Forests dominate the landscape at high latitudes in the boreal regions and contribute significantly to the global carbon stock. Large areas are protected and provide possibilities to analyze natural forest dynamics including resilience to climate change. In Fennoscandia, Scots pine (Pinus sylvestris L.) and downy birch (Betula pubescens Ehrh.) often coexist in natural forests close to the limits of their ecological ranges. Tree growth in these forests is generally thought to be limited by temperature, and changes in growth trends can therefore serve as early indicators of the impact of global warming on natural ecosystems. We sampled 592 Scots pine and downy birch trees along two elevational gradients spanning the transition from the forest zone to the coniferous treeline in Tjeggelvas nature reserve, northern Sweden. Based on the tree-ring data, we compared annual basal area increment (BAI) trends from 1902 to 2021, analyzed the ring-width indices (RWI) in relation to local climate data, and investigated trends in climate-growth relationships. We found that the mean annual growth of both species was higher in more recent years than at the beginning of the 20th century. The RWI were positively correlated with summer temperatures, however, we found a much stronger relationship for Scots pine than downy birch. We noticed a decrease in the importance of summer temperature for Scots pine growth, whereas the importance of late spring temperatures increased over the 120-year-long study period. Due to strongly positive BAI trends combined with a decrease in temperature sensitivity, the overall conclusion of our study is that the influence of increasing temperatures is still positive and outweighs the negative impacts of climate change on Scots pine growth in natural forests in northern Sweden, particularly at higher elevations. Natural forests are important natural experiments that contrast the managed forests and are key to understanding the latter.
{"title":"Elevation-dependent tree growth response to climate in a natural Scots pine/downy birch forest in northern Sweden.","authors":"Magdalena Fassl, Tuomas Aakala, Lars Östlund","doi":"10.1002/pei3.10140","DOIUrl":"10.1002/pei3.10140","url":null,"abstract":"<p><p>Forests dominate the landscape at high latitudes in the boreal regions and contribute significantly to the global carbon stock. Large areas are protected and provide possibilities to analyze natural forest dynamics including resilience to climate change. In Fennoscandia, Scots pine (<i>Pinus sylvestris</i> L.) and downy birch (<i>Betula pubescens</i> Ehrh.) often coexist in natural forests close to the limits of their ecological ranges. Tree growth in these forests is generally thought to be limited by temperature, and changes in growth trends can therefore serve as early indicators of the impact of global warming on natural ecosystems. We sampled 592 Scots pine and downy birch trees along two elevational gradients spanning the transition from the forest zone to the coniferous treeline in Tjeggelvas nature reserve, northern Sweden. Based on the tree-ring data, we compared annual basal area increment (BAI) trends from 1902 to 2021, analyzed the ring-width indices (RWI) in relation to local climate data, and investigated trends in climate-growth relationships. We found that the mean annual growth of both species was higher in more recent years than at the beginning of the 20th century. The RWI were positively correlated with summer temperatures, however, we found a much stronger relationship for Scots pine than downy birch. We noticed a decrease in the importance of summer temperature for Scots pine growth, whereas the importance of late spring temperatures increased over the 120-year-long study period. Due to strongly positive BAI trends combined with a decrease in temperature sensitivity, the overall conclusion of our study is that the influence of increasing temperatures is still positive and outweighs the negative impacts of climate change on Scots pine growth in natural forests in northern Sweden, particularly at higher elevations. Natural forests are important natural experiments that contrast the managed forests and are key to understanding the latter.</p>","PeriodicalId":74457,"journal":{"name":"Plant-environment interactions (Hoboken, N.J.)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10984726/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140338540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-29eCollection Date: 2024-04-01DOI: 10.1002/pei3.10139
Thais Guillen, Michael Kessler, Jürgen Homeier
Ferns are known to have a lower incidence of mycorrhization than angiosperms. It has been suggested that this results from carbon being more limiting to fern growth than nutrient availability, but this assertion has not been tested yet. In the present study, we took advantage of a fertilization experiment with nitrogen and phosphorus on cloud forest plots of the Ecuadorean Andes for 15 years. A previous analysis revealed changes in the abundances of fern species in the fertilized plots compared to the control plots and hypothesized that this might be related to the responses of the mycorrhizal relationships to nutrient availability. We revisited the plots to assess the root-associated fungal communities of two epiphytic and two terrestrial fern species that showed shifts in abundance. We sampled and analyzed the roots of 125 individuals following a metabarcoding approach. We recovered 1382 fungal ASVs, with a dominance of members of Tremellales (Basidiomycota) and Heliotales (Ascomycota). The fungal diversity was highly partitioned with little overlap between individuals. We found marked differences between terrestrial and epiphytic species, with the latter fundamentally missing arbuscular mycorrhizal fungi (AMF). We found no effect of fertilization on the diversity or relative abundance of the fungal assemblages. Still, we observed a direct impact of phosphorus fertilization on its concentration in the fern leaves. We conclude that fern-fungi relationships in the study site are not restricted by nutrient availability and suggest the existence of little specificity on the fungal partners relative to the host fern species.
