Plant Species Research Articles

Ensemble Techniques in Plant Nutrient Deficiency Detection: A Survey

Abstract: Plant nutrient deficiency detection represents a critical challenge in modern agriculture, significantly im- pacting crop health, yield, and sustainable farming practices. This survey paper presents a comprehensive analysis of ensemble learning techniques for automated detection of plant nutrient deficiencies through image analysis. Our research evaluates a hybrid approach combining MobileNet’s efficient feature extraction capabilities with ensemble methods including Random Forest and Gradient Boosting algorithms. The methodology encompasses three key compo- nents: feature extraction using MobileNet’s lightweight architecture for processing plant leaf images, implementation of individual classification models, and development of ensemble techniques that leverage the strengths of multiple clas- sifiers. Through extensive experimentation and comparative analysis, our findings demonstrate that ensemble methods consistently outperform individual models, achieving superior accuracy in detecting nutrient deficiencies across various plant species. The integration of MobileNet with ensemble techniques provides a robust framework that balances com- putational efficiency with prediction accuracy. This research contributes to the advancement of precision agriculture by proposing a scalable, real-time solution for nutrient deficiency detection that can be practically implemented in field conditions, ultimately supporting improved crop management decisions and agricultural productivity..

Nature’s Library - Plant Identification Made Easy using Machine Learning

Plant species identification is essential for botany, agriculture, and environmental preservation. Manual observationbased traditional approaches take a lot of time and are prone to mistakes. The book "Nature's Library: Leaf Identification Made Easy Using Machine Learning" provides a scalable and effective method for classifying plants based on their leaves by utilising support vector machines (SVMs) and artificial neural networks (ANNs). To deal with changes in illumination, orientation, and background, the system processes leaf images using techniques like resizing, normalisation, and augmentation. Leaf characteristics including vein patterns, texture, and form are taken out and examined. While SVM provides robust classification in smaller feature spaces, ANNs automatically identify patterns in the derived data. Both models perform well when benchmarked for accuracy, precision, recall, and F1-score. Applications include mobile phones, agriculture, and biodiversity monitoring

Effects of three pretreatments on seed germination and seedling growth of Mansonia altissima (A. Chev.) in a nursery, a timber species exploited in Cote d'Ivoire

Côte d'Ivoire's forests are a reservoir of biodiversity. Indeed, they offer a diverse ecosystem service. However, they are subject to strong anthropogenic pressures, which have resulted in the disappearance of several plant species. This was the case of Mansonia altissima, a species renowned for the quality of its wood. Given the importance of this species, there is an urgent need to focus on its conservation. It is in this context that this study aims to improve seed multiplication and the growth of M. altissima seedlings with a view to using them in reforestation. To achieve this, three pretreatments were applied to the seeds. These were the control (T0), shelled and unsoaked winged fruit (T1) and winged fruit soaked in cold water for 48 hours and then shelled (T2). Data collected using a data collection form were subjected to statistical analysis. Results showed that T2 treatment recorded the best germination rate (83%). In terms of seedling growth, the pretreatments had a significant effect on seedling diameter (P > 0.05). As for height, which averaged around 8 cm, and number of leaves, which averaged 6 per individual for each pretreatment, no significant effect was observed. However, for a multiplication of the species, the pretreatment (T2) where the winged fruits are soaked in ordinary water for 48 h and then shelled is recommended.

An ethnobotanical survey of medicinal plants used in the Boujdour Province, Morocco

An ethnobotanical survey was carried out across the province of Boujdour in southern Morocco, with the aim of collecting detailed information about the use of medicinal and aromatic plants and evaluating the region's potential in contributing to traditional medicine. The 630 questionnaires used in the ethnobotanical survey show that of the 64 species of plants used which belong to 26 families, the Fabaceae family top the list as the primary contributor (10 species at a rate of 15,62 %). The leaves are the most used parts with a rate of 51.61%). The most widely used pharmaceutical form is the decoction with a rate of 42,58%. The oral route is the most used mode of administration with 69,32%. Of all the disorders and infections treated, the medicinal and aromatic plants identified were used in the treatment of 54 digestive diseases, with correspond to 31,58% of the diseases treated. The results obtained are a very valuable source of information for the region studied and for the national medicinal flora. They can be considered as a source of information for scientific research in the field of phytochemistry and pharmacology and for the purpose of searching for new natural substances.

