Pub Date : 2026-01-23DOI: 10.1016/j.aquabot.2026.103995
Carly Dempsey , Jamie L. Knaub , Marguerite S. Koch
Extensive development of a lacunal system of aerenchyma (air space tissue) is important in wetland plants, particularly seagrasses that colonize highly organic tropical marine environments. However, the lacunal architecture in seagrasses is not well studied. Here, we utilize micro-computed tomography (µCT) imaging to quantify the volume of aerenchyma across tissue types (leaf, rhizome, and root) in three dominant tropical seagrass species (Thalassia testudinum, Syringodium filiforme, and Halodule wrightii) growing in highly anaerobic sediment in Florida Bay. The advantage of applying µCT imagery is that internal aerenchyma 3D structure can be examined at a high resolution (<9 µm) without tissue fixation or manual cross-sectioning required in more traditional techniques. We performed µCT scans of each species and tissue type, and quantified percent aerenchyma as tissue volume. We found that all species examined had an aerenchyma volume 38–45% of the tissue, indicating a large volume of air space. We also found significant differences in aerenchyma volume between tissue types and species, significant interactions, and identified constricted regions. This study demonstrates that µCT imaging is a viable approach to investigate lacunal architecture with implications for gas transport critical for wetland plants exposed to hypoxia.
{"title":"Wetland plant aerenchyma volume quantified using micro-computed tomography: Tropical seagrasses as a case study","authors":"Carly Dempsey , Jamie L. Knaub , Marguerite S. Koch","doi":"10.1016/j.aquabot.2026.103995","DOIUrl":"10.1016/j.aquabot.2026.103995","url":null,"abstract":"<div><div>Extensive development of a lacunal system of aerenchyma (air space tissue) is important in wetland plants, particularly seagrasses that colonize highly organic tropical marine environments. However, the lacunal architecture in seagrasses is not well studied. Here, we utilize micro-computed tomography (µCT) imaging to quantify the volume of aerenchyma across tissue types (leaf, rhizome, and root) in three dominant tropical seagrass species (<em>Thalassia testudinum, Syringodium filiforme,</em> and <em>Halodule wrightii</em>) growing in highly anaerobic sediment in Florida Bay. The advantage of applying µCT imagery is that internal aerenchyma 3D structure can be examined at a high resolution (<9 µm) without tissue fixation or manual cross-sectioning required in more traditional techniques. We performed µCT scans of each species and tissue type, and quantified percent aerenchyma as tissue volume. We found that all species examined had an aerenchyma volume 38–45% of the tissue, indicating a large volume of air space. We also found significant differences in aerenchyma volume between tissue types and species, significant interactions, and identified constricted regions. This study demonstrates that µCT imaging is a viable approach to investigate lacunal architecture with implications for gas transport critical for wetland plants exposed to hypoxia.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"205 ","pages":"Article 103995"},"PeriodicalIF":2.6,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-17DOI: 10.1016/j.aquabot.2026.103997
Petra Hájková , Jolanta Pilch , Włodzimierz Margielewski , Renata Stachowicz-Rybka , Krzysztof Buczek
The aquatic moss Sarmentypnum trichophyllum (Warnst.) Hedenäs, nowadays occurring most frequently in the northern parts of Eurasia and North America, with only disjunct occurrences in the high altitudes of the more southern areas, has been discovered in the late glacial minerogenic sediments of the present-day Kotoń landslide fen (Beskid Makowski Mountains, the Outer Western Carpathians, S Poland, 739 m a.s.l.). As inferred from the sediment type (organic silt) and the presence of accompanying macrofossils of vascular plants, Sarmentypnum trichophyllum grew in the clear-water oligo- to mesotrophic waterbody surrounded by arctic steppe-tundra. These conditions probably reflected the cold and dry climate of the short GI-1d/Older Dryas climatic cooling 14,070 ± 72 to ca. 13,900 ± 56 cal BP (ca. 170 years). The glacial occurrence of this species in lower latitudes suggests the relict character of today´s populations with disjunct southern occurrences. It seems that S. trichophyllum might be more distributed in Central Europe during the late glacial period.
