Digestive Enzymes in Insectivorous Plants*

Amagase, Shizuko

doi:10.1093/oxfordjournals.jbchem.a129899

Cited by 49 publications

(10 citation statements)

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“…These enzymes in part originate from the plant itself, where they are secreted by digestive cellular glands that are located in the surface of the lower zone within the pitcher [8], [9]. The characteristics of the enzymes derived from the Nepenthes species have been investigated in previous studies, and the enzymes include at least proteases [10]–[12], chitinases [12], [13], phosphatases [8], [14], and glucosidases [14].…”

Section: Introductionmentioning

confidence: 99%

In Situ Enzyme Activity in the Dissolved and Particulate Fraction of the Fluid from Four Pitcher Plant Species of the Genus Nepenthes

et al. 2011

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The genus Nepenthes, a carnivorous plant, has a pitcher to trap insects and digest them in the contained fluid to gain nutrient. A distinctive character of the pitcher fluid is the digestive enzyme activity that may be derived from plants and dwelling microbes. However, little is known about in situ digestive enzymes in the fluid. Here we examined the pitcher fluid from four species of Nepenthes. High bacterial density was observed within the fluids, ranging from 7×106 to 2.2×108 cells ml−1. We measured the activity of three common enzymes in the fluid: acid phosphatases, β-d-glucosidases, and β-d-glucosaminidases. All the tested enzymes detected in the liquid of all the pitcher species showed activity that considerably exceeded that observed in aquatic environments such as freshwater, seawater, and sediment. Our results indicate that high enzyme activity within a pitcher could assist in the rapid decomposition of prey to maximize efficient nutrient use. In addition, we filtered the fluid to distinguish between dissolved enzyme activity and particle-bound activity. As a result, filtration treatment significantly decreased the activity in all enzymes, while pH value and Nepenthes species did not affect the enzyme activity. It suggested that enzymes bound to bacteria and other organic particles also would significantly contribute to the total enzyme activity of the fluid. Since organic particles are themselves usually colonized by attached and highly active bacteria, it is possible that microbe-derived enzymes also play an important role in nutrient recycling within the fluid and affect the metabolism of the Nepenthes pitcher plant.

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Section: Introductionmentioning

confidence: 99%

In Situ Enzyme Activity in the Dissolved and Particulate Fraction of the Fluid from Four Pitcher Plant Species of the Genus Nepenthes

et al. 2011

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“…When an insect becomes stuck to the adhesive bubble, the movement of the insect generates a series of action potentials along with the tentacles, which trigger the tentacles to bend inward [2,3]. The bending brings the insect into a closer contact with other tentacles, including shorter specialized tentacles that further trigger the leaf to secrete digestive enzymes [4-9]. Digestion serves as a signal to release hormones that allow the leaf blade to curl tightly around the prey for complete digestion and absorption of nutrients [10].…”

Section: Introductionmentioning

confidence: 99%

Nanofibers and nanoparticles from the insect-capturing adhesive of the Sundew (Drosera) for cell attachment

Zhang

Lenaghan

Xia

et al. 2010

Journal of Nanobiotechnology

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BackgroundThe search for naturally occurring nanocomposites with diverse properties for tissue engineering has been a major interest for biomaterial research. In this study, we investigated a nanofiber and nanoparticle based nanocomposite secreted from an insect-capturing plant, the Sundew, for cell attachment. The adhesive nanocomposite has demonstrated high biocompatibility and is ready to be used with minimal preparation.ResultsAtomic force microscopy (AFM) conducted on the adhesive from three species of Sundew found that a network of nanofibers and nanoparticles with various sizes existed independent of the coated surface. AFM and light microscopy confirmed that the pattern of nanofibers corresponded to Alcian Blue staining for polysaccharide. Transmission electron microscopy identified a low abundance of nanoparticles in different pattern form AFM observations. In addition, energy-dispersive X-ray spectroscopy revealed the presence of Ca, Mg, and Cl, common components of biological salts. Study of the material properties of the adhesive yielded high viscoelasticity from the liquid adhesive, with reduced elasticity observed in the dried adhesive. The ability of PC12 neuron-like cells to attach and grow on the network of nanofibers created from the dried adhesive demonstrated the potential of this network to be used in tissue engineering, and other biomedical applications.ConclusionsThis discovery demonstrates how a naturally occurring nanofiber and nanoparticle based nanocomposite from the adhesive of Sundew can be used for tissue engineering, and opens the possibility for further examination of natural plant adhesives for biomedical applications.

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“…Nepenthesin (Nep) [5,6] is an acid proteinase secreted in the pitcher of Nepenthes species. So far, the acid proteinases from Nepenthes and Drosera species were only partially purified and poorly characterized [7][8][9][10][11][12]. Although they were shown to be members of aspartic proteinases (APs) [9,11], none of the enzymes secreted from carnivorous plants *Address correspondence to this author at the Laboratory of Molecular Biochemistry, School of Life Science, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan; Fax: +81-426-76-7149; E-mail: kenjitak@ls.toyaku.ac.jp…”

Section: Introductionmentioning

confidence: 99%

Nepenthesin, a Unique Member of a Novel Subfamily of Aspartic Proteinases: Enzymatic and Structural Characteristics

Takahashi

Athauda²,

Matsumoto³

et al. 2005

CPPS

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Carnivorous plants are known to secrete acid proteinases to digest prey, mainly insects, for nitrogen uptake. In our recent study, we have purified, for the first time, to homogeneity two acid proteinases, nepenthesin I (Nep I) and nepenthesin II (Nep II) from the pitcher fluid of Nepenthes distillatoria and investigated their enzymatic and structural characteristics. Both enzymes were optimally active at pH approx. 2.6 toward acid-denatured hemoglobin; the specificity of Nep I toward oxidized insulin B chain appears to be similar, but slightly wider than those of other aspartic proteinases (APs). At or below 50 degrees C both enzymes were remarkably stable; especially Nep I was extremely stable over a wide range of pH from 3 to 10 for over 30 days. This suggests an evolutionary adaptation of the enzymes to their specific habitat. We have also cloned the cDNAs and deduced the complete amino acid sequences of the precursors of Nep I and Nep II from the pitcher tissue of Nepenthes gracilis. Although the corresponding mature enzymes are homologous with ordinary pepsin-type APs, both enzymes had a high content of cysteine residues (12 residues per molecule), which are assumed to form six unique disulfide bonds as suggested by computer modeling and are thought to contribute toward the remarkable stability of Neps. Moreover, the amino acid sequence identity of Neps with ordinary APs, including plant vacuolar APs, are remarkably low (approx. 20%), and phylogenetic comparison shows that Neps are distantly related to them to form a novel subfamily of APs with a high content of cysteine residues and a characteristic insertion, named 'the Nep-type AP (NAP)-specific insertion', including a large number of novel, orthologous plant APs emerging in the gene/protein databases.

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Digestive Enzymes in Insectivorous Plants*

Cited by 49 publications

References 0 publications

In Situ Enzyme Activity in the Dissolved and Particulate Fraction of the Fluid from Four Pitcher Plant Species of the Genus Nepenthes

In Situ Enzyme Activity in the Dissolved and Particulate Fraction of the Fluid from Four Pitcher Plant Species of the Genus Nepenthes

Nanofibers and nanoparticles from the insect-capturing adhesive of the Sundew (Drosera) for cell attachment

Nepenthesin, a Unique Member of a Novel Subfamily of Aspartic Proteinases: Enzymatic and Structural Characteristics

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