Plants from invasive populations often have higher growth rates than conspecifics from native populations due to better environmental adaptability. However, the roles of improved chlorophyll fluorescence or antioxidant defenses in helping them to grow better under adverse situations are insufficient, even though this is a key physiological question for elucidating mechanisms of plant invasion. Here, we conducted experiments with eight native (China) and eight introduced (US) populations of Chinese tallow tree (Triadica sebifera). We tested how salinity, nutrients (overall amount or N:P in two separate experiments) and their interaction affected T. sebifera aboveground biomass, leaf area, chlorophyll fluorescence and antioxidant defenses. Plants from introduced populations were larger than those from native populations but salinity and nutrient shortage (low nutrients or high N:P) reduced this advantage, possibly reflecting differences in chlorophyll fluorescence based on their higher PSII maximum photochemical efficiency (Fv/Fm) and PSI maximum photo-oxidizsable P700 in higher nutrient conditions. Native population plants had lower Fv/Fm with saline. Except in high nutrients/ N:P with salinity, introduced population plants had lower electron transfer rate and photochemical quantum yield. There were no differences in antioxidant defenses between introduced and native populations except accumulation of hydrogen peroxide (H2O2) which was lower for introduced populations. Low nutrients, high N:P or salinity increased total antioxidant capacity and H2O2. Our results indicate that nutrients and salinity induce differences in H2O2 contents and chlorophyll fluorescence characteristics between introduced and native populations of an invasive plant, illuminating adaptive mechanisms using photosynthetic physiological descriptors in order to predict invasions.
{"title":"Chlorophyll fluorescence characteristics and H2O2 contents of Chinese tallow tree are dependent on population origin, nutrients and salinity","authors":"Mengyue He, Lihong Ge, Xue Hui, Wenrao Li, Jianqing Ding, Evan Siemann","doi":"10.1093/aobpla/plae024","DOIUrl":"https://doi.org/10.1093/aobpla/plae024","url":null,"abstract":"Plants from invasive populations often have higher growth rates than conspecifics from native populations due to better environmental adaptability. However, the roles of improved chlorophyll fluorescence or antioxidant defenses in helping them to grow better under adverse situations are insufficient, even though this is a key physiological question for elucidating mechanisms of plant invasion. Here, we conducted experiments with eight native (China) and eight introduced (US) populations of Chinese tallow tree (Triadica sebifera). We tested how salinity, nutrients (overall amount or N:P in two separate experiments) and their interaction affected T. sebifera aboveground biomass, leaf area, chlorophyll fluorescence and antioxidant defenses. Plants from introduced populations were larger than those from native populations but salinity and nutrient shortage (low nutrients or high N:P) reduced this advantage, possibly reflecting differences in chlorophyll fluorescence based on their higher PSII maximum photochemical efficiency (Fv/Fm) and PSI maximum photo-oxidizsable P700 in higher nutrient conditions. Native population plants had lower Fv/Fm with saline. Except in high nutrients/ N:P with salinity, introduced population plants had lower electron transfer rate and photochemical quantum yield. There were no differences in antioxidant defenses between introduced and native populations except accumulation of hydrogen peroxide (H2O2) which was lower for introduced populations. Low nutrients, high N:P or salinity increased total antioxidant capacity and H2O2. Our results indicate that nutrients and salinity induce differences in H2O2 contents and chlorophyll fluorescence characteristics between introduced and native populations of an invasive plant, illuminating adaptive mechanisms using photosynthetic physiological descriptors in order to predict invasions.","PeriodicalId":48955,"journal":{"name":"AoB Plants","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140829189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fiona Ruth Worthy, Douglas Allen Shaefer, Dhanushka Wanasinghe, Jian Chu Xu, Li Song Wang, Xin Yu Wang
Background and Aims Cyanobacteria require liquid water for photosynthesis, whereas green algae can photosynthesise with water vapour alone. We discovered that several Lobaria spp. which normally have cyanobacteria as the sole photobiont, in some regions of the trans-Himalayas also harboured green algae. We tested whether green algal acquisition was: limited to high elevations; obtained from neighbouring chloro-Lobaria species; enabled photosynthesis at low humidity. Methods Lobaria spp. were collected from 2000 – 4000 m elevation. Spectrophotometry quantified green algal abundance by measuring chlorophyll b (absent in cyanobacteria). Thalli cross-sections visually confirmed green algal presence. We sequenced gene regions: Lobaria (ITS-EF-1α-RPB2), green algae (18S-RBC-L) and Nostoc (16S). Phylogenetic analysis determined myco-photobiont associations. We used a custom closed-circuit gas exchange system with an infrared gas analyzer to measure CO2 exchange rates for desiccated specimens at 33%, 76%, 86% and 98% humidity. Key results Cross-sections revealed that the photobiont layers in putative cyano-Lobaria contained both cyanobacteria and green algae, indicating that they should be considered chloro-cyanolichens. Chloro-Lobaria had no visible cephalodia nor cyanobacteria in the photobiont layer. Chloro-Lobaria and chloro-cyano-Lobaria had comparable levels of chlorophyll b. Chloro-Lobaria usually contained Symbiochloris. Chloro-cyano-Lobaria mainly associated with Parachloroidium and Nostoc; infrequently with Symbiochloris, Apatococcus, Chloroidium, Pseudochlorella, Trebouxia. Sequences from two green algal genera were obtained from within some thalli. Desiccated specimens of every Lobaria species could attain net photosynthesis with light exposure and 33% humidity. CO2 exchange dynamics over a five-day period differed between species. Conclusions At all elevations, chloro-cyano-Lobaria spp. had abundant green algae in the photobiont layer, but green algal strains mostly differed to those of chloro-Lobaria spp. Both chloro-Lobaria and chloro-cyano-Lobaria were capable of conducting photosynthesis without liquid water. The data strongly suggest that they attained positive net photosynthesis.