水栖苔藓（warst .）Hedenäs，现在最常出现在欧亚大陆和北美的北部，只在较南部的高海拔地区不间断地出现，已在当今kotoski滑坡区（Beskid Makowski Mountains，外西部喀尔巴阡山脉，波兰南部，739 m a.s.l）的冰川晚期成矿沉积物中被发现。从沉积物类型（有机淤泥）和伴随的维管植物大型化石的存在推断，沙门草木生长在被北极草原-冻土带包围的淡水型中营养型水体中。这些条件可能反映了较短的GI-1d/ old Dryas气候冷却14070 ± 72 ~ 13900 ± 56 cal BP（约170年）的寒冷干燥气候。这一物种在低纬度地区的冰河时期的出现，表明了今天在南方出现的种群的残余物特征。似乎在冰川晚期，S. trichophyllum可能更多地分布在中欧地区。
{"title":"Sarmentypnum trichophyllum (Warnst.) Hedenäs, a rare boreal-arctic aquatic moss, first recorded in the glacial sediments of Central Europe","authors":"Petra Hájková , Jolanta Pilch , Włodzimierz Margielewski , Renata Stachowicz-Rybka , Krzysztof Buczek","doi":"10.1016/j.aquabot.2026.103997","DOIUrl":"10.1016/j.aquabot.2026.103997","url":null,"abstract":"<div><div>The aquatic moss <em>Sarmentypnum trichophyllum</em> (Warnst.) Hedenäs<em>,</em> nowadays occurring most frequently in the northern parts of Eurasia and North America, with only disjunct occurrences in the high altitudes of the more southern areas, has been discovered in the late glacial minerogenic sediments of the present-day Kotoń landslide fen (Beskid Makowski Mountains, the Outer Western Carpathians, S Poland, 739 m a.s.l.). As inferred from the sediment type (organic silt) and the presence of accompanying macrofossils of vascular plants, <em>Sarmentypnum trichophyllum</em> grew in the clear-water oligo- to mesotrophic waterbody surrounded by arctic steppe-tundra. These conditions probably reflected the cold and dry climate of the short GI-1d/Older Dryas climatic cooling 14,070 ± 72 to ca. 13,900 ± 56 cal BP (ca. 170 years). The glacial occurrence of this species in lower latitudes suggests the relict character of today´s populations with disjunct southern occurrences. It seems that <em>S. trichophyllum</em> might be more distributed in Central Europe during the late glacial period.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103997"},"PeriodicalIF":2.6,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-17DOI: 10.1016/j.aquabot.2026.103996
Irina Bodnar, Evgenia Cheban
The content of macroelements in plants is regulated by genetic factors and depends on the environment. Plant ionome is species-specific, the impact of stressors, imbalance of mineral nutrition, including excessive intake of heavy metals, changes the level of macro- and microelements, which affects the physiological state of plants, growth and development. In this work, it is shown that the impact of heavy metals (Cu2 +, Cd2+, Zn2+) and gamma radiation led to a change in the accumulation of Ca2+, Mg2+ and K+ in Lemna minor L., which is a model plant in ecotoxicological experiments and is promising for phytoremediation of polluted water bodies. With the considered effects, a dose-dependent decrease in growth was observed in the form of a decrease in the total area of duckweed fronds; the toxicity series for this group of metals is Cu2+>Cd2+>Zn2+. Duckweed can be classified as an accumulator of heavy metals; aquatic plants accumulated Zn2+ most efficiently (BCF>1000). The general change in the macronutrient profile under the influence of heavy metals and radiation was an increase in Ca2+ accumulation. The Mg2+ level increased after irradiation (42, 63 Gy), exposure to Cd2+ (12.6 μM), Zn2+ (3.15, 6.3, 12.6 μM) and Cu2+ (3.15, 6.3 μM). The K+ content decreased under the influence of chemical agents (Cu2+), but did not change after irradiation. The obtained data can be used in assessing the quality of natural and waste waters with the interpretation of the plant ionome as a stress biomarker.
