Root Oxygen Research Articles

A fast, efficient and high-throughput procedure involving laser microdissection and RT droplet digital PCR for tissue-specific expression profiling of rice roots

BackgroundIn rice, the cortex and outer tissues play a key role in submergence tolerance. The cortex differentiates into aerenchyma, which are air-containing cavities that allow the flow of oxygen from shoots to roots, whereas exodermis suberification and sclerenchyma lignification limit oxygen loss from the mature parts of roots by forming a barrier to root oxygen loss (ROL). The genes and their networks involved in the cellular identity and differentiation of these tissues remain poorly understood. Identification and characterization of key regulators of aerenchyma and ROL barrier formation require determination of the specific expression profiles of these tissues.ResultsWe optimized an approach combining laser microdissection (LM) and droplet digital RT-PCR (ddRT-PCR) for high-throughput identification of tissue-specific expression profiles. The developed protocol enables rapid (within 3 days) extraction of high-quality RNA from root tissues with a low contamination rate. We also demonstrated the possibility of extracting RNAs from paraffin blocks stored at 4 °C without any loss of quality. We included a detailed troubleshooting guide that should allow future users to adapt the proposed protocol to other tissues and/or species. We demonstrated that our protocol, which combines LM with ddRT-PCR, can be used as a complementary tool to in situ hybridization for tissue-specific characterization of gene expression even with a low RNA concentration input. We illustrated the efficiency of the proposed approach by validating three of four potential tissue-specific candidate genes detailed in the RiceXpro database.ConclusionThe detailed protocol and the critical steps required to optimize its use for other species will democratize tissue-specific transcriptome approaches combining LM with ddRT-PCR for analyses of plants.

Assembly and variation of root-associated microbiota of rice during their vegetative growth phase with and without lindane pollutant

Soil-derived microbiota associated with plant roots are conducive to plant growth and stress resistance. However, the spatio-temporal dynamics of microbiota in response to organochlorine pollution during the unstable vegetative growth phase of rice is not well understood. In this study, we focused on the rice (Oryza sativa L.) microbiota across the bulk soil, rhizosphere and endosphere compartments during the vegetative growth phase in two different soils with and without lindane pollutant. The results showed that the factors of growth time, soil types and rhizo-compartments had significant influence on the microbial communities of rice, while lindane mostly stimulated the construction of endosphere microbiota at the vegetative phase. Active rice root-soil-microbe interactions induced an inhibition effect on lindane removal at the later vegetative growth phase in rice-growth-dependent anaerobic condition, likely due to the root oxygen loss and microbial mediated co-occurring competitive electron-consuming redox processes in soils. Each rhizo-compartment owned distinct microbial communities, and therefore, presented specific ecologically functional categories, while the moderate functional differences were also affected by plants species and residual pollution stress. This work revealed the underground micro-ecological process of microbiota and especially their potential linkage to the natural attenuation of residual organochlorine such as lindane.

Metabolic Responses to Waterlogging Differ between Roots and Shoots and Reflect Phloem Transport Alteration in Medicago truncatula.

Root oxygen deficiency that is induced by flooding (waterlogging) is a common situation in many agricultural areas, causing considerable loss in yield and productivity. Physiological and metabolic acclimation to hypoxia has mostly been studied on roots or whole seedlings under full submergence. The metabolic difference between shoots and roots during waterlogging, and how roots and shoots communicate in such a situation is much less known. In particular, the metabolic acclimation in shoots and how this, in turn, impacts on roots metabolism is not well documented. Here, we monitored changes in the metabolome of roots and shoots of barrel clover (Medicago truncatula), growth, and gas-exchange, and analyzed phloem sap exudate composition. Roots exhibited a typical response to hypoxia, such as γ-aminobutyrate and alanine accumulation, as well as a strong decline in raffinose, sucrose, hexoses, and pentoses. Leaves exhibited a strong increase in starch, sugars, sugar derivatives, and phenolics (tyrosine, tryptophan, phenylalanine, benzoate, ferulate), suggesting an inhibition of sugar export and their alternative utilization by aromatic compounds production via pentose phosphates and phosphoenolpyruvate. Accordingly, there was an enrichment in sugars and a decline in organic acids in phloem sap exudates under waterlogging. Mass-balance calculations further suggest an increased imbalance between loading by shoots and unloading by roots under waterlogging. Taken as a whole, our results are consistent with the inhibition of sugar import by waterlogged roots, leading to an increase in phloem sugar pool, which, in turn, exert negative feedback on sugar metabolism and utilization in shoots.