{"title":"Acquisition of green algal photobionts enables both chlorolichens and chloro-cyanolichens to activate photosynthesis at low humidity without liquid water","authors":"Fiona Ruth Worthy, Douglas Allen Shaefer, Dhanushka Wanasinghe, Jian Chu Xu, Li Song Wang, Xin Yu Wang","doi":"10.1093/aobpla/plae025","DOIUrl":"https://doi.org/10.1093/aobpla/plae025","url":null,"abstract":"Background and Aims Cyanobacteria require liquid water for photosynthesis, whereas green algae can photosynthesise with water vapour alone. We discovered that several Lobaria spp. which normally have cyanobacteria as the sole photobiont, in some regions of the trans-Himalayas also harboured green algae. We tested whether green algal acquisition was: limited to high elevations; obtained from neighbouring chloro-Lobaria species; enabled photosynthesis at low humidity. Methods Lobaria spp. were collected from 2000 – 4000 m elevation. Spectrophotometry quantified green algal abundance by measuring chlorophyll b (absent in cyanobacteria). Thalli cross-sections visually confirmed green algal presence. We sequenced gene regions: Lobaria (ITS-EF-1α-RPB2), green algae (18S-RBC-L) and Nostoc (16S). Phylogenetic analysis determined myco-photobiont associations. We used a custom closed-circuit gas exchange system with an infrared gas analyzer to measure CO2 exchange rates for desiccated specimens at 33%, 76%, 86% and 98% humidity. Key results Cross-sections revealed that the photobiont layers in putative cyano-Lobaria contained both cyanobacteria and green algae, indicating that they should be considered chloro-cyanolichens. Chloro-Lobaria had no visible cephalodia nor cyanobacteria in the photobiont layer. Chloro-Lobaria and chloro-cyano-Lobaria had comparable levels of chlorophyll b. Chloro-Lobaria usually contained Symbiochloris. Chloro-cyano-Lobaria mainly associated with Parachloroidium and Nostoc; infrequently with Symbiochloris, Apatococcus, Chloroidium, Pseudochlorella, Trebouxia. Sequences from two green algal genera were obtained from within some thalli. Desiccated specimens of every Lobaria species could attain net photosynthesis with light exposure and 33% humidity. CO2 exchange dynamics over a five-day period differed between species. Conclusions At all elevations, chloro-cyano-Lobaria spp. had abundant green algae in the photobiont layer, but green algal strains mostly differed to those of chloro-Lobaria spp. Both chloro-Lobaria and chloro-cyano-Lobaria were capable of conducting photosynthesis without liquid water. The data strongly suggest that they attained positive net photosynthesis.","PeriodicalId":48955,"journal":{"name":"AoB Plants","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140828897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rice leaf blades have intricate-shaped mesophyll cells (MCs) with a large volume of chloroplasts enhancing gas exchange between stroma and intercellular airspace (IAS). Since the rice MCs do not form palisade or spongy tissue cells and are considered as monotypic cells, the structural analysis of MCs in the middle part of the leaf tissue has been done, neglecting the various shapes of MCs can be observed on the cross-section of rice leaves. Moreover, the middle MC layer is sandwiched between the upper and lower layers and is more restricted in its demand for light and CO2 entering from the outside. Therefore, the different layers of MCs may differ in their sensitivity to salt stress that causes structural changes in cells. This study aims to elucidate the intra- and extra-cellular structures of MC in different layers of leaf tissue and determine how salinity affects the MC structure in each layer. The mesophyll tissue was divided into adaxial, middle, and abaxial layers, and eight MCs and chloroplast regions were selected from each layer and reconstructed into 3D representations. The whole leaf anatomical and physiological parameters were measured to find the effects of salinity stress on the MC structures. The 3D analysis of rice leaf tissue revealed the different structures of MCs with greater diversity in the adaxial and abaxial layers than in the middle layer. Salinity stress reduced the size and height of the MCs and coverage of the chloroplast on the cytoplasm periphery of the adaxial and abaxial layers, as well as the chloroplast size of adaxial MCs. These results reveal the variation of rice MC in leaf tissue and suggest the higher sensitivity to salt stress in the adaxial mesophyll among the layers, which may partly account for the decrease in photosynthetic capacity.
