Carnivorous plants secrete digestive enzymes for prey degradation. Although carnivorous plants have a polyphyletic origin and evolved several times independently, they surprisingly co-opted similar digestive enzymes during convergent evolution. However, despite having similar digestive enzymes, the mode of their regulation strongly differs across different phylogenetic lineages. But what factors are responsible for such diversity in their digestion? By combining phylogenetic relationships of digestive fluid proteins and biochemical data, the analyses showed that phylogeny seems to be a significant factor determining the regulation of digestion, but environment (water vs terrestrial) and type of trap do not affect regulation. The oldest carnivorous plant lineage, Caryophyllales, co-opted phytohormone jasmonic acid (JA) for regulation of digestive enzyme activity. However, the remaining orders of carnivorous plants do not accumulate JA in response to prey capture, and their digestive enzyme activity is not responsive to exogenous JA application. Instead, they use different modes of regulation, for example, development/senescence, osmotically induced and constitutive. These different modes of regulation can be explained by co-option, albeit of similar genes but different paralogs with different cis regulatory elements that have been fine-tuned during evolution.

• Klíčová slova
• Venus flytrap, carnivorous plants, digestive enzymes, jasmonic acid, pitcher plant,
• MeSH
• biologická evoluce * MeSH
• cyklopentany metabolismus   MeSH
• fylogeneze MeSH
• masožravé rostliny * fyziologie   enzymologie   genetika   MeSH
• oxylipiny metabolismus   MeSH
• trávení * MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• cyklopentany MeSH
• jasmonic acid MeSH Prohlížeč
• oxylipiny MeSH

Carnivorous plants from the order Caryophyllales co-opted plant phytohormones from a group of jasmonates to regulate digestive enzyme activity. However, not all genera of carnivorous plants have been thoroughly explored, and the digestive physiology of Australian carnivorous rainbow plants of the genus Byblis (order Lamiales) is poorly understood. Here, we investigated the composition of digestive enzymes in the secreted fluid of Byblis filifolia using LC/MS, measured enzyme activity, and analysed tissue phytohormone levels after experimental feeding with fruit flies and coronatine application. Several hydrolytic digestive enzymes were identified in the secreted digestive fluid, the levels of which clearly increased in the presence of insect prey. However, in contrast to the sundew Drosera capensis, endogenous jasmonates do not accumulate, and coronatine, a molecular mimic of jasmonates, is unable to trigger enzyme secretion. Our results showed that B. filifolia is fully carnivorous, with its own digestive enzyme repertoire. However, in contrast to carnivorous genera from the Caryophyllales order, these enzymes are not regulated by jasmonates. This indicates that jasmonates have not been repeatedly co-opted to regulate digestive enzyme activity during the evolution of carnivorous plants.

• Klíčová slova
• Byblis, Carnivorous plant, Drosera, digestive enzyme, jasmonic acid, phytohormones, sundew,
• MeSH
• aminokyseliny metabolismus   farmakologie   MeSH
• Caryophyllales * enzymologie   fyziologie   metabolismus   MeSH
• cyklopentany * metabolismus   MeSH
• Drosera fyziologie   MeSH
• indeny metabolismus   farmakologie   MeSH
• masožravé rostliny * enzymologie   fyziologie   metabolismus   MeSH
• oxylipiny * metabolismus   MeSH
• regulátory růstu rostlin * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aminokyseliny MeSH
• coronatine MeSH Prohlížeč
• cyklopentany * MeSH
• indeny MeSH
• jasmonic acid MeSH Prohlížeč
• oxylipiny * MeSH
• regulátory růstu rostlin * MeSH

The carnivorous plants in the order Caryophyllales co-opted jasmonate signalling from plant defence to botanical carnivory. However, carnivorous plants have at least 11 independent origins, and here we ask whether jasmonate signalling has been co-opted repeatedly in different evolutionary lineages. We experimentally wounded and fed the carnivorous plants Sarracenia purpurea (order Ericales), Cephalotus follicularis (order Oxalidales), Drosophyllum lusitanicum (order Caryophyllales), and measured electrical signals, phytohormone tissue level, and digestive enzymes activity. Coronatine was added exogenously to confirm the role of jasmonates in the induction of digestive process. Immunodetection of aspartic protease and proteomic analysis of digestive fluid was also performed. We found that prey capture induced accumulation of endogenous jasmonates only in D. lusitanicum, in accordance with increased enzyme activity after insect prey or coronatine application. In C. follicularis, the enzyme activity was constitutive while in S. purpurea was regulated by multiple factors. Several classes of digestive enzymes were identified in the digestive fluid of D. lusitanicum. Although carnivorous plants from different evolutionary lineages use the same digestive enzymes, the mechanism of their regulation differs. All investigated genera use jasmonates for their ancient role, defence, but jasmonate signalling has been co-opted for botanical carnivory only in some of them.

