Nepenthesin protease activity indicates digestive fluid dynamics in carnivorous nepenthes plants.
Carnivorous plants use different morphological features to attract, trap and digest prey, mainly insects. Plants from the genus Nepenthes possess specialized leaves called pitchers that function as pitfall-traps. These pitchers are filled with a digestive fluid that is generated by the plants themselves. In order to digest caught prey in their pitchers, Nepenthes plants produce various hydrolytic enzymes including aspartic proteases, nepenthesins (Nep). Knowledge about the generation and induction of these proteases is limited. Here, by employing a FRET (fluorescent resonance energy transfer)-based technique that uses a synthetic fluorescent substrate an easy and rapid detection of protease activities in the digestive fluids of various Nepenthes species was feasible. Biochemical studies and the heterologously expressed Nep II from Nepenthes mirabilis proved that the proteolytic activity relied on aspartic proteases, however an acid-mediated auto-activation mechanism was necessary. Employing the FRET-based approach, the induction and dynamics of nepenthesin in the digestive pitcher fluid of various Nepenthes plants could be studied directly with insect (Drosophila melanogaster) prey or plant material. Moreover, we observed that proteolytic activity was induced by the phytohormone jasmonic acid but not by salicylic acid suggesting that jasmonate-dependent signaling pathways are involved in plant carnivory.
Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, D-07745, Jena, Germany.
Franziska
F
Buch
Department of Medical Microbiology and Infectious Diseases, Erasmus MC, `s-Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands; Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and VU University Amsterdam, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands.
Wendy E
WE
Kaman
Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and VU University Amsterdam, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands.
Floris J
FJ
Bikker
Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, D-07745, Jena, Germany.
Ayufu
A
Yilamujiang
Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, D-07745, Jena, Germany.
Axel
A
Mithöfer
D057055:Aspartic Acid Proteases / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D003517:Cyclopentanes / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D020387:Food Chain; D019684:Magnoliopsida / Q000201:enzymology* / Q000502:physiology*; D054883:Oxylipins / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D020156:Salicylic Acid / Q000378:metabolism; D013379:Substrate Specificity
D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; C011006:jasmonic acid; D057055:Aspartic Acid Proteases; D020156:Salicylic Acid