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Functional characterization of a class III acid endochitinase from the traps of the carnivorous pitcher plant genus, Nepenthes

Carnivory in plants is an adaptation strategy to nutrient-poor environments and soils. Carnivorous plants obtain some additional mineral nutrients by trapping and digesting prey; the genus Nepenthes is helped by its specialized pitcher traps. To make the nutrients available, the caught prey needs to...

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Autores principales: Rottloff, Sandy, Stieber, Regina, Maischak, Heiko, Turini, Florian G., Heubl, Günther, Mithöfer, Axel
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3170555/
https://www.ncbi.nlm.nih.gov/pubmed/21633084
http://dx.doi.org/10.1093/jxb/err173
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author Rottloff, Sandy
Stieber, Regina
Maischak, Heiko
Turini, Florian G.
Heubl, Günther
Mithöfer, Axel
author_facet Rottloff, Sandy
Stieber, Regina
Maischak, Heiko
Turini, Florian G.
Heubl, Günther
Mithöfer, Axel
author_sort Rottloff, Sandy
collection PubMed
description Carnivory in plants is an adaptation strategy to nutrient-poor environments and soils. Carnivorous plants obtain some additional mineral nutrients by trapping and digesting prey; the genus Nepenthes is helped by its specialized pitcher traps. To make the nutrients available, the caught prey needs to be digested, a process that requires the concerted activity of several hydrolytic enzymes. To identify and investigate the various enzymes involved in this process, fluid from Nepenthes traps has been analysed in detail. In this study, a novel type of Nepenthes endochitinase was identified in the digestion fluid of closed pitchers. The encoding endochitinase genes have been cloned from eight different Nepenthes species. Among these, the deduced amino acid sequence similarity was at least 94.9%. The corresponding cDNA from N. rafflesiana was heterologously expressed, and the purified protein, NrChit1, was biochemically characterized. The enzyme, classified as a class III acid endochitinase belonging to family 18 of the glycoside hydrolases, is secreted into the pitcher fluid very probably due to the presence of an N-terminal signal peptide. Transcriptome analyses using real-time PCR indicated that the presence of prey in the pitcher up-regulates the endochitinase gene not only in the glands, which are responsible for enzyme secretion, but at an even higher level, in the glands’ surrounding tissue. These results suggest that in the pitchers’ tissues, the endochitinase as well as other proteins from the pitcher fluid might fulfil a different, primary function as pathogenesis-related proteins.
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spelling pubmed-31705552011-09-12 Functional characterization of a class III acid endochitinase from the traps of the carnivorous pitcher plant genus, Nepenthes Rottloff, Sandy Stieber, Regina Maischak, Heiko Turini, Florian G. Heubl, Günther Mithöfer, Axel J Exp Bot Research Papers Carnivory in plants is an adaptation strategy to nutrient-poor environments and soils. Carnivorous plants obtain some additional mineral nutrients by trapping and digesting prey; the genus Nepenthes is helped by its specialized pitcher traps. To make the nutrients available, the caught prey needs to be digested, a process that requires the concerted activity of several hydrolytic enzymes. To identify and investigate the various enzymes involved in this process, fluid from Nepenthes traps has been analysed in detail. In this study, a novel type of Nepenthes endochitinase was identified in the digestion fluid of closed pitchers. The encoding endochitinase genes have been cloned from eight different Nepenthes species. Among these, the deduced amino acid sequence similarity was at least 94.9%. The corresponding cDNA from N. rafflesiana was heterologously expressed, and the purified protein, NrChit1, was biochemically characterized. The enzyme, classified as a class III acid endochitinase belonging to family 18 of the glycoside hydrolases, is secreted into the pitcher fluid very probably due to the presence of an N-terminal signal peptide. Transcriptome analyses using real-time PCR indicated that the presence of prey in the pitcher up-regulates the endochitinase gene not only in the glands, which are responsible for enzyme secretion, but at an even higher level, in the glands’ surrounding tissue. These results suggest that in the pitchers’ tissues, the endochitinase as well as other proteins from the pitcher fluid might fulfil a different, primary function as pathogenesis-related proteins. Oxford University Press 2011-08 2011-06-01 /pmc/articles/PMC3170555/ /pubmed/21633084 http://dx.doi.org/10.1093/jxb/err173 Text en © 2011 The Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.5), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. This paper is available online free of all access charges (see http://jxb.oxfordjournals.org/open_access.html for further details)
spellingShingle Research Papers
Rottloff, Sandy
Stieber, Regina
Maischak, Heiko
Turini, Florian G.
Heubl, Günther
Mithöfer, Axel
Functional characterization of a class III acid endochitinase from the traps of the carnivorous pitcher plant genus, Nepenthes
title Functional characterization of a class III acid endochitinase from the traps of the carnivorous pitcher plant genus, Nepenthes
title_full Functional characterization of a class III acid endochitinase from the traps of the carnivorous pitcher plant genus, Nepenthes
title_fullStr Functional characterization of a class III acid endochitinase from the traps of the carnivorous pitcher plant genus, Nepenthes
title_full_unstemmed Functional characterization of a class III acid endochitinase from the traps of the carnivorous pitcher plant genus, Nepenthes
title_short Functional characterization of a class III acid endochitinase from the traps of the carnivorous pitcher plant genus, Nepenthes
title_sort functional characterization of a class iii acid endochitinase from the traps of the carnivorous pitcher plant genus, nepenthes
topic Research Papers
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3170555/
https://www.ncbi.nlm.nih.gov/pubmed/21633084
http://dx.doi.org/10.1093/jxb/err173
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