• Klíčová slova
• Aspartic protease, carnivorous plant, digestive enzymes, electrical signal, jasmonic acid, phytohormone, plant defence, wounding,
• MeSH
• masožravci * MeSH
• masožravé rostliny * MeSH
• proteomika MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• coronatine MeSH Prohlížeč
• jasmonic acid MeSH Prohlížeč

In his famous book Insectivorous plants, Charles Darwin observed that the bending response of tentacles in the carnivorous sundew plant Drosera rotundifolia was not triggered by a drop of water, but rather the application of many dissolved chemicals or mechanical stimulation. In this study, we tried to reveal this 150-years-old mystery using methods not available in his time. We measured electrical signals, phytohormone tissue level, enzyme activities and an abundance of digestive enzyme aspartic protease droserasin in response to different stimuli (water drop, ammonia, mechanostimulation, chitin, insect prey) in Cape sundew (Drosera capensis). Drops of water induced the lowest number of action potentials (APs) in the tentacle head, and accumulation of jasmonates in the trap was not significantly different from control plants. On the other hand, all other stimuli significantly increased jasmonate accumulation; the highest was found after the application of insect prey. Drops of water also did not induce proteolytic activity and an abundance of aspartic protease droserasin in contrast to other stimuli. We found that the tentacles of sundew plants are not responsive to water drops due to an inactive jasmonic acid signalling pathway, important for the induction of significant digestive enzyme activities.

• Klíčová slova
• abscisic acid, aspartic protease, carnivorous plant, digestive enzyme, jasmonic acid, sundew,
• Publikační typ
• časopisecké články MeSH

• MeSH
• biologická evoluce * MeSH
• masožravé rostliny * MeSH
• smyslové orgány MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND AND AIMS: The carnivorous pitcher plants of the genus Nepenthes have evolved modified leaves that act as pitcher traps. The traps are specialized for prey attraction, capture, digestion and nutrient uptake but not for photosynthetic assimilation. METHODS: In this study, we used antibodies against different photosynthetic (D1, Lhcb2, Lhcb4, RbcL) and respiratory-related (AOX, COXII) proteins for semi-quantification of these proteins in the assimilation part of the leaves and the pitcher traps of different Nepenthes species and hybrids. Different functional zones of the trap and the traps from different ontogenetic stages were investigated. The pitcher traps of the distantly related species Sarracenia purpurea ssp. venosa were used as an outgroup. In addition, chlorophyll fluorescence and infrared gas analysis were used for measurements of the net rate of photosynthesis (AN) and respiration in the dark (RD). KEY RESULTS: The pitcher traps contained the same or lower abundance of photosynthesis-related proteins in accordance with their low AN in comparison to the assimilation part of the leaves. Surprisingly, all traps contained a high amount of alternative oxidase (AOX) and low amount of cytochrome c oxidase subunit II (COX II) than in the assimilation part of the leaves. Thermal imaging did not confirm the role of AOX in pitcher thermogenesis. CONCLUSIONS: The pitcher traps contain a high amount of AOX enzyme. The possible role of AOX in specialized pitcher tissue is discussed based on knowledge of the role and function of AOX in non-carnivorous plants. The roles of AOX in prey attraction, balance between light and dark reactions of photosynthesis, homeostasis of reactive oxygen species, digestive physiology and nutrient assimilation are discussed.

• Klíčová slova
• Nepenthes, Sarracenia purpurea, Alternative oxidase, carnivorous plant, cytochrome c oxidase, photosynthesis, pitcher plant, respiration,
• MeSH
• masožravé rostliny * MeSH
• mitochondriální proteiny MeSH
• organické látky MeSH
• oxidoreduktasy MeSH
• rostlinné proteiny metabolismus   MeSH
• Sarraceniaceae * metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alternative oxidase MeSH Prohlížeč
• mitochondriální proteiny MeSH
• nepenthe MeSH Prohlížeč
• organické látky MeSH
• oxidoreduktasy MeSH
• rostlinné proteiny MeSH