Nepenthes Pitcher Research Articles

TOXICITY TEST (LD-50) of HERBAL PREPARATIONS Nepenthes ampularia AS The STANDARD of SECURITY of JAMU HYPERTENSION

The excavation of the potential utilization of herbs as a plant biopharma or as a material to manufacture. There is empirical evidence that Nepenthes has been used as a lowering of hypertension by taking a decoction of its pitchers. For the use and utilization as a medicinal plant need to be done research that refers to the scientifically certified Jamu. The research aims to detect acute toxic effects so that can be obtained the water safety overview Nepenthes pitchers. The toxicity test was carried out by the Brine Shrimp Lethality Test (BSLT), Artemia salina larva with four extract concentrations (0, 10, 500, 1000 ppm). Based on the results of toxic tests showed that the death rate of A. salina at all levels of concentration is 0 deaths. It is evidence that Nepenthes ampularia is not toxic to A. salina..

Bioinspired Two-Dimensional Structure with Asymmetric Wettability Barriers for Unidirectional and Long-Distance Gas Bubble Delivery Underwater.

Gas bubble manipulations in liquid have long been a concern because of their vital roles in various gas-related fields. To deal with the weakness in long-distance gas transportation of previous works, we took inspiration from the ridgelike structure on Nepenthes pitcher's peristome and successfully prepared a two-dimensional superaerophilic surface decorated with asymmetric aerophobic barriers capable of unidirectional and long-distance gas bubble delivery. For the first time, this process was investigated by in situ bubble-releasing experiments recorded by a high-speed camera and finite element modeling, which demonstrates a kinetic process regulated by the anisotropic motion resistance arising from the patterns. Furthermore, the Nepenthes alata-inspired two-dimensional surface (NATS) was integrated into a water electrolysis system for H2 directional transportation and efficient collection. As a result, the NATS design was proved to be a potential solution for facile manipulation of gas bubbles and provides a simple, adaptive, and reliable strategy for long-range gas transport underwater.

WO3-based slippery coatings with long-term stability for efficient fog harvesting

Inspired by Nepenthes pitcher plants, slippery liquid-infused porous surfaces (SLIPSs) have attracted wide attention and exhibited remarkable liquid repellency, droplet motion control and antifouling properties. However, lubricant-impregnated surfaces have poor durability, leading to loss of control of the movements of droplets during applications. Herein, WO3-based slippery coatings with high stability were prepared by the spray method and photocatalytic reaction. Notably, on the basis of the hierarchical structures, the strong intermolecular forces between the polydimethylsiloxane brush and silicone oil led to the formation of a stable lubricant layer on the WO3-based slippery coating, which can suppress lubricant loss during water collection. After a series of stability tests, such as high-speed centrifugation, long-term storage, acidic solution and multiple heating/cooling cycles, the biomimetic slippery surface still displays excellent surface-slippery stability. Furthermore, the slippery surface exhibits superior water mist capture, water droplet expansion and harvested water removal abilities, leading to good water collection performance. The silicone oil content in the collected water was 28 mg/L, demonstrating that the loss of oil was lower during the water collection process. Even under harsh environments, including multiple heating/cooling cycles, long-term storage and high shear force, lubricant-impregnated coatings can also maintain good water collection efficiency. Therefore, these slippery coatings are promising for widespread application.

Self-healing solid slippery surface with porous structure and enhanced corrosion resistance

