BACKGROUND: Species of the carnivorous family Lentibulariaceae exhibit the smallest genomes in flowering plants. We explored the hypothesis that their minute genomes result from the unique mitochondrial cytochrome c oxidase (COX) mutation. The mutation may boost mitochondrial efficiency, which is especially useful for suction-bladder traps of Utricularia, but also increase DNA-damaging reactive oxygen species, leading to genome shrinkage through deletion-biased DNA repair. We aimed to explore the impact of this mutation on genome size, providing insights into genetic mutation roles in plant genome evolution under environmental pressures. METHODS: We compiled and measured genome and mean chromosome sizes for 127 and 67 species, respectively, representing all three genera (Genlisea, Pinguicula and Utricularia) of Lentibulariaceae. We also isolated and analysed COX sequences to detect the mutation. Through phylogenetic regressions and Ornstein-Uhlenbeck models of trait evolution, we assessed the impact of the COX mutation on the genome and chromosome sizes across the family. RESULTS: Our findings reveal significant correlations between the COX mutation and smaller genome and chromosome sizes. Specifically, species carrying the ancestral COX sequence exhibited larger genomes and chromosomes than those with the novel mutation. This evidence supports the notion that the COX mutation contributes to genome downsizing, with statistical analyses confirming a directional evolution towards smaller genomes in species harbouring these mutations. CONCLUSIONS: Our study confirms that the COX mutation in Lentibulariaceae is associated with genome downsizing, probably driven by increased reactive oxygen species production and subsequent DNA damage requiring deletion-biased repair mechanisms. While boosting mitochondrial energy output, this genetic mutation compromises genome integrity and may potentially affect recombination rates, illustrating a complex trade-off between evolutionary advantages and disadvantages. Our results highlight the intricate processes by which genetic mutations and environmental pressures shape genome size evolution in carnivorous plants.

• Klíčová slova
• Genlisea, Pinguicula, Utricularia, Carnivory, Lentibulariaceae, chromosome size, cytochrome oxidase, genome size, recombination rate, smallest genomes,
• MeSH
• délka genomu * MeSH
• fylogeneze MeSH
• genom rostlinný * MeSH
• Magnoliopsida genetika   MeSH
• molekulární evoluce MeSH
• mutace MeSH
• respirační komplex IV genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• respirační komplex IV MeSH

BACKGROUND AND AIMS: Turions are vegetative, dormant overwintering organs formed in aquatic plants in response to unfavourable ecological conditions. Contents of cytokinin (CK), auxin metabolites and abscisic acid (ABA) as main growth and development regulators were compared in innately dormant autumnal turions of 22 aquatic plant species of different functional ecological or taxonomic groups with those in non-dormant winter apices in three aquatic species and with those in spring turions of four species after their overwintering. METHODS: The hormones were analysed in miniature turion samples using ultraperformance liquid chromatography coupled with triple quadrupole mass spectrometry. KEY RESULTS: In innately dormant turions, the total contents of each of the four main CK types, biologically active forms and total CKs differed by two to three orders of magnitude across 22 species; the proportion of active CK forms was 0.18-67 %. Similarly, the content of four auxin forms was extremely variable and the IAA proportion as the active form was 0.014-99 %. The ABA content varied from almost zero to 54 µmol kg-1 dry weight and after overwintering it usually significantly decreased. Of all functional traits studied, hormone profiles depended most on the place of turion sprouting (surface vs bottom) and we suggest that this trait is crucial for turion ecophysiology. CONCLUSIONS: The key role of ABA in regulating turion dormancy was confirmed. However, the highly variable pattern of the ABA content in innately dormant and in overwintered turions indicates that the hormonal mechanism regulating the innate dormancy and its breaking in turions is not uniform within aquatic plants.

• Klíčová slova
• ABA, Cytokinins, auxins, functional traits, innate and imposed dormancy, mature winter buds, overwintering, phylogenetic correction, quiescence,
• MeSH
• cytokininy * metabolismus   MeSH
• kyselina abscisová metabolismus   analýza   MeSH
• kyseliny indoloctové metabolismus   MeSH
• regulátory růstu rostlin * metabolismus   MeSH
• vegetační klid fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cytokininy * MeSH
• kyselina abscisová MeSH
• kyseliny indoloctové MeSH
• regulátory růstu rostlin * MeSH

Carnivorous plants of the genus Utricularia (bladderwort) form modified leaves into suction bladder traps. The bladders are metabolically active plant tissue with high rates of mitochondrial respiration (RD). In general, plants possess two mitochondrial electron transport pathways to reduce oxygen to water: cytochrome and an alternative. Due to the high metabolic rate in the bladders, it is tempting to assume that the bladders prefer the cytochrome c oxidative pathway. Surprisingly, we revealed that alternative oxidase (AOX), which yields only a little ATP, is much more abundant in the bladders of Utricularia reflexa in comparison with the shoots. This pattern is similar to the carnivorous plants with passive pitcher traps (e.g. Sarracenia, Nepenthes) and seems to be widespread across many carnivorous taxa. The exact role of AOX in the traps of carnivorous plants remains to be investigated.