植物体内大量元素的含量既受遗传因素的调控，又受环境的影响。植物离子素具有物种特异性，受胁迫源的影响，矿质营养失衡，包括重金属摄入过量，改变了宏量和微量元素的水平，从而影响植物的生理状态、生长发育。本文研究表明，重金属（Cu2 +,Cd2+, Zn2+）和γ辐射的影响会导致lena minor L.中Ca2+， Mg2+和K+的积累发生变化，lena minor L.是一种生态毒理学实验的模式植物，有望用于污染水体的植物修复。考虑到这些效应，浮萍叶总面积的减少是一种剂量依赖性的生长减少；该组金属的毒性系列为Cu2+>；Cd2+>Zn2+。浮萍可归类为重金属的蓄积者；水生植物积累Zn2+效率最高（BCF>1000）。在重金属和辐射的影响下，宏量营养素的总体变化是Ca2+积累的增加。辐照（42,63 Gy）、Cd2+（12.6 μM）、Zn2+（3.15, 6.3, 12.6 μM）和Cu2+（3.15, 6.3 μM）后，Mg2+水平升高。化学药剂（Cu2+）对K+含量的影响有所降低，但辐照后没有变化。所获得的数据可用于评估自然和废水的质量，并解释植物离子素作为应激生物标志物。
{"title":"The ionome of aquatic plants Lemna minor L. under abiotic stresses","authors":"Irina Bodnar, Evgenia Cheban","doi":"10.1016/j.aquabot.2026.103996","DOIUrl":"10.1016/j.aquabot.2026.103996","url":null,"abstract":"<div><div>The content of macroelements in plants is regulated by genetic factors and depends on the environment. Plant ionome is species-specific, the impact of stressors, imbalance of mineral nutrition, including excessive intake of heavy metals, changes the level of macro- and microelements, which affects the physiological state of plants, growth and development. In this work, it is shown that the impact of heavy metals (Cu<sup>2 +</sup>, Cd<sup>2+</sup>, Zn<sup>2+</sup>) and gamma radiation led to a change in the accumulation of Ca<sup>2+</sup>, Mg<sup>2+</sup> and K<sup>+</sup> in <em>Lemna minor</em> L., which is a model plant in ecotoxicological experiments and is promising for phytoremediation of polluted water bodies. With the considered effects, a dose-dependent decrease in growth was observed in the form of a decrease in the total area of duckweed fronds; the toxicity series for this group of metals is Cu<sup>2+</sup>>Cd<sup>2+</sup>>Zn<sup>2+</sup>. Duckweed can be classified as an accumulator of heavy metals; aquatic plants accumulated Zn<sup>2+</sup> most efficiently (BCF>1000). The general change in the macronutrient profile under the influence of heavy metals and radiation was an increase in Ca<sup>2+</sup> accumulation. The Mg<sup>2+</sup> level increased after irradiation (42, 63 Gy), exposure to Cd<sup>2+</sup> (12.6 μM), Zn<sup>2+</sup> (3.15, 6.3, 1<sup>2.</sup>6 μM) and Cu<sup>2+</sup> (3.15, 6.3 μM). The K<sup>+</sup> content decreased under the influence of chemical agents (Cu<sup>2+</sup>), but did not change after irradiation. The obtained data can be used in assessing the quality of natural and waste waters with the interpretation of the plant ionome as a stress biomarker.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103996"},"PeriodicalIF":2.6,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-09DOI: 10.1016/j.aquabot.2026.103991
Athita Senayai , Suzanne L. Chmilar , Dilini Abeyrama , Theresa M. Burg , Robert A. Laird , Ekaphan Kraichak
Demographic senescence involves population-level declines in survival and reproduction with increasing age Duckweeds provide excellent models for plant senescence research due to their rapid clonal propagation and short lifespans. While caloric restriction (CR) extends lifespans in heterotrophs, its effect on plants remains poorly understood. We investigated demographic senescence and CR effects by reducing light intensity in two duckweed species: Wolffia brasiliensis Wedd. and Lemna aequinoctialis Welw. Using longitudinal laboratory studies of 336 individual plants per species, we recorded daily reproduction from birth to death under controlled light treatments. Both species exhibited significant demographic senescence, with survival data fitting logistic models for W. brasiliensis across treatments, while L. aequinoctialis fit Weibull (full light) and logistic (dim light) models. Generalized estimating equations revealed significant age-related declines in daily reproduction probability across all treatments (p < 0.001). CR significantly extended mean lifespan in both species: from 26.11 days (full light) to 28.45 days (dim light) in W. brasiliensis (p < 0.001) and from 24.74 days (full light) to 33.67 days (dim light) in L. aequinoctialis (p < 0.001). While total offspring production remained similar between treatments, the intrinsic rate of increase measured at the individual level (r) was significantly higher under full light. These findings demonstrate demographic senescence across duckweed genera and suggest that CR can extend lifespan in photoautotrophic organisms. Temporal scaling analysis revealed complete conservation of senescence trajectories in W. brasiliensis, while a marginally non-significant difference was detected in L. aequinoctialis (p = 0.065), suggesting potential species-specific responses to CR that warrant further investigation.
