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Suicmez B, Avci M. Distribution patterns of Quercus ilex from the last interglacial period to the future by ecological niche modeling. Ecol Evol 2023; 13:e10606. [PMID: 37869430 PMCID: PMC10585444 DOI: 10.1002/ece3.10606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 08/19/2023] [Accepted: 09/27/2023] [Indexed: 10/24/2023] Open
Abstract
The plants' geographic distribution is affected by natural or human-induced climate change. Numerous studies at both the global and regional levels currently focus on the potential changes in plant distribution areas. Ecological niche modeling can help predict the likely distribution of species according to environmental variables under different climate scenarios. In this study, we predicted the potential geographic distributions of Quercus ilex L. (holm oak), a keystone species of the Mediterranean ecosystem, for the Last Interglacial period (LIG: ~130 Ka), the Last Glacial Maximum (LGM: ~22 Ka), mid-Holocene (MH: ~6 Ka), and future climate scenarios (Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios) for 2050-2070 obtained from CCSM4 and MIROC-ESM global climate scenarios respectively. The models were produced with algorithms from the R-package "biomod2" and assessed by AUC of the receiver operating characteristic plot and true skill statistics. Aside from BIOCLIM (SRE), all model algorithms performed similarly and produced projections that are supported by good evaluation scores, although random forest (RF) slightly outperformed all the others. Additionally, distribution maps generated for the past period were validated through a comparison with pollen data acquired from the Neotoma Pollen Database. The results revealed that southern areas of the Mediterranean Basin, particularly coastal regions, served as long-term refugia for Q. ilex, which was supported by fossil pollen data. Furthermore, the models suggest long-term refugia role for Anatolia and we argue that Anatolia may have served as a founding population for the species. Future climate scenarios indicated that Q. ilex distribution varied by region, with some areas experiencing range contractions and others range expands. This study provides significant insights into the vulnerability of the Q. ilex to future climate change in the Mediterranean ecosystem and highlights the crucial role of Anatolia in the species' historical distribution.
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Affiliation(s)
- Burak Suicmez
- Istanbul University, Institute of Social SciencesIstanbulTürkiye
| | - Meral Avci
- Department of Geography, Faculty of LettersIstanbul UniversityIstanbulTürkiye
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Lin L, Jiang XL, Guo KQ, Byrne A, Deng M. Climate change impacts the distribution of Quercus section Cyclobalanopsis (Fagaceae), a keystone lineage in East Asian evergreen broadleaved forests. PLANT DIVERSITY 2023; 45:552-568. [PMID: 37936812 PMCID: PMC10625921 DOI: 10.1016/j.pld.2023.03.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 03/27/2023] [Accepted: 03/31/2023] [Indexed: 11/09/2023]
Abstract
East Asian evergreen broadleaved forests (EBFLs) harbor high species richness, but these ecosystems are severely impacted by global climate change and deforestation. Conserving and managing EBLFs requires understanding dominant tree distribution dynamics. In this study, we used 29 species in Quercus section Cyclobalanopsis-a keystone lineage in East Asian EBLFs-as proxies to predict EBLF distribution dynamics using species distribution models (SDMs). We examined climatic niche overlap, similarity, and equivalency among seven biogeographical regions' species using 'ecospat'. We also estimated the effectiveness of protected areas in the predicted range to elucidate priority conservation regions. Our results showed that the climatic niches of most geographical groups differ. The western species under the Indian summer monsoon regime were mainly impacted by temperature factors, whereas precipitation impacted the eastern species under the East Asian summer monsoon regime. Our simulation predicted a northward range expansion of section Cyclobalanopsis between 2081 and 2100, except for the ranges of the three Himalayan species analyzed, which might shrink significantly. The greatest shift of highly suitable areas was predicted for the species in the South Pacific, with a centroid shift of over 300 km. Remarkably, only 7.56% of suitable habitat is currently inside protected areas, and the percentage is predicted to continue declining in the future. To better conserve Asian EBLFs, establishing nature reserves in their northern distribution ranges, and transplanting the populations with predicted decreasing numbers and degraded habitats to their future highly suitable areas, should be high-priority objectives.