• A solid slippery surface was successfully fabricated via a facile method. • The slippery surface showed good chemical and mechanical stability. • The slippery surface showed superior corrosion resistance and self-healing property. The corrosion issue of metals is common and has significant impact on social development. In recent decades, the novel slippery surface (lubricant infused surface) inspired by “Nepenthes pitcher plant” has attracted extensive attentions for corrosion protection on account of its superior water repellency. However, most of the construction process for slippery surface was complex and the lubricant was easy to be dissipated in air or liquid environment. In this work, a facile hydrogen bubble dynamic template method (HBTM) was applied to construct porous structure, and the stable phase-change material paraffin was then infused into the porous structure for solid slippery surface. The results showed that the morphology of obtained sample constructed at 3 A·cm −2 exhibited a homogeneously porous structure. In addition, the slippery surface could be self-healing with thermally assistant after mechanical abrasion. More importantly, the slippery surface showed excellent anti-corrosion performance with a corrosion current density of 1.138 × 10 −7 A cm −2 . It was worth mentioning that the corrosion resistance of the slippery surface was still very good even after immersion in NaCl solution for 3 weeks. The fourier transform infrared spectroscopy and ultraviolet results revealed that the dissolution of paraffin in NaCl solution can be neglected, indicating an excellent stability. Thus, the facile method has great significance for guiding the fabrication of slippery surface and we envision that the solid slippery surface can effectively protect metal materials from corrosion.

On the regulation of dissolved oxygen by Nepenthes pitchers

The digestive fluid of tropical pitcher plants (Nepenthaceae: Nepenthes L.) typically harbor communities of symbiotic organisms in nature, an example of a phytotelm ecosystem. While the inhabitants of pitchers (primarily the arthropods) have been described and studied from a community ecology perspective for over a century, many abiotic properties of the fluid environment have not been thoroughly documented. As the abiotic properties of the pitcher fluid micro-environment may have fitness and/or functional consequences on the inhabitants, it is of interest to examine intra and interspecific variation in fluid properties. Here I report observations of dissolved oxygen levels in Nepenthes pitchers. I find evidence that Nepenthes pitchers actively modify dissolved oxygen levels in the fluid and that this oxygenation ability may vary ontogenetically, with relatively hypoxic conditions in newly opened pitchers and high oxygen levels maintained in more mature pitchers.

Biomimicking properties of cellulose nanofiber under ethanol/water mixture

The two types of cellulose nanofiber (CNF) surface characteristics were evaluated by oil contact angle under ethanol–water solution at several concentrations as well as in air. Wood pulp-based 2,2,6,6-tetramethylpiperidine-1-oxylradical (TEMPO)-oxidized cellulose nanofiber (TOCNF) sheets and bamboo-derived mechanical counter collision cellulose nanofiber (ACC-CNF) sheets were fabricated by casting followed by drying. The CNF shows underwater superoleophobic mimicking fish skin properties and slippery surface mimicking Nepenthes pitcher. The underwater superoleophobic properties of CNF was evaluated theoretically and experimentally. The theoretical calculation and experimental results of contact angle showed a large deviation. The roughness, zeta potential, and water absorption at different concentrations were key factors that determine the deviation. Antifouling investigation revealed that CNF was a good candidate for antifouling material.

Ontogeny and Anatomy of the Dimorphic Pitchers of Nepenthes rafflesiana Jack.

An enigmatic feature of tropical pitcher plants belonging to the genus Nepenthes is their dimorphic prey-capturing pitfall traps. In many species, the conspicuously shaped upper and lower pitchers grow from a swollen leaf tendril tip until finally opening as insect-alluring devices. Few have studied the ontogeny of these traps from an anatomical and quantitative morphological perspective. We investigated whether the anatomy and development of lower and upper type pitchers of N. rafflesiana differ or overlap in terms of 3D geometric morphology and microstructure progression and presence. We hypothesized that there is an overlap in the initial, but not all, developmental stages of the two pitcher types and that one pitcher type is suspended in development. We identified four important morphological changes of pitcher ontogeny and defined these as curvation, elongation, inflation and maturation phases. Pitcher length indicated progress through developmental phases, and we propose to use it as a tool for indication of developmental stage. Microstructure development coincided with the developmental phases defined. Additionally, we discovered a new anatomical feature of extrafloral nectariferous peristomal glands between the inner peristome ridges of upper and lower pitchers being hollow and analyze the chemistry of the sugars on the outside of these glands. Ontogenetic shape analysis indicated that upper and lower pitcher types develop with similar phase progression but have no directly overlapping morphology. This means that upper pitchers are not a derived state from lower pitchers. Independent developmental programs evolved to produce distinctly shaped upper and lower pitchers in Nepenthes, likely to exploit different food sources.

