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1.
Nat Commun ; 13(1): 3185, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35676261

RESUMO

Due to massive energetic investments in woody support structures, trees are subject to unique physiological, mechanical, and ecological pressures not experienced by herbaceous plants. Despite a wealth of studies exploring trait relationships across the entire plant kingdom, the dominant traits underpinning these unique aspects of tree form and function remain unclear. Here, by considering 18 functional traits, encompassing leaf, seed, bark, wood, crown, and root characteristics, we quantify the multidimensional relationships in tree trait expression. We find that nearly half of trait variation is captured by two axes: one reflecting leaf economics, the other reflecting tree size and competition for light. Yet these orthogonal axes reveal strong environmental convergence, exhibiting correlated responses to temperature, moisture, and elevation. By subsequently exploring multidimensional trait relationships, we show that the full dimensionality of trait space is captured by eight distinct clusters, each reflecting a unique aspect of tree form and function. Collectively, this work identifies a core set of traits needed to quantify global patterns in functional biodiversity, and it contributes to our fundamental understanding of the functioning of forests worldwide.


Assuntos
Árvores , Biodiversidade , Florestas , Casca de Planta/fisiologia , Folhas de Planta/fisiologia , Raízes de Plantas/fisiologia , Sementes/fisiologia , Árvores/fisiologia , Madeira/fisiologia
2.
Nat Commun ; 13(1): 2381, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35501313

RESUMO

The relationships that control seed production in trees are fundamental to understanding the evolution of forest species and their capacity to recover from increasing losses to drought, fire, and harvest. A synthesis of fecundity data from 714 species worldwide allowed us to examine hypotheses that are central to quantifying reproduction, a foundation for assessing fitness in forest trees. Four major findings emerged. First, seed production is not constrained by a strict trade-off between seed size and numbers. Instead, seed numbers vary over ten orders of magnitude, with species that invest in large seeds producing more seeds than expected from the 1:1 trade-off. Second, gymnosperms have lower seed production than angiosperms, potentially due to their extra investments in protective woody cones. Third, nutrient-demanding species, indicated by high foliar phosphorus concentrations, have low seed production. Finally, sensitivity of individual species to soil fertility varies widely, limiting the response of community seed production to fertility gradients. In combination, these findings can inform models of forest response that need to incorporate reproductive potential.


Assuntos
Florestas , Sementes , Fertilidade , Reprodução , Sementes/fisiologia , Árvores
3.
Int J Mol Sci ; 23(9)2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35563227

RESUMO

A timely and efficient seed germination is critical for plantlets' establishment and robustness as well as plant development and plant performance in both natural ecosystems and agrosystems [...].


Assuntos
Germinação , Sementes , Ecossistema , Regulação da Expressão Gênica de Plantas , Germinação/fisiologia , Plantas , Sementes/fisiologia , Transdução de Sinais
4.
Sci Rep ; 12(1): 8793, 2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35614333

RESUMO

The monitoring and evaluating the physical and physiological quality of seeds throughout storage requires technical and financial resources and is subject to sampling and laboratory errors. Therefore, machine learning (ML) techniques could help optimize the processes and obtain accurate results for decision-making in the seed storage process. This study aimed to analyze the performance of ML algorithms from variables monitored during seed conditioning (temperature and packaging) and storage time to predict the physical and physiological quality of stored soybean seeds. Data analysis was performed using the Artificial Neural Networks, decision tree algorithms REPTree and M5P, Random Forest, and Linear Regression. In predicting seed quality, the combination of the input variables temperature and storage time for REPTree and Random Forest algorithms outperformed the linear regression, providing higher accuracy indices. Among the most important results, it was observed for apparent specific mass that T + P + ST, T + ST, P + ST, and ST had the highest r means and the lowest MAE means, however, Person's r coefficient for these inputs was 0.63 and the MAE between 9.59 to 10.47. The germination results for inputs T + P + ST and T + ST had the best results (r = 0.65 and r = 0.67, respectively) in the ANN, REPTree, M5P and RF models. Using computational intelligence algorithms is an excellent alternative to predict the quality of soybean seeds from the information of easy-to-measure variables.