• Klíčová slova
• Alternative oxidase, bladderwort, carnivorous plants, cytochrome c oxidase, light harvesting antennae, respiration,
• MeSH
• adenosintrifosfát MeSH
• cytochromy c * MeSH
• kyslík MeSH
• listy rostlin * MeSH
• voda MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenosintrifosfát MeSH
• cytochromy c * MeSH
• kyslík MeSH
• voda MeSH

BACKGROUND: Carnivorous plants are an ecological group of approx. 810 vascular species which capture and digest animal prey, absorb prey-derived nutrients and utilize them to enhance their growth and development. Extant carnivorous plants have evolved in at least ten independent lineages, and their adaptive traits represent an example of structural and functional convergence. Plant carnivory is a result of complex adaptations to mostly nutrient-poor, wet and sunny habitats when the benefits of carnivory exceed the costs. With a boost in interest and extensive research in recent years, many aspects of these adaptations have been clarified (at least partly), but many remain unknown. SCOPE: We provide some of the most recent insights into substantial ecophysiological, biochemical and evolutional particulars of plant carnivory from the functional viewpoint. We focus on those processes and traits in carnivorous plants associated with their ecological characterization, mineral nutrition, cost-benefit relationships, functioning of digestive enzymes and regulation of the hunting cycle in traps. We elucidate mechanisms by which uptake of prey-derived nutrients leads to stimulation of photosynthesis and root nutrient uptake. CONCLUSIONS: Utilization of prey-derived mineral (mainly N and P) and organic nutrients is highly beneficial for plants and increases the photosynthetic rate in leaves as a prerequisite for faster plant growth. Whole-genome and tandem gene duplications brought gene material for diversification into carnivorous functions and enabled recruitment of defence-related genes. Possible mechanisms for the evolution of digestive enzymes are summarized, and a comprehensive picture on the biochemistry and regulation of prey decomposition and prey-derived nutrient uptake is provided.

• Klíčová slova
• Dionaea, Drosera, Nepenthes, Carnivorous plant, co-option, cost–benefit relationships, digestive enzymes, evolution of carnivory, hunting cycle, mineral nutrient economy, regulation of enzyme secretion, terrestrial and aquatic species,
• MeSH
• fotosyntéza MeSH
• listy rostlin MeSH
• masožravci * MeSH
• rostliny * genetika   MeSH
• živiny MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: The cost-benefit model for the evolution of botanical carnivory provides a conceptual framework for interpreting a wide range of comparative and experimental studies on carnivorous plants. This model assumes that the modified leaves called traps represent a significant cost for the plant, and this cost is outweighed by the benefits from increased nutrient uptake from prey, in terms of enhancing the rate of photosynthesis per unit leaf mass or area (AN) in the microsites inhabited by carnivorous plants. SCOPE: This review summarizes results from the classical interpretation of the cost-benefit model for evolution of botanical carnivory and highlights the costs and benefits of active trapping mechanisms, including water pumping, electrical signalling and accumulation of jasmonates. Novel alternative sequestration strategies (utilization of leaf litter and faeces) in carnivorous plants are also discussed in the context of the cost-benefit model. CONCLUSIONS: Traps of carnivorous plants have lower AN than leaves, and the leaves have higher AN after feeding. Prey digestion, water pumping and electrical signalling represent a significant carbon cost (as an increased rate of respiration, RD) for carnivorous plants. On the other hand, jasmonate accumulation during the digestive period and reprogramming of gene expression from growth and photosynthesis to prey digestion optimizes enzyme production in comparison with constitutive secretion. This inducibility may have evolved as a cost-saving strategy beneficial for carnivorous plants. The similarities between plant defence mechanisms and botanical carnivory are highlighted.