{"title":"Demographic senescence and lifespan extension by caloric restriction in two duckweed species (Wolffia brasiliensis and Lemna aequinoctialis)","authors":"Athita Senayai , Suzanne L. Chmilar , Dilini Abeyrama , Theresa M. Burg , Robert A. Laird , Ekaphan Kraichak","doi":"10.1016/j.aquabot.2026.103991","DOIUrl":"10.1016/j.aquabot.2026.103991","url":null,"abstract":"<div><div>Demographic senescence involves population-level declines in survival and reproduction with increasing age Duckweeds provide excellent models for plant senescence research due to their rapid clonal propagation and short lifespans. While caloric restriction (CR) extends lifespans in heterotrophs, its effect on plants remains poorly understood. We investigated demographic senescence and CR effects by reducing light intensity in two duckweed species: <em>Wolffia brasiliensis</em> Wedd. and <em>Lemna aequinoctialis</em> Welw. Using longitudinal laboratory studies of 336 individual plants per species, we recorded daily reproduction from birth to death under controlled light treatments. Both species exhibited significant demographic senescence, with survival data fitting logistic models for <em>W. brasiliensis</em> across treatments, while <em>L. aequinoctialis</em> fit Weibull (full light) and logistic (dim light) models. Generalized estimating equations revealed significant age-related declines in daily reproduction probability across all treatments (<em>p</em> < 0.001). CR significantly extended mean lifespan in both species: from 26.11 days (full light) to 28.45 days (dim light) in <em>W. brasiliensis</em> (<em>p</em> < 0.001) and from 24.74 days (full light) to 33.67 days (dim light) in <em>L. aequinoctialis</em> (<em>p</em> < 0.001). While total offspring production remained similar between treatments, the intrinsic rate of increase measured at the individual level (<em>r</em>) was significantly higher unde<em>r</em> full light. These findings demonstrate demographic senescence across duckweed genera and suggest that CR can extend lifespan in photoautotrophic organisms. Temporal scaling analysis revealed complete conservation of senescence trajectories in <em>W. brasiliensis</em>, while a marginally non-significant difference was detected in <em>L. aequinoctialis</em> (<em>p</em> = 0.065), suggesting potential s<em>p</em>ecies-specific responses to CR that warrant further investigation.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103991"},"PeriodicalIF":2.6,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-07DOI: 10.1016/j.aquabot.2026.103989
Mi Yeon Yang , Prismabella Wilis Andiska , Myung Sook Kim
Anotrichium tenue, a red algal species historically reported from diverse coastal regions, has long been exemplified the challenges of taxonomy due to its subtle morphological variation and unclear species boundaries. In this study, we conducted an integrative reassessment of Korean specimens previously attributed to A. tenue, using detailed morphological analyses and molecular phylogenetics based on plastid-encoded rbcL and psbA sequences. Our results revealed two genetically distinct and morphologically diagnosable lineages, described herein as Anotrichium flammeum sp. nov. and Anotrichium dokdoensis sp. nov. To describe the diagnostic characteristics of the two new species, A. flammeum sp. nov. is characterized by secund to irregular branching and up to 12 tetrasporangia per node, while A. dokdoensis sp. nov. exhibits profuse trichoblasts and up to 40 tetrasporangia arranged terminally to subterminally. Both species are clearly distinct from the topotype of A. tenue collected from the Mediterranean region, both molecularly and morphologically. Additionally, our analyses indicate that several specimens previously identified as A. furcellatum are conspecific with A. yagii, highlighting a long-standing case of misidentification. These findings underscore the hidden diversity within Anotrichium and emphasize the importance of integrating molecular and morphological data in resolving species boundaries in red algae.
{"title":"Molecular phylogenetic reassessment of Anotrichium (Ceramiales, Rhodophyta) from Korea, with two new species A. flammeum and A. dokdoensis","authors":"Mi Yeon Yang , Prismabella Wilis Andiska , Myung Sook Kim","doi":"10.1016/j.aquabot.2026.103989","DOIUrl":"10.1016/j.aquabot.2026.103989","url":null,"abstract":"<div><div><em>Anotrichium tenue</em>, a red algal species historically reported from diverse coastal regions, has long been exemplified the challenges of taxonomy due to its subtle morphological variation and unclear species boundaries. In this study, we conducted an integrative reassessment of Korean specimens previously attributed to <em>A. tenue</em>, using detailed morphological analyses and molecular phylogenetics based on plastid-encoded <em>rbc</em>L and <em>psb</em>A sequences. Our results revealed two genetically distinct and morphologically diagnosable lineages, described herein as <em>Anotrichium flammeum</em> sp. nov. and <em>Anotrichium dokdoensis</em> sp. nov. To describe the diagnostic characteristics of the two new species, <em>A. flammeum</em> sp. nov. is characterized by secund to irregular branching and up to 12 tetrasporangia per node, while <em>A. dokdoensis</em> sp. nov. exhibits profuse trichoblasts and up to 40 tetrasporangia arranged terminally to subterminally. Both species are clearly distinct from the topotype of <em>A. tenue</em> collected from the Mediterranean region, both molecularly and morphologically. Additionally, our analyses indicate that several specimens previously identified as <em>A. furcellatum</em> are conspecific with <em>A. yagii</em>, highlighting a long-standing case of misidentification. These findings underscore the hidden diversity within <em>Anotrichium</em> and emphasize the importance of integrating molecular and morphological data in resolving species boundaries in red algae.