Assuntos
Aprendizado de Máquina , Soja , Algoritmos , Inteligência Artificial , Humanos , Sementes/fisiologia
5.
Phytopathology ; 112(5): 1103-1117, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35365054

RESUMO

Promoting seed decay is an ecological approach to reducing weed persistence in the soil seedbank. Previous work demonstrated that Fusarium avenaceum F.a.1 decays dormant Avena fatua (wild oat) caryopses and induces several defense enzyme activities in vitro. The objectives of this study were to obtain a global perspective of proteins expressed after F.a.1-caryopsis colonization by conducting proteomic evaluations on (i) leachates, soluble extrinsic (seed-surface) proteins released upon washing caryopses in buffer and (ii) proteins extracted from whole caryopses; interactions with aluminum (Al) were also evaluated in the latter study because soil acidification and associated metal toxicity are growing problems. Of the 119 leachate proteins classified as defense/stress, 80 were induced or repressed. Defense/stress proteins were far more abundant in A. fatua (35%) than in F.a.1 (12%). Avena defense/stress proteins were also the most highly regulated category, with 30% induced and 35% repressed by F.a.1. Antifungal proteins represented 36% of Avena defense proteins and were the most highly regulated, with 36% induced and 37% repressed by F.a.1. These results implicate selective regulation of Avena defense proteins by F.a.1. Fusarium proteins were also highly abundant in the leachates, with 10% related to pathogenicity, 45% of which were associated with host cell wall degradation. In whole caryopsis extracts, fungal colonization generally resulted in induction of a similar set of Avena proteins in the presence and absence of Al. Results advance the hypothesis that seed decay pathogens elicit intricate and dynamic biochemical responses in dormant seeds.


Assuntos
Avena , Fusarium , Proteínas de Choque Térmico/metabolismo , Doenças das Plantas , Proteoma , Proteômica , Sementes/fisiologia , Solo
6.
Am J Bot ; 109(3): 486-493, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35253221

RESUMO

PREMISE: Does the seed size-seed number allocation trade-off model apply to long-term persistent soil seed banks? This trade-off between seed size versus number of seeds produced is usually applied at a single population on an annual basis. Our question is how this model might apply to close relatives that produce dormant seed forming long-term persistent soil seed banks. These two criteria allow a focus on divergent evolution of conspecifics and permits us to isolate seed size in the spectrum of life history traits that may be influencing seed traits, and on how seed size influences accumulation and persistence in the soil. METHODS: In California, Arctostaphylos species only produce physiologically dormant seed that are fire-stimulated and that vary in seed size permitting seed size-seed bank density relationship as a test of the seed size-seed number allocation model. Soil seed banks of 10 species of Arctostaphylos were sampled with fruit volumes ranging from 21-1063 mm3 . Seed bank density was determined by hand extraction from soil samples. RESULTS: We found that seed bank densities were significantly negatively related to fruit or seed size. CONCLUSIONS: Rather than an issue of allocational trade-off between size and number, we interpret these results as reflecting seed predation and postfire seedling establishment. Seed bank densities, even after decades, generally were less than one or two-year's seed production, suggesting intense seed predation. Burial by scatter-hoarding rodents provided sufficient seeds deep enough for survival of fire. Variation on seed size suggests seedling establishment constraints, but it needs further research.


Assuntos
Incêndios , Banco de Sementes , Plântula , Sementes/fisiologia , Solo
7.
New Phytol ; 234(5): 1770-1781, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35292965

RESUMO

Seed dormancy is an important life history state that increases survival and fitness of seed plants, and thus it has attracted much attention. However, global biogeography, effects of paleoenvironment, evolutionary roles of dormancy transitions, and differences in adaptations of seed dormancy between life-forms are poorly understood. We compiled global distribution records for seed dormancy of 12 743 species and their phylogeny to explore the biogeographic patterns, environmental drivers, and evolutionary transitions between seed dormancy and nondormancy. Biogeographic patterns reveal a low proportion of dormancy in tropical rainforest regions and arctic regions and a high proportion of dormancy in remaining tropical, subtropical, and temperate regions for all species and woody species. Herbaceous plants show a greater proportion of dormancy in most global regions except arctic regions. Seasonal environments have a consistent positive influence on the dormancy pattern for both life-forms, but precipitation and temperature were important driving factors for woody and herbaceous plants, respectively. Seed dormancy was the dominating state during the evolutionary history of seed plants, and dormancy transitions had a significant relationship with paleotemperatures. Dormancy and nondormancy transitions in response to fluctuating environments during long-term evolutionary history may have played important roles in the diversification of seed plants. Our results add to the current knowledge about seed dormancy from macro-adaptive perspectives and the potential adaptive mechanisms of seed plants.