Dual role of macrophytes in constructed wetland-microbial fuel cells using pyrrhotite as cathode material: A comparative assessment

In the recent years many studies have shown that wetland plants play beneficial roles in bioelectricity enhancement in constructed wetland-microbial fuel cell (CW-MFC) because of the exudation of root oxygen and root exudates. In this study, the long-term roles of plants on the bioelectricity generation and contaminant removal were investigated in multi-anode (Anode1 and Anode2) and single cathode CW-MFCs. The electrode distances were 20 cm between Anode1-cathode and 10 cm between Anode2-cathode, respectively. Additionally, the employment of natural conductive pyrrhotite mineral as cathode material was firstly investigated in CW-MFC system. A cathode potential of −98 ± 52 mV to −175 ± 60 mV was achieved in the unplanted (CW-MFC 1), and planted CW-MFCs with Iris pseudacorus (CW-MFC 2), Lythrum salicaria (CW-MFC 3), and Phragmites australis (CW-MFC 4). The maximum power densities of Anode1-cathode and Anode2-cathode were 8.23 and 15.29 mW/m2 in CW-MFC 1, 8.51 and 1.67 mW/m2 in CW-MFC 2, 5.67 and 3.15 mW/m2 in CW-MFC 3, and 7.59 and 14.71 mW/m2 in CW-MFC 4, respectively. Interestingly, smaller power density was observed at Anode2-cathode, which has shorter electrode distance than Anode1-cathode in both CW-MFC 2 and CW-MFC 3, which indicates the negative role of oxygen released from the flourished plant roots at Anode2 micro-environment in power production. Therefore, recovering power from commercial CW-MFCs with flourished plants will be a challenge. The contradiction between keeping short electrode distance and avoiding the interference from plant roots to maintain anaerobic anode may be solved by the proposed modular CW-MFCs.

Root oxygen mitigates methane fluxes in tropical peatlands

Tropical peatlands are a globally important source of methane, a potent greenhouse gas. Vegetation is critical in regulating fluxes, providing a conduit for emissions and regular carbon inputs. However, plant roots also release oxygen, which might mitigate methane efflux through oxidation prior to emission from the peat surface. Here we show, using in situ mesocosms, that root exclusion can reduce methane fluxes by a maximum of 92% depending on species, likely driven by the significant decrease in root inputs of oxygen and changes in the balance of methane transport pathways. Methanotroph abundance decreased with reduced oxygen input, demonstrating a likely mechanism for the observed response. These first methane oxidation estimates for a tropical peatland demonstrate that although plants provide an important pathway for methane loss, this can be balanced by the influence of root oxygen inputs that mitigate peat surface methane emissions.

Synergistic control of internal phosphorus loading from eutrophic lake sediment using MMF coupled with submerged macrophytes