Pitchers of Nepenthes khasiana express several digestive-enzyme encoding genes, harbor mostly fungi and probably evolved through changes in the expression of leaf polarity genes

BackgroundA structural phenomenon seen in certain lineages of angiosperms that has captivated many scholars including Charles Darwin is the evolution of plant carnivory. Evidently, these structural features collectively termed carnivorous syndrome, evolved to aid nutritional acquisition from attracted, captured and digested prey. We now understand why plant carnivory evolved but how carnivorous plants acquired these attributes remains a mystery. In an attempt to understand the evolution of Nepenthes pitcher and to shed more light on its role in prey digestion, we analyzed the transcriptome data of the highly specialized Nepenthes khasiana leaf comprising the leaf base lamina, tendril and the different parts/zones of the pitcher tube viz. digestive zone, waxy zone and lid.ResultsIn total, we generated around 262 million high-quality Illumina reads. Reads were pooled, normalized and de novo assembled to generate a reference transcriptome of about 412,224 transcripts. We then estimated transcript abundance along the N. khasiana leaf by mapping individual reads from each part/zone to the reference transcriptome. Correlation-based hierarchical clustering analysis of 27,208 commonly expressed genes indicated functional relationship and similar cellular processes underlying the development of the leaf base and the pitcher, thereby implying that the Nepenthes pitcher is indeed a modified leaf. From a list of 2386 differentially expressed genes (DEGs), we identified transcripts encoding key enzymes involved in prey digestion and protection against pathogen attack, some of which are expressed at high levels in the digestive zone. Interestingly, many of these enzyme-encoding genes are also expressed in the unopened N. khasiana pitcher. Transcripts showing homology to both bacteria and fungi were also detected; and in the digestive zone, fungi are more predominant as compared to bacteria. Taking cues from histology and scanning electron microscopy (SEM) photomicrographs, we found altered expressions of key regulatory genes involved in leaf development. Of particular interest, the expression of class III HOMEODOMAIN-LEUCINE ZIPPER (HD-ZIPIII) and ARGONAUTE (AGO) genes were upregulated in the tendril.ConclusionsOur findings suggest that N. khasiana pitchers employ a wide range of enzymes for prey digestion and plant defense, harbor microbes and probably evolved through altered expression of leaf polarity genes.

Disentangling the role of surface topography and intrinsic wettability in the prey capture mechanism of Nepenthes pitcher plants

Nepenthes pitcher plants capture prey with leaves specialised as pitfall traps. Insects are trapped when they ‘aquaplane’ on the pitcher rim (peristome), a surface structured with macroscopic and microscopic radial ridges. What is the functional significance of this hierarchical surface topography? Here, we use insect pad friction measurements, photolithography, wetting experiments and physical modelling to demonstrate that the ridges enhance the trap's efficacy by satisfying two functional demands on prey capture: Macroscopic ridges restrict lateral but enhance radial spreading of water, thereby creating continuous slippery tracks which facilitate prey capture when little water is present. Microscopic ridges, in turn, ensure that the water film between insect pad and peristome remains stable, causing insects to aquaplane. In combination, the hierarchical ridge structure hence renders the peristome wettable, and water films continuous, so avoiding the need for a strongly hydrophilic surface chemistry, which would compromise resistance to desiccation and attract detrimental contamination.

Static and dynamic behaviour of aqueous drops on thin lubricating fluid-coated slippery (LCS) surfaces

Inspired by Nepenthes pitcher plants, lubricating fluid infused slippery (LIS) surfaces have recently gained tremendous attention from various research groups. We, alternatively, present lubricating fluid-coated slippery (LCS) surfaces based on smooth solid surfaces. The biggest advantage of LCS surfaces over LIS surfaces is that solid surfaces need not be rough or porous. We discuss that the surface energy of the underlying solid surfaces plays the most important role in preparing the LCS surfaces. Lubricating fluid-coated hydrophilic surfaces result in sinking aqueous drops due to the instability of the thin lubricating film. Additionally, stable and floating aqueous drops are observed on similar hydrophobic surfaces. We also observed that the presence of surface roughness enhances the stability and performance of LCS surfaces. Later we discuss various characteristics of LCS surfaces and its effects on the static and dynamic behaviour of aqueous drops on LCS surfaces.

