Aquatic Herb Research Articles

Anti-enteric efficacy and mode of action of tridecanoic acid methyl ester isolated from Monochoria hastata (L.) Solms leaf.

Monochoria hastata (L.) Solms (family Pontederiaceae), an ethnomedicinal aquatic herb, is used to remedy several gastrointestinal diseases by various ethnic groups in India. The present study aimed to purify and characterize the antibacterial active ingredient against gastrointestinal (GI) diseases and its mode of action using in vitro experimental models. The active lead molecule in the ethyl acetate extract (EA-Mh) fraction has been purified and characterized through high-performance liquid chromatography (HPLC), proton nuclear magnetic resonance (1H NMR), and electrospray ionization mass spectrometry (ESI-MS) methods. The anti-enteric efficacy has been evaluated against enteropathogenic Gram-positive and Gram-negative bacteria by minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), lactate dehydrogenase (LDH), and scanning electron microscopy (SEM) studies. The synergistic and antagonistic studies were done on E. coli MTCC 723 using standard antibiotics (ampicillin and kanamycin, final conc. 50µg/ml) in a sterilized 96-well micro-plate, incubated at 37 ℃ for 24h. The chromatographic and spectroscopic analyses revealed the presence of tridecanoic acid methyl ester (TAME) in the bioactive fraction. The compound causes significant extracellular leakage activity by disrupting cellular morphology in the Enterococcus faecalis MCC 2041T and Salmonella enterica serovar Typhimurium MTCC 98, at a dose of 375μg/ml and 750μg/ml, respectively. The SEM study shows a significant rupturing of E. coli and E. faecalis cells due to TAME induced autolysis. It has synergistic activity with ampicillin. The in silico molecular docking through the AutoDock Vina 4.2 and GROMACS (ver. 5.1) Charmm27 force field results showed that the TAME had a strong binding affinity Escherichia coli DNA Gyrase B (PDB ID: 5l3j.pdb) protein and caused conformational changes. Thus, the manuscript reports the first time on the characterization of TAME from this plant with a detailed antibacterial mode of action studies.

Identification, Characterization, and Expression Analysis of Carotenoid Biosynthesis Genes and Carotenoid Accumulation in Watercress (Nasturtium officinale R. Br.)

Watercress (Nasturtium officinale R. Br.) is an important aquatic herb species belonging to the Brassicaceae family. It has various medicinal properties and has been utilized for the treatment of cancer and other diseases; however, currently available genomic information regarding this species is limited. Here, we performed the first comprehensive analysis of the carotenoid biosynthesis pathway (CBP) genes of N. officinale, which were identified from next-generation sequencing data. We identified and characterized 11 putative carotenoid pathway genes; among these, nine full and two partial open reading frames were determined. These genes were closely related to CBP genes of the other higher plants in the phylogenetic tree. Three-dimensional structure analysis and multiple alignments revealed several distinct conserved motifs, including aspartate or glutamate residues, carotene-binding motifs, and dinucleotide-binding motifs. Quantitative reverse transcription-polymerase chain reaction results showed that the CBP was expressed in a tissue-specific manner: expression levels of NoPSY, NoPDS, NoZDS-p, NoCrtISO, NoLCYE, NoCHXE-p, and NoCCD were highest in the flower, whereas NoLCYB, NoCHXB, NoZEP, and NoNCED were highest in the leaves. Stems, roots, and seeds did not show a significant change in the expression compared to the leaves and flowers. High-performance liquid chromatography analysis of the same organs showed the presence of seven distinct carotenoid compounds. The total carotenoid content was highest in the leaves followed by flowers, seeds, stems, and roots. Among the seven individual carotenoids, the levels of six carotenoids (i.e., 13-Z-β-carotene, 9-Z-β-carotene, E-β-carotene, lutein, violaxanthin, and β-cryptoxanthin) were highest in the leaves. The highest content was observed for lutein, followed by E-β-carotene, and 9-Z-β-carotene; these carotenoids were much higher in the leaves compared to the other organs. The results will be useful references for further molecular genetics and functional studies involving this species and other closely related species.