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Affiliation(s)
- Lin Lin
- School of Ecology and Environmental Sciences, Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Institute of Biodiversity, Yunnan University, Kunming 650500, Yunnan, China
- Laboratory of Ecology and Evolutionary Biology, State Key Laboratory for Conservation and Utilization of BioResources in Yunnan, Yunnan University, Kunming 650500, Yunnan, China
| | - Xiao-Long Jiang
- College of Forestry, Central South University of Forestry and Technology, Changsha 410004, Hunan, China
| | - Kai-Qi Guo
- College of Forestry, Central South University of Forestry and Technology, Changsha 410004, Hunan, China
- Shanghai Chenshan Botanical Garden, Shanghai 201602, China
| | - Amy Byrne
- The Morton Arboretum, Lile, IL 60532-1293, USA
| | - Min Deng
- School of Ecology and Environmental Sciences, Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Institute of Biodiversity, Yunnan University, Kunming 650500, Yunnan, China
- Laboratory of Ecology and Evolutionary Biology, State Key Laboratory for Conservation and Utilization of BioResources in Yunnan, Yunnan University, Kunming 650500, Yunnan, China
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3
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Zhong Y, Zhong Y, Xie Y, Lei Y, Wei B, Liu J, Yu M. Climate and fragment area jointly affect the annual dynamics of seedlings in different functional groups in the Thousand Island Lake. FRONTIERS IN PLANT SCIENCE 2023; 14:1200520. [PMID: 37389292 PMCID: PMC10303124 DOI: 10.3389/fpls.2023.1200520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 05/22/2023] [Indexed: 07/01/2023]
Abstract
Habitat fragmentation and climate change are the two main threats to global biodiversity. Understanding their combined impact on plant community regeneration is vital for predicting future forest structure and conserving biodiversity. This study monitored the seed production, seedling recruitment and mortality of woody plants in the Thousand Island Lake, a highly fragmented anthropogenic archipelago, for 5 years. We analyzed the seed-seedling transition, seedling recruitment and mortality of different functional groups in the fragmented forests and conducted correlation analyses involving climatic factors, island area, and plant community abundance. Our results showed that: 1) shade-tolerant and evergreen species had higher seed-seedling transition, seedling recruitment and survival rate than shade-intolerant and deciduous species in time and space, and these advantages increased with the island area. 2) Seedlings in different functional groups responded differently to island area, temperature and precipitation. 3) Increasing active accumulated temperature (the sum of the mean daily temperature above 0 °C) significantly increased seedling recruitment and survival, and warming climate favored the regeneration of evergreen species. 4) The seedling mortality rate of all plant functional groups increased with the increase of island area, but the increasing strength weakened significantly with the increase of the annual maximum temperature. These results suggested that the dynamics of woody plant seedlings varied among functional groups, and can be regulated separately and jointly by fragmentation and climate.
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Affiliation(s)
- Yuping Zhong
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Yuchen Zhong
- College of Life Sciences, Zhejiang University, Hangzhou, China
- Hangzhou Xuejun High School, Hangzhou, China
| | - Yuchu Xie
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Yanping Lei
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Boliang Wei
- College of Life Sciences, Zhejiang University, Hangzhou, China
- Wuyanling National Nature Reserve Administration of Zhejiang, Wenzhou, China
| | - Jinliang Liu
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
| | - Mingjian Yu
- College of Life Sciences, Zhejiang University, Hangzhou, China
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Kang H, Jaganathan GK, Han Y, Li J, Liu B. Revisiting the pericarp as a barrier restricting water entry/loss from cotyledons and embryonic axis of temperate desiccation-sensitive Quercus acorns. PLANTA 2023; 257:33. [PMID: 36609883 DOI: 10.1007/s00425-022-04061-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 12/21/2022] [Indexed: 06/17/2023]
Abstract
Fully mature acorns of Quercus variabilis, Q. aliena, Q. mongolica, and Q. glandulifera are desiccation-sensitive. X-ray computer tomography showed that cotyledons shrink during drying, but embryos are protected. Information available on recalcitrant acorns of tropical and sub-tropical species of Quercus suggests that an impermeable pericarp, which limits the entry and loss of water only through the hilum (scar), is the underlying mechanism that prevents drying of the embryo axis following dispersal until the germination season. However, there is a lack of consensus supporting this proposition across species, and it is not well understood if such mechanisms occur in temperate Quercus species. This study investigated the significance of the acorn pericarp for temperate oak species and presents an ecological framework based on the post-dispersal climatic conditions. Using Quercus variabilis, Q. aliena, Q. mongolica, and Q. glandulifera acorns, the relationship between moisture content (MC) and germination was established, and X-ray computed tomography (X-ray CT) was used to understand the internal structural changes of cotyledons and embryonic axis occurring during desiccation. Water entry and exit routes through the scar, pericarp and apex were determined by imbibition and drying experiments. Climatic data and acorn morphological characteristics and germination were subjected to a principal component analysis (PCA). Freshly dispersed acorns of all species had a moisture content (MC) above 35% fresh weight (FW) basis, but drying to 15-10% MC resulted in complete loss of viability, implying recalcitrance behaviour. X-ray CT images suggested that the pericarp offers some protection to cotyledons and embryonic axis during desiccation, but it is contingent on MC. Extensive drying to a low MC with the scar and apex covered with vaseline resulted in internal tissues shrinkage, corresponding with viability loss. Water could enter or exit through the pericarp, albeit at a much slower rate than through the scar. A combination of factors including acorn anatomy, moisture content at the time of dispersal, microhabitat, the position of acorns in the soil prevent embryo desiccation below the critical MC and thus promotes survival of acorns on/in the soil during winter in temperate regions. Pericarp anatomy, to some extent, prevents excessive drying of the embryonic axis by slowing water movement, but prolonged drying or predatory pressure could result in pericarp cracks, favouring the absorption of water during sporadic rain. In the latter case, the survival of acorns possibly depends extensively on the continuous erratic rainfall, i.e. continuous wet-dry cycle, but in-situ experiments are yet to be performed to test this hypothesis.