Salvinia-like slippery surface with stable and mobile water/air contact line.

Superhydrophobic surfaces are widely used in many industrial settings, and mainly consist of rough solid protrusions that entrap air to minimize the liquid/solid area. The stability of the superhydrophobic state favors relatively small spacing between protrusions. However, this in turn increases the lateral adhesion force that retards the mobility of drops. Here we propose a novel approach that optimizes both properties simultaneously. Inspired by the hydrophobic leaves of Salvinia molesta and the slippery Nepenthes pitcher plants, we designed a Salvinia-like slippery surface (SSS) consisting of protrusions with slippery heads. We demonstrate that compared to a control surface, the SSS exhibits increased stability against pressure and impact, and enhanced lateral mobility of water drops as well as reduced hydrodynamic drag. We also systematically investigate the wetting dynamics on the SSS. With its easy fabrication and enhanced performance, we envision that SSS will be useful in a variety of fields in industry.

Interfacial Strategies for Smart Slippery Surfaces

The problem of contact line pinning on surfaces is pervasive and contributes to problems from ring stains to ice formation. Here we provide a single conceptual framework for interfacial strategies encompassing five strategies for modifying the solid-liquid interface to remove pinning and increase droplet mobility. Three biomimetic strategies are included, (i) reducing the liquid-solid interfacial area inspired by the Lotus effect, (ii) converting the liquid-solid contact to a solid-solid contact by the formation of a liquid marble inspired by how galling aphids remove honeydew, and (iii) converting the liquid-solid interface to a liquid-lubricant contact by the use of a lubricant impregnated surface inspired by the Nepenthes Pitcher plant. Two further strategies are, (iv) converting the liquid-solid contact to a liquid-vapor contact by using the Leidenfrost effect, and (v) converting the contact to a liquid-liquid-like contact using slippery omniphobic covalent attachment of a liquid-like coating (SOCAL). Using these approaches, we explain how surfaces can be designed to have smart functionality whilst retaining the mobility of contact lines and droplets. Furthermore, we show how droplets can evaporate at constant contact angle, be positioned using a Cheerios effect, transported by boundary reconfiguration in an energy invariant manner, and drive the rotation of solid components in a Leidenfrost heat engine. Our conceptual framework enables the rationale design of surfaces which are slippery to liquids and is relevant to a diverse range of applications.

WO3-Based Slippery Liquid-Infused Porous Surfaces with Long-Term Stability.

Slippery liquid-infused porous surfaces (SLIPS) inspired by Nepenthes pitcher plants exhibit excellent hydrophobicity, antifouling and anti-icing properties, and long-term durability under pressure and temperature. SLIPS have potential applications including in biomedical devices, self-cleaning structures, and water-resistant coatings. A big challenge posed by SLIPS is the durability of the lubricant in the porous layer. Herein, uniform tungsten oxide nanofiber networks were synthesized on the surface of stainless steel through a simple one-step hydrothermal method. WO3 nanofiber networks on stainless steels were chemically modified, filled with a lubricant, and prepared as SLIPS with excellent liquid repellency and good anti-biofouling properties. The relationship of the nanostructures and the slippery properties of the obtained WO3-based SLIPS have been investigated in detail in this work. The liquid retention and long-term stability of the SLIPS were characterized using high shear force and water flow impact. We found that the long-term durability of the SLIPS is strongly related to the diameters and the Brunauer-Emmett-Teller surface areas of the WO3 nanostructures. The durability of the SLIPS is better when the diameter of the WO3 nanostructures is smaller. The WO3-based SLIPS prepared in this work exhibit outstanding slippery property, anti-biofouling, and long-term stability under extreme conditions such as high shear rate and water washing and thus may have potential application for surface modification of medical devices in the future.