• Klíčová slova
• Action potential, Dionaea, Drosera, Nepenthes, Venus flytrap, botanical carnivory, carnivorous plant, cost–benefit, electrical signalling, jasmonates,
• MeSH
• biologická evoluce * MeSH
• biologické modely * MeSH
• Droseraceae fyziologie   MeSH
• fyziologie rostlin * MeSH
• signální transdukce MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

BACKGROUND AND AIMS: Rootless carnivorous plants of the genus Utricularia are important components of many standing waters worldwide, as well as suitable model organisms for studying plant-microbe interactions. In this study, an investigation was made of the importance of microbial dinitrogen (N2) fixation in the N acquisition of four aquatic Utricularia species and another aquatic carnivorous plant, Aldrovanda vesiculosa. METHODS: 16S rRNA amplicon sequencing was used to assess the presence of micro-organisms with known ability to fix N2. Next-generation sequencing provided information on the expression of N2 fixation-associated genes. N2 fixation rates were measured following (15)N2-labelling and were used to calculate the plant assimilation rate of microbially fixed N2. KEY RESULTS: Utricularia traps were confirmed as primary sites of N2 fixation, with up to 16 % of the plant-associated microbial community consisting of bacteria capable of fixing N2. Of these, rhizobia were the most abundant group. Nitrogen fixation rates increased with increasing shoot age, but never exceeded 1·3 μmol N g(-1) d. mass d(-1). Plant assimilation rates of fixed N2 were detectable and significant, but this fraction formed less than 1 % of daily plant N gain. Although trap fluid provides conditions favourable for microbial N2 fixation, levels of nif gene transcription comprised <0·01 % of the total prokaryotic transcripts. CONCLUSIONS: It is hypothesized that the reason for limited N2 fixation in aquatic Utricularia, despite the large potential capacity, is the high concentration of NH4-N (2·0-4·3 mg L(-1)) in the trap fluid. Resulting from fast turnover of organic detritus, it probably inhibits N2 fixation in most of the microorganisms present. Nitrogen fixation is not expected to contribute significantly to N nutrition of aquatic carnivorous plants under their typical growth conditions; however, on an annual basis the plant-microbe system can supply nitrogen in the order of hundreds of mg m(-2) into the nutrient-limited littoral zone, where it may thus represent an important N source.

• Klíčová slova
• 15N2 labelling, Aldrovanda vesiculosa, N nutrition, U. australis, U. intermedia, U. reflexa, Utricularia vulgaris, aquatic carnivorous plants, daily nitrogen gain, nitrogen fixation, periphyton, traps,
• MeSH
• amoniové sloučeniny analýza   MeSH
• Bacteria genetika   izolace a purifikace   metabolismus   MeSH
• bakteriální RNA chemie   genetika   MeSH
• Droseraceae metabolismus   mikrobiologie   MeSH
• dusík metabolismus   MeSH
• ekologie MeSH
• ekosystém MeSH
• fixace dusíku * MeSH
• izotopy dusíku MeSH
• Magnoliopsida metabolismus   mikrobiologie   MeSH
• molekulární sekvence - údaje MeSH
• RNA ribozomální 16S chemie   genetika   MeSH
• sekvence nukleotidů MeSH
• sekvenční analýza RNA MeSH
• voda metabolismus   MeSH
• výhonky rostlin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• amoniové sloučeniny MeSH
• bakteriální RNA MeSH
• dusík MeSH
• izotopy dusíku MeSH
• RNA ribozomální 16S MeSH
• voda MeSH

UNLABELLED: BACKROUND AND AIMS: It has been suggested that the rate of net photosynthesis (AN) of carnivorous plants increases in response to prey capture and nutrient uptake; however, data confirming the benefit from carnivory in terms of increased AN are scarce and unclear. The principal aim of our study was to investigate the photosynthetic benefit from prey capture in the carnivorous sundew Drosera capensis. METHODS: Prey attraction experiments were performed, with measurements and visualization of enzyme activities, elemental analysis and pigment quantification together with simultaneous measurements of gas exchange and chlorophyll a fluorescence in D. capensis in response to feeding with fruit flies (Drosophila melanogaster). KEY RESULTS: Red coloration of tentacles did not act as a signal to attract fruit flies onto the traps. Phosphatase, phophodiesterase and protease activities were induced 24 h after prey capture. These activities are consistent with the depletion of phosphorus and nitrogen from digested prey and a significant increase in their content in leaf tissue after 10 weeks. Mechanical stimulation of tentacle glands alone was not sufficient to induce proteolytic activity. Activities of β-D-glucosidases and N-acetyl-β-D-glucosaminidases in the tentacle mucilage were not detected. The uptake of phosphorus from prey was more efficient than that of nitrogen and caused the foliar N:P ratio to decrease; the contents of other elements (K, Ca, Mg) decreased slightly in fed plants. Increased foliar N and P contents resulted in a significant increase in the aboveground plant biomass, the number of leaves and chlorophyll content as well as AN, maximum quantum yield (Fv/Fm) and effective photochemical quantum yield of photosystem II (ΦPSII). CONCLUSIONS: According to the stoichiometric relationships among different nutrients, the growth of unfed D. capensis plants was P-limited. This P-limitation was markedly alleviated by feeding on fruit flies and resulted in improved plant nutrient status and photosynthetic performance. This study supports the original cost/benefit model proposed by T. Givnish almost 30 years ago and underlines the importance of plant carnivory for increasing phosphorus, and thereby photosynthesis.