{"title":"Fern mycorrhizae do not respond to fertilization in a tropical montane forest.","authors":"Thais Guillen, Michael Kessler, Jürgen Homeier","doi":"10.1002/pei3.10139","DOIUrl":"10.1002/pei3.10139","url":null,"abstract":"<p><p>Ferns are known to have a lower incidence of mycorrhization than angiosperms. It has been suggested that this results from carbon being more limiting to fern growth than nutrient availability, but this assertion has not been tested yet. In the present study, we took advantage of a fertilization experiment with nitrogen and phosphorus on cloud forest plots of the Ecuadorean Andes for 15 years. A previous analysis revealed changes in the abundances of fern species in the fertilized plots compared to the control plots and hypothesized that this might be related to the responses of the mycorrhizal relationships to nutrient availability. We revisited the plots to assess the root-associated fungal communities of two epiphytic and two terrestrial fern species that showed shifts in abundance. We sampled and analyzed the roots of 125 individuals following a metabarcoding approach. We recovered 1382 fungal ASVs, with a dominance of members of Tremellales (Basidiomycota) and Heliotales (Ascomycota). The fungal diversity was highly partitioned with little overlap between individuals. We found marked differences between terrestrial and epiphytic species, with the latter fundamentally missing arbuscular mycorrhizal fungi (AMF). We found no effect of fertilization on the diversity or relative abundance of the fungal assemblages. Still, we observed a direct impact of phosphorus fertilization on its concentration in the fern leaves. We conclude that fern-fungi relationships in the study site are not restricted by nutrient availability and suggest the existence of little specificity on the fungal partners relative to the host fern species.</p>","PeriodicalId":74457,"journal":{"name":"Plant-environment interactions (Hoboken, N.J.)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10979390/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140337999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-21eCollection Date: 2024-02-01DOI: 10.1002/pei3.10135
Laura M Ladwig, Jessica R Lucas
Myxospermy, the release of seed mucilage upon hydration, plays multiple roles in seed biology. Here, we explore whether seed mucilage occurs in a suite of temperate grassland species to test if the prevalence of species producing seed mucilage is associated with habitat type or seed characteristics. Seventy plant species found in wet or dry North American temperate grasslands were tested for the presence of seed mucilage through microscopic examination of seeds imbibed with histochemical stain for mucilage. Mucilage production was compared among species with different moisture requirements and seed mass. In this study, 43 of 70 of species tested produced seed mucilage. Seed mucilage did not differ based on habitat type, species moisture requirements, or seed mass. Most seed mucilage was non-adherent and did not remain stuck to the seed after extrusion. Seed mucilage was a common trait in the surveyed temperate grassland species and was observed in 61% of evaluated species. Surprisingly, seed mucilage was more common in temperate grasslands than in previous ecological surveys from arid/semiarid systems, which found 10%-31% myxospermous species. Given the high prevalence, seed mucilage may influence seedling ecology in temperate grasslands and requires further investigation.