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103989"},"PeriodicalIF":2.6,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-07DOI: 10.1016/j.aquabot.2026.103994
Jonas de Azevedo , Francisco Arenas , Aldo Barreiro , João N. Franco
Herbivory is intensifying on many temperate reefs under ocean warming and tropicalisation, raising concerns for canopy-forming seaweeds. Along the Portuguese coast, the obligate herbivore Sarpa salpa is abundant and frequently observed grazing on kelps and fucoids. We tested whether wild S. salpa shows consistent feeding preferences among four habitat-forming brown macroalgae—Laminaria ochroleuca, Fucus spiralis, Sargassum muticum and Cystoseira humilis—and whether simple stoichiometric signals (C and N) align with observed choices. Using outdoor, submerged mesocosms at Sines region (SW Portugal), we ran four sequential no-choice trials conducted over a 12-day period (with 48 h intervals between session) followed by choice assays (days 5–6). Consumption was recorded as 24-h wet-mass loss, standardised to grazer biomass (g·kg⁻¹), and elemental C and N were measured in algal tissues and fish faeces to infer assimilation. Fish readily consumed all species in no-choice trials, indicating no gross non-palatability. Under simultaneous availability, however, S. salpa consistently consumed more F. spiralis, L. ochroleuca and S. muticum than C. humilis, revealing non-uniform selection. Tissue composition differed among species: L. ochroleuca had the highest N and lowest C:N ratio, which aligned with the highest apparent N assimilation by the fish. This clear link between simple stoichiometry and assimilation suggests that species-specific nutritional payoffs are a key mechanistic driver of preference. Given the warming and tropicalising context of NE Atlantic reefs, this trait-based selectivity is significant: it may amplify canopy vulnerability (particularly of high-quality species) and favour turf-dominated states at warm range margins. We recommend integrating herbivory metrics (selectivity, bite rates, grazer biomass) into monitoring, conservation and restoration to safeguard Portuguese marine forests.
{"title":"Grazing preferences of Sarpa salpa on temperate habitat-forming macroalgae","authors":"Jonas de Azevedo , Francisco Arenas , Aldo Barreiro , João N. Franco","doi":"10.1016/j.aquabot.2026.103994","DOIUrl":"10.1016/j.aquabot.2026.103994","url":null,"abstract":"<div><div>Herbivory is intensifying on many temperate reefs under ocean warming and tropicalisation, raising concerns for canopy-forming seaweeds. Along the Portuguese coast, the obligate herbivore <em>Sarpa salpa</em> is abundant and frequently observed grazing on kelps and fucoids. We tested whether wild <em>S. salpa</em> shows consistent feeding preferences among four habitat-forming brown macroalgae—<em>Laminaria ochroleuca</em>, <em>Fucus spiralis</em>, <em>Sargassum muticum</em> and <em>Cystoseira humilis</em>—and whether simple stoichiometric signals (C and N) align with observed choices. Using outdoor, submerged mesocosms at Sines region (SW Portugal), we ran four sequential no-choice trials conducted over a 12-day period (with 48 h intervals between session) followed by choice assays (days 5–6). Consumption was recorded as 24-h wet-mass loss, standardised to grazer biomass (g·kg⁻¹), and elemental C and N were measured in algal tissues and fish faeces to infer assimilation. Fish readily consumed all species in no-choice trials, indicating no gross non-palatability. Under simultaneous availability, however, <em>S. salpa</em> consistently consumed more <em>F. spiralis</em>, <em>L. ochroleuca</em> and <em>S. muticum</em> than <em>C. humilis</em>, revealing non-uniform selection. Tissue composition differed among species: <em>L. ochroleuca</em> had the highest N and lowest C:N ratio, which aligned with the highest apparent N assimilation by the fish. This clear link between simple stoichiometry and assimilation suggests that species-specific nutritional payoffs are a key mechanistic driver of preference. Given the warming and tropicalising context of NE Atlantic reefs, this trait-based selectivity is significant: it may amplify canopy vulnerability (particularly of high-quality species) and favour turf-dominated states at warm range margins. We recommend integrating herbivory metrics (selectivity, bite rates, grazer biomass) into monitoring, conservation and restoration to safeguard Portuguese marine forests.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103994"},"PeriodicalIF":2.6,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-06DOI: 10.1016/j.aquabot.2026.103993