水稻叶片具有错综复杂的叶绿体中层细胞（MCs），叶绿体体积较大，可加强基质和细胞间空隙（IAS）之间的气体交换。由于水稻中叶细胞不形成栅状或海绵状组织细胞，被认为是单型细胞，因此只对叶片组织中间部分的中叶细胞进行结构分析，而忽略了在水稻叶片横截面上可以观察到的各种形状的中叶细胞。此外，中间 MC 层夹在上下层之间，对从外部进入的光照和 CO2 的需求受到较大限制。因此，不同的 MC 层对盐胁迫的敏感性可能不同，盐胁迫会导致细胞结构发生变化。本研究旨在阐明不同层叶片组织中 MC 的细胞内和细胞外结构，并确定盐分对各层 MC 结构的影响。 研究人员将叶肉组织分为正面层、中间层和背面层，并从每层叶肉组织中选取八个 MC 和叶绿体区域进行三维重建。测量了整个叶片的解剖和生理参数，以发现盐胁迫对 MC 结构的影响。 对水稻叶片组织的三维分析表明，叶片正面层和背面层的 MCs 结构各不相同，其多样性高于中间层。盐分胁迫降低了正面和背面层 MCs 的大小和高度、叶绿体在细胞质外围的覆盖率以及正面 MCs 的叶绿体大小。 这些结果揭示了水稻叶片组织中 MC 的变异，表明叶片各层中叶轴层对盐胁迫的敏感性更高，这可能是光合作用能力下降的部分原因。
{"title":"Structural changes of mesophyll cells in the rice leaf tissue in response to salinity stress based on the three-dimensional analysis","authors":"Rachana Ouk, T. Oi, Daisuke Sugiura, M. Taniguchi","doi":"10.1093/aobpla/plae016","DOIUrl":"https://doi.org/10.1093/aobpla/plae016","url":null,"abstract":"\u0000 \u0000 \u0000 Rice leaf blades have intricate-shaped mesophyll cells (MCs) with a large volume of chloroplasts enhancing gas exchange between stroma and intercellular airspace (IAS). Since the rice MCs do not form palisade or spongy tissue cells and are considered as monotypic cells, the structural analysis of MCs in the middle part of the leaf tissue has been done, neglecting the various shapes of MCs can be observed on the cross-section of rice leaves. Moreover, the middle MC layer is sandwiched between the upper and lower layers and is more restricted in its demand for light and CO2 entering from the outside. Therefore, the different layers of MCs may differ in their sensitivity to salt stress that causes structural changes in cells. This study aims to elucidate the intra- and extra-cellular structures of MC in different layers of leaf tissue and determine how salinity affects the MC structure in each layer.\u0000 \u0000 \u0000 \u0000 The mesophyll tissue was divided into adaxial, middle, and abaxial layers, and eight MCs and chloroplast regions were selected from each layer and reconstructed into 3D representations. The whole leaf anatomical and physiological parameters were measured to find the effects of salinity stress on the MC structures.\u0000 \u0000 \u0000 \u0000 The 3D analysis of rice leaf tissue revealed the different structures of MCs with greater diversity in the adaxial and abaxial layers than in the middle layer. Salinity stress reduced the size and height of the MCs and coverage of the chloroplast on the cytoplasm periphery of the adaxial and abaxial layers, as well as the chloroplast size of adaxial MCs.\u0000 \u0000 \u0000 \u0000 These results reveal the variation of rice MC in leaf tissue and suggest the higher sensitivity to salt stress in the adaxial mesophyll among the layers, which may partly account for the decrease in photosynthetic capacity.\u0000","PeriodicalId":48955,"journal":{"name":"AoB Plants","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140666245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shanice Van Haeften, Yichen Kang, Caitlin Dudley, Andries Potgieter, Hannah Robinson, Eric Dinglasan, Kylie Wenham, Thomas Noble, Lisa Kelly, Colin A Douglas, Lee Hickey, Millicent R Smith
Mungbean [Vigna radiata (L.) R. Wilczek var. radiata] is an important source of plant protein for consumers and a high-value export crop for growers across Asia, Australia, and Africa. However, many commercial cultivars are highly vulnerable to biotic stresses, which rapidly reduces yield within the season. Fusarium oxysporum is a soil-borne pathogen that is a growing concern for mungbean growers globally. This pathogen causes Fusarium wilt by infecting the root system of the plant resulting in devastating yield reductions. To understand the impact of Fusarium on mungbean development and productivity and to identify tolerant genotypes, a panel of 23 diverse accessions were studied. Field trials conducted in 2016 and 2021 in Warwick, Queensland, Australia under rainfed conditions investigated the variation in phenology, canopy and yield component traits under disease and disease-free conditions. Analyses revealed a high degree of genetic variation for all traits. By comparing the performance of these traits across these two environments, we identified key traits that underpin yield under disease and disease-free conditions. Aboveground biomass components at 50% flowering were identified as significant drivers of yield development under disease-free conditions and when impacted by Fusarium resulted in up to 96% yield reduction. Additionally, eight genotypes were identified to be tolerant to Fusarium. These genotypes were found to display differing phenological and morphological behaviours, thereby demonstrating the potential to breed for tolerant lines with a range of diverse trait variations. The identification of tolerant genotypes that sustain yield under disease pressure may be exploited in crop improvement programs.