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Affiliation(s)
- Han Kang
- Germplasm Conservation Laboratory, Department of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, People's Republic of China
| | - Ganesh K Jaganathan
- Germplasm Conservation Laboratory, Department of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, People's Republic of China.
| | - Yingying Han
- Germplasm Conservation Laboratory, Department of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, People's Republic of China
| | - Jiajin Li
- Germplasm Conservation Laboratory, Department of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, People's Republic of China
| | - Baolin Liu
- Germplasm Conservation Laboratory, Department of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, People's Republic of China
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Xia K, Daws MI, Peng LL. Climate drives patterns of seed traits in Quercus species across China. THE NEW PHYTOLOGIST 2022; 234:1629-1638. [PMID: 35306670 DOI: 10.1111/nph.18103] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 03/03/2022] [Indexed: 05/26/2023]
Abstract
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.
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Affiliation(s)
- Ke Xia
- School of Ecology and Environmental Sciences, Yunnan University, Kunming, 650091, Yunnan, China
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Institute of Biodiversity, Yunnan University, Kunming, 650504, Yunnan, China
| | - Matthew I Daws
- Environment Department, Alcoa of Australia Ltd, Huntly Mine, off Del Park Road, PO Box 172, Pinjarra, WA, 6208, Australia
| | - Lin-Lin Peng
- School of Ecology and Environmental Sciences, Yunnan University, Kunming, 650091, Yunnan, China
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Institute of Biodiversity, Yunnan University, Kunming, 650504, Yunnan, China
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Escandón M, Bigatton ED, Guerrero-Sánchez VM, Hernández-Lao T, Rey MD, Jorrín-Novo JV, Castillejo MA. Identification of Proteases and Protease Inhibitors in Seeds of the Recalcitrant Forest Tree Species Quercus ilex. FRONTIERS IN PLANT SCIENCE 2022; 13:907042. [PMID: 35832232 PMCID: PMC9271950 DOI: 10.3389/fpls.2022.907042] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 06/06/2022] [Indexed: 05/09/2023]
Abstract
Proteases and protease inhibitors have been identified in the recalcitrant species Quercus ilex using in silico and wet methods, with focus on those present in seeds during germination. In silico analyses showed that the Q. ilex transcriptome database contained 2,240 and 97 transcripts annotated as proteases and protease inhibitors, respectively. They belonged to the different families according to MEROPS, being the serine and metallo ones the most represented. The data were compared with those previously reported for other Quercus species, including Q. suber, Q. lobata, and Q. robur. Changes in proteases and protease inhibitors alongside seed germination in cotyledon and embryo axis tissues were assessed using proteomics and in vitro and in gel activity assays. Shotgun (LC-MSMS) analysis of embryo axes and cotyledons in nonviable (NV), mature (T1) and germinated (T3) seeds allowed the identification of 177 proteases and 12 protease inhibitors, mostly represented by serine and metallo types. Total protease activity, as determined by in vitro assays using azocasein as substrate, was higher in cotyledons than in embryo axes. There were not differences in activity among cotyledon samples, while embryo axis peaked at germinated T4 stage. Gel assays revealed the presence of protease activities in at least 10 resolved bands, in the Mr range of 60-260 kDa, being some of them common to cotyledons and embryo axes in either nonviable, mature, and germinated seeds. Bands showing quantitative or qualitative changes upon germination were observed in embryo axes but not in cotyledons at Mr values of 60-140 kDa. Proteomics shotgun analysis of the 10 bands with protease activity supported the results obtained in the overall proteome analysis, with 227 proteases and 3 protease inhibitors identified mostly represented by the serine, cysteine, and metallo families. The combined use of shotgun proteomics and protease activity measurements allowed the identification of tissue-specific (e.g., cysteine protease inhibitors in embryo axes of mature acorns) and stage-specific proteins (e.g., those associated with mobilization of storage proteins accumulated in T3 stage). Those proteins showing differences between nonviable and viable seeds could be related to viability, and those variables between mature and germinated could be associated with the germination process. These differences are observed mostly in embryo axes but not in cotyledons. Among them, those implicated in mobilization of reserve proteins, such as the cathepsin H cysteine protease and Clp proteases, and also the large number of subunits of the CNS and 26S proteasome complex differentially identified in embryos of the several stages suggests that protein degradation via CNS/26S plays a major role early in germination. Conversely, aspartic proteases such as nepenthesins were exclusively identified in NV seeds, so their presence could be used as indicator of nonviability.