Biomimetic partition structure infused by nano-compositing liquid to form bio-inspired self-healing surface for corrosion inhibition

Finding versatile coating to prohibit three-dimensional corrosion propagation on metal surface is of essential importance. In this report, inspired by the natural pomegranate fruit, we have fabricated the partition structure by electrochemical method. The as-built Ce(OH)3 nanowall structure has circumvented the partition structure to inhibit the horizontal corrosion propagation on metal surface. Moreover, the partition structure is modified to realize superhydrophobicity and superoleophilicity wettability. Endowed by the two properties, binary-phase fluid is used to infuse the as-modified partition structure to form nano-compositing liquid infused surface (NCLIS). In vertical direction, the upgraded Nepenthes pitcher plant inspired surface has afforded much higher corrosion inhibition effect to the underneath metal substrate. After immersion for 600 h, Z0.01Hz of NCLIS is still as high as 1.19 × 108 Ω·cm2, which is ca. 2 orders of the magnitude larger than CS covered by liquid infused surface (LIS CS) with the same immersion period in seawater. Moreover, NCLIS coating shows self-healing capability to the underlying metal in atmospheric and seawater environment, even enduring the external mechanical damage. Therefore, the dual biomimetics of pomegranate and Nepenthes pitcher plant has afforded a versatile strategy to inhibit the corrosion from the horizontal and vertical directions.

Flexible Functional Surface for Efficient Water Collection.

Inspired by both the water collection strategy of desert beetles and the lubrication effect of Nepenthes pitcher plants, a new flexible functional surface for water collection is designed and can be easily fabricated. Such a functional surface consists mainly of a superhydrophobic region and a hydrophobic region with infused lubricating oil. Different functional patterns can be easily manipulated by different templates. Due to the flexibility of the surface, not only a two-dimensional surface but also a three-dimensional one can be designed. Directional water collection can be achieved. Furthermore, it is an integrative bioinspired functional surface that does not require any tailoring. Compared with existing functional surfaces, the present surface has higher water collection efficiency in fog and such a function can last 15 days. The functional degraded surfaces can also be easily reused.

A Bioinspired Slippery Surface with Stable Lubricant Impregnation for Efficient Water Harvesting.

Inspired by Nepenthes pitcher plants, slippery liquid-infused porous surfaces (SLIPS) have recently attracted increasing attention for directional transport and movement manipulation of water droplets. Nevertheless, infused lubricants are generally instable and easy to deviate from such surfaces during applications, resulting in the lost control on the fog capture and motion of droplets as well as serious risk of water safety. Here, a highly stable SLIPS with improved lubricant storage is developed through the structure design of synergistically constructing regular micro-pincushion and nanoparticles. Notably, on the basis of the microstructure, the presence of nano-architecture shows great contribution to obviously increased capillary force as well as suppressed lubricant loss during water collection. Featuring the stable surface-slippery property, the biomimetic SLIPS displays well maintained dropwise coalescence of water from fog and efficient water harvesting performance. The water collection efficiency is as high as 852 mg cm-2 h-1 and is stable within continuous 20 h application. This fundamental illustration of structural synergism can be further applied to construct more new water manipulation and harvesting platforms with stably slippery surfaces/interfaces.

A bioinspired lubricant infused surface with transparency, hot liquid boiling resistance and long-term stability for food applications

Inspired by the Nepenthes pitcher plant, the HAP and oleic acid prepared Lubricant Infused Surface (LIS) that exhibits liquid repellency and slipperiness has huge potential in various fields.