绿豆 [Vigna radiata (L.) R. Wilczek var. radiata] 是消费者重要的植物蛋白来源，也是亚洲、澳大利亚和非洲种植者的高价值出口作物。然而，许多商业栽培品种极易受到生物胁迫的影响，从而在一季内迅速减产。Fusarium oxysporum 是一种土传病原体，是全球绿豆种植者日益关注的问题。这种病原体通过感染植物根系引起镰刀菌枯萎病，导致毁灭性减产。为了了解镰刀菌对绿豆生长发育和产量的影响，并确定耐受的基因型，研究人员对 23 个不同的品种进行了研究。2016 年和 2021 年，在澳大利亚昆士兰州沃里克市的雨水灌溉条件下进行了田间试验，调查了病害和无病害条件下的物候、冠层和产量成分性状的变化。分析表明，所有性状的遗传变异程度都很高。通过比较这些性状在两种环境下的表现，我们确定了在有病和无病条件下支撑产量的关键性状。在无病害条件下，50%开花期的地上生物量成分被确定为产量发展的重要驱动因素，而当受到镰刀菌影响时，产量减少高达96%。此外，还确定了 8 个耐镰刀菌的基因型。发现这些基因型表现出不同的表观和形态行为，从而证明了培育具有一系列不同性状变异的耐受性品系的潜力。在作物改良计划中，可以利用鉴定出的耐受性基因型来维持病害压力下的产量。
{"title":"Fusarium wilt constrains mungbean yield due to reduction in source availability","authors":"Shanice Van Haeften, Yichen Kang, Caitlin Dudley, Andries Potgieter, Hannah Robinson, Eric Dinglasan, Kylie Wenham, Thomas Noble, Lisa Kelly, Colin A Douglas, Lee Hickey, Millicent R Smith","doi":"10.1093/aobpla/plae021","DOIUrl":"https://doi.org/10.1093/aobpla/plae021","url":null,"abstract":"Mungbean [Vigna radiata (L.) R. Wilczek var. radiata] is an important source of plant protein for consumers and a high-value export crop for growers across Asia, Australia, and Africa. However, many commercial cultivars are highly vulnerable to biotic stresses, which rapidly reduces yield within the season. Fusarium oxysporum is a soil-borne pathogen that is a growing concern for mungbean growers globally. This pathogen causes Fusarium wilt by infecting the root system of the plant resulting in devastating yield reductions. To understand the impact of Fusarium on mungbean development and productivity and to identify tolerant genotypes, a panel of 23 diverse accessions were studied. Field trials conducted in 2016 and 2021 in Warwick, Queensland, Australia under rainfed conditions investigated the variation in phenology, canopy and yield component traits under disease and disease-free conditions. Analyses revealed a high degree of genetic variation for all traits. By comparing the performance of these traits across these two environments, we identified key traits that underpin yield under disease and disease-free conditions. Aboveground biomass components at 50% flowering were identified as significant drivers of yield development under disease-free conditions and when impacted by Fusarium resulted in up to 96% yield reduction. Additionally, eight genotypes were identified to be tolerant to Fusarium. These genotypes were found to display differing phenological and morphological behaviours, thereby demonstrating the potential to breed for tolerant lines with a range of diverse trait variations. The identification of tolerant genotypes that sustain yield under disease pressure may be exploited in crop improvement programs.","PeriodicalId":48955,"journal":{"name":"AoB Plants","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140602198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recent changes in water availability can be crucial for the development, growth, and carbon budget of forests. Therefore, our aim was to determine the effect of reduced throughfall and severe summer drought on stem CO2 efflux as a function of temperature and stem increment. Stem CO2 efflux was measured using the chamber method on oak and hornbeam under four treatments: coppice, thinned-coppice, and both coppice and thinned-coppice with 30%-reduced throughfall. The first year of the experiment had favourable soil water availability and the second year was characterized by a dry summer. While reduced throughfall had no effect on stem CO2 efflux, the summer drought decreased efflux by 43-81% during July and August. The stem CO2 efflux was reduced less severely (by 13-40%) in September when the drought persisted but the stem increment was already negligible. The stem increment was also strongly affected by the drought, which was reflected in its paired relationship with stem CO2 efflux over the two experimental years. The study showed that summer dry periods significantly and rapidly reduce stem CO2 efflux, whereas a constant 30% rainfall reduction needs probably a longer time to affect stem properties, and indirectly stem CO2 efflux.