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Affiliation(s)
- Monica Escandón
- Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, University of Córdoba, Córdoba, Spain
| | - Ezequiel D. Bigatton
- Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, University of Córdoba, Córdoba, Spain
- Agricultural Microbiology, Faculty of Agricultural Science, National University of Córdoba, CONICET, Córdoba, Argentina
| | - Victor M. Guerrero-Sánchez
- Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, University of Córdoba, Córdoba, Spain
| | - Tamara Hernández-Lao
- Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, University of Córdoba, Córdoba, Spain
| | - Maria-Dolores Rey
- Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, University of Córdoba, Córdoba, Spain
| | - Jesus V. Jorrín-Novo
- Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, University of Córdoba, Córdoba, Spain
- Jesus V. Jorrín-Novo,
| | - Maria Angeles Castillejo
- Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, University of Córdoba, Córdoba, Spain
- *Correspondence: Maria Angeles Castillejo,
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Le Roncé I, Toïgo M, Dardevet E, Venner S, Limousin JM, Chuine I. Resource manipulation through experimental defoliation has legacy effects on allocation to reproductive and vegetative organs in Quercus ilex. ANNALS OF BOTANY 2020; 126:1165-1179. [PMID: 32686832 PMCID: PMC7684701 DOI: 10.1093/aob/mcaa137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND AND AIMS In plants, high costs of reproduction during some years can induce trade-offs in resource allocation with other functions such as growth, survival and resistance against herbivores or extreme abiotic conditions, but also with subsequent reproduction. Such trade-offs might also occur following resource shortage at particular moments of the reproductive cycle. Because plants are modular organisms, strategies for resource allocation to reproduction can also vary among hierarchical levels. Using a defoliation experiment, our aim was to test how allocation to reproduction was impacted by resource limitation. METHODS We applied three levels of defoliation (control, moderate and intense) to branches of eight Quercus ilex trees shortly after fruit initiation and measured the effects of resource limitation induced by leaf removal on fruit development (survival, growth and germination potential) and on the production of vegetative and reproductive organs the year following defoliation. KEY RESULTS We found that defoliation had little impact on fruit development. Fruit survival was not affected by the intense defoliation treatment, but was reduced by moderate defoliation, and this result could not be explained by an upregulation of photosynthesis. Mature fruit mass was not affected by defoliation, nor was seed germination success. However, in the following spring defoliated branches produced fewer shoots and compensated for leaf loss by overproducing leaves at the expense of flowers. Therefore, resource shortage decreased resource allocation to reproduction the following season but did not affect sex ratio. CONCLUSIONS Our results support the idea of a regulation of resource allocation to reproduction beyond the shoot scale. Defoliation had larger legacy effects than immediate effects.