Yan Chen , Jia Xi , Zuoliang Sun , Jingjing Yang , Gaojie Li , Xuyao Zhao , Liyuan Zhang , Hongwen Hu , Chunnan Ye , Hongwei Hou
Spirodela polyrhiza has great advantages for energy production, sewage treatment, toxicity experiments, and biomonitoring. However, low transformation efficiency and long-cycle transformation time remain an urgent problem. In this research, we established an optimized frond-mediated genetic transformation protocol achieving 37.35 % efficiency within 51 days—a 3.2-fold improvement over existing methods (11.48 %, 164 days). Frond-based transformation data indicated that vacuum treatment could be applied to increase the frond transformation efficiency in S. polyrhiza. To validate this system's reliability, we employed it to investigate the cooperative functions of three natural resistance-associated macrophage protein (Nramp) transporters (SpNramps) in S. polyrhiza under cadmium (Cd) stress. Heterologous co-expression of SpNramps in yeast resulted in reduced Cd accumulation and heightened Cd sensitivity. However, SpNramps overexpression increased the tolerance to Cd by promoting its growth and enhancing Mn absorption at 150 μM Cd. Collectively, this study presented the first report on the frond-based transformation system in S. polyrhiza, which enables rapid functional validation of multi-gene regulatory networks in aquatic plants, laying the foundation for further functional studies. Our study also offered a new solution to increase Cd tolerance in plants and gained new insights into both basic and applied research by using the co-overexpression strategy.
{"title":"A novel frond-based genetic transformation method in Spirodela polyrhiza: Reliability reconfirmed through functional analysis of SpNramps co-overexpression under cadmium stress","authors":"Yan Chen , Jia Xi , Zuoliang Sun , Jingjing Yang , Gaojie Li , Xuyao Zhao , Liyuan Zhang , Hongwen Hu , Chunnan Ye , Hongwei Hou","doi":"10.1016/j.aquabot.2026.103993","DOIUrl":"10.1016/j.aquabot.2026.103993","url":null,"abstract":"<div><div><em>Spirodela polyrhiza</em> has great advantages for energy production, sewage treatment, toxicity experiments, and biomonitoring. However, low transformation efficiency and long-cycle transformation time remain an urgent problem. In this research, we established an optimized frond-mediated genetic transformation protocol achieving 37.35 % efficiency within 51 days—a 3.2-fold improvement over existing methods (11.48 %, 164 days). Frond-based transformation data indicated that vacuum treatment could be applied to increase the frond transformation efficiency in <em>S. polyrhiza</em>. To validate this system's reliability, we employed it to investigate the cooperative functions of three natural resistance-associated macrophage protein (Nramp) transporters (<em>SpNramps</em>) in <em>S. polyrhiza</em> under cadmium (Cd) stress. Heterologous co-expression of <em>SpNramps</em> in yeast resulted in reduced Cd accumulation and heightened Cd sensitivity. However, <em>SpNramps</em> overexpression increased the tolerance to Cd by promoting its growth and enhancing Mn absorption at 150 μM Cd. Collectively, this study presented the first report on the frond-based transformation system in <em>S. polyrhiza</em>, which enables rapid functional validation of multi-gene regulatory networks in aquatic plants, laying the foundation for further functional studies. Our study also offered a new solution to increase Cd tolerance in plants and gained new insights into both basic and applied research by using the co-overexpression strategy.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103993"},"PeriodicalIF":2.6,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145938686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-06DOI: 10.1016/j.aquabot.2026.103992
Zhihao Qian , Jinming Chen
Brasenia schreberi is a critically endangered aquatic plant species found sparsely distributed in freshwater ponds and lakes across China. Here, we used RAD-seq to assess the genetic diversity, population structure, and local adaptation of 20 wild populations of this species. Our results revealed extremely low genetic diversity and strong genetic differentiation among populations, likely driven by predominant clonal reproduction and restricted gene flow due to habitat fragmentation. Population structure analyses revealed two major genetic groups. Redundancy analysis demonstrated that this genetic differentiation was caused by the divergent selection due to environmental difference. We further identified 170 candidate genes under selective pressure, which were enriched in functions related to regulation of chromatin organization and modification and abiotic stress response. Our findings have significant implications for the conservation management of B. schreberi and similar endangered aquatic plants, and provide valuable genetic resources for future conservation efforts.