Assuntos
Dormência de Plantas , Sementes , Aclimatação , Evolução Biológica , Germinação , Dormência de Plantas/fisiologia , Plantas , Floresta Úmida , Sementes/fisiologia
8.
New Phytol ; 234(5): 1629-1638, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35306670

RESUMO

Traits enabling seeds to survive post-dispersal desiccation and subsequently germinate are important aspects of plant regeneration for species with desiccation-sensitive seeds. However, how desiccation and germination-related traits co-vary and relate to patterns of climate variation are unknown. We investigated physiological traits related to desiccation and germination of desiccation-sensitive seeds from 19 Quercus species, which typically dominate subalpine, subtropical and temperate forests in China. The results demonstrate a strong relationship between climate and seed traits consistent with a hypothesis of minimizing seed death from desiccation. Seeds of subalpine species were most desiccation sensitive and died fastest when dried. These species avoided drought and cold by germinating rapidly. Subtropical and temperate oaks had more variable strategies to minimize the risk of mortality reflecting a continuum between traits that facilitate rapid germination (with the risk of rapid desiccation) and slow germination (and slow desiccation). Across the Quercus species, the relative level of seed desiccation sensitivity, which we predicted to be important for reducing the risk of drying related mortality, was independent of climate. For desiccation-sensitive seeds this suggests a more diverse range of strategies for minimizing desiccation risk than reported previously.


Assuntos
Quercus , China , Clima , Germinação/fisiologia , Quercus/fisiologia , Sementes/fisiologia
9.
J Plant Physiol ; 272: 153670, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35316704

RESUMO

Seeds often exhibit great plasticity of germination in response to environmental variability and uncertainty. The causes of this plasticity, however, remain poorly understood, and comparative phylogenic analyses of such plasticity are rare. Here, we analyzed a field germination dataset including 474 species exposed to three different levels of light availability, using comparative phylogenetic methods. We calculated the plasticity of germination in response to light availability (PGGP) based on the maximum germination proportion (GPmax), PGT50 based on the time required to reach 50% of GPmax, PGRGV based on the relative germination velocity (RGV), and PGTotal based on all three of these germination traits. We found that closely related species shared similar light plasticity of germination behavior. Different aspects of germination plasticity in response to light availability were related to specific traits or local environment. PGGP was associated with adult longevity and local water habitat, while PGT50 was related to seed mass and local water habitat, and PGRGV was marginally significantly related to plant height. PGTotal was significantly associated with adult longevity and water habitat. These results suggested that different aspects of germination plasticity were located at specific niche dimension, and local habitats with sufficient soil moisture induced great plasticity germination in response to light environment. As such, they can simplify our understanding of germination, promote the exploration of the general law of germination, and further increase our understanding of species diversity maintenance, adaptation, and evolution from the perspective of germination.


Assuntos
Germinação , Sementes , Germinação/fisiologia , Filogenia , Sementes/fisiologia , Tibet , Água
10.
Int J Mol Sci ; 23(3)2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35163798

RESUMO

Plants have evolved seeds to permit the survival and dispersion of their lineages by providing nutrition for embryo growth and resistance to unfavorable environmental conditions. Seed formation is a complicated process that can be roughly divided into embryogenesis and the maturation phase, characterized by accumulation of storage compound, acquisition of desiccation tolerance, arrest of growth, and acquisition of dormancy. Concerted regulation of several signaling pathways, including hormonal and metabolic signals and gene networks, is required to accomplish seed formation. Recent studies have identified the major network of genes and hormonal signals in seed development, mainly in maturation. Gibberellin (GA) and abscisic acids (ABA) are recognized as the main hormones that antagonistically regulate seed development and germination. Especially, knowledge of the molecular mechanism of ABA regulation of seed maturation, including regulation of dormancy, accumulation of storage compounds, and desiccation tolerance, has been accumulated. However, the function of ABA and GA during embryogenesis still remains elusive. In this review, we summarize the current understanding of the sophisticated molecular networks of genes and signaling of GA and ABA in the regulation of seed development from embryogenesis to maturation.