{"title":"Does lower water availability limit stem CO2 efflux of oak and hornbeam coppices?","authors":"Eva Darenova, Robert Knott, Tomáš Vichta","doi":"10.1093/aobpla/plae023","DOIUrl":"https://doi.org/10.1093/aobpla/plae023","url":null,"abstract":"Recent changes in water availability can be crucial for the development, growth, and carbon budget of forests. Therefore, our aim was to determine the effect of reduced throughfall and severe summer drought on stem CO2 efflux as a function of temperature and stem increment. Stem CO2 efflux was measured using the chamber method on oak and hornbeam under four treatments: coppice, thinned-coppice, and both coppice and thinned-coppice with 30%-reduced throughfall. The first year of the experiment had favourable soil water availability and the second year was characterized by a dry summer. While reduced throughfall had no effect on stem CO2 efflux, the summer drought decreased efflux by 43-81% during July and August. The stem CO2 efflux was reduced less severely (by 13-40%) in September when the drought persisted but the stem increment was already negligible. The stem increment was also strongly affected by the drought, which was reflected in its paired relationship with stem CO2 efflux over the two experimental years. The study showed that summer dry periods significantly and rapidly reduce stem CO2 efflux, whereas a constant 30% rainfall reduction needs probably a longer time to affect stem properties, and indirectly stem CO2 efflux.","PeriodicalId":48955,"journal":{"name":"AoB Plants","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140602228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
André Dunedin Gossweiler, Brian C Smart, Brent S Hulke
The expansive range of Lewis flax (Linum lewisii Pursh.), an herbaceous perennial, exposes the species to a diversity of climatic conditions. As interest in the domestication and adoption of perennial crop alternatives grows and interest in this species for natural area restoration continues, the assurance of a commercial plant variety’s ability to endure the full range of possible climatic extremes is paramount. This study examines the freezing tolerance of a geographically representative sampling of 44 Lewis flax accessions at winter temperature extremes experienced in the northern Great Plains of the United States. Survival analysis models were adapted to include temperature exposure, in replacement of ordinal time typically used in such models, to produce statistics evaluating reactions to extreme temperatures that Lewis flax would encounter in our field environments. Our results revealed Lewis flax is more freezing tolerant than previously reported, and revealed four accessions with significantly superior genetic freezing tolerance than the released ‘Maple Grove’ cultivar. Furthermore, regrowth analyses indicate variation among accessions not associated with survival, which could lead to improving regrowth rate and survival simultaneously. These findings and their methodology expand the understanding of Lewis flax adaptation for winter hardiness and offer an efficient, new model that can be used to evaluate freezing tolerance at ordinal temperatures without requiring extensive prior physiological knowledge for a species.
{"title":"Survival analysis of freezing stress in the North American native perennial flax, Linum lewisii Pursh","authors":"André Dunedin Gossweiler, Brian C Smart, Brent S Hulke","doi":"10.1093/aobpla/plae022","DOIUrl":"https://doi.org/10.1093/aobpla/plae022","url":null,"abstract":"The expansive range of Lewis flax (Linum lewisii Pursh.), an herbaceous perennial, exposes the species to a diversity of climatic conditions. As interest in the domestication and adoption of perennial crop alternatives grows and interest in this species for natural area restoration continues, the assurance of a commercial plant variety’s ability to endure the full range of possible climatic extremes is paramount. This study examines the freezing tolerance of a geographically representative sampling of 44 Lewis flax accessions at winter temperature extremes experienced in the northern Great Plains of the United States. Survival analysis models were adapted to include temperature exposure, in replacement of ordinal time typically used in such models, to produce statistics evaluating reactions to extreme temperatures that Lewis flax would encounter in our field environments. Our results revealed Lewis flax is more freezing tolerant than previously reported, and revealed four accessions with significantly superior genetic freezing tolerance than the released ‘Maple Grove’ cultivar. Furthermore, regrowth analyses indicate variation among accessions not associated with survival, which could lead to improving regrowth rate and survival simultaneously. These findings and their methodology expand the understanding of Lewis flax adaptation for winter hardiness and offer an efficient, new model that can be used to evaluate freezing tolerance at ordinal temperatures without requiring extensive prior physiological knowledge for a species.","PeriodicalId":48955,"journal":{"name":"AoB Plants","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140601475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
It is of great significance to study the plant morphological structure for improving crop yield and achieving efficient use of resources. Three dimensional (3D) information can more accurately describe the morphological and structural characteristics of crop plants. Automatic acquisition of 3D information is one of the key steps in plant morphological structure research. Taking wheat as the research object, we propose a point cloud data-driven 3D reconstruction method that achieves 3D structure reconstruction and plant morphology parameterization at the phytomer scale. Specifically, we use the MVS-Pheno platform to reconstruct the point cloud of wheat plants and segment organs through the deep learning algorithm. On this basis, we automatically reconstructed the 3D structure of leaves and tillers and extracted the morphological parameters of wheat. The results show that the semantic segmentation accuracy of organs is 95.2%, and the instance segmentation accuracy AP50 is 0.665. The R2 values for extracted leaf length, leaf width, leaf attachment height, stem leaf angle, tiller length, and spike length were 0.97, 0.80, 1.00, 0.95, 0.99, and 0.95, respectively. This method can significantly improve the accuracy and efficiency of 3D morphological analysis of wheat plants, providing strong technical support for research in fields such as agricultural production optimization and genetic breeding.