{"title":"Genetic diversity and adaptive genetic divergence of endangered aquatic plant Brasenia schreberi in China revealed by RAD-seq","authors":"Zhihao Qian , Jinming Chen","doi":"10.1016/j.aquabot.2026.103992","DOIUrl":"10.1016/j.aquabot.2026.103992","url":null,"abstract":"<div><div><em>Brasenia schreberi</em> is a critically endangered aquatic plant species found sparsely distributed in freshwater ponds and lakes across China. Here, we used RAD-seq to assess the genetic diversity, population structure, and local adaptation of 20 wild populations of this species. Our results revealed extremely low genetic diversity and strong genetic differentiation among populations, likely driven by predominant clonal reproduction and restricted gene flow due to habitat fragmentation. Population structure analyses revealed two major genetic groups. Redundancy analysis demonstrated that this genetic differentiation was caused by the divergent selection due to environmental difference. We further identified 170 candidate genes under selective pressure, which were enriched in functions related to regulation of chromatin organization and modification and abiotic stress response. Our findings have significant implications for the conservation management of <em>B. schreberi</em> and similar endangered aquatic plants, and provide valuable genetic resources for future conservation efforts.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103992"},"PeriodicalIF":2.6,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145938687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.aquabot.2026.103990
Alex Ricardo Schneider , Felipe de Souza Dutra , Aline Nunes , Alex Alves dos Santos , Eva Regina Oliveira , Gadiel Zilto Azevedo , Susane Lopes , Giuseppina Pace Pereira Lima , Sidnei Moura , Marcelo Maraschin
This study presents the first seasonal biochemical characterization of the red seaweed Kappaphycus alvarezii cultivated in southern Brazil (Santa Catarina state - SC). Algal biomass was sampled in triplicate from two distinct farm sites (RIB and PAL) at the beginning and end of each season over one year. We analyzed total carbohydrates (TC), soluble sugars (TSS), starch (TS), secondary metabolites carotenoids (TCN), phenolics (TPC), flavonoids (TFC), total lipids (TL), and fatty acid (FA) profiles. Results were subjected to a two-way ANOVA, followed by the Scott-Knott test and principal component analysis (PCA), revealing significant effects (p < 0.05) of site, season, and their interaction. TSS was markedly higher in spring (38.9 mg/g) than autumn (11.3 mg/g), while TL peaked in autumn (up to 5.1 %). Secondary metabolites showed strong seasonal trends; TPC was higher in spring (113.7 mg/100 g) and summer (100.6 mg/100 g), and TCN was highest in summer (816.2 mg/100 g). In contrast, TC (427.9–566.0 mg/g) and TFC (7.7–10.6 mg/100 g) showed no significant seasonal variation, as well as FA, dominated by heptadecanoic (C17:0 – 29.8 %) and linolelaidic (C18:2n6t – 13.6 %) acids. PCA confirmed a clear separation of metabolic profiles by site and season, associating spring/summer samples from one location with high TPC and TSS, and from the other with high TS and TCN. These findings establish a crucial baseline and support the development of seasonal harvest windows to optimize the emerging seaweed cultivation sites in southern Brazil.
{"title":"Seasonal biochemical characterization of the red seaweed Kappaphycus alvarezii cultivated in southern Brazil","authors":"Alex Ricardo Schneider , Felipe de Souza Dutra , Aline Nunes , Alex Alves dos Santos , Eva Regina Oliveira , Gadiel Zilto Azevedo , Susane Lopes , Giuseppina Pace Pereira Lima , Sidnei Moura , Marcelo Maraschin","doi":"10.1016/j.aquabot.2026.103990","DOIUrl":"10.1016/j.aquabot.2026.103990","url":null,"abstract":"<div><div>This study presents the first seasonal biochemical characterization of the red seaweed <em>Kappaphycus alvarezii</em> cultivated in southern Brazil (Santa Catarina state - SC). Algal biomass was sampled in triplicate from two distinct farm sites (RIB and PAL) at the beginning and end of each season over one year. We analyzed total carbohydrates (TC), soluble sugars (TSS), starch (TS), secondary metabolites carotenoids (TCN), phenolics (TPC), flavonoids (TFC), total lipids (TL), and fatty acid (FA) profiles. Results were subjected to a two-way ANOVA, followed by the Scott-Knott test and principal component analysis (PCA), revealing significant effects (p < 0.05) of site, season, and their interaction. TSS was markedly higher in spring (38.9 mg/g) than autumn (11.3 mg/g), while TL peaked in autumn (up to 5.1 %). Secondary metabolites showed strong seasonal trends; TPC was higher in spring (113.7 mg/100 g) and summer (100.6 mg/100 g), and TCN was highest in summer (816.2 mg/100 g). In contrast, TC (427.9–566.0 mg/g) and TFC (7.7–10.6 mg/100 g) showed no significant seasonal variation, as well as FA, dominated by heptadecanoic (C17:0 – 29.8 %) and linolelaidic (C18:2n6t – 13.6 %) acids. PCA confirmed a clear separation of metabolic profiles by site and season, associating spring/summer samples from one location with high TPC and TSS, and from the other with high TS and TCN. These findings establish a crucial baseline and support the development of seasonal harvest windows to optimize the emerging seaweed cultivation sites in southern Brazil.