Assuntos
Ácido Abscísico/metabolismo , Giberelinas/metabolismo , Sementes/fisiologia , Vias Biossintéticas , Regulação da Expressão Gênica de Plantas , Germinação , Dormência de Plantas , Proteínas de Plantas/genética
11.
Sensors (Basel) ; 22(4)2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-35214417

RESUMO

Previous studies have demonstrated that light quality critically affects plant development and growth; however, the response depends upon the plant species. This research aims to examine the effects of different light wavelengths on sunflower (Helianthus annuus) sprouts that were stimulated during the night. Natural light and narrow-band light-emitting diodes (LEDs) were used for an analysis of sunflower sprouts grown under full light and specific light wavelengths. Sunflower seeds were germinated under different light spectra including red, blue, white, and natural light. Luminosity, temperature, and humidity sensors were installed in the plant nursery and remotely monitored and recorded by an Internet of Things (IoT) device. The experiment examined seed germination for seven days. The results showed that the red light had the most influence on sunflower seed germination, while the natural light had the most influence on the increase in the root and hypocotyl lengths.


Assuntos
Asteraceae , Helianthus , Internet das Coisas , Germinação/fisiologia , Sementes/fisiologia
12.
Plant Biol (Stuttg) ; 24(3): 464-472, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35226384

RESUMO

Seed germination characteristics help predict the degree of invasive success of a species based on capacity of the seeds to germinate and recruit into novel habitats. Hyptis suaveolens (L.) Poit. (Bush mint, Pignut; Lamiaceae) is an invasive plant that is spreading throughout tropical and subtropical regions worldwide. We conducted a study to understand the role of seed size dimorphism in differentiation of germination niche in H. suaveolens. We subjected small and large seeds to varying environmental conditions of temperature (°C), photoperiod (light/dark), salt (NaCl; mM), pH, osmotic potential (MPa), different soil types and ratios (clay:sand) and burial depth (cm). Different germination indices were calculated and their interaction with seed dimorphism studied. There was a significant interaction (P < 0.001) between germination indices and seed dimorphism throughout the treatments. Large seeds had higher germination percentage and rate, indicating higher germination capacity. In addition, these displayed more asynchronous germination under various environments. Small seeds, on the other hand, required a longer germination time as compared to large seeds, indicating slower germination. Differential responses of the two seed morphs to varying environmental conditions, therefore, help H. suaveolens to differentiate its germination niche and establish in heterogeneous environments. These findings will help in devising appropriate management and eradication strategies based on germination ecology of seeds.


Assuntos
Germinação , Hyptis , Sementes/fisiologia , Caracteres Sexuais , Temperatura
13.
J Exp Bot ; 73(8): 2454-2468, 2022 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-35106531

RESUMO

Understanding how the environment regulates seed-bank dormancy changes is essential for forecasting seedling emergence in actual and future climatic scenarios, and to interpret studies of dormancy mechanisms at physiological and molecular levels. Here, we used a population threshold modelling approach to analyse dormancy changes through variations in the thermal range permissive for germination in buried seeds of Arabidopsis thaliana Cvi, a winter annual ecotype. Results showed that changes in dormancy level were mainly associated with variations in the higher limit of the thermal range permissive for germination. Changes in this limit were positively related to soil temperature during dormancy release and induction, and could be predicted using thermal time. From this, we developed a temperature-driven simulation to predict the fraction of the seed bank able to germinate in a realistic global warming scenario that approximated seedling emergence timing. Simulations predicted, in accordance with seedling emergence observed in the field, an increase in the fraction of the seed bank able to emerge as a result of global warming. In addition, our results suggest that buried seeds perceive changes in the variability of the mean daily soil temperature as the signal to change between dormancy release and induction according to the seasons.