What is left in miombo woodlands? Rarity and commonness of woody species, commercial timber species, and lawful harvestable diameter classes.

Mozambican miombo woodlands (MWs) have been experiencing severe anthropogenic threats, recognized to have an impact on plant species distribution, occurrence, diversity, and rarity patterns. Based on 3725 0.1ha plots distributed across the country's MWs, this study aimed to assess the species rarity and commonness, protection status, and availability of commercial timber in MWs under varied environmental conditions. Results show that, out of the 515 tree and shrub species found, 45% were rare, while just 10% were highly protected. Nine of the 112 commercial miombo species were not observed, and 15 were rare. Commercial-sized trees of the top nine desired species were extremely rare, some species had only 1 tree per 20ha and stem forms unsuitable for sawmilling. Selective overharvesting has also affected trees with no minimum felling diameter. Brachystegia spiciformis, B. boehmii, and Julbernardia globiflora stood out among the few timber species with commercially viable populations. MWs in the semi-arid ecoregion have lower species richness, fewer commercially viable populations, and a higher number of poorly protected species (51%). The rainy ecoregion has the highest percentage of poorly protected species (61%). Based on the results obtained, it was recommended that (1) timber harvesting should be restricted to the humid ecoregion, prohibited for the timber species that were either absent or rare, and halted for the top nine desired species; (2) except B. spiciformis, B. boehmii, and J. globiflora, MWs should preferably undergo a forest closure period corresponding to at least one cutting cycle; (3) to ensure long-term viability, a minimum harvestable density for commercial-sized trees should be determined for each species.

Plant Diversity Reduces the Risk of Antibiotic Resistance Genes in Agroecosystems.

Despite advances in dispersal mechanisms and risk assessment of antibiotic resistance genes (ARGs), how plants influence ARG contamination in agricultural soils remains underexplored. Here, the impacts of plant species and diversity on ARGs and mobile genetic elements (MGEs) in three agricultural soils are comprehensively investigated in a pot experiment. The results indicate that increased plant diversity reduces ARGs and MGEs abundance by 19.2%-51.2%, whereas plant species exhibit inconsistent and soil-dependent effects. Potential bacterial hosts harboring abundant ARGs have greater relative abundance than nonhosts, and both their richness and cumulative relative abundance are reduced by plant diversity. Notably, hosts inhibited by plant diversity present a greater relative abundance than the other hosts. The enriched compounds in root exudates due to plant diversity play a more important role in the metabolic network and contribute to rebalancing of the abundance of potential hosts and nonhosts. An independent test using pure organics reveals that higher resource diversity, resulting from increased plant diversity, reduces the relative abundance and mobility of abundant and high-risk ARGs. This study highlights the resource-mediated mitigation of the risks posed by ARG contamination and indicates that ensuring plant and resource diversity is a promising strategy for controlling ARGs in agroecosystems.

Plant interactions associated with a directional shift in the richness range size relationship during the Glacial-Holocene transition in the Arctic

A nearly ubiquitous negative relationship between taxonomic richness and mean range-size (average area of taxa) is observed across space. However, the complexity of the mechanism limits its applicability for conservation or range prediction. We explore whether the relationship holds over time, and whether plant speciation, environmental heterogeneity, or plant interactions are major factors of the relationship within northeast Siberia and Alaska. By analysing sedimentary ancient DNA from seven lakes, we reconstruct plant richness, biotic environmental heterogeneity, and mean range-size over the last 30,000 years. We find positive richness to range-size relationships during the glacial period, shifting to negative during the interglacial period. Our results indicate neither speciation nor environmental heterogeneity is the principal driver. Network analyses show more positive interactions during the glacial period, which may contribute to positive richness to range-size relationships. Conversely, in the interglacial environment, negative interactions may result in negative relationships. Our findings suggest potential susceptibility to invasion but conservation advantages in far northern tundra given their positive interactions.

