to date. HOSPI-A6 and -A7 contain an unusual reactive site, i.e. Leu-Met at the P1-P1' position and have strong inhibitory activity against trypsin, α-chymotrypsin, and elastase. Analysis of the cDNA encoding HOSPIs revealed that the precursors have HOSPI-like domains repeated at least twice with a defined linker sequence connecting individual domains. Lastly, mutational analysis of HOSPIs suggested that the linker sequence does not affect the inhibitory activity, and a Thr residue at the P2 site and a Pro at the P3' site are crucial for elastase inhibition. Using mammalian proteases as representative model system, we gain novel insight into the sequence diversity and proteolytic activity of plant BBI. These results may aid the rational design of BBI peptides with potent and distinct inhibitory activity against human, pathogen, or insect serine proteinases.

Novel composite foam made from starch and water hyacinth with beeswax coating for food packaging applications.

A novel composite foam was prepared from native cassava starch and water hyacinth (WH) by baking in a hot mold. The effects of WH powder content (0, 3, 5, 7 or 10 wt%, dry starch basis) on the properties of the starch foam were investigated. A starch foam formulation with 5 wt% WH powder exhibited the highest flexural stress at maximum load (3.42 MPa), the highest flexural strain (extension) at maximum load (3.52%), the highest modulus (232.00 MPa), the lowest moisture content (6.77%) and the most uniform cell size distribution (0.44 ± 0.09 mm). Moreover, mechanical properties of starch foam with 5 wt% WH powder were better than the same properties of some commercial foams. After being coated with beeswax, the starch foams retained their shape after immersion in distilled water and their water solubility was significantly reduced. Results indicated that a starch foam/5 wt% WH composite with beeswax coating was a biodegradable foam that could possibly replace commercial non-degradable foam.

Extracellular ionic fluxes suggest the basis for cellular life at the 1/f ridge of extended criticality.

The criticality hypothesis states that a system may be poised in a critical state at the boundary between different types of dynamics. Previous studies have suggested that criticality has been evolutionarily selected, and examples have been found in cortical cell cultures and in the human nervous system. However, no one has yet reported a single- or multi-cell ensemble that was investigated ex vivo and found to be in the critical state. Here, the precise 1/f noise was found for pollen tube cells of optimum growth and for the physiological ("healthy") state of blood cells. We show that the multi-scale processes that arise from the so-called critical phenomena can be a fundamental property of a living cell. Our results reveal that cell life is conducted at the border between order and disorder, and that the dynamics themselves drive a system towards a critical state. Moreover, a temperature-driven re-entrant state transition, manifest in the form of a Lorentz resonance, was found in the fluctuation amplitude of the extracellular ionic fluxes for the ensemble of elongating pollen tubes of Nicotiana tabacum L. or Hyacintus orientalis L. Since this system is fine-tuned for rapid expansion to reach the ovule at a critical temperature which results in fertilisation, the core nature of criticality (long-range coherence) offers an explanation for its potential in cell growth. We suggest that the autonomous organisation of expansive growth is accomplished by self-organised criticality, which is an orchestrated instability that occurs in an evolving cell.

Green Route for the Removal of Pb from Aquatic Environment.