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Affiliation(s)
- Iris Le Roncé
- CEFE, Univ. Montpellier, CNRS, EPHE, IRD, Univ. Paul Valéry Montpellier 3, Montpellier, France
| | - Maude Toïgo
- CEFE, Univ. Montpellier, CNRS, EPHE, IRD, Univ. Paul Valéry Montpellier 3, Montpellier, France
| | - Elia Dardevet
- CEFE, Univ. Montpellier, CNRS, EPHE, IRD, Univ. Paul Valéry Montpellier 3, Montpellier, France
| | - Samuel Venner
- Laboratoire de Biométrie et Biologie Évolutive, UMR 5558, Université de Lyon, Université Lyon 1, CNRS, Villeurbanne, France
| | - Jean-Marc Limousin
- CEFE, Univ. Montpellier, CNRS, EPHE, IRD, Univ. Paul Valéry Montpellier 3, Montpellier, France
| | - Isabelle Chuine
- CEFE, Univ. Montpellier, CNRS, EPHE, IRD, Univ. Paul Valéry Montpellier 3, Montpellier, France
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Amimi N, Dussert S, Vaissayre V, Ghouil H, Doulbeau S, Costantini C, Ammari Y, Joët T. Variation in seed traits among Mediterranean oaks in Tunisia and their ecological significance. ANNALS OF BOTANY 2020; 125:891-904. [PMID: 31904087 PMCID: PMC7218815 DOI: 10.1093/aob/mcz211] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 01/02/2020] [Indexed: 05/28/2023]
Abstract
BACKGROUND AND AIMS Oaks are the foundation and dominant tree species of most Mediterranean forests. As climate models predict dramatic changes in the Mediterranean basin, a better understanding of the ecophysiology of seed persistence and germination in oaks could help define their regeneration niches. Tunisian oaks occupy distinct geographical areas, which differ in their rainfall and temperature regimes, and are thus a valuable model to investigate relationships between seed traits and species ecological requirements. METHODS Seed morphological traits, desiccation sensitivity level, lethal freezing temperature, embryonic axis and cotyledon sugar and lipid composition, and seed and acorn germination rates at various constant temperatures were measured in Quercus canariensis, Q. coccifera, Q. ilex and Q. suber, using seeds sampled in 22 Tunisian woodlands. KEY RESULTS Only faint differences were observed for desiccation sensitivity in the oak species studied. By contrast, the species differed significantly in sensitivity to freezing, germination rates at low temperature and base temperature. Quercus ilex and Q. canariensis, which occur at high elevations where frost events are frequent, showed the lowest freezing sensitivity. A significant correlation was found between hexose contents in the embryonic axis and freezing tolerance. Significant interspecific differences in the time for seeds to germinate and the time for the radicle to pierce the pericarp were observed. The ratio of pericarp mass to acorn mass differed significantly among the species and was negatively correlated with the acorn germination rate. Quercus coccifera, which is frequent in warm and arid environments, showed the highest acorn germination rate and synchrony. CONCLUSIONS Seed lethal temperature, seed germination time at low temperatures, the ratio of pericarp mass to acorn mass and the embryonic axis hexose content appeared to be key functional traits that may influence the geographical ranges and ecological requirements of Mediterranean oaks in Tunisia.
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Affiliation(s)
- Nabil Amimi
- Laboratoire d’Ecologie Forestière, INRGREF Tunis, Rue Hédi EL Karray El Menzah IV, BP 10, 2080 Ariana, Tunisia
- Faculté des Sciences de Bizerte, Université de Carthage, 7021 Jarzouna, Tunisia
| | - Stéphane Dussert
- IRD, Université Montpellier, UMR DIADE, BP 64501, 34394 Montpellier, France
| | - Virginie Vaissayre
- IRD, Université Montpellier, UMR DIADE, BP 64501, 34394 Montpellier, France
| | - Hana Ghouil
- Faculté des Sciences de Bizerte, Université de Carthage, 7021 Jarzouna, Tunisia
| | - Sylvie Doulbeau
- IRD, Université Montpellier, UMR DIADE, BP 64501, 34394 Montpellier, France
| | | | - Youssef Ammari
- Laboratoire d’Ecologie Forestière, INRGREF Tunis, Rue Hédi EL Karray El Menzah IV, BP 10, 2080 Ariana, Tunisia
| | - Thierry Joët
- IRD, Université Montpellier, UMR DIADE, BP 64501, 34394 Montpellier, France
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Xu P, Cai W. Function of Brassica napus BnABI3 in Arabidopsis gs1, an Allele of AtABI3, in Seed Development and Stress Response. FRONTIERS IN PLANT SCIENCE 2019; 10:67. [PMID: 30804960 PMCID: PMC6370748 DOI: 10.3389/fpls.2019.00067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 01/17/2019] [Indexed: 05/30/2023]
Abstract
Abscisic acid (ABA) has been implicated in plant adaptation to various environmental stresses in addition to the regulation of seed dormancy and leaf senescence. ABI3 is a B3 domain-containing family protein and functions in the ABA signaling pathway during seed development. To date, the ABI3 orthologous have not been studied in Brassica napus. The aim of this study is to investigate the function of BnABI3 in plant development and stress response. Here, we identified an Arabidopsis line (gs1) from a population of mutagenized seeds and showed that GS1 is a new allele of AtABI3. When the Arabidopsis gs1 mutant was transformed with the BnABI3 gene, the transformed plants produced seeds that turned yellow and acquired desiccation tolerance. Moreover, BnABI3 regulates seed coat development and mucilage secretion by directly targeting the AtMUM1 and AtGATL5 genes. In addition, we showed that BnABI3 expression rescued gs1 freezing-induced green seed coloration by targeting AtSGR1/2 in transgenic Arabidopsis. BnABI3 is also involved in lateral root development and conferred a novel interaction between ABA and auxin signaling in roots. The potential role of ABI3 protein in endoplasmic reticulum homoeostasis was also tested. Altogether, our results indicated that BnABI3 mediates both plant development and the stress response.