Temperature-dependent variations in under-canopy herbaceous foliar diseases following shrub encroachment in grasslands

Shrub encroachment into grasslands poses a global concern, impacting species biodiversity and ecosystem functioning. Yet, the effect of shrub encroachment on herbaceous diseases and the dependence of that effect on climatic factors remain ambiguous. This study spans over 4,000 km, examining significant variability in temperature and precipitation. Our findings reveal that herbaceous plant species richness diminishes the pathogen load of foliar fungal diseases of herbaceous plants in both shrub and grassland patches. Temperature emerges as the primary driver of variations in herbaceous biomass and pathogen load within herbaceous plant communities. Disparities in herbaceous biomass between shrub and grassland patches elucidate changes in pathogen load. In colder regions, shrub encroachment diminishes herbaceous biomass and pathogen load. Conversely, in warmer regions, shrubs either do not reduce or even amplify pathogen load. These discoveries underscore the necessity for adaptive management strategies tailored to specific shrub encroachment scenarios.

Nanosensor for Fe(II) and Fe(III) Allowing Spatiotemporal Sensing in Planta.

Fluorescent nanosensors operating in planta have shown recent success toward informing basic plant biology and agricultural applications. We developed near-infrared (NIR) fluorescent nanosensors using the Corona Phase Molecular Recognition (CoPhMoRe) technique that distinguish Fe(II) and Fe(III) species with limit of detection as low as 10 nM. An anionic poly(p-phenyleneethynylene) (PPE) polyelectrolyte wrapped single-walled carbon nanotube (SWNT) shows up to 200% turn-on and 85% turn-off responses to Fe(II) and Fe(III), respectively, allowing spatial and temporal analysis of iron uptake in both foliar and root-to-shoot pathways. Our findings reveal species-dependent iron uptake efficiency, mobility, and utilization rates, which we show is primarily affected by the chelation status of iron source and by plant physiological conditions such as iron deficiency and treatment with the stress hormone, abscisic acid (ABA). The broad applicability of this sensor across important plant species highlights the potential of nanotechnology-enabled sensors to enable precise and sustainable nutrient management.

Molecular docking and differential rbcl gene expression reveal variation in glyphosate herbicide tolerance of sugarcane varieties.

Glyphosate is an extensively employed herbicide in agriculture, specifically for sugarcane cultivation. The situation is different with the extensive physiological and genetic effects exerted by this herbicide on a range of plant species, including sugarcane, whose model basis is still poorly characterized, although its primary mode of action, which acts on the EPSPS enzyme in the shikimic acid pathway, is completely elucidated. The current study was aimed at investigating the stability of glyphosate formulation, molecular interactions of glyphosate formulation with rbcL enzyme associated with chlorophyll metabolism, and its effects on varieties of sugarcane. The stability of a ground-up glyphosate formulation was assessed under accelerated storage conditions. Molecular docking was performed to analyze interactions between glyphosate derivatives and rbcL. Two sugarcane varieties (G84-47 and GT54-9) were treated with increasing glyphosate concentrations (0.2, 0.4, and 0.8 mg L-1) to evaluate effects on chlorophyll content, plant height, herbicide tolerance, and rbcL expression. The formulation showed good stability with minor degradation (47.55-47.14%). N-Nitrosoglyphosate and 2-(phosphonomethylamino)acetic acid exhibited favorable binding affinities with rbcL. Glyphosate treatment reduced chlorophyll content and plant height dose-dependently, with G84-47 showing higher sensitivity. GT54-9 demonstrated higher herbicide tolerance in survival analysis. rbcL expression remained stable in G84-47 but was significantly upregulated in GT54-9 under high herbicide stress. This study reveals genetic variability in sugarcane responses to glyphosate, with variety-specific mechanisms underlying stress adaptation. The inducible rbcL expression in tolerant varieties provides insights into herbicide resistance mechanisms. These findings can inform marker-assisted breeding and improve agronomic practices for enhanced sugarcane cultivation resilience and sustainability.

Ecological filters shape arbuscular mycorrhizal fungal communities in the rhizosphere of secondary vegetation species in a temperate forest.