Sediment phosphorus (P) is the main source of endogenous P for lake eutrophication. An in-situ combined technology for determination the removal effect of sediment P in all fractions was first developed using the novel modified maifanite (MMF) and submerged macrophytes in this study. MMF was synthesized using an acidification process (2.5 mol/L H2SO4) and then a calcination (400 °C) method. The morphology and structure of MMF were characterized by XRD, SEM, XPS, and BET. We tested the removal effects of sediment P by MMF and submerged macrophytes in combination and separately. The results demonstrated that the synergistic removal capacity of sediment P using MMF coupled with submerged macrophytes was higher than the sum of them applied separately. MMF could promote the submerged macrophytes growth and enhance the adsorption of extra P on MMF through root oxygenation and nutrient allocation. The microcosm experiment results showed that sediment from fMMF+V. spiralis exhibited the most microbial diversity and abundance among the sediment. The combination of MMF and submerged macrophytes increased the Firmicutes abundance and decreased the Bacteroidetes. These results indicated that adsorption-biological technology can be regarded as a novel and competitive technology to the endogenous pollution control in eutrophic shallow lakes.

Behavior assessment of sulfonamides and N4-acetyl sulfonamides from wastewater effluent in subsurface constructed wetlands: Removal, distribution, and biotransformation

Wastewater treatment plant (WWTP) is the point source of antibiotic contamination, yet the removal of antibiotics from WWTP effluent has not been given necessary attention. In this study, subsurface constructed wetlands (SCWs) were used to investigate the removal, distribution, and biotransformation of sulfonamides (SAs) and their N4-acetyl sulfonamides (Ac-SAs) from wastewater effluent. The results showed that SCWs was demonstrated as capable for removing SAs with their Ac-SAs efficiently from WWTP effluent. The removal of SAs was significantly impacted by the occurrence of biotransformation behavior of SAs, not only SAs degraded into Ac-SAs, but also some Ac-SAs converted into SAs. Microbial aerobic degradation is the major removal pathway of SAs and Ac-SAs in the SCWs. SCW configuration such as vertical flow is conductive to the oxygen transport inside system and therefore promote the aerobic process of contaminants. Plants also play an important role on affecting the temporal and spatial variation of SAs through rhizosphere effect, i.e. accumulating SAs in the vegetation biomass by plant uptake and transpiration, concentrating SAs in the root zone by rhizosphere sorption and interception, and enhancing microbial influence on their aerobic decomposition by root oxygen release. The knowledge obtained in this study will be helpful for advanced purification of WWTP discharge and bioremediation of antibiotic contamination.

Evidence of a trade-off between root aeration and architecture in Vallisneria natans in the presence of Pseudomonas putida KT2440

In this work, we investigated the relationship between root plasticity and root oxygen dynamics in the presence of plant growth-promoting rhizobacteria (PGPR). A gnotobiotic system was used to study how the root architecture, radial O2-loss patterns, and internal O2 transport of the eelgrass Vallisneria natans (Hydrocharitaceae) changed in response to inoculation with a common soil PGPR, Pseudomonas putida (KT2440). Our results showed no radial O2-loss barrier in the roots of V. natans, meaning that the entire root surface exhibited the same capacity for O2 release. However, this morphological trait stimulated external oxygen demand in KT2440, thus reducing internal root O2 transport. Moreover, the distribution of root hairs (RHs), which was modified by exposure to KT2440, also significantly impacted internal O2 transport. The altered RH distribution minimized oxygen loss on the upper half of the root, and dense adventitious roots with overlapping rhizospheres enabled a highly oxygenated zone around the root base. Thus, these changes protect roots against low oxygen conditions. Furthermore, the presence of many RHs on the roots’ lower halves can increase nutrient absorption from anoxic sediments. In conclusion, this study demonstrates a complex trade-off between root aeration and architecture in V. natans that may help this plant adapt to submerged conditions when KT2440 is present.