Coastal morphodynamics and Holocene environmental changes in the Pearl River Delta, southern China: New evidence from palynological records

Coastal morphodynamics and environmental changes have been obviously altered by global warming, sea-level fluctuations, and human activities. Palynological analysis is one of the most important tools for providing information on vegetation, climate, and environmental change, which can be relatively sensitive indicators of human activity during the Holocene. However, Holocene coastal morphodynamics and palynological evidence from the Pearl River Delta and coastal areas has not been sufficiently studied. In this paper, we carry out analyses using detailed grain-size and palynological records of pollen, spores, freshwater algae, and marine dinoflagellate cysts from Borehole QZK13 in the Pearl River Estuary (PRE), southern China. The results show information relating coastal morphodynamics, vegetation evolution, climate changes, and anthropogenic activities during the Holocene based on radiocarbon chronology. In general, the PRE experienced marine transgressive processes; sea-level and the coastline tended to migrate landward between 10,700 and 4250 cal yr BP. Meanwhile, abundant arboreal pollen (mainly Castanopsis, Quercus-evergreen, Oleaceae, and Castanea) and small amounts of non-arboreal pollen (mainly Poaceae, Cyperaceae, and Artemisia) were observed in Borehole QZK13, which suggests that subtropical evergreen broadleaved forests were distributed throughout the PRE and adjacent areas, and relatively warm and moist climatic conditions were present during the early-middle Holocene. After that, there were relatively cool and wet climatic conditions, and marine regressive processes occurred in the PRE during the Late Holocene (ca. 4250–960 cal yr BP) indicated by an abrupt increase in aquatic herbs and Dicranopteris. Moreover, we hypothesize that the Neolithic “cultural fault” in the PRE is likely related to frequent storm surges induced by extreme typhoon events that occurred ca. 3000–2700 yr BP.

The complete chloroplast genome of Sparganium fallax (Typhaceae)

Sparganium fallax is an aquatic perennial herb distributed in eastern Asia. The complete chloroplast genome of S. fallax was sequenced and assembled. The genome size was 161,838 bp in length with 36.8% GC content. Its quadripartite structure consisted of the large single copy (LSC, 89,042 bp) and small single copy (SSC, 18,774bp) regions, separated by a pair of inverted repeats (IRS) of 27,011bp. The genome contained 114 genes, including 80 protein-coding genes, 30 tRNA genes, and four rRNA genes. The phylogenetic analysis within order Poales including three Sparganium species showed that Sparganium is monophyletic and most closely related to Typha.

Distribución en Chile y colonización del río Cayumapu (Valdivia) por el macrófito acuático invasor Limnobium laevigatum

Limnobium laevigatum is an invasive aquatic herb that increases its range in Chile to displace native species from its place in the coastal zonation of the fresh water bodies. Seasonal biomass production and reproduction of this species are studied in the Sanctuary of Nature “Carlos Anwandter” in Valdivia, Chile. The change experienced by the coastal zonation of the river is established due to the aggressiveness of this invasive species, which was favored by the eutrophication of the waters. The average annual biomass reaches 6,140 kg/ha. The organs with the greatest contribution to biomass are the emergent leaves and the roots. Biomass production was higher in summer and lower in spring, when high values of necromass were also measured, indicating the presence of an unknown deleterious factor. The biomass of roots and emerging leaves has the same seasonal route with a decrease in spring, while the swimming leaves and the necromass show an inverse behavior. The presence of flowers and fruits was confirmed, which supports the hypothesis proposed of sexual reproduction for the Valdivian populations. Finally, a phenological diagram indicates the presence of viable fruits and seeds throughout the year.

Thermal requirements and germination niche breadth of Polygonum ferrugineum Wedd. from southeastern Brazil

AbstractTemperature may regulate seed dormancy and germination and determine the geographical distribution of species. The present study investigated the thermal limits for seed germination of Polygonum ferrugineum (Polygonaceae), an aquatic emergent herb distributed throughout tropical and subtropical America. Seed germination responses to light and temperature were evaluated both before (control) and after stratification at 10, 15 and 20°C for 7, 14 and 28 d. Germination of control seeds was ~50% at 10 and 15°C, and they did not germinate from 20 to 30°C. The best stratification treatment was 7 d at 10°C, where seed germination was >76% in the dark for all temperatures, except at 30°C, and < 60% in light conditions. A thermal time approach was applied to the seed germination results. Base temperature (Tb) was 6.3°C for non-dormant seeds and optimal temperature (To) was 20.6°C, ceiling temperature (Tc (<50)) was 32.8°C, and thermal time requirement for 50% germination was 44.4°Cd. We concluded that a fraction of P. ferrugineum seeds is dormant, has a narrow thermal niche to germinate (10 and 15°C) and that cold stratification (10°C) alleviated dormancy and amplified the thermal range permissive for germination of the species. Consequently, P. ferrugineum is expected to occur in colder environments, for example, at high altitudes. Higher temperatures decrease the probabilities of alleviate dormancy and the ability of their seeds to germinate.