The community assembly of arbuscular mycorrhizal fungi (AMF) in the rhizosphere results from the recruitment and selection of different AMF species with different functional traits. The aim of this study was to analyze the relationship between biotic and abiotic factors and the AMF community assembly in the rhizosphere of four secondary vegetation (SV) plant species in a temperate forest. We selected four sites at two altitudes, and we marked five individuals per plant species at each site. Soil rhizosphere samples were collected from each SV plant species, during the rainy and dry seasons. Soil samples from the rhizosphere of each plant species were analyzed for AMF spores, organic matter (OM), pH, soil moisture, and available phosphorus, and nitrogen. Three ecological filters influenced the AMF community assembly: host plant identity, abiotic factors, and AMF species co-occurrence. This assembly consisted of 61 AMF species, with different β-diversity values among plant species across seasons and altitudes. Canonical correspondence analysis revealed that AMF community composition is linked to OM and available P and N, with only a few AMF species co-occurring, while most do not. Our study highlights how ecological filters shape AMF structure, which is essential for understanding how soil and environmental factors affect AMF in SV plant species across seasons and altitudes.

Co-cropping of Bornmuellera emarginata, Lupinus albus and Imperata cylindrica: a study of metal uptake interactions and nickel phytoextraction efficiency

Co-cropping of hyperaccumulators is still poorly understood, while associations between hyperaccumulators and other plant species may promote beneficial plant interactions and lead to increased metal phytoextraction from contaminated soils. The aim of this study was to evaluate the phytoextraction potential of the Ni-hyperaccumulator Bornmuellera emarginata in different co-cropping combinations with Lupinus albus and Imperata cylindrica. Plants were grown in ultramafic soil in a growth chamber for 45 days and Al, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn concentrations in roots and leaves were analyzed. Translocation factors were used to evaluate Ni phytoextraction. Bornmuellera emarginata accumulated foliar Ni at contents ranging from 3,410 to 6,500 mg kg−1, with mean Ni concentrations in roots being seven times lower than in shoots (625–878 mg kg−1). Co-cropping led to a reduction in biomass (25–62%) of B. emarginata and did not substantially increase Ni concentrations in shoots. To conclude, intercropping did not significantly enhance Ni phytoextraction by B. emarginata. However, B. emarginata and L. albus in co-cropping showed high translocations (>1) for Co, Mn, Ni, and Zn, highlighting the potential of combining hyperaccumulators with other plant species as a viable strategy for phytoremediation of areas contaminated by multiple metals.

Harnessing Spectral Libraries From AVIRIS-NG Data for Precise PFT Classification: A Deep Learning Approach.

The generation of spectral libraries using hyperspectral data allows for the capture of detailed spectral signatures, uncovering subtle variations in plant physiology, biochemistry, and growth stages, marking a significant advancement over traditional land cover classification methods. These spectral libraries enable improved forest classification accuracy and more precise differentiation of plant species and plant functional types (PFTs), thereby establishing hyperspectral sensing as a critical tool for PFT classification. This study aims to advance the classification and monitoring of PFTs in Shoolpaneshwar wildlife sanctuary, Gujarat, India using Airborne Visible/Infrared Imaging Spectrometer-Next Generation (AVIRIS-NG) and machine learning techniques. A comprehensive spectral library was developed, encompassing data from 130 plant species, with a focus on their spectral features to support precise PFT classification. The spectral data were collected using AVIRIS-NG hyperspectral imaging and ASD Handheld Spectroradiometer, capturing a wide range of wavelengths (400-1600 nm) to encompass the key physiological and biochemical traits of the plants. Plant species were grouped into five distinct PFTs using Fuzzy C-means clustering. Key spectral features, including band reflectance, vegetation indices, and derivative/continuum properties, were identified through a combination of ISODATA clustering and Jeffries-Matusita (JM) distance analysis, enabling effective feature selection for classification. To assess the utility of the spectral library, three advanced machine learning classifiers-Parzen Window (PW), Gradient Boosted Machine (GBM), and Stochastic Gradient Descent (SGD)-were rigorously evaluated. The GBM classifier achieved the highest accuracy, with an overall accuracy (OAA) of 0.94 and a Kappa coefficient of 0.93 across five PFTs.