Assuntos
Arabidopsis , Arabidopsis/fisiologia , Germinação/fisiologia , Aquecimento Global , Dormência de Plantas/fisiologia , Estações do Ano , Plântula/fisiologia , Sementes/fisiologia , Solo , Temperatura
14.
Proc Natl Acad Sci U S A ; 119(9)2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35217598

RESUMO

Seed vigor in crops is important in terms of improving grain quality and germplasm conservation; however, little is known about its regulatory mechanisms through the encoded proteome and gene network. Comparative analyses of transcriptome (RNA sequencing [RNA-seq]) and broadly targeted metabolic profiling of two subspecific rice cultivars with distinct seed vigor during accelerated aging revealed various biological pathways and metabolic processes as key influences explaining trait differences. RNA-seq coexpression regulatory network analyses identified several transcription factors, including bZIP23 and bZIP42, that act as nodes in the gene network. Importantly, transgenic seeds of overexpression of bZIP23 enhanced seed vigor, whereas its gene knockout reduced seed vigor, suggesting that the protein it encodes functions as a positive regulator. Similarly, overexpression and knockout of PER1A that encodes a key player in the detoxification pathway enhanced and decreased seed vigor, respectively. We further demonstrated a direct interaction of the PER1A promoter with bZIP23 in seeds, which activates the expression of PER1A, and the genetic evidence suggested that bZIP23 most likely functions in a common pathway with and acts upstream of PER1A to modulate seed vigor. In addition, the control of seed vigor by the bZIP23-PER1A module was connected with that of the abscisic acid signaling pathway. Collectively, we revealed the genetic architecture of variation in seed vigor and uncovered the bZIP23-PER1A-mediated detoxification pathway that enhances the trait in rice.


Assuntos
Genoma de Planta , Vigor Híbrido , Metaboloma , Oryza/embriologia , Peroxirredoxinas/metabolismo , Proteínas de Plantas/metabolismo , Sementes/fisiologia , Ácido Abscísico/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Oryza/genética , Oryza/metabolismo , Sementes/metabolismo , Transdução de Sinais
15.
Plant Cell Environ ; 45(5): 1457-1473, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35188276

RESUMO

Re-establishment of desiccation tolerance is essential for the survival of germinated seeds facing water deficit in the soil. The molecular and ultrastructural features of desiccation tolerance maintenance and loss within the nuclear compartment are not fully resolved. In the present study, the impact of desiccation-induced genotoxic stress on nucleolar ultrastructure and ribogenesis was explored along the rehydration-dehydration cycle applied in standard seed vigorization protocols. Primed and overprimed Medicago truncatula seeds, obtained through hydropriming followed by desiccation (dry-back), were analysed. In contrast to desiccation-tolerant primed seeds, overprimed seeds enter irreversible germination and do not survive dry-back. Reactive oxygen species, DNA damage and expression profiles of antioxidant/DNA Damage Response genes were measured, as main hallmarks of the seed response to desiccation stress. Nuclear ultrastructural features were also investigated. Overprimed seeds subjected to dry-back revealed altered rRNA accumulation profiles and up-regulation of genes involved in ribogenesis control. The signal molecule PAP (3'-phosphoadenosine 5'-phosphate) accumulated during dry-back only in primed seeds, as a distinctive feature of desiccation tolerance. The presented results show the molecular and ultrastructural landscapes of the seed desiccation response, including substantial changes in nuclear organization.


Assuntos
Medicago truncatula , Difosfato de Adenosina , Dano ao DNA , Dessecação , Germinação/fisiologia , Medicago truncatula/metabolismo , Sementes/fisiologia
16.
Plant Cell Environ ; 45(5): 1474-1489, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35199338