AIM AND OBJECTIVE: Wastewater treatment/remediation is a very important process that has a great environmental and economic impact. Therefore, it is crucial to innovate different methods to remove pollutants of different sources from wastewater. This work was conducted in order to study the removal of lead (Pb+2) from wastewater using microspheres of composites of sodium alginate, cellulose and chitosan, as well as using a cost-effective green route through composites of sodium alginate and dried water hyacinth. MATERIALS AND METHODS: Molecular modeling at B3LYP/6-31g(d,p) was utilized to study sodium alginate, cellulose and chitosan. Sodium alginate was cross-linked with calcium chloride to form microspheres, then both sodium alginate/cellulose and sodium alginate/chitosan were also crosslinked as 50/50 to form microspheres. The roots of the aquatic plant water hyacinth in dry form were added to the cross-linked sodium alginate for up to 70%. SEM and FTIR were employed to study the surface of the prepared microspheres and their structures respectively. Atomic absorption spectroscopy was used to study the levels of Pb. RESULTS: Molecular modeling indicated that the blending of such structures enhances their ability to bind with surrounding molecules owing to their ability to form hydrogen bonds. SEM results indicated that homogeneous structures of cellulose and chitosan are deformed when blended with sodium alginate, and FTIR confirmed the proper formation of the desired blends. Microspheres from sodium alginate showed the ability to remove Pb+2 from wastewater. SEM indicated further deformation in the morphology with the roughness of sodium alginate/water hyacinth microspheres, while FTIR confirmed the uniform matrices of the microspheres. The removal of Pb+2 was enhanced because of the addition of dried water hyacinth's roots. CONCLUSION: Modeling, experimental and kinetic data highlight sodium alginate/water hyacinth root as a green route to remediate Pb+2 from wastewater.

Dynamic distribution of ARGONAUTE1 (AGO1) and ARGONAUTE4 (AGO4) in Hyacinthus orientalis L. pollen grains and pollen tubes growing in vitro.

The transcriptional and posttranscriptional AGO-mediated control of gene expression may play important roles during male monocot gametophyte development. In this report, we demonstrated dynamic changes in the spatiotemporal distribution of AGO1 and AGO4, which are key proteins of the RNA-induced silencing complex (RISC) in Hyacinthus orientalis male gametophyte development. During maturation of the bicellular pollen grains and in vitro pollen tube growth, the pattern of AGO1 localization was correlated with previously observed transcriptional activity of the cells. During the period of high transcriptional activity, AGO1 is associated with chromatin while the clustered distribution of AGO1 in the interchromatin areas is accompanied by condensation of chromatin and the gradual transcriptional silencing of both cells in mature, dehydrated pollen. During pollen tube growth and the restarting of RNA synthesis in the vegetative nucleus, AGO1 is dispersed in the chromatin. Additionally, the gradual increase in the cytoplasmic pool of AGO1 in the elongating pollen tube indicates the activation of the posttranscriptional gene silencing (PTGS) pathway. During pollen tube growth in the generative cell and in the sperm cells, AGO1 is present mainly in the areas between highly condensed chromatin clusters. Changes in the distribution of AGO4 that indicated the possibility of spatiotemporal organization in the RNA-directed DNA methylation (RdDM) process (cytoplasmic and nuclear steps) were also observed during hyacinth male gametophyte development. Based on our findings, we propose that in the germinating pollen tube, the cytoplasmic assembly of AGO4/siRNA takes place and that the mature complexes could be transported to the nucleus to carry out their function during the next steps of pollen tube growth.

Influence of flow on phosphorus-dynamics and particle size in agricultural drainage ditch sediments.

Particle size is one factor affecting phosphorus (P) dynamics in soils and sediments. This study investigated how flow facilitated by hydraulic pumps and aquatic vegetation species water lettuce (Pistia stratiotes) and water hyacinth (Eichhornia crassipes) affected particle size and P-dynamics in organic sediments in agricultural drainage ditches. Sediments with finer particle size (>0.002 mm) were hypothesized to contain greater total P (TP) and less labile P than sediments with coarser particle size. Particle size was determined using a LS 13 320 Laser Diffraction Particle Size Analyzer. Sediments were tested for pH, TP, and organic matter. Fractions of P were determined using a sequential fractionation experiment and 31P Nuclear Magnetic Resonance (NMR) Spectroscopy. Larger average particle size and lower average total P concentrations were found in the inflows of the field ditches compared to the outflows. Presence of flow and aquatic vegetation did not have a significant impact on particle size, TP, or labile P fractions. Median (p = 0.10) particle size was not significantly correlated to TP. Overall, there was an average trend of coarser particle size and lower P concentrations in the inflow compared to the outflow. The presence of inorganic limerock could have affected results due to increased P adsorption capacity and larger average particle size compared to the organic fraction of the sediment.