Intraspecific facilitation explains the persistence of Phragmites australis in modified coastal wetlands

AbstractCoastal exploitation and human‐mediated modifications have markedly altered the community composition and functioning of coastal wetlands worldwide. Although recent work has shown that harnessing positive density‐dependent feedbacks can greatly enhance the recovery of habitat‐modifying species in degraded wetlands, the role of these intraspecific feedbacks in explaining the persistence of altered, unfavorable plant communities remains largely unexplored. Here, we experimentally tested whether intraspecific facilitation may explain the persistence of common reed (Phragmites australis) in human‐modified coastal wetlands. We performed a full‐factorial mesocosm experiment crossing low‐density pioneer versus high‐density established development stages with saline (20 psu) versus freshwater conditions. Results showed a clear shift in plant growth response from intraspecific competition under freshwater conditions to self‐facilitation in saline treatments. We identified two positive feedback mechanisms enabling the established treatment to overcome salinity stress: (1) Enhanced root oxygenation of the sediment at higher plant density decreased accumulation and intrusion of phytotoxic sulfide, and (2) density‐dependent rainwater infiltration into the soil lowered salinity in the dense root mat, preventing salt stress. Our study demonstrates that intraspecific facilitation can be an important factor in explaining the persistence of Phragmites australis in coastal wetlands. We emphasize the importance of integrating positive interactions in coastal restoration but argue that they should either be harnessed when restoring vegetation or broken when eradication of nontarget species is the management objective.

Post-harvest performance of ready-to-eat wild rocket salad as affected by growing period, soilless cultivation system and genotype

The present study focuses on the effect of growing period (autumn-winter and winter-spring), soilless cultivation system (floating system and ebb and flow system) and genotype (‘Naturelle’ and ‘Nature’) on the post-harvest performance of wild rocket salad.Changes in bio-physical characteristics (weight losses, main colour indices, the concentration of dry matter and chlorophylls), physiological characteristics (relative water content, osmotic potential, electrolytic leakage), antioxidant compounds (vitamin C, phenolic compounds, carotenoids), glucosinulates, and activity of antioxidant enzymes (CAT-catalase; APX-ascorbate peroxidase; SOD-superoxide dismutase; GR-glutathione reductase) were evaluated in wild rocket salad after 7 days of cold storage.Wild rocket salad grown under winter spring conditions and in a floating system was more prone to post-harvest quality decay as highlighted by higher electrolyte leakage and osmotic potential, and lower relative water content, greater weight losses due to respiration activity, and a rapid breakdown of colour to yellowness. A higher shelf-life of the product grown under less photo-thermal stressing condition (autumn-winter cycle) was attributable to less physiologically stressed raw material and to a rise in non-enzymatic antioxidant compounds, namely carotenoids, phenols, and vitamin C (ascorbic acid), all effective at contrasting oxidative stress during storage. The higher shelf-life of the product grown in an ebb and flow system (lower losses of mass and lower visual decay) and of ‘Nature’ (a higher retention of the green colour) under autumn-winter conditions, seems to be imputable both to a higher efficiency of antioxidant enzyme activity (APX and CAT) and to a greater content of antioxidant compounds, mainly carotenoids. The role of individual glucosinolates in delaying senescence was only observed as a genotype-specific response of ‘Nature’ to the root oxygen limitation occurring with the floating system.

Methylated Thioarsenates and Monothioarsenate Differ in Uptake, Transformation, and Contribution to Total Arsenic Translocation in Rice Plants.

Methylated and inorganic thioarsenates have recently been reported from paddy fields besides the better-known oxyarsenates. Methylated thioarsenates are highly toxic for humans, yet their uptake, transformation, and translocation in rice plants is unknown. Here, hydroponic experiments with 20 day old rice plants showed that monomethylmonothioarsenate (MMMTA), dimethylmonothioarsenate (DMMTA), and monothioarsenate (MTA) were taken up by rice roots and could be detected in the xylem. Total arsenic (As) translocation from roots to shoots was higher for plants exposed to DMMTA, MTA, and dimethylarsenate (DMAV) compared to MMMTA and monomethylarsenate (MMAV). All thioarsenates were partially transformed in the presence of rice roots, but processes and extents differed. MMMTA was subject to abiotic oxidation and largely dethiolated to MMAV already outside the plant, probably due to root oxygen loss. DMMTA and MTA were not oxidized abiotically. Crude protein extracts showed rapid enzymatic reduction for MTA but not for DMMTA. Our study implies that DMMTA has the highest potential to contribute to total As accumulation in grains either as DMAV or partially as DMMTA. DMMTA has once been detected in rice grains using enzymatic extraction. By routine acid extraction, DMMTA is determined as DMAV and thus escapes regulation despite its toxicity.