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103990"},"PeriodicalIF":2.6,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145938588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The occurrence of circumpolar and suboceanic species of long-stalked pondweed (Potamogeton praelongus) in the Czech Republic (furthermore CZ) has a relict character, and the species is on the verge of extinction there. At present, there is only one site (out of 20 historically known ones) in which it occurs naturally, and this is an oxbow of the Orlice river at the Stříbrný rybník (Silvery Pond) in Hradec Králové in Eastern Bohemia. The CZ is situated near the southern border of the P. praelongus distribution area, and it offers suboptimal environmental conditions for this species. This is indicated not only by water and sediment chemical and physical properties and extinction of native aquatic plant species in the 20 historically known Czech sites (oxbows and backwater pools) but also by the populations' status of common species. This critically endangered species has narrow ecological preferences to pH (alkaline) and water transparency (light-demanding) and also sensitive to the eutrophication and related changes of sites. It is synergistically negatively impacted by other numerous factors. We found out that water temperature higher than 25 °C damages this species. Short-time events like floods, annual weather fluctuations decrease its vitality and regeneration ability in shallow biotops (predominating in the CZ). Human activities and invasions of alien species also significantly intensify this trend in the CZ. The reintroduction of this species into restored backwater pools in the Protected Landscape Area called Kokořínsko and Máchův kraj is only a temporary solution for its survival, but thanks to it, these source populations can supply new individuals for re-colonization of new suitable sites in river floodplains. Artificial water reservoirs like flooded mining areas (sand pits, coal mining basins) could be temporarily beneficial for the P. praelongus survival, too. Furthermore, the restoration of oxbows in river floodplains and their natural geomorphology has recently started in the CZ, aiming to revitalize the aquatic biota. The restoration success depends strongly on the protection of river floodplains against overexploitation and contra-productive activities by lobby groups.
{"title":"Protection of Potamogeton praelongus in the Czech Republic, using temporary artificial backwater pools and restored natural sites","authors":"Romana Prausová , Adriana Svobodová , Lenka Šafářová , Simona Poláková","doi":"10.1016/j.aquabot.2025.103987","DOIUrl":"10.1016/j.aquabot.2025.103987","url":null,"abstract":"<div><div>The occurrence of circumpolar and suboceanic species of long-stalked pondweed (<em>Potamogeton praelongus</em>) in the Czech Republic (furthermore CZ) has a relict character, and the species is on the verge of extinction there. At present, there is only one site (out of 20 historically known ones) in which it occurs naturally, and this is an oxbow of the Orlice river at the Stříbrný rybník (Silvery Pond) in Hradec Králové in Eastern Bohemia. The CZ is situated near the southern border of the <em>P. praelongus</em> distribution area, and it offers suboptimal environmental conditions for this species. This is indicated not only by water and sediment chemical and physical properties and extinction of native aquatic plant species in the 20 historically known Czech sites (oxbows and backwater pools) but also by the populations' status of common species. This critically endangered species has narrow ecological preferences to pH (alkaline) and water transparency (light-demanding) and also sensitive to the eutrophication and related changes of sites. It is synergistically negatively impacted by other numerous factors. We found out that water temperature higher than 25 °C damages this species. Short-time events like floods, annual weather fluctuations decrease its vitality and regeneration ability in shallow biotops (predominating in the CZ). Human activities and invasions of alien species also significantly intensify this trend in the CZ. The reintroduction of this species into restored backwater pools in the Protected Landscape Area called Kokořínsko and Máchův kraj is only a temporary solution for its survival, but thanks to it, these source populations can supply new individuals for re-colonization of new suitable sites in river floodplains. Artificial water reservoirs like flooded mining areas (sand pits, coal mining basins) could be temporarily beneficial for the <em>P. praelongus</em> survival, too. Furthermore, the restoration of oxbows in river floodplains and their natural geomorphology has recently started in the CZ, aiming to revitalize the aquatic biota. The restoration success depends strongly on the protection of river floodplains against overexploitation and contra-productive activities by lobby groups.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103987"},"PeriodicalIF":2.6,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145938587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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