{"title":"Seed mucilage in temperate grassland species is unrelated to moisture requirements.","authors":"Laura M Ladwig, Jessica R Lucas","doi":"10.1002/pei3.10135","DOIUrl":"10.1002/pei3.10135","url":null,"abstract":"<p><p>Myxospermy, the release of seed mucilage upon hydration, plays multiple roles in seed biology. Here, we explore whether seed mucilage occurs in a suite of temperate grassland species to test if the prevalence of species producing seed mucilage is associated with habitat type or seed characteristics. Seventy plant species found in wet or dry North American temperate grasslands were tested for the presence of seed mucilage through microscopic examination of seeds imbibed with histochemical stain for mucilage. Mucilage production was compared among species with different moisture requirements and seed mass. In this study, 43 of 70 of species tested produced seed mucilage. Seed mucilage did not differ based on habitat type, species moisture requirements, or seed mass. Most seed mucilage was non-adherent and did not remain stuck to the seed after extrusion. Seed mucilage was a common trait in the surveyed temperate grassland species and was observed in 61% of evaluated species. Surprisingly, seed mucilage was more common in temperate grasslands than in previous ecological surveys from arid/semiarid systems, which found 10%-31% myxospermous species. Given the high prevalence, seed mucilage may influence seedling ecology in temperate grasslands and requires further investigation.</p>","PeriodicalId":74457,"journal":{"name":"Plant-environment interactions (Hoboken, N.J.)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10880130/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139934590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-04eCollection Date: 2024-02-01DOI: 10.1002/pei3.10134
Erica Jaakkola, Heidi Hellén, Stefan Olin, Håkan Pleijel, Toni Tykkä, Thomas Holst
Oxidative stress from ozone (O3) causes plants to alter their emission of biogenic volatile organic compounds (BVOC) and their photosynthetic rate. Stress reactions from O3 on birch trees can result in prohibited plant growth and lead to increased BVOC emission rates as well as changes in their compound blend to emit more monoterpenes (MT) and sesquiterpenes (SQT). BVOCs take part in atmospheric reactions such as enhancing the production of secondary organic aerosols (SOA). As the compound blend and emission rate change with O3 stress, this can influence the atmospheric conditions by affecting the production of SOA. Studying the stress responses of plants provides important information on how these reactions might change, which is vital to making better predictions of the future climate. In this study, measurements were taken to find out how the leaves of mature mountain birch trees (Betula pubescens ssp. czerepanovii) respond to different levels of elevated O3 exposure in situ depending on leaf age. We found that leaves from both early and late summers responded with induced SQT emission after exposure to 120 ppb O3. Early leaves were, however, more sensitive to increased O3 concentrations, with enhanced emission of green leaf volatiles (GLV) and tendencies of both induced leaf senescence as well as poor recovery in the photosynthetic rate between exposures. Late leaves had more stable photosynthetic rates throughout the experiment and responded less to exposure at different O3 levels.
{"title":"Ozone stress response of leaf BVOC emission and photosynthesis in mountain birch (<i>Betula pubescens</i> spp. <i>czerepanovii</i>) depends on leaf age.","authors":"Erica Jaakkola, Heidi Hellén, Stefan Olin, Håkan Pleijel, Toni Tykkä, Thomas Holst","doi":"10.1002/pei3.10134","DOIUrl":"10.1002/pei3.10134","url":null,"abstract":"<p><p>Oxidative stress from ozone (O<sub>3</sub>) causes plants to alter their emission of biogenic volatile organic compounds (BVOC) and their photosynthetic rate. Stress reactions from O<sub>3</sub> on birch trees can result in prohibited plant growth and lead to increased BVOC emission rates as well as changes in their compound blend to emit more monoterpenes (MT) and sesquiterpenes (SQT). BVOCs take part in atmospheric reactions such as enhancing the production of secondary organic aerosols (SOA). As the compound blend and emission rate change with O<sub>3</sub> stress, this can influence the atmospheric conditions by affecting the production of SOA. Studying the stress responses of plants provides important information on how these reactions might change, which is vital to making better predictions of the future climate. In this study, measurements were taken to find out how the leaves of mature mountain birch trees (<i>Betula pubescens</i> ssp. <i>czerepanovii</i>) respond to different levels of elevated O<sub>3</sub> exposure in situ depending on leaf age. We found that leaves from both early and late summers responded with induced SQT emission after exposure to 120 ppb O<sub>3</sub>. Early leaves were, however, more sensitive to increased O<sub>3</sub> concentrations, with enhanced emission of green leaf volatiles (GLV) and tendencies of both induced leaf senescence as well as poor recovery in the photosynthetic rate between exposures. Late leaves had more stable photosynthetic rates throughout the experiment and responded less to exposure at different O<sub>3</sub> levels.</p>","PeriodicalId":74457,"journal":{"name":"Plant-environment interactions (Hoboken, N.J.)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10840370/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139699112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-07eCollection Date: 2024-02-01DOI: 10.1002/pei3.10132