Use of XRD and SEM/EDX to predict age and sex from fire-affected dental remains.

In fire scenarios, the application and accuracy of traditional odontological methods are often limited. Crystalline studies and elemental profiling have been evaluated for their applicability in determining biological profiles (age and sex) from human dentition, particularly fire- and heat-affected dental remains. Thirty-seven teeth were paired according to tooth type and donor age/sex for the analysis of crown and root surfaces pre- and post-incineration using X-ray diffraction (XRD) and scanning electron microscopy (SEM/EDX). In unburned crowns, carbon (C) content showed a positive correlation with age, whereas phosphorus (P) and calcium (Ca) contents showed a negative correlation with age. In unburned roots, C, P and Ca contents also showed significant changes that were opposite of those observed in the crowns. In relation to sex, females exhibited a higher C ratio than males, whereas males showed significantly higher levels of oxygen (O), P and Ca in unburned roots. Incineration resulted in an increase in the crystallite size that correlated with increasing temperature. No differences in hydroxyapatite (HA) crystallite size were found between age groups; however, unburned teeth from females exhibited a larger crystallite size than did those from males. The challenges of using XRD with a 3D sample were overcome to allow analysis of whole teeth in a nondestructive manner. Further studies may be useful in helping predict the temperature of a fire.

Treatment of Anaerobic Digester Effluent Using Acorus calamus: Effects on Plant Growth and Tissue Composition.

The responses of Acorus calamus under greenhouse conditions for 56 days when exposed to three dilutions (25%, 50%, and undiluted) of anaerobic digester effluent from a swine farm were determined. Plant growth, morphology, pigments, and minerals in plant tissues as well as water quality were investigated. The plants grew well in all concentrations of anaerobic digester effluent with no statistically significant effects on plant growth and morphology, and without any toxicity symptoms. The NH4+ concentrations in leaves and roots and the NO3− concentrations in leaves as well as the nitrogen, phosphorus, and potassium concentrations in the plant tissues increased with increasing effluent concentration. The nutrients in the anaerobic digester effluent were removed effectively (NH4-N > 99% removal; PO4-P > 80% removal), with highest removal rates in the undiluted digester effluent. The removal of total suspended solids (>80% in 42 days) and chemical oxygen demand (37–53%) were lower. The dissolved oxygen concentration in the anaerobic digester effluent increased overtime, probably because of root oxygen release. It is concluded that Acorus calamus could be a promising species for treating high-strength wastewater with high nutrient concentrations, such as effluents from anaerobic digesters as well as other types of agricultural wastewaters.

Synergistic removal effect of P in sediment of all fractions by combining the modified bentonite granules and submerged macrophyte

The removal efficiency of sediment phosphorus (P) with the in-situ synergistic effect of modified bentonite granules (MBG) and Vallisneria spiralis (V. spiralis) in West Lake, Hangzhou, China was investigated for the first time in the study. CMBG-Na10-450 (nitrification (10% Na2CO3)-calcination (450 °C) combined modification) was prepared and characterized, and the removal effects of sediment P of all fractions with CMBG-Na10-450 and V. spiralis in combination and separately were evaluated in batch experiments. Results showed that CMBG-Na10-450 could promote the growth of V. spiralis, and the residual P of the sediment not adsorbed on CMBG-Na10-450 was changed through root oxygenation and nutrition allocation, and then enhanced the extra P adsorption on CMBG-Na10-450. The combination of MBG and V. spiralis exhibited a synergistic removal effect higher than the summation of MBG and V. spiralis applied separately. The results of microcosm experiments showed that the combination of CMBG-Na10-450 and V. spiralis enhanced the function of P metabolism by increasing the special genus that belongs to the family Erysipelotrichaceae.