Assessing and optimizing the potential for climate change mitigation and carbon sequestration in urban residential green spaces: energizing sustainable cities

IntroductionUrban green spaces play a crucial role in mitigating climate change by sequestering atmospheric carbon dioxide. This study aimed to evaluate the carbon sequestration potential of common plant species in urban residential areas and provide recommendations for optimizing green space design and management.MethodsThe research was conducted in four residential areas of Nanjing, China, where key growth parameters of 20 plant species, including evergreen trees, deciduous trees, evergreen shrubs, and deciduous shrubs, were measured. The assimilation method was employed to calculate carbon sequestration per unit canopy area and for entire plants.ResultsThe results showed that the carbon sequestration capacities of different plant species and types exhibited significant differences, with p-values less than 0.05. In terms of daily carbon sequestration per unit canopy projection area, the ranking was as follows: evergreen trees > evergreen shrubs > deciduous trees > deciduous shrubs. For total plant carbon sequestration, the ranking was: evergreen trees > deciduous trees > evergreen shrubs > deciduous shrubs. Evergreen trees performed excellently in both carbon sequestration metrics, with the average daily carbon sequestration per unit canopy projection area and for the entire plant being 18.0024 g/(m2·d) and 462.28 g/d, respectively. The study also observed seasonal variations, with carbon sequestration rates being higher in autumn and summer compared to spring and winter. During the summer, the average daily carbon sequestration per unit canopy projection area and for the entire plant were 11.975 g/(m2·d) and 161.744 g/d, respectively, while in autumn, these values were 13.886 g/(m2·d) and 98.458 g/d. Seasonal variations were also observed, with autumn and summer exhibiting higher carbon sequestration rates compared to spring and winter. Additionally, CO2 concentrations were monitored across the four residential areas, providing insights into the spatial and temporal dynamics of carbon sequestration.DiscussionBased on the findings, optimization strategies were proposed, such as prioritizing the selection and integration of high-performing evergreen tree species in urban green space design and incorporating diverse plant types to enhance year-round carbon sequestration. This study contributes to the development of sustainable urban planning and landscape management practices, promoting the role of green spaces in mitigating climate change and enhancing urban resilience.

Comparative analysis of phytonutrients of Moringa oleifera leaves from South Africa and Nigeria, and their antimicrobial and antioxidant potentials by UPLC-ESI-QToF-MS and OPLS-DA chemometric analysis

BackgroundMoringa oleifera Lam. has bioactive phytonutrients in abundance and offers diverse health benefits. The leaves of this plant have established significance in traditional medicine and nutrition. It is traditionally used by Nigerian and South African mothers to mitigate undernutrition. Usually, the powder leaves are added to porridge to feed the children. This study aimed to conduct a comparative analysis of the phytonutrients (nutrients protectors) or supplements, antioxidant, and antimicrobial potentials of M. oleifera leaves from Nigeria and South Africa to benchmark quality control protocols for commercial beverages such as Moringa porridge.MethodsStandard techniques, including high-performance liquid chromatography-photodiode array and ultra-high-performance liquid chromatography electrospray ionization quadruple time-of-flight mass spectrometry (UPLC-ESI-QToF-MS) and chemometrics orthogonal partial least square discriminant analysis (OPLS-DA) were employed for phytoconstituents fingerprinting. Whereas the antioxidant potentials of the extracts were determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide scavenging assays, the antimicrobial potentials of the extracts were evaluated using minimum inhibitory concentrations protocol.ResultsThe chemometric analysis with a line regression (R2) = 0.97 revealed 70% significant similarities in the phytonutrients of samples between the two regions and an intriguing 30% variation within the same plant species. In addition, kaempferol, quercetin, luteolin, tangutorid E, and podophyllotoxin, among others were annotated as the major phytonutrients in the samples. The antioxidant assays unveiled concentration-dependent trends with scavenging activity of up to 98% (half-maximal inhibitory concentration [IC50] = 0.14 mg/mL) for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 87% (IC50 = 0.28 mg/mL) for hydrogen peroxide assay. All the test extracts did not exhibit good to significant antibacterial inhibitory effect (minimum inhibitory concentration [MIC] = 1.25 mg/mL) compared to ciprofloxacin (MIC = 0.0156–0.0039 mg/mL).ConclusionThe variations in the phytonutrients of the same M. oleifera species harvested from different countries could have dire consequences including potential health risks and even death. This study should serve as a benchmark toward the phytonutrients and marketing implications on the quality of products formulated with samples harvested from different growth environments and exists as a reference for further research into the cultivation and marketing of M. oleifera leaves in South Africa.