RESUMO

Seed germination is a physiological process regulated by multiple factors. Abscisic acid (ABA) can inhibit seed germination to improve seedling survival under conditions of abiotic stress, and this process is often regulated by light signals. Constitutive photomorphogenic 1 (COP1) is an upstream core repressor of light signals and is involved in several ABA responses. Here, we demonstrate that COP1 is a negative regulator of the ABA-mediated inhibition of seed germination. Disruption of COP1 enhanced Arabidopsis seed sensitivity to ABA and increased reactive oxygen species (ROS) levels. In seeds, ABA induced the translocation of COP1 to the cytoplasm, resulting in enhanced ABA-induced ROS levels. Genetic evidence indicated that HY5 and ABI5 act downstream of COP1 in the ABA-mediated inhibition of seed germination. ABA-induced COP1 cytoplasmic localization increased HY5 and ABI5 protein levels in the nucleus, leading to increased expression of ABI5 target genes and ROS levels in seeds. Together, our results reveal that ABA-induced cytoplasmic translocation of COP1 activates the HY5-ABI5 pathway to promote the expression of ABA-responsive genes and the accumulation of ROS during ABA-mediated inhibition of seed germination. These findings enhance the role of COP1 in the ABA signal transduction pathway.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ácido Abscísico/metabolismo , Ácido Abscísico/farmacologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Citosol/metabolismo , Regulação da Expressão Gênica de Plantas , Germinação/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Sementes/fisiologia , Transdução de Sinais
17.
New Phytol ; 234(3): 850-866, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35175638

RESUMO

Reactive oxygen species (ROS) release seed dormancy through an unknown mechanism. We used different seed dormancy-breaking treatments to decipher the dynamics and localization of ROS production during seed germination. We studied the involvement of ROS in the breaking of Arabidopsis seed dormancy by cold stratification, gibberellic acid (GA3 ) and light. We characterized the effects of these treatments on abscisic acid and gibberellins biosynthesis and signalling pathways. ROS, mitochondrial redox status and peroxisomes were visualized and/or quantified during seed imbibition. Finally, we performed a cytogenetic characterization of the nuclei from the embryonic axes during seed germination. We show that mitochondria participate in the early ROS production during seed imbibition and that a possible involvement of peroxisomes in later stages should still be analysed. At the time of radicle protrusion, ROS accumulated within the nucleus, which correlated with nuclear expansion and chromatin decompaction. Taken together, our results provide evidence of the role of ROS trafficking between organelles and of the nuclear redox status in the regulation of seed germination by dormancy.


Assuntos
Arabidopsis , Dormência de Plantas , Ácido Abscísico/metabolismo , Ácido Abscísico/farmacologia , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Germinação , Giberelinas/metabolismo , Giberelinas/farmacologia , Dormência de Plantas/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Sementes/fisiologia
18.
Glob Chang Biol ; 28(9): 3066-3082, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35170154

RESUMO

Significant gaps remain in understanding the response of plant reproduction to environmental change. This is partly because measuring reproduction in long-lived plants requires direct observation over many years and such datasets have rarely been made publicly available. Here we introduce MASTREE+, a data set that collates reproductive time-series data from across the globe and makes these data freely available to the community. MASTREE+ includes 73,828 georeferenced observations of annual reproduction (e.g. seed and fruit counts) in perennial plant populations worldwide. These observations consist of 5971 population-level time-series from 974 species in 66 countries. The mean and median time-series length is 12.4 and 10 years respectively, and the data set includes 1122 series that extend over at least two decades (≥20 years of observations). For a subset of well-studied species, MASTREE+ includes extensive replication of time-series across geographical and climatic gradients. Here we describe the open-access data set, available as a.csv file, and we introduce an associated web-based app for data exploration. MASTREE+ will provide the basis for improved understanding of the response of long-lived plant reproduction to environmental change. Additionally, MASTREE+ will enable investigation of the ecology and evolution of reproductive strategies in perennial plants, and the role of plant reproduction as a driver of ecosystem dynamics.