Study on gas exchange and antioxidant system of solanaceous species under water logged conditions

The aim of our work is to study gas exchange and antioxidant system in nine wild solanaceous species Solanum indicum, Solanum macrocarpon, Solanum acculeatissimum, Solanum sysimbrifolium, Solanum nigrum, Solanum viarum, Solanum insimum Solanum torvum, and Solanum macranthum under water logging condition. Experiments were laid in factorial completely randomized design with three replications. Photosynthesis and stomatal conductance decreased and closure of stomata was quick during flooding conditions in all the Solanum species. Species Solanum torvum performed photosynthetically better under flooding and also had better stomatal conductance. The antioxidants like SOD, catalase and peroxidase activity was significantly increased during the period of waterlogging and lipid peroxidation (MDA) content was decreased in tolerant Solanum species. An increase in the some parameters associated with oxidative stress, namely peroxides production, lipid peroxidation, and electrolyte leakage, reveals that root oxygen deficiency caused photooxidative damage in all rootstocks of solanaceous species. The ability to maintain a balance between the formation and detoxification of activated oxygen species appeared likely to increase the survival potential and the tolerance of the plants against varying oxidative stress. On basis of our observation, we conclude that species with higher photosynthetic rate and antioxidant system had improved waterlogging stress tolerance.

Pilot-scale demonstration of phytoremediation of PAH-contaminated sediments by Hydrilla verticillata and Vallisneria spiralis

ABSTRACTThe results of phytoremediation of sediments contaminated with polycyclic aromatic hydrocarbons (PAHs) by two submerged aquatic plants (Vallisneria spiralis and Hydrilla verticillata) at pilot scale were reported for the first time in this study. During a 108-day period, the plants grew well, and more PAHs were dissipated in planted sediments than in unplanted sediments. At the end, dissipation ratios of phenanthrene and pyrene were 85.9% and 79.1% in sediments planted with V. spiralis, 76.3% and 64.6% in sediments planted with H. verticillata, but only 64.8% and 55.8% in unplanted sediments. V. spiralis exhibited higher phytoremediation ability, which was significantly related to its root oxygenation as indicated by the redox potential in sediments. The remediation results at pilot scale were also compared with those previously obtained in our laboratory. The ratio of root weight to sediment weight showed a similar trend to PAH dissipation enhancement. Bioconcentration factors of PAHs in the two plants were larger in the pilot experiment than in the laboratory tests as a result of quicker increase of plant weight in the pilot experiment.

Physiological basis of maize growth and productivity–A review†

In recent years, major research activities have been directed on the physiological basis of maize growth and productivity. With respect to vegetative growth, researches have been undertaken on leaf development, distribution of oxygen in roots, growth analysis and factors influencing these activities. Besides, several modelling approaches have been undertaken for the prediction of grain yield. With respect to reproductive growth, major attentions have been given on the development of floral meristem, the effect of silk age on fertilisation and pollination. Some studies have been undertaken on transpiration, photosynthesis, oxidative stress, phototropism, tocopherol, water management, drought stress, salinity tolerance, cold tolerance and mineral nutritions. Very few studies have been undertaken for the selection of the genotypes resistant to these stress factors. Among these, a great emphasis has been given on photosynthesis. All these phenomena are directly or indirectly related with maize productivity. There is a great necessity to formulate adequate strategies for managing the crop under adverse agro-climatic conditions and the selection of crop cultivars for adaptation under these adverse situations.

A Hardy Plant Facilitates Nitrogen Removal via Microbial Communities in Subsurface Flow Constructed Wetlands in Winter.