Brian Wilsey, Andrew Kaul, H Wayne Polley
Climate change has initiated movement of both native and non-native (exotic) species across the landscape. Exotic species are hypothesized to establish from seed more readily than comparable native species. We tested the hypothesis that seed limitation is more important for exotic species than native grassland species. We compared seed limitation and invasion resistance over three growing seasons between 18 native and 18 exotic species, grown in both monocultures and mixtures in a field experiment. Half of the plots received a seed mix of the contrasting treatment (i.e., exotic species were seeded into native plots, and native species were seeded into exotic plots), and half served as controls. We found that (1) establishment in this perennial grassland is seed limited, (2) establishment from seed is greater in exotic than native species, and (3) community resistance to seedling establishment was positively related to diversity of extant species, but only in native communities. Native-exotic species diversity and composition differences did not converge over time. Our results imply that native to exotic transformations occur when diversity declines in native vegetation and exotic seeds arrive from adjacent sites, suggesting that managing for high diversity will reduce transformations to exotic dominance.
{"title":"Establishment from seed is more important for exotic than for native plant species.","authors":"Brian Wilsey, Andrew Kaul, H Wayne Polley","doi":"10.1002/pei3.10132","DOIUrl":"10.1002/pei3.10132","url":null,"abstract":"<p><p>Climate change has initiated movement of both native and non-native (exotic) species across the landscape. Exotic species are hypothesized to establish from seed more readily than comparable native species. We tested the hypothesis that seed limitation is more important for exotic species than native grassland species. We compared seed limitation and invasion resistance over three growing seasons between 18 native and 18 exotic species, grown in both monocultures and mixtures in a field experiment. Half of the plots received a seed mix of the contrasting treatment (i.e., exotic species were seeded into native plots, and native species were seeded into exotic plots), and half served as controls. We found that (1) establishment in this perennial grassland is seed limited, (2) establishment from seed is greater in exotic than native species, and (3) community resistance to seedling establishment was positively related to diversity of extant species, but only in native communities. Native-exotic species diversity and composition differences did not converge over time. Our results imply that native to exotic transformations occur when diversity declines in native vegetation and exotic seeds arrive from adjacent sites, suggesting that managing for high diversity will reduce transformations to exotic dominance.</p>","PeriodicalId":74457,"journal":{"name":"Plant-environment interactions (Hoboken, N.J.)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10840371/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139699267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Haftay Hailu Gebremedhn, Sintayehu Werkneh Dejene, Samuel Tuffa, Yayneshet Tesfay, Sylvanus Mensah, Adam John Mears Devenish
Abstract Traditional grazing management practices are central to rangeland productivity and biodiversity. However, the degradation of rangelands and loss of ecosystem services have raised concerns about the future of pastoralism as a form of land use. It is imperative to understand how these practices influence vegetation attributes, e.g., herbaceous species diversity and composition, growth forms (grass, forbs), life form (annuals, perennials), tree metrics (density, canopy cover, and biomass). This study evaluates vegetation shifts under three grazing management practices‐enclosures, open grazing, and browsing lands‐in the Somali pastoral ecosystem of Ethiopia. Enclosures exhibited the highest diversity in herbaceous species, with open grazing lands favoring forbs and annuals. Distinct compositional shifts in herbaceous species were observed across regimes, especially in grass and annuals. Enclosures had three times higher herbage biomass of open grazing and double that of browsing management practice. Conversely, browsing management practices presented optimal wood biomass, density, and canopy cover. The results highlight that a transition to combined enclosure and browsing practices can elevate plant production and diversity, benefiting the Somali rangeland economy. Consequently, dryland restoration should incorporate indigenous knowledge to ensure future rangeland sustainability and biodiversity preservation.