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Romero-Rodríguez MC, Archidona-Yuste A, Abril N, Gil-Serrano AM, Meijón M, Jorrín-Novo JV. Germination and Early Seedling Development in Quercus ilex Recalcitrant and Non-dormant Seeds: Targeted Transcriptional, Hormonal, and Sugar Analysis. FRONTIERS IN PLANT SCIENCE 2018; 9:1508. [PMID: 30405659 PMCID: PMC6204751 DOI: 10.3389/fpls.2018.01508] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 09/26/2018] [Indexed: 05/15/2023]
Abstract
Seed germination and early seedling development have been studied in the recalcitrant species Quercus ilex using targeted transcriptional, hormonal, and sugar analysis. Embryos and seedlings were collected at eight morphologically defined developmental stages, S0-S7. A typical triphasic water uptake curve was observed throughout development, accompanied by a decrease in sucrose and an increase in glucose and fructose. Low levels of abscisic acid (ABA) and high levels of gibberellins (GAs) were observed in mature seeds. Post-germination, indole-3-acetic acid (IAA), increased, whereas GA remained high, a pattern commonly observed during growth and development. The abundance of transcripts from ABA-related genes was positively correlated with the changes in the content of the phytohormone. Transcripts of the drought-related genes Dhn3 and GolS were more abundant at S0, then decreased in parallel with increasing water content. Transcripts for Gapdh, and Nadh6 were abundant at S0, supporting the occurrence of an active metabolism in recalcitrant seeds at the time of shedding. The importance of ROS during germination is manifest in the high transcript levels for Sod and Gst, found in mature seeds. The results presented herein help distinguish recalcitrant (e.g., Q. ilex) seeds from their orthodox counterparts. Our results indicate that recalcitrance is established during seed development but not manifest until germination (S1-S3). Post-germination the patterns are quite similar for both orthodox and recalcitrant seeds.
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Affiliation(s)
- M. Cristina Romero-Rodríguez
- Department of Biochemistry and Molecular Biology, Agrifood Campus of International Excellence, University of Córdoba, Córdoba, Spain
- Departamento de Química Biológica, Dirección de Investigación, Facultad de Ciencias Químicas, Universidad Nacional de Asunción, San Lorenzo, Paraguay
- Centro Multidisciplinario de Investigaciones Tecnológicas, Dirección General de Investigación Científica y Tecnológica, Universidad Nacional de Asunción, San Lorenzo, Paraguay
| | - Antonio Archidona-Yuste
- Department of Biochemistry and Molecular Biology, Agrifood Campus of International Excellence, University of Córdoba, Córdoba, Spain
- Instituto de Agricultura Sostenible, Consejo Superior de Investigaciones Científicas, Campus de Excelencia Internacional Agroalimentario, Córdoba, Spain
| | - Nieves Abril
- Department of Biochemistry and Molecular Biology, Agrifood Campus of International Excellence, University of Córdoba, Córdoba, Spain
| | - Antonio M. Gil-Serrano
- Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Seville, Spain
| | - Mónica Meijón
- Plant Physiology Lab, Department of Organisms and Systems Biology, Faculty of Biology, University of Oviedo, Oviedo, Spain
| | - Jesús V. Jorrín-Novo
- Department of Biochemistry and Molecular Biology, Agrifood Campus of International Excellence, University of Córdoba, Córdoba, Spain
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11
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Pérez-Ruiz CL, Badano EI, Rodas-Ortiz JP, Delgado-Sánchez P, Flores J, Douterlungne D, Flores-Cano JA. Climate change in forest ecosystems: A field experiment addressing the effects of raising temperature and reduced rainfall on early life cycle stages of oaks. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2018. [DOI: 10.1016/j.actao.2018.08.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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12
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Desiccation Response of Seeds of Himalayan Oak, Quercus floribunda Lindl. ex A. Camus. NATIONAL ACADEMY SCIENCE LETTERS 2018. [DOI: 10.1007/s40009-018-0741-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Vaz TAA, Rodrigues-Junior AG, Davide AC, Nakamura AT, Toorop PE. A role for fruit structure in seed survival and germination of Swartzia langsdorffii Raddi beyond dispersal. PLANT BIOLOGY (STUTTGART, GERMANY) 2018; 20:263-270. [PMID: 29164747 DOI: 10.1111/plb.12671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 11/16/2017] [Indexed: 06/07/2023]