Study on structural characterization, physicochemical properties and digestive properties of euryale ferox resistant starch

At present, the raw materials for industrialized RS3 products are relatively simple and its purity is low. In addition, the correlation between structure and digestion characteristics of RS3 are rarely studied. In this study, euryale ferox, a kind of annual aquatic herb crop with high content of starch was used as a raw material to prepare RS3 by different methods, including autoclaving, enzymolysis-autoclaving and dual enzymolysis, respectively. The results showed that there were significant differences in the structure and physicochemical properties of the different euryale ferox resistant-enhanced and purified resistant starches (p < 0.05). Purified euryale ferox resistant starches belonged to B + V type crystal and had high thermal stability. After digestion, the structure and thermal properties of euryale ferox resistant-enhanced starches changed a lot. The digestion rate and estimated glycemic index (eGI) of the three kinds of purified euryale ferox RS3 were lower than 20% and 50%, respectively.

The complete chloroplast genome of Ottelia acuminate var. crispa, an endangered aquatic herb with extremely narrow distribution

Ottelia acuminate var. crispa is an endangered aquatic herb with extremely narrow distribution. In this study, we assembled the chloroplast genome of this species based on the second-generation high-throughput sequencing. The genome is 157,783 bp in length with a typical quadripartite structure including a large single-copy region (LSC) of 88,294 bp, a small single-copy region (SSC) of 49,379 bp, and a pair of inverted repeats (IRs) of 10,055 bp each. A total of 128 genes were annotated, including 83 protein-coding genes (PCG), 37 tRNA genes, and 8 rRNA genes. The phylogenetic tree shows that O. acuminate var. crispa has a close relationship with the genus Elodea. The chloroplast genome presented here provides a valuable resource to conserve this endangered species.

Chloroplast genome of Trapa bispinosa Roxb. (Trapa, Lythraceae)

Trapa bispinosa Roxb. is an annual aquatic herb with great significance of medicinal, edible and economic value. Here, we reported the complete chloroplast genome sequence of Trapa bispinosa and conducted preliminary investigation of its phylogenetic relationship with other related species. As the result showed, the whole chloroplast genome size was 155,556 bp consisting of four adjoining regions, i.e., a large/small single copy (LSC, 88,506 bp/SSC, 18,274 bp) region and two inverted repeat (IRs, 24,388 bp) regions. Among 112 identified unique genes were 78 protein coding genes, 30 transfer RNA (tRNA) genes, and four ribosomal RNA (rRNA) genes. Trapa spp. were precisely clustered as a monophyly, and simultaneously, the closest relation between Trapa bispinosa and Trapa natans were strongly supported in the maximum likelihood analysis.

Variation and potential influence factors of foliar pH in land-water ecozones of three small plateau lakes

Abstract Aims Foliar pH of terrestrial plants, a trait tightly associated with plant physiology and nutrient utilization, varies with plant functional types (PFTs) and environmental changes. However, it is yet unclear about the variation in foliar pH of aquatic plants, and the difference between aquatic and terrestrial plants. Methods Foliar pH, leaf carbon, nitrogen content of plants along the lakeshore zones and the environmental conditions (water or soil pH, water status) of the corresponding vegetation of three small plateau lakes were investigated, to determine the variation and potential influence factors of foliar pH at both PFT and community levels. Important Findings Foliar pH varied largely among aquatic plants, and across aquatic, helophytic and terrestrial plants. Floating-leaved macrophytes had more acidic foliage (pH = 4.21 ± 0.05) than emergent (5.71 ± 0.07) and submerged macrophytes (5.82 ± 0.06). Foliar pH of aquatic herbs (5.43 ± 0.10) was lower than that of helophytic (6.12 ± 0.07) and terrestrial herbs (5.74 ± 0.05). Terrestrial herbs had significantly higher foliar pH than woody plants. The variation in foliar pH across PFTs may be mainly ascribed to leaf structure, light utilization and nutrient characteristics. Consistent with the pattern on PFT level, aquatic communities had more acidic foliage than terrestrial communities, which was mainly shaped by species composition, water status and environmental pH. This study documented the first-time foliar pH of aquatic plants, and comparison of foliar pH among various plant types at a landscape scale. Our results provide bases for further exploration of the underlying mechanism and its ecological significance for wetland ecosystems.