{"title":"The dynamics of vegetation diversity and biomass under traditional grazing in Ethiopia's Somali rangeland","authors":"Haftay Hailu Gebremedhn, Sintayehu Werkneh Dejene, Samuel Tuffa, Yayneshet Tesfay, Sylvanus Mensah, Adam John Mears Devenish","doi":"10.1002/pei3.10127","DOIUrl":"https://doi.org/10.1002/pei3.10127","url":null,"abstract":"Abstract Traditional grazing management practices are central to rangeland productivity and biodiversity. However, the degradation of rangelands and loss of ecosystem services have raised concerns about the future of pastoralism as a form of land use. It is imperative to understand how these practices influence vegetation attributes, e.g., herbaceous species diversity and composition, growth forms (grass, forbs), life form (annuals, perennials), tree metrics (density, canopy cover, and biomass). This study evaluates vegetation shifts under three grazing management practices‐enclosures, open grazing, and browsing lands‐in the Somali pastoral ecosystem of Ethiopia. Enclosures exhibited the highest diversity in herbaceous species, with open grazing lands favoring forbs and annuals. Distinct compositional shifts in herbaceous species were observed across regimes, especially in grass and annuals. Enclosures had three times higher herbage biomass of open grazing and double that of browsing management practice. Conversely, browsing management practices presented optimal wood biomass, density, and canopy cover. The results highlight that a transition to combined enclosure and browsing practices can elevate plant production and diversity, benefiting the Somali rangeland economy. Consequently, dryland restoration should incorporate indigenous knowledge to ensure future rangeland sustainability and biodiversity preservation.","PeriodicalId":74457,"journal":{"name":"Plant-environment interactions (Hoboken, N.J.)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135433003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Plants possess myriad defenses against their herbivores, including constitutive and inducible chemical compounds and regrowth strategies known as tolerance. Recent studies have shown that plant tolerance and resistance are positively associated given they are co‐localized in the same molecular pathway, the oxidative pentose phosphate pathway. However, given that both defensive strategies utilize carbon skeletons from a shared resource pool in the oxidative pentose phosphate pathway there are likely costs in maintaining both resistance‐tolerance strategies. Here we investigate fitness costs in maintaining both strategies by utilizing a double knockout of cyp79B2 and cyp79B3 , key enzymes in the biosynthetic process of indole glucosinolates, which convert tryptophan to indole‐3‐acetaldoxime (IAOx) and is further used to produce indole glucosinolates. These mutant plants are devoid of any indole glucosinolates thus reducing plant resistance. Results show that knocking out indole glucosinolate production and thus one of the resistance pathways leads to an approximate 94% increase in fitness compensation shifting the undercompensating wild‐type Columbia‐0 to an overcompensating genotype following damage. We discuss the potential mechanistic basis for the observed patterns.