Abstract
Diaspore structure has been hypothesised to play a role in seed viability and/or germination of recalcitrant seeds, especially for Swartzia langsdorffii. Thus, this work aims to (i) investigate the in situ contribution of pericarp and aril on seed viability and germination, and (ii) identify morphoanatomical traits of S. langsdorffii diaspores that allow its desiccation-sensitive seeds to remain viable. The role of the pericarp and aril in seed survival and germination was investigated by placing the whole fruit, whole seeds (arillate seed) and bare seeds (without aril) in soil in the forest understorey, assessing germination, emergence, dead, firm and predated seeds, and water content of pericarps, arils and seeds. Correlation analysis was performed between environmental variables and physiological parameters. Histochemical features of diaspores were also investigated. Pericarp water content fell after several months, while the aril maintained its water content. Seeds did not lose water even without the presence of the pericarp and aril. However, presence of the pericarp promoted seed water content, viability and germination long after dispersal. The embryo had a thickened outer periclinal cell wall. Pericarp and aril are not essential to prevent water loss in seeds, but do help to retain seed moisture, favouring viability maintenance and promoting germination during the rainy season. Morphoanatomical features of seeds are suggested as main factors that reduce water loss. Survival of these desiccation-sensitive seeds upon dispersal during the dry season appears to be facilitated by multiple diaspore features that prevent viability loss.
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Affiliation(s)
- T A A Vaz
- Laboratório de Sementes Florestais, Departamento de Ciências Florestais, Universidade Federal de Lavras, Lavras, Brazil
- Departamento de Ciências e Linguagens, Instituto Federal de Ciência e Tecnologia de Minas Gerais, Bambuí, Brazil
| | - A G Rodrigues-Junior
- Laboratório de Fisiologia Vegetal, Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - A C Davide
- Laboratório de Sementes Florestais, Departamento de Ciências Florestais, Universidade Federal de Lavras, Lavras, Brazil
| | - A T Nakamura
- Instituto de Ciências Agrárias, Universidade Federal de Uberlândia, Monte Carmelo, Brazil
| | - P E Toorop
- Comparative Plant and Fungal Biology Department, Royal Botanic Gardens, West Sussex, UK
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Chen H, Yu X, Zhang X, Yang L, Huang X, Zhang J, Pritchard HW, Li W. Phospholipase Dα1-mediated phosphatidic acid change is a key determinant of desiccation-induced viability loss in seeds. PLANT, CELL & ENVIRONMENT 2018; 41:50-63. [PMID: 28152567 DOI: 10.1111/pce.12925] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 12/31/2016] [Indexed: 06/06/2023]
Abstract
High sensitivity of seeds to water loss is a widespread phenomenon in the world's plant species. The molecular basis of this trait is poorly understood but thought to be associated with critical changes in membrane function. We profiled membrane lipids of seeds in eight species with varying levels of desiccation tolerance and found a close association between reducing seed viability and increasing phosphatidic acid (PA). We applied hydration-dehydration cycles to Arabidopsis seeds, which are normally desiccation tolerant, to mimic the onset of desiccation sensitivity with progression towards germination and examined the role of phospholipase D (PLD) in desiccation stress-induced production of PA. We found that PLDα1 became more abundant and migrated from the cytosol to the membrane during desiccation, whereas PLDδ did not change, and that all desiccation-induced PA was derived from PLDα1 hydrolysis. When PLDα1 was suppressed, the germination level after each hydration-dehydration cycle improved significantly. We further demonstrated that PLDα1-mediated PA formation modulates desiccation sensitivity as applying its inhibitor improved seed desiccation tolerance and its suppression in protoplasts enhanced survival under dehydration. The insights provided by comparative lipidomics enable us to propose a new membrane-based model for seed desiccation stress and survival.