{"title":"Using high-throughput phenotype platform MVS-Pheno to reconstruct the 3D morphological structure of wheat","authors":"Wenrui Li, Sheng Wu, Weiliang Wen, Xianju Lu, Haishen Liu, Minggang Zhang, Pengliang Xiao, Xinyu Guo, Chunjiang Zhao","doi":"10.1093/aobpla/plae019","DOIUrl":"https://doi.org/10.1093/aobpla/plae019","url":null,"abstract":"\u0000 It is of great significance to study the plant morphological structure for improving crop yield and achieving efficient use of resources. Three dimensional (3D) information can more accurately describe the morphological and structural characteristics of crop plants. Automatic acquisition of 3D information is one of the key steps in plant morphological structure research. Taking wheat as the research object, we propose a point cloud data-driven 3D reconstruction method that achieves 3D structure reconstruction and plant morphology parameterization at the phytomer scale. Specifically, we use the MVS-Pheno platform to reconstruct the point cloud of wheat plants and segment organs through the deep learning algorithm. On this basis, we automatically reconstructed the 3D structure of leaves and tillers and extracted the morphological parameters of wheat. The results show that the semantic segmentation accuracy of organs is 95.2%, and the instance segmentation accuracy AP50 is 0.665. The R2 values for extracted leaf length, leaf width, leaf attachment height, stem leaf angle, tiller length, and spike length were 0.97, 0.80, 1.00, 0.95, 0.99, and 0.95, respectively. This method can significantly improve the accuracy and efficiency of 3D morphological analysis of wheat plants, providing strong technical support for research in fields such as agricultural production optimization and genetic breeding.","PeriodicalId":48955,"journal":{"name":"AoB Plants","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140366576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Premise Heterostyly, a genetic style polymorphism, is linked to symmetric pollen transfer, vital for its maintenance. Clonal growth typically impacts sexual reproduction by influencing pollen transfer. However, the floral morph variation remains poorly understood under the combined effects of pollinators and clonal growth in heterostyly characterized by negative frequency-dependent selection and disassortative mating. Methods We estimated morph ratios, ramets per genet, and heterostylous syndrome, and quantified legitimate pollen transfer via clonal growth, pollinators, and reciprocal herkogamy between floral morphs in Limonium otolepis, a fragmented population composed of five subpopulations in the desert environment of northwestern China, with small flower and large floral morph variation. Results All subpopulations but one exhibited pollen-stigma morphology dimorphism. The compatibility between mating types with different pollen-stigma morphologies remained consistent regardless of reciprocal herkogamy. Biased ratios and ramets per genet of the two mating types with distinct pollen-stigma morphologies caused asymmetric pollen flow and varying fruit sets in all subpopulations. Short-tongued insects were the primary pollinators due to small flower sizes. However, pollen-feeding Syrphidae sp. triggered asymmetry in pollen flow between high and low sex organs, with short-styled morphs having lower stigma pollen depositions and greater variation. Clonal growth amplified this variation by reducing intermorph pollen transfer. Conclusions Pollinators and clonal growth jointly drive floral morph variation. H-morphs with the same stigma-anther position and self-incompatibility, which mitigate the disadvantages of sunken low sex organs with differing from the classical homostyly, might arise from long- and short-styled morphs through a “relaxed selection”. This study is the first to uncover the occurrence of the H-morph and its associated influencing factors in a distylous plant featuring clonal growth, small flowers, and a fragmented population.