A DOF transcriptional repressor-gibberellin feedback loop plays a crucial role in modulating light-independent seed germination.

Plants evolved several strategies to cope with the ever-changing environment. One example of this is given by seed germination, which must occur when environmental conditions are suitable for plant life. In the model system Arabidopsis thaliana seed germination is induced by light; however in nature, seeds of several plant species can germinate regardless of this stimulus. Whereas the molecular mechanisms triggered by light for seed germination are well understood, the ones permitting plants to germinate in the dark are still vague mostly due to the lack of suitable model systems. Here we employ Cardamine hirsuta, a close Arabidopsis relative, as a powerful model system to uncover the molecular mechanisms underlying light-independent germination. Comparing Cardamine and Arabidopsis we show that the maintenance of the pro-germination hormone Gibberellin (GA) levels prompt Cardamine seeds to germinate in dark and light conditions. Via genetic and molecular biology experiments, we show that the Cardamine DOF transcriptional repressor DOF AFFECTING GERMINATION 1 (ChDAG1), homologous to the Arabidopsis DAG1 transcription factor, is involved in this process functioning to mitigate GA levels via negative regulation of ChGA3OX1 and ChGA3OX2 gibberellin biosynthetic genes, independently of light conditions. We also demonstrate that this mechanism is likely to be conserved in other Brassica species capable of germinating in dark conditions, such as Lepidium sativum and Camelina sativa. Our data support the proposal that Cardamine is a new model system suitable for light-independent germination studies. Exploiting this system we also resolved a long-time question about the mechanisms controlling the light-independent germination in plants, opening new frontiers for future studies.

Climate Change and Plant Foods: The Influence of Environmental Stressors on Plant Metabolites and Future Food Sources

Climate change is reshaping global agriculture by altering temperature regimes and other environmental conditions, with profound implications for food security and agricultural productivity. This review examines how key environmental stressors—such as extreme temperatures, water scarcity, increased salinity, UV-B radiation, and elevated concentrations of ozone and CO2—impact the nutritional quality and bioactive compounds in plant-based foods. These stressors can modify the composition of essential nutrients, particularly phytochemicals, which directly affect the viability of specific crops in certain regions and subsequently influence human dietary patterns by shifting the availability of key food resources. To address these challenges, there is growing interest in resilient plant species, including those with natural tolerance to stress and genetically modified variants, as well as in alternative protein sources derived from plants. Additionally, unconventional food sources, such as invasive plant species and algae, are being explored as sustainable solutions for future nutrition.

Hotter temperatures alter riparian plant outcomes under regulated river conditions

AbstractClimate change and river regulation alter environmental controls on riparian plant occurrence and cover worldwide. Simultaneous changes to river flow and air temperature could result in unanticipated plant responses to novel environmental conditions. Increasing temperature could alter riparian plant response to hydrology and other factors, while river regulation may exacerbate environmental stress through novel flows like those resulting from power generation. Further, plant establishment and growth may require differing conditions, which may be decoupled by novel conditions. Using a large dataset that spans a natural 5°C mean annual temperature (MAT) gradient and a Bayesian model that integrates plant occurrence and cover, we address four questions: (1) Does hotter MAT modify plant response to hydrology, substrate composition, topography, and cover of co‐occurring plant species? (2) Does the timing of hydropower tides benefit some species over others? (3) Does dam‐induced erosion hinder riparian species more than upland species? (4) Do occurrence and cover respond to different environmental variables, allowing for decoupling of life history processes? We addressed these questions with data collected along 364 km of the Colorado River downstream of Glen Canyon Dam, Arizona, United States of America. Occurrence and cover class were recorded in >10,000 plots from 2016 to 2020, along with environmental covariates that repeat across the climate gradient. For 36 species, plant occurrence and cover were modeled with respect to MAT, hydrology, substrate, topography, other plant cover, and their interactions with MAT. There were four key results. (1) Increasing MAT will not only directly influence plants but will mediate their responses to the environment, including greater dependence on stable water supplies. (2) The timing of hydropower tides shapes plant community composition. (3) Dam‐related erosion has an outsized effect on riparian species, which could lead to a loss of regionally unique plant species. (4) For all species, the most important covariates driving occurrence differed from those for cover, suggesting the potential for these life stages to be decoupled. Not only will climate change and river regulation independently alter plant distributions, interactions among hotter temperature, dam‐controlled flow patterns, and limited fine sediments will determine which species flourish or perish under future conditions.