Application of aquatic plants in urban ecological construction of Kunming

Aquatic plants play an important role in urban construction. According to the application status of aquatic plants in urban construction of Kunming, It is suggested that aquatic herbs should be used as the main plant to optimize the allocation; Reasonable harvest management should be carried out; Effective control of aquatic plant biomass and other measures. To construct a biodiversity aquatic plant community. Accelerate the pace of urban ecological construction.

Intersexual mimicry and imperfect deceit of a threatened aquatic herb Ottelia acuminata

AbstractMimicry of non‐rewarding flowers to rewarding flowers has been accepted as a strategy to improve pollination success in angiosperms. It has been proposed that this mechanism depends on whether potential pollinators can discriminate between the flowers. In this study, the intersexual mimicry and deceit pollination were studied in a threatened dioecious aquatic herb, Ottelia acuminata. Its female flowers resemble male flowers in morphology and odor compounds, to avoid discrimination by pollinators and outcompete male flowers in attracting the pollinators using stronger scents and bigger flowers. However, an obvious visit bias of its pollinator (Apis cerana) to male flowers was detected, suggesting that bees can distinguish the rewarding males from non‐rewarding females. Although the deceit was not successful, pollination was not seriously undermined because pollen limitation was found to be low in the sampled natural population. We speculate that, due to “accidental” visits on female flowers and “mistake” pollinations, pollen limitation could be mitigated by a high frequency of pollen donors, and is correlated with the size and sex ratio of a population. Ottelia acuminata is a threatened dioecious aquatic herb. We suggest that developing multi‐stakeholder coalitions should be encouraged to save the threatened edible and ornamental plant species in China. We hope this study could provide new insights into understanding of the role of intersexual mimicry in other flowering plants.

A Critical Cross-Species Comparison of Pollen from Nelumbo nucifera Gaertn. vs. Nymphaea lotus L. for Authentication of Thai Medicinal Herbal Tea.

“Bau Luang” or Nelumbo nucifera Gaertn. is an aquatic medicinal herb that has been used as a component of traditional medicines, medicinal products, and herbal tea for good health, particularly in Asia. The stamen of N. nucifera is an important part of this medicinal plant that is used in the form of dried and/or powdered stamens for herbal tea as well as the main ingredient of some traditional remedies. However, there is another aquatic herb called “Bau Sai” or Nymphaea lotus L. that is distributed in similar locations. Living plants of these two aquatic species may be classified according to their morphology, but the dried and powdered stamens of these two medicinal species are difficult to distinguish. The major reason of adulteration is the higher price of Bau Luang stamen. As a result, various methods of authentication, such as pollen micromorphology evaluation using scanning electron microscopy (SEM) analysis, bioinformatics analysis of two nuclear and plastic DNA markers, phytochemical stamen profiling, and Fourier transform infrared (FTIR) analysis of stamen plant material authentication from Bau Luang and Bau Sai, have been used in this present research in order to avoid some adulteration and/or misuse between the dried stamens of Bau Luang and Bau Sai. These results showed that the micro-morphology of pollen (size of pollen grain, number of apertures, and surface ornamentation) from the SEM analysis, some phytochemical compounds and the FTIR sporopollenin-to-protein ratio signal analysis are potential tools for authentication and identification of these two medicinal plants from their dried-stamen materials. This model of investigation may also be used to distinguish dried plant material from other problematic plant groups.