{"title":"Molecular constraints on tolerance‐resistance trade‐offs: Is there a cost?","authors":"J. Miles Mesa, Ken N. Paige","doi":"10.1002/pei3.10125","DOIUrl":"https://doi.org/10.1002/pei3.10125","url":null,"abstract":"Abstract Plants possess myriad defenses against their herbivores, including constitutive and inducible chemical compounds and regrowth strategies known as tolerance. Recent studies have shown that plant tolerance and resistance are positively associated given they are co‐localized in the same molecular pathway, the oxidative pentose phosphate pathway. However, given that both defensive strategies utilize carbon skeletons from a shared resource pool in the oxidative pentose phosphate pathway there are likely costs in maintaining both resistance‐tolerance strategies. Here we investigate fitness costs in maintaining both strategies by utilizing a double knockout of cyp79B2 and cyp79B3 , key enzymes in the biosynthetic process of indole glucosinolates, which convert tryptophan to indole‐3‐acetaldoxime (IAOx) and is further used to produce indole glucosinolates. These mutant plants are devoid of any indole glucosinolates thus reducing plant resistance. Results show that knocking out indole glucosinolate production and thus one of the resistance pathways leads to an approximate 94% increase in fitness compensation shifting the undercompensating wild‐type Columbia‐0 to an overcompensating genotype following damage. We discuss the potential mechanistic basis for the observed patterns.","PeriodicalId":74457,"journal":{"name":"Plant-environment interactions (Hoboken, N.J.)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135112741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Nanobubble (NB) water has been shown to promote the growth of several types of plants and animals, but the mechanism underlying this promoting effect remains unclear. The present study evaluated the mechanism by which NBs maintain the freshness of cut flowers by keeping cut chrysanthemum ( Chrysanthemum morifolium Ramat.) flowers at the bud stage in vase water containing air NBs. The condition of petals and leaves was assessed to determine the vase life of these cut flowers. The NB treatment delayed bud opening and petal senescence of the inflorescences. Water absorption and transpiration by cut flower stems were lower in NB water than in distilled water (DW). Furthermore, when all the leaves were removed from the cut flower stems, no significant difference in vase life was observed between NB water and DW. These findings indicate that the inhibition of transpiration from leaves prolonged the vase life of NB‐treated cut chrysanthemum flowers. In the early stage of the treatment, NB treatment significantly reduced transpiration without closing stomata, suggesting that the reduction in transpiration observed in the NB‐treated plants might be due to the suppression of cuticular transpiration, defined as water loss through the epidermis. Surface tension, one of the important driving forces of water movement in plants, was not affected by the presence of NBs in water. To our knowledge, this is the first report to show that transpiration from leaves is inhibited by NB treatment.
{"title":"Nanobubbles in vase water inhibit transpiration and prolong the vase life of cut chrysanthemum flowers","authors":"Rie Nakazawa, Akito Tanaka, Naoki Hata, Hisato Minagawa, Emiko Harada","doi":"10.1002/pei3.10124","DOIUrl":"https://doi.org/10.1002/pei3.10124","url":null,"abstract":"Abstract Nanobubble (NB) water has been shown to promote the growth of several types of plants and animals, but the mechanism underlying this promoting effect remains unclear. The present study evaluated the mechanism by which NBs maintain the freshness of cut flowers by keeping cut chrysanthemum ( Chrysanthemum morifolium Ramat.) flowers at the bud stage in vase water containing air NBs. The condition of petals and leaves was assessed to determine the vase life of these cut flowers. The NB treatment delayed bud opening and petal senescence of the inflorescences. Water absorption and transpiration by cut flower stems were lower in NB water than in distilled water (DW). Furthermore, when all the leaves were removed from the cut flower stems, no significant difference in vase life was observed between NB water and DW. These findings indicate that the inhibition of transpiration from leaves prolonged the vase life of NB‐treated cut chrysanthemum flowers. In the early stage of the treatment, NB treatment significantly reduced transpiration without closing stomata, suggesting that the reduction in transpiration observed in the NB‐treated plants might be due to the suppression of cuticular transpiration, defined as water loss through the epidermis. Surface tension, one of the important driving forces of water movement in plants, was not affected by the presence of NBs in water. To our knowledge, this is the first report to show that transpiration from leaves is inhibited by NB treatment.","PeriodicalId":74457,"journal":{"name":"Plant-environment interactions (Hoboken, N.J.)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135316378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sabrina Dookie, Sirpaul Jaikishun, Abdullah Adil Ansari
Abstract Mangrove leaves have unique features that enable them to cope with shifting environmental conditions while preserving their general functionality and efficiency. We examined the morphological characteristics and chlorophyll content (spectroscopically) of 600 mature Avicennia germinans leaves selected from 30 trees located in one degraded, one restored, and one natural mangrove ecosystem along Guyana's coastline. Systematic sampling was carried out using the closest individual sampling method in the wet and dry seasons. We hypothesized that both habitat type and seasonality influence the leaf traits and chlorophyll content of A. germinans. Our findings showed that A. germinans leaves are mesophyllous, and traits such as leaf perimeter, area, length, width, dry mass, wet mass, turgid mass, leaf‐specific area, and relative water content showed fluctuations in ecosystems (one‐way ANOVA, p < .05) as well as seasonally (paired t ‐test, p < .05). Substantial, positive correlations ( p < .05, R > .75) were also established for over 10 leaf parameters in both seasons while PCA and multiple regression analyses further confirmed the strong relationships between leaf morphological features and their respective locations. Changes in chlorophyll concentration were most noticeable in the degraded ecosystem while variations in leaf traits were more pronounced in the restored mangrove area. This may be due to the various disturbances found in each ecosystem coupled with fluctuations in the seasons. Our results demonstrate that mangroves, to some extent, alter their plant structures to cope with environmental stressors present in the various ecosystems they thrive in to maintain their survival.