The plants effect in subsurface flow constructed wetlands (SSF-CWs) is controversial, especially at low temperatures. Consequently, several SSF-CWs planted with Iris pseudacorus (CWI) or Typha orientalis Presl. (CWT) and several unplanted ones (CWC) were set up and fed with secondary effluent of sewage treatment plant during the winter in Eastern China. The 16S rDNA Illumina Miseq sequencing analysis indicated the positive effects of I. pseudacorus on the bacterial community richness and diversity in the substrate. Moreover, the community compositions of the bacteria involved with denitrification presented a significant difference in the three systems. Additionally, higher relative abundances of nitrifying bacteria (0.4140%, 0.2402% and 0.4318% for Nitrosomonas, Nitrosospira and Nitrospira, respectively) were recorded in CWI compared with CWT (0.2074%, 0.0648% and 0.0181%, respectively) and CWC (0.3013%, 0.1107% and 0.1185%, respectively). Meanwhile, the average removal rates of NH4+-N and TN in CWI showed a prominent advantage compared to CWC, but no distinct advantage was found in CWT. The hardy plant I. pseudacorus, which still had active root oxygen release in cold temperatures, positively affected the abundance of nitrifying bacteria in the substrate, and accordingly was supposed to contribute to a comparatively high nitrogen removal efficiency of the system during the winter.

Root oxygen loss from Raphia taedigera palms mediates greenhouse gas emissions in lowland neotropical peatlands

Aims Little is known about the influence of vegetation on the timing and quantities of greenhouse gas fluxes from lowland Neotropical peatlands to the atmosphere. To address this knowledge gap, we investigated if palm forests moderate greenhouse gas fluxes from tropical peatlands due to radial oxygen loss from roots into the peat matrix.

Water‐level fluctuations affect sediment properties, carbon flux and growth of the isoetid Littorella uniflora in oligotrophic lakes

Summary Amphibious isoetids such as Littorella uniflora dominate the littoral zone in north‐temperate oligotrophic, softwater lakes. Accumulation of labile organic matter in the sediments from eutrophication represents a threat to isoetids because of insufficient root oxygenation, reduced anchorage and enhanced growth of taller competitors. These threats might be alleviated by fluctuating water levels potentially increasing sediment mineralisation and plant growth. We hypothesised that L. uniflora would produce higher areal biomass when sediments are drained because air exposure assists oxygenation, mineralisation and consolidation of sediments. If so, changing water level offers a possible restoration measure. We tested this hypothesis by measuring sediment metabolism and plant performance under drained, fluctuating and submerged conditions in the laboratory and along an elevation gradient in the field in natural and organically enriched sandy sediments. Laboratory and field experiments confirmed that L. uniflora grew in biomass under all conditions and maintained high leaf chlorophyll and photosynthesis. Increase in plant biomass was highest under drained conditions, particularly for roots probably in response to higher sediment oxygenation and leaf transpiration. The increase in biomass was lowest under fluctuating conditions as a logical consequence of higher costs of frequent shifts between aerial and aquatic growth forms. In the laboratory experiment, mineralisation of sediment organic matter was 5.5‐fold higher under drained compared to submerged conditions in un‐vegetated sediments measured as release of CO2. Fluctuating conditions led to an intermediary release of CO2. In vegetated sediments, part of the CO2 released from mineralisation was incorporated into plant biomass, and taking this into account yielded twofold increase in mineralisation rate from submerged and fluctuating to drained conditions. During the field experiment, a substantial part of the added organic matter was mineralised particularly in the dry part of the gradient. The proportion of reduced Fe2+ to total Fe as a measure of oxygenation of sediments declined from submerged to fluctuating and permanently drained sediments. The proportion of reduced Fe2+ was lower in plant covered than bare sediments reflecting root release of O2. Drainage and air contact increased sediment density and thus potentially the root anchorage compared to submerged conditions. Periodic drainage and air exposure of isoetid beds is a natural phenomenon in oligotrophic lakes causing beneficial sediment conditions for isoetids and positively affect the growth of L. uniflora. Reinstating water‐level fluctuations in regulated lakes or periodically lowering water levels could be used as a restoration measure.