Design and preparation of bioinspired slippery liquid-infused porous surfaces with anti-icing performance via delayed phase inversion process

In recent years, slippery liquid-infused porous surfaces (SLIPSs) have been designed and prepared through miming Nepenthes pitcher plants because of their enormous potential applications in water repellency, anti-icing and anti-fouling. In this work, a PTFE-PVDF composite membrane with hierarchical micro/nano/porous structure and superhydrophobicity was designed and fabricated by immobilizing polytetrafluoroethylene (PTFE) nanoparticles on a polyvinylidene fluoride (PVDF) membrane through delayed phase inversion process. Then three lubricants of polydimethylsiloxane (PDMS), ethyl oleate and perfluoro polyether (PFPE) were infused into the PTFE-PVDF composite membranes, respectively, to gain three kinds of SLIPSs, resulting in the property transformation of composite membranes from superhydrophobicity to slippery performance. Wettability, transparency, durability and anti-icing performance of three SLIPSs were investigated. The ethyl oleate infusion surface had outstanding water-repellent ability with minimum water sliding angle of 8°. PDMS infusion surface had better transparency. The SLIPSs also possessed excellent oil-holding capacity with less changes of wetting behaviors for PDMS and PFPE infusion surface in 20 days. In addition, comparing with superhydrophobic surface and glass slide, three SLIPSs had better icing delay property. Moreover, their ice adhesion strengths were less than 20 kPa, especially the value of PFPE infusion surface was 13.9 kPa, showing excellent anti-icing performance. Furthermore, after experiencing 10 icing/melting cycles, they still maintained less ice adhesion strengths, which displayed outstanding durability. This research is expected to supply a simplified method to fabricate hierarchical micro/nano/porous structure and then gain high performance SLIPSs.

Inquiline predator increases nutrient-cycling efficiency of Nepenthes rafflesiana pitchers.

The modified-leaf pitchers of Nepenthes rafflesiana pitcher plants are aquatic, allochthonous ecosystems that are inhabited by specialist inquilines and sustained by the input of invertebrate prey. Detritivorous inquilines are known to increase the nutrient-cycling efficiency (NCE) of pitchers but it is unclear whether predatory inquilines that prey on these detritivores decrease the NCE of pitchers by reducing detritivore populations or increase the NCE of pitchers by processing nutrients that may otherwise be locked up in detritivore biomass. Nepenthosyrphus is a small and poorly studied genus of hoverflies and the larvae of one such species is a facultatively detritivorous predator that inhabits the pitchers of N. rafflesiana. We fitted a consumer-resource model to experimental data collected from this system. Simulations showed that systems containing the predator at equilibrium almost always had higher NCEs than those containing only prey (detritivore) species. We showed using a combination of simulated predator/prey exclusions that the processing of the resource through multiple pathways and trophic levels in this system is more efficient than that accomplished through fewer pathways and trophic levels. Our results thus support the vertical diversity hypothesis, which predicts that greater diversity across trophic levels results in greater ecosystem functioning.

Sex is determined by XY chromosomes across the radiation of dioecious Nepenthes pitcher plants.

Species with separate sexes (dioecy) are a minority among flowering plants, but dioecy has evolved multiple times independently in their history. The sex‐determination system and sex‐linked genomic regions are currently identified in a limited number of dioecious plants only. Here, we study the sex‐determination system in a genus of dioecious plants that lack heteromorphic sex chromosomes and are not amenable to controlled breeding: Nepenthes pitcher plants. We genotyped wild populations of flowering males and females of three Nepenthes taxa using ddRAD‐seq and sequenced a male inflorescence transcriptome. We developed a statistical tool (privacy rarefaction) to distinguish true sex specificity from stochastic noise in read coverage of sequencing data from wild populations and identified male‐specific loci and XY‐patterned single nucleotide polymorphsims (SNPs) in all three Nepenthes taxa, suggesting the presence of homomorphic XY sex chromosomes. The male‐specific region of the Y chromosome showed little conservation among the three taxa, except for the essential pollen development gene DYT1 that was confirmed as male specific by PCR in additional Nepenthes taxa. Hence, dioecy and part of the male‐specific region of the Nepenthes Y‐chromosomes likely have a single evolutionary origin.