红树林树叶具有独特的特征,使它们能够应对不断变化的环境条件,同时保持其一般功能和效率。本文研究了圭亚那沿岸退化、恢复和自然红树林生态系统中30棵树的600片成熟Avicennia germinans叶片的形态特征和叶绿素含量(光谱)。在干湿季节采用最接近的个体抽样方法进行系统抽样。我们推测,生境类型和季节对发芽芽草叶片性状和叶绿素含量都有影响。研究结果表明,发芽草叶片为中叶类,叶片周长、面积、长度、宽度、干质量、湿质量、膨松质量、叶比面积和相对含水量等性状在生态系统中呈波动趋势(单向方差分析,p <.05)以及季节性(配对t检验,p <. 05)。实质性的正相关(p <.05, R >两个季节的10多个叶片参数均建立了0.75),PCA和多元回归分析进一步证实了叶片形态特征与各自位置之间的密切关系。在退化生态系统中,叶绿素浓度的变化最为显著,而在红树林恢复区,叶片性状的变化更为明显。这可能是由于在每个生态系统中发现的各种干扰加上季节的波动。我们的研究结果表明,红树林在某种程度上改变了它们的植物结构,以应对它们赖以生存的各种生态系统中存在的环境压力。
{"title":"<i>Avicennia germinans</i> leaf traits in degraded, restored, and natural mangrove ecosystems of Guyana","authors":"Sabrina Dookie, Sirpaul Jaikishun, Abdullah Adil Ansari","doi":"10.1002/pei3.10126","DOIUrl":"https://doi.org/10.1002/pei3.10126","url":null,"abstract":"Abstract Mangrove leaves have unique features that enable them to cope with shifting environmental conditions while preserving their general functionality and efficiency. We examined the morphological characteristics and chlorophyll content (spectroscopically) of 600 mature Avicennia germinans leaves selected from 30 trees located in one degraded, one restored, and one natural mangrove ecosystem along Guyana's coastline. Systematic sampling was carried out using the closest individual sampling method in the wet and dry seasons. We hypothesized that both habitat type and seasonality influence the leaf traits and chlorophyll content of A. germinans. Our findings showed that A. germinans leaves are mesophyllous, and traits such as leaf perimeter, area, length, width, dry mass, wet mass, turgid mass, leaf‐specific area, and relative water content showed fluctuations in ecosystems (one‐way ANOVA, p < .05) as well as seasonally (paired t ‐test, p < .05). Substantial, positive correlations ( p < .05, R > .75) were also established for over 10 leaf parameters in both seasons while PCA and multiple regression analyses further confirmed the strong relationships between leaf morphological features and their respective locations. Changes in chlorophyll concentration were most noticeable in the degraded ecosystem while variations in leaf traits were more pronounced in the restored mangrove area. This may be due to the various disturbances found in each ecosystem coupled with fluctuations in the seasons. Our results demonstrate that mangroves, to some extent, alter their plant structures to cope with environmental stressors present in the various ecosystems they thrive in to maintain their survival.","PeriodicalId":74457,"journal":{"name":"Plant-environment interactions (Hoboken, N.J.)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136012875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rice is more vulnerable to drought than maize, wheat, and sorghum because its water requirements remain high throughout the rice life cycle. The effects of drought vary depending on the timing, intensity, and duration of the events, as well as on the rice genotype and developmental stage. It can affect all levels of organization, from genes to the cells, tissues, and/or organs. In this study, a moderate water deficit was applied to two contrasting rice genotypes, IAC 25 and CIRAD 409, during their reproductive stage. Multi-level transcriptomic, metabolomic, physiological, and morphological analyses were performed to investigate the complex traits involved in their response to drought. Weighted gene network correlation analysis was used to identify the specific molecular mechanisms regulated by each genotype, and the correlations between gene networks and phenotypic traits. A holistic analysis of all the data provided a deeper understanding of the specific mechanisms regulated by each genotype, and enabled the identification of gene markers. Under non-limiting water conditions, CIRAD 409 had a denser shoot, but shoot growth was slower despite better