• Klíčová slova
• Carnivorous plant, Drosera capensis, cape sundew, cost/benefit, digestive enzymes, fruit flies, nitrogen, phosphorus, photosynthesis, sundew,
• MeSH
• chlorofyl a MeSH
• chlorofyl analýza   MeSH
• Drosera fyziologie   MeSH
• Drosophila melanogaster MeSH
• dusík metabolismus   MeSH
• enzymy metabolismus   MeSH
• fosfor metabolismus   MeSH
• fotosyntéza fyziologie   MeSH
• listy rostlin fyziologie   MeSH
• masožravci * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chlorofyl a MeSH
• chlorofyl MeSH
• dusík MeSH
• enzymy MeSH
• fosfor MeSH

Aquatic Utricularia species usually grow in standing, nutrient-poor humic waters. They take up all necessary nutrients either directly from the water by rootless shoots or from animal prey by traps. The traps are hollow bladders, 1-6 mm long with elastic walls and have a mobile trap door. The inner part of the trap is densely lined with quadrifid and bifid glands and these are involved in the secretion of digestive enzymes, resorption of nutrients and pumping out the water. The traps capture small aquatic animals but they also host a community of microorganisms considered as commensals. How do these perfect traps function, kill and digest their prey? How do they provide ATP energy for their demanding physiological functions? What are the nature of the interactions between the traps and the mutualistic microorganisms living inside as commensals? In this mini review, all of these questions are considered from an ecophysiologist's point of view, based on the most recent literature data and unpublished results. A new concept on the role of the commensal community for the plants is presented.

• MeSH
• ekosystém * MeSH
• kyslík metabolismus   MeSH
• Magnoliopsida enzymologie   fyziologie   MeSH
• potravní řetězec MeSH
• voda fyziologie   MeSH
• vodní organismy fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• kyslík MeSH
• voda MeSH

BACKGROUND AND AIMS: Species of Utricularia and Genlisea (Lentibulariaceae) are carnivorous, capturing small prey in traps which are physiologically very active, with abundant quadrifid and bifid glands. Traps of Utricularia have walls composed of two cell layers, and are filled with water. Diverse communities of commensal microorganisms often live inside the traps. Genlisea forms long, hollow subterranean traps of foliar origin, growing in anoxic wet substrate. Knowledge of the O(2) concentrations inside Utricularia and Genlisea traps is vital for understanding their physiological functioning and conditions for the life of commensals. To test the hypothesis that prey are killed by anoxia inside the traps, and to measure respiration of traps, [O(2)] was measured in the fluid in mature traps of these species. METHODS: Oxygen concentration and electrical redox potential were measured using a small Clark-type oxygen sensor and a miniature platinum electrode, respectively, in the fluid of excised and intact traps of six aquatic Utricularia species and in Genlisea hispidula traps. KEY RESULTS: Steady-state [O(2)] in the traps of both genera always approached zero (median 0.0-4.7 microm). The [O(2)] decreased after electrodes were inserted into Utricularia traps at a rate which ranged from 0.09 to 1.23 mm h(-1) and was lower in traps of irradiated and intact shoots with higher [O(2)] in shoot tissues. Redox potential ranged from -24 to -105 mV in the traps, confirming the very small or zero [O(2)]. CONCLUSIONS: Very small or zero [O(2)], effectively anoxia, is demonstrated in Utricularia and Genlisea traps. This is probably below the critical [O(2)] for prey survival, and causes captured prey to die of suffocation. Internal trap glands and trap commensals are considered to be adapted to facultative anoxia interrupted by limited periods of higher [O(2)] after firings.

• MeSH
• kyslík metabolismus   MeSH
• Magnoliopsida metabolismus   MeSH
• oxidace-redukce MeSH
• světlo MeSH
• výhonky rostlin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• kyslík MeSH