Genetic Variation of the Novel Badnaviruses Infecting Nelumbo Nucifera Based on the RT/RNase H Coding Region Sequences

Lotus (Nelumbo nucifera Gaertn.) is an economically important perennial aquatic herb plant in China. Presently, viral diseases caused by Cucumber mosaic virus (CMV) and Dasheen mosaic virus (DsMV) are detected in lotus. In this study, the putatively novel badnaviruses from lotus plants (LBVs) were identified using next-generation sequencing of siRNAs and conventional Sanger sequencing based on the RT/RNase H coding region sequences. Lotus plants infected by LBVs harbored virus quasispecies. A unique recombination event of LBVs was found in a single lotus plant. Sap inoculation showed that LBVs could actively replicate in the lotus plants, but without a wide host range. The field survey of 43 lotus plants in Jiangsu Province showed a prevalence of 62.8% for LBVs, confirming that it is widely distributed in Jiangsu Province of China.

Vegetation Dynamics and Diversity Status in Mughal Garden Wah, Pakistan

Classification and ordination of vegetation of Mughal Garden, Wah, Pakistan was done along with assessment of diversity status. A total of 45 species were recorded in vegetation survey belonging to 24 families with Asteraceae and Poaceae being the largest families. Herbs dominated the flora of Wah Garden by 44.4%, shrubs 15.5%, trees 13.3%, grasses 11.1%, creeping herbs 11.1%, ferns 2.2% and aquatic herbs 2.2%. About 35.5% species were annuals, 28.8% perennials, 13.3% annuals or perennials, 8.8% annuals or biennials, 8.8% deciduous, 2.2% coniferous and evergreen species. In case of life form of species, Therophytes and Megaphanerophytes were the most prevalent among species indirect ordination techniques TWINSPAN and DCA were employed that produced two major groups which were further divided into five communities and three major groups, respectively. Shannon-Wiener diversity index, Simpson Index of diversity and Hill’s N1 and N2 diversity numbers were calculated and verified by data attribute plot through DCA suggesting reduced species diversity as Shannon-Wiener diversity index ranged between 0 and 1.67 due to increased anthropogenic activity. The outcome of this research will be useful in providing information on identification of species that are present, their distribution patterns, and classification which would help in management and conservation of native vegetation in future.

The complete chloroplast genome sequence of Brasenia schreberi (Cabombaceae)

Brasenia schreberi is a perennial aquatic herb. We determined the complete chloroplast genome sequence for B. schreberi using Illumina sequencing data. The complete chloroplast sequence is 158,993 bp, include large single-copy (LSC) region of 88,779 bp, small single-copy (SSC) region of 21,665 bp, a pair of invert repeats (IR) regions of 21,078 bp. Plastid genome contains 132 genes, 87 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic analysis base on 12 chloroplast genomes indicates that B. schreberi is sister to Cabomba spp. in Cabombaceae.

Fishing for iodine: what aquatic foraging by bonobos tells us about human evolution

BackgroundExpansion of brain tissue and development of advanced cognitive skills are characteristic traits of human evolution. Their emergence has been causally linked to the intake of nutrients that promote brain development and iodine is considered a critical resource. Rich sources of iodine exist in coastal areas and evolutionary scenarios associate the progressive development of brain size and cognitive skills to such landscapes. This raises the question of how early hominins living in continental areas could have met their iodine requirements. One way to explore this question is to use information from hominoid primates as a proxy for the nutritional ecology of early hominins. Bonobos are particularly interesting in this context as they are restricted to the central part of the Congo basin, an area considered to be iodine deficient based on human standards.MethodsPooled samples of fruit, terrestrial and aquatic herbs were used to assess mineral content with an inductively coupled plasma optical emission spectrometer. Iodine content was measured with the catalytic technique of Sandell-Kolthoff and two separate inductively coupled plasma mass spectrometry methods.ResultsNutritional analyses revealed that the mineral content of aquatic herbs is higher than in other plant foods. Moreover, two species of aquatic herbs consumed by bonobos contain iodine concentrations that are almost equivalent to marine algae.ConclusionsThese data challenge the general notion that the Congo basin is iodine deficient and demonstrate that its lowland forest offers natural sources of iodine in concentrations high enough to prevent iodine deficiency in hominoids and humans.