{"title":"Floral morph variation mediated by clonal growth and pollinator functional groups of Limonium otolepis in a heterostylous fragmented population","authors":"Dengfu Ren, Fangfang Jiao, Aiqin Zhang, Jing Zhao, Jing Zhang","doi":"10.1093/aobpla/plae020","DOIUrl":"https://doi.org/10.1093/aobpla/plae020","url":null,"abstract":"Premise Heterostyly, a genetic style polymorphism, is linked to symmetric pollen transfer, vital for its maintenance. Clonal growth typically impacts sexual reproduction by influencing pollen transfer. However, the floral morph variation remains poorly understood under the combined effects of pollinators and clonal growth in heterostyly characterized by negative frequency-dependent selection and disassortative mating. Methods We estimated morph ratios, ramets per genet, and heterostylous syndrome, and quantified legitimate pollen transfer via clonal growth, pollinators, and reciprocal herkogamy between floral morphs in Limonium otolepis, a fragmented population composed of five subpopulations in the desert environment of northwestern China, with small flower and large floral morph variation. Results All subpopulations but one exhibited pollen-stigma morphology dimorphism. The compatibility between mating types with different pollen-stigma morphologies remained consistent regardless of reciprocal herkogamy. Biased ratios and ramets per genet of the two mating types with distinct pollen-stigma morphologies caused asymmetric pollen flow and varying fruit sets in all subpopulations. Short-tongued insects were the primary pollinators due to small flower sizes. However, pollen-feeding Syrphidae sp. triggered asymmetry in pollen flow between high and low sex organs, with short-styled morphs having lower stigma pollen depositions and greater variation. Clonal growth amplified this variation by reducing intermorph pollen transfer. Conclusions Pollinators and clonal growth jointly drive floral morph variation. H-morphs with the same stigma-anther position and self-incompatibility, which mitigate the disadvantages of sunken low sex organs with differing from the classical homostyly, might arise from long- and short-styled morphs through a “relaxed selection”. This study is the first to uncover the occurrence of the H-morph and its associated influencing factors in a distylous plant featuring clonal growth, small flowers, and a fragmented population.","PeriodicalId":48955,"journal":{"name":"AoB Plants","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140312684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mingli Hu, Zhanhong Ren, Ning Rong, Mei Bai, Hong Wu, Ming Yang
Evolution of cellular characteristics is a fundamental aspect of evolutionary biology, but knowledge about evolution at the cellular level is very limited. In particular, whether a certain intracellular characteristic evolved in angiosperms, and what significance of such evolution is to angiosperms, if it exists, are important and yet unanswered questions. We have found that bidirectional cytokinesis occurs or likely occurs in male meiosis in extant basal and near-basal angiosperm lineages, which differs from the unidirectional cytokinesis in male meiosis in monocots and eudicots. This pattern of cytokinesis in angiosperms seems to align with the distribution pattern of angiosperms with the lineages basal to monocots and eudicots living in tropical, subtropical, or temperate environments and monocots and eudicots in an expanded range of environments including tropical, subtropical, temperate, subarctic and arctic environments. These two cytokinetic modes seem to result from two phragmoplast types, respectively. A phragmoplast in the bidirectional cytokinesis dynamically associate with the leading edge of a growing cell plate whereas a phragmoplast in the unidirectional cytokinesis is localized to an entire division plane. The large assembly of microtubules in the phragmoplast in unidirectional cytokinesis may be indicative of increased microtubule stability compared with that of the small microtubule assembly in the phragmoplast in bidirectional cytokinesis. Microtubules could conceivably increase their stability from evolutionary changes in tubulins and/or microtubule-associated proteins. Microtubules are very sensitive to low temperatures, which should be a reason for plants to be sensitive to low temperatures. If monocots and eudicots have more stable microtubules than other angiosperms, they will be expected to deal with low temperatures better than other angiosperms. Future investigations into the male meiotic cytokinetic directions, microtubule stability at low temperatures, and proteins affecting microtubule stability in more species may shed light on how plants evolved to inhabit cold environments.