Response of Leaf Non-Structural Carbohydrates to Elevation in Dioecious Plants, Populus cathayana and Hippophae rhamnoides

Non-structural carbohydrates (NSCs) can reflect the balance of resource allocation and trade-offs, as well as the adaptability of plants to the environment. Alterations in environmental conditions across an elevation gradient may impact the carbon balance within leaves. Nonetheless, it remains highly uncertain whether the effect of elevation on NSCs differs among species and sexes. To reveal the response patterns of leaf NSCs in dioecious plants with elevation, Populus cathayana Rehd. and Hippophae rhamnoides L., distributed at four elevations in the subalpine region of western Sichuan, China, were selected, and female and male leaves were sampled and measured for their contents of NSCs, soluble sugar, and starch. Meanwhile, the relationships of NSCs, soluble sugar, and starch with leaf nitrogen and phosphorus were analyzed. The results showed that the elevational patterns of NSCs were mainly dependent on species and were slightly affected by sex. Leaf NSCs in both sexes of P. cathayana did not exhibit significant linear changes, whereas those in H. rhamnoides increased significantly and linearly with elevation. For P. cathayana, a significant increase in leaf starch with elevation was only found in female plants and may benefit from phosphorus deficiency, as it was significantly negatively correlated with phosphorus. However, leaf soluble sugar and starch between sexes of H. rhamnoides showed similar patterns of significant increases with elevation, and they were not correlated significantly with nitrogen and phosphorus. This might be due to H. rhamnoides, which is a nitrogen-fixing plant and thereby did not show deficiencies or limitations in nitrogen and phosphorus, as shown by the decreased or unchanged elevational patterns of nitrogen/phosphorus, starch/phosphorus, and soluble sugar/phosphorus. Overall, our results emphasize that species, rather than sex, is an important factor influencing the elevational pattern of NSCs, but for specific species, such as P. cathayana, in this study, there was a divergence in the elevational response of the allocation of starch and soluble sugar between sexes, reflecting the specific adaptive strategies of different plant species or sexes in response to changes in the growing environment.

Copper-Induced Transgenerational Plasticity in Plant Defence Boosts Aphid Fitness.

Transgenerational plasticity in plants is an increasingly recognized phenomenon, yet it is mostly unclear whether transgenerational plasticity is relevant to both the fitness of the plant and its interacting species. Using monoclonal strains of the giant duckweed (Spirodela polyrhiza) and its native herbivore, the waterlily aphid (Rhopalosiphum nymphaeae), we assessed whether pre-treating plants with copper excess, both indoors and outdoors, induces transgenerational plasticity in plant defences that alter plant and herbivore fitness. Outdoors, copper pre-treatment tended to increase plant growth rates under recurring copper excess. Indoors, copper pre-treatment either increased or decreased plant growth rates under recurring conditions, depending on the plant genotype. Copper pre-treatment induced anthocyanins that protected plants against copper toxicity, and these elevated levels were transgenerationally retained. Copper pre-treatment also transgenerationally increased the levels of 12-oxo-phytodienoic acid (OPDA), a jasmonate precursor. Nevertheless, aphids grew up to 50% better when the plants were pre-treated with copper. The increased aphid growth was likely caused by transgenerationally elevated OPDA levels, as aphids grew better when jasmonates were externally applied to plants. Taken together, this study shows that transgenerational plasticity is relevant to both plant and herbivore fitness, which highlights the role of transgenerational plasticity in plant evolution and species interactions.