Aún existen importantes vacíos en la comprensión de la respuesta reproductiva de las plantas al cambio medioambiental, en parte, porque su monitoreo en especies de plantas longevas requiere una observación directa durante muchos años, y estos conjuntos de datos rara vez han estado disponibles. Aquí presentamos a MASTREE +, una base de datos que recopila series de tiempo de la reproducción de las plantas de todo el planeta, poniendo a disposición estos datos de libre acceso para la comunidad científica. MASTREE + incluye 73.828 puntos de observación de la reproducción anual georreferenciados (ej. conteos de semillas y frutos) en poblaciones de plantas perennes en todo el mundo. Estas observaciones consisten en 5971 series temporales a nivel de población provenientes de 974 especies en 66 países. La mediana de la duración de las series de tiempo es de 10 años (media = 12.4 años) y el conjunto de datos incluye 1.122 series de al menos dos décadas (≥20 años de observaciones). Para un subconjunto de especies bien estudiadas, MASTREE +incluye un amplio conjunto de series temporales replicadas en gradientes geográficos y climáticos. Describimos el conjunto de datos de acceso abierto disponible como un archivo.csv y presentamos una aplicación web asociada para la exploración de datos. MASTREE+ proporcionará la base para mejorar la comprensión sobre la respuesta reproductiva de plantas longevas al cambio medioambiental. Además, MASTREE+ facilitará los avances en la investigación de la ecología y la evolución de las estrategias reproductivas en plantas perennes y el papel de la reproducción vegetal como determinante de la dinámica de ecosistemas.


Assuntos
Ecossistema , Reprodução , Ecologia , Plantas , Sementes/fisiologia
19.
Oecologia ; 198(4): 865-875, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34999943

RESUMO

Environmentally cued germination may play an important role in promoting coexistence in Mediterranean annual plant systems if it causes niche differentiation across heterogeneous microsite conditions. In this study, we tested how microsite conditions experienced by seeds in the field and light conditions in the laboratory influenced germination in 12 common annual plant species occurring in the understorey of the York gum-jam woodlands in southwest Western Australia. Specifically, we hypothesized that if germination promotes spatial niche differentiation, then we should observe species-specific germination responses to light. In addition, we hypothesized that species' laboratory germination response may depend on the microsite conditions experienced by seeds while buried. We tested the laboratory germination response of seeds under diurnally fluctuating light and complete darkness, which were collected from microsites spanning local-scale environmental gradients known to influence community structure in this system. We found that seeds of 6 out of the 12 focal species exhibited significant positive germination responses to light, but that the magnitude of these responses varied greatly with the relative light requirement for germination ranging from 0.51 to 0.86 for these species. In addition, germination increased significantly across a gradient of canopy cover for two species, but we found little evidence to suggest that species' relative light requirement for germination varied depending on seed bank microsite conditions. Our results suggest that variability in light availability may promote coexistence in this system and that the microsite conditions seeds experience in the intra-growing season period can further nuance species germination behaviour.


Assuntos
Germinação , Sementes , Austrália , Germinação/fisiologia , Luz , Dormência de Plantas/fisiologia , Estações do Ano , Sementes/fisiologia , Temperatura
20.
Am J Bot ; 109(3): 366-376, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34973037

RESUMO

PREMISE: Maternal effects have been demonstrated to affect offspring performance in many organisms, and in plants, seeds are important mediators of these effects. Some woody plant species maintain long-lasting canopy seed banks as an adaptation to wildfires. Importantly, these seeds stored in serotinous cones are produced by the mother plant under varying ontogenetic and physiological conditions. METHODS: We sampled the canopy seed bank of a highly serotinous population of Pinus pinaster to test whether maternal age and growth and the environmental conditions during each crop year affected seed mass and ultimately germination and early survival. After determining retrospectively the year of each seed cohort, we followed germination and early survival in a semi-natural common garden. RESULTS: Seed mass was related to maternal age and growth at the time of seed production; i.e., slow-growing, older mothers had smaller seeds, and fast-growing, young mothers had larger seeds, which could be interpreted either as a proxy of senescence or as a maternal strategy. Seed mass had a positive effect on germination success, but aside from differences in seed mass, maternal age had a negative effect and diameter had a positive effect on germination timing and subsequent survival. CONCLUSIONS: The results highlight the importance of maternal conditions combined with seed mass in shaping seedling establishment. Our findings open new insights in the offspring performance deriving from long-term canopy seed banks, which may have high relevance for plant adaptation.


Assuntos
Banco de Sementes , Traqueófitas , Germinação/fisiologia , Humanos , Idade Materna , Estudos Retrospectivos , Sementes/fisiologia
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