{"title":"A possible pattern in the evolution of male meiotic cytokinesis in angiosperms","authors":"Mingli Hu, Zhanhong Ren, Ning Rong, Mei Bai, Hong Wu, Ming Yang","doi":"10.1093/aobpla/plae017","DOIUrl":"https://doi.org/10.1093/aobpla/plae017","url":null,"abstract":"Evolution of cellular characteristics is a fundamental aspect of evolutionary biology, but knowledge about evolution at the cellular level is very limited. In particular, whether a certain intracellular characteristic evolved in angiosperms, and what significance of such evolution is to angiosperms, if it exists, are important and yet unanswered questions. We have found that bidirectional cytokinesis occurs or likely occurs in male meiosis in extant basal and near-basal angiosperm lineages, which differs from the unidirectional cytokinesis in male meiosis in monocots and eudicots. This pattern of cytokinesis in angiosperms seems to align with the distribution pattern of angiosperms with the lineages basal to monocots and eudicots living in tropical, subtropical, or temperate environments and monocots and eudicots in an expanded range of environments including tropical, subtropical, temperate, subarctic and arctic environments. These two cytokinetic modes seem to result from two phragmoplast types, respectively. A phragmoplast in the bidirectional cytokinesis dynamically associate with the leading edge of a growing cell plate whereas a phragmoplast in the unidirectional cytokinesis is localized to an entire division plane. The large assembly of microtubules in the phragmoplast in unidirectional cytokinesis may be indicative of increased microtubule stability compared with that of the small microtubule assembly in the phragmoplast in bidirectional cytokinesis. Microtubules could conceivably increase their stability from evolutionary changes in tubulins and/or microtubule-associated proteins. Microtubules are very sensitive to low temperatures, which should be a reason for plants to be sensitive to low temperatures. If monocots and eudicots have more stable microtubules than other angiosperms, they will be expected to deal with low temperatures better than other angiosperms. Future investigations into the male meiotic cytokinetic directions, microtubule stability at low temperatures, and proteins affecting microtubule stability in more species may shed light on how plants evolved to inhabit cold environments.","PeriodicalId":48955,"journal":{"name":"AoB Plants","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140297479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pramod Rathor, Punita Upadhyay, Aman Ullah, Linda Yuya Gorim, Malinda S Thilakarathna
Humic acids have been widely used for centuries to enhance plant growth and productivity. The beneficial effects of humic acids have been attributed to different functional groups and phytohormone-like compounds enclosed in macrostructure. However, the mechanisms underlying the plant growth-promoting effects of humic acids are only partially understood. We hypothesize that the bio-stimulatory effect of humic acids is mainly due to the modulation of innate pathways of auxin and cytokinin biosynthesis in treated plants. A physiological investigation along with molecular characterization was carried out to understand the mechanism of bio-stimulatory effects of humic acid. A gene expression analysis was performed for the genes involved in auxin and cytokinin biosynthesis pathways in wheat seedlings. Furthermore, Arabidopsis thaliana transgenic lines generated by fusing the auxin-responsive DR5 and cytokinin-responsive ARR5 promoter to ß-glucuronidase (GUS) reporter were used to study the GUS expression analysis in humic acid treated seedlings. This study demonstrates that humic acid treatment improved the shoot and root growth of wheat seedlings. The expression of several genes involved in auxin (Tryptophan Aminotransferase of Arabidopsis and Gretchen Hagen 3.2) and cytokinin (Lonely Guy3) biosynthesis pathways was up-regulated in humic acid treated seedlings compared to the control. Furthermore, GUS expression analysis showed that bioactive compounds of humic acid stimulate endogenous auxin and cytokinin-like activities. This study is the first report in which using ARR5 :GUS lines we demonstrate the biostimulants activity of humic acid.
{"title":"Humic Acid Improves Wheat Growth by Modulating Auxin and Cytokinin Biosynthesis Pathways","authors":"Pramod Rathor, Punita Upadhyay, Aman Ullah, Linda Yuya Gorim, Malinda S Thilakarathna","doi":"10.1093/aobpla/plae018","DOIUrl":"https://doi.org/10.1093/aobpla/plae018","url":null,"abstract":"Humic acids have been widely used for centuries to enhance plant growth and productivity. The beneficial effects of humic acids have been attributed to different functional groups and phytohormone-like compounds enclosed in macrostructure. However, the mechanisms underlying the plant growth-promoting effects of humic acids are only partially understood. We hypothesize that the bio-stimulatory effect of humic acids is mainly due to the modulation of innate pathways of auxin and cytokinin biosynthesis in treated plants. A physiological investigation along with molecular characterization was carried out to understand the mechanism of bio-stimulatory effects of humic acid. A gene expression analysis was performed for the genes involved in auxin and cytokinin biosynthesis pathways in wheat seedlings. Furthermore, Arabidopsis thaliana transgenic lines generated by fusing the auxin-responsive DR5 and cytokinin-responsive ARR5 promoter to ß-glucuronidase (GUS) reporter were used to study the GUS expression analysis in humic acid treated seedlings. This study demonstrates that humic acid treatment improved the shoot and root growth of wheat seedlings. The expression of several genes involved in auxin (Tryptophan Aminotransferase of Arabidopsis and Gretchen Hagen 3.2) and cytokinin (Lonely Guy3) biosynthesis pathways was up-regulated in humic acid treated seedlings compared to the control. Furthermore, GUS expression analysis showed that bioactive compounds of humic acid stimulate endogenous auxin and cytokinin-like activities. This study is the first report in which using ARR5 :GUS lines we demonstrate the biostimulants activity of humic acid.","PeriodicalId":48955,"journal":{"name":"AoB Plants","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140297455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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