photosynthetic performance. Under water deficit, CIRAD 409 was weakly affected regardless of the plant level analyzed. In contrast, IAC 25 had reduced growth and reproductive development. It regulated transcriptomic and metabolic activities at a high level, and activated a complex gene regulatory network involved in growth-limiting processes. By comparing two contrasting genotypes, the present study identified the regulation of some fundamental processes and gene markers, that drive rice development, and influence its response to water deficit, in particular, the importance of the biosynthetic and regulatory pathways for cell wall metabolism. These key processes determine the biological and mechanical properties of the cell wall and thus influence plant development, organ expansion, and turgor maintenance under water deficit. Our results also question the genericity of the antagonism between morphogenesis and organogenesis observed in the two genotypes.
{"title":"A multi-level approach reveals key physiological and molecular traits in the response of two rice genotypes subjected to water deficit at the reproductive stage.","authors":"Bénédicte Favreau, Camille Gaal, Isabela Pereira de Lima, Gaétan Droc, Sandrine Roques, Armel Sotillo, Florence Guérard, Valérie Cantonny, Bertrand Gakière, Julie Leclercq, Tanguy Lafarge, Marcel de Raissac","doi":"10.1002/pei3.10121","DOIUrl":"10.1002/pei3.10121","url":null,"abstract":"<p><p>Rice is more vulnerable to drought than maize, wheat, and sorghum because its water requirements remain high throughout the rice life cycle. The effects of drought vary depending on the timing, intensity, and duration of the events, as well as on the rice genotype and developmental stage. It can affect all levels of organization, from genes to the cells, tissues, and/or organs. In this study, a moderate water deficit was applied to two contrasting rice genotypes, IAC 25 and CIRAD 409, during their reproductive stage. Multi-level transcriptomic, metabolomic, physiological, and morphological analyses were performed to investigate the complex traits involved in their response to drought. Weighted gene network correlation analysis was used to identify the specific molecular mechanisms regulated by each genotype, and the correlations between gene networks and phenotypic traits. A holistic analysis of all the data provided a deeper understanding of the specific mechanisms regulated by each genotype, and enabled the identification of gene markers. Under non-limiting water conditions, CIRAD 409 had a denser shoot, but shoot growth was slower despite better photosynthetic performance. Under water deficit, CIRAD 409 was weakly affected regardless of the plant level analyzed. In contrast, IAC 25 had reduced growth and reproductive development. It regulated transcriptomic and metabolic activities at a high level, and activated a complex gene regulatory network involved in growth-limiting processes. By comparing two contrasting genotypes, the present study identified the regulation of some fundamental processes and gene markers, that drive rice development, and influence its response to water deficit, in particular, the importance of the biosynthetic and regulatory pathways for cell wall metabolism. These key processes determine the biological and mechanical properties of the cell wall and thus influence plant development, organ expansion, and turgor maintenance under water deficit. Our results also question the genericity of the antagonism between morphogenesis and organogenesis observed in the two genotypes.</p>","PeriodicalId":74457,"journal":{"name":"Plant-environment interactions (Hoboken, N.J.)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10564380/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41222851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}