Palynological record of Holocene climate change from a Sphagnum peat mire on Qizimei Mountain, Central China

The palynological sequence in core QZMS from Qizimei Mountain, central China, reflects the vegetation and climate dynamics since 12,900 calibrated years before present (cal yr BP). A palynological analysis demonstrated that the temperate deciduous broadleaved and coniferous mixed forest that was present from 12,900 to 10,600 cal yr BP changed to a deciduous broadleaved and coniferous mixed forest from 10,600 to 10,300 cal yr BP due to climate warming. From 10,300 to 7000 cal yr BP, a subtropical and temperate broadleaved and coniferous mixed forest was present. Then, the climate cooled from 7000 to 3000 cal yr BP. The variations in freshwater algae and Sphagnum (AS) and aquatic herbs (AH) indicate that rainfall increased from the early Holocene to 6890 cal yr BP and then gradually decreased. This change in rainfall coincided with changes in the Asian Summer Monsoon (ASM) and rainfall patterns in southern and northern China during different periods. The rainfall pattern was dominated by a shift in the summer rainbelt in the Chinese ASM region, which was mainly driven by orbitally forced changes in insolation and shifts in the El Nino/Southern Oscillation during the Holocene.

Study of Jinchuan Mire in NE China II: Peatland development, carbon accumulation and climate change during the past 1000 years

Peat properties including porosity, dry bulk density (DBD), ash content (and their XRD and SEM), TOC, humification and plant macrofossil were measured in the well dated, young peat profiles of Jinchuan Mire in southeast Jilin of China. Base on the properties and depositional rates (Li et al., 2019) of JC1 (50-cm long) and JCA (92-cm long), carbon accumulation rates (RCAs) have been calculated for different periods and processes of peatland development over the past 1000 years have been described. The long term variations of the RCAs between Jinchuan Mire and nearby Baijianghe Mire (Xia et al., 2019) during the past 1000 years matched reasonably well, reflecting similar carbon accumulation rates under the same climatic control even though the plant species could be very different in the two mires. Enhanced detrital content caused by surface runoff due to heavy rains with decline of wood% in plant remains probably reflect wet climates; and vice versa. In comparisons with regional climatic records, we describe the development of Jinchuan Mire as follow: (1) relatively warm and wet climates between 1000 CE and 1150 CE reflected by dominant herb species (>95%) with low wood% and no Sphagnum%, low DBD and detritus, and high TOC% and porosity. A dry climate occurred during 1150–1200 CE to lower the water table and enable growth of mosses in the mire. (2) Wet and cooling conditions during 1200–1370 CE supported well development of Sphagnum mosses and good development of the mire. (3) A climatic change from wet/cool to cold/dry between 1370 CE and 1440 CE caused disappear of Sphagnum mosses. (4) During the Little Ice Age (1440–1850 CE), cold and dry conditions led to poor peat development without Sphagnum mosses. (5) After 1850 CE, warm and wet conditions were in favor of aquatic herb growth. (6) Human impact caused anomaly peat accumulation with mainly tree species and detritus between 1950 and 1965. The peatland has been recovered from natural condition and development of Sphagnum mosses since 1965. Estimated RCAs in the hummock site and the lawn site are 320 gC/m2/y and 63 gC/m2/y, respectively during 1970–2010. Estimation of carbon accumulation over the entire peatland needs more work.

Molecular cloning and biochemical characterization of a new flavonoid glycosyltransferase from the aquatic plant lotus

Lotus (Nelumbo nucifera Gaertn.), one of the earliest plants in angiosperms, is a perennial aquatic herb widely distributed throughout Eastern Asia. Quercetin and its glycosides are the most abundant phenolic compounds in lotus with multiple pharmacological activities. Although many flavonoid O-glycosyltransferases involved in the biosynthesis of quercetin glycosides have been identified from terrestrial plants, no glycosyltransferase has been identified in aquatic plants. In this study, a new glycosyltransferase (NpUGT6) was identified from the embryo of Nelumbo nucifera (Nelumbinis Plumula). Function characterization demonstrated that NpUGT6 exhibited a robust capability to regio- and stereo-specific O-glycosylation at the 3-hydroxy group of quercetin scaffolds with UDP-glucose. Moreover, the O-glycosylation catalyzed by NpUGT6 was reversible. NpUGT6 is the first identified flavonoid O-glycosyltransferase from aquatic plants. Its sequence will provide useful guidance for the discovery of additional flavonoid glycosyltransferses in Nymphaeaceae and other aquatic plants.