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Affiliation(s)
- Hongying Chen
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Xiaomei Yu
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Xudong Zhang
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Lan Yang
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Xing Huang
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
- Department of Phytopathology, College of Plant Protection, Yunnan Agriculture University, 650201, China
| | - Jie Zhang
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Hugh W Pritchard
- Royal Botanic Gardens, Kew, Wakehurst Place, West Sussex, RH17 6TN, UK
| | - Weiqi Li
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
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Loayza AP, Herrera-Madariaga MA, Carvajal DE, García-Guzmán P, Squeo FA. Conspecific plants are better 'nurses' than rocks: consistent results revealing intraspecific facilitation as a process that promotes establishment in a hyper-arid environment. AOB PLANTS 2017; 9:plx056. [PMID: 29218138 PMCID: PMC5710651 DOI: 10.1093/aobpla/plx056] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 10/19/2017] [Indexed: 05/30/2023]
Abstract
Harsh environmental conditions in arid ecosystems limit seedling recruitment to microhabitats under nurse structures, such as shrubs or rocks. These structures, however, do not necessarily afford the same benefits to plants because nurse rocks provide only physical nurse effects, whereas nurse plants can provide both physical and biological nurse effects. Nevertheless, if the nurse plant is a conspecific, the benefits it provides may be outweighed by higher mortality due to negative density-dependent processes; consequently, negative density-dependence is expected to limit plants from acting as nurses to their own seedlings. The degree to which an abiotic nurse may be more beneficial than a conspecific one remains largely unexplored. Here, we examine the role and elucidate the mechanisms by which conspecific plants and rocks promote plant establishment in a hyper-arid desert. For 4 years, we examined establishment patterns of Myrcianthes coquimbensis (Myrtaceae), a threatened desert shrub that recruits solely in rock cavities and under conspecific shrubs. Specifically, we characterized these microhabitats, as well as open interspaces for comparison, and conducted germination, seed removal and seedling survival experiments. Our results revealed that conspecific shrubs and nurse rocks modified environmental conditions in similar ways; soil and air temperatures were lower, and water availability was higher than in open interspaces. We found no evidence on negative density-dependent recruitment: seed removal was lowest and seedling emergence highest under conspecific plants, moreover seedling survival probabilities were similar in rock cavities and under conspecific plants. We conclude that the probability of establishment was highest under conspecific plants than in other microhabitats, contrasting what is expected under the Janzen-Connell recruitment model. We suggest that for species living in stressful environments, population regulation may be a function of positive density-dependence and intraspecific facilitation may be a process that promotes the persistence of some plant species within a community.
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Affiliation(s)
- Andrea P Loayza
- Department of Biology, University of La Serena, Av. Raúl Bitrán 1305, La Serena 1720256, Chile
| | | | - Danny E Carvajal
- Department of Biology, University of La Serena, Av. Raúl Bitrán 1305, La Serena 1720256, Chile
- Institute of Ecology and Biodiversity (IEB), Las Palmeras 3425, Ñuñoa, Santiago 7800003, Chile
| | - Patricio García-Guzmán
- Department of Biology, University of La Serena, Av. Raúl Bitrán 1305, La Serena 1720256, Chile
- Institute of Ecology and Biodiversity (IEB), Las Palmeras 3425, Ñuñoa, Santiago 7800003, Chile
| | - Francisco A Squeo
- Department of Biology, University of La Serena, Av. Raúl Bitrán 1305, La Serena 1720256, Chile
- Institute of Ecology and Biodiversity (IEB), Las Palmeras 3425, Ñuñoa, Santiago 7800003, Chile
- Center for Advanced Studies in Arid Zones (CEAZA), Av. Raúl Bitrán 1305, La Serena 1720256, Chile
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16
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Singh SP, Phartyal SS, Rosbakh S. Tree seed traits' response to monsoon climate and altitude in Indian subcontinent with particular reference to the Himalayas. Ecol Evol 2017; 7:7408-7419. [PMID: 28944026 PMCID: PMC5606906 DOI: 10.1002/ece3.3181] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 05/11/2017] [Accepted: 05/26/2017] [Indexed: 11/08/2022] Open
Abstract
Seed traits are related to several ecological attributes of a plant species, including its distribution. While the storage physiology of desiccation-sensitive seeds has drawn considerable attention, their ecology has remained sidelined, particularly how the strong seasonality of precipitation in monsoonal climate affects their temporal and spatial distribution. We compiled data on seed mass, seed desiccation behavior, seed shedding, and germination periodicity in relation to monsoon and altitude for 198 native tree species of Indian Himalayas and adjoining plains to find out (1) the adaptive significance of seed mass and seed desiccation behavior in relation to monsoon and (2) the pattern of change in seed mass in relation to altitude, habitat moisture, and succession. The tree species fall into three categories with respect to seed shedding and germination periodicities: (1) species in which both seed shedding and germination are synchronized with monsoon, referred to as monsoon-synchronized (MS, 46 species); (2) species in which seed germination is synchronized with monsoon, but seeds are shed several months before monsoon, referred to as partially monsoon-synchronized (PMS, 112 species); and (3) species in which both shedding and germination occur outside of monsoon months, referred to as monsoon-desynchronized (MD, 39 species). The seed mass of MS species (1,718 mg/seed) was greater than that of PMS (627 mg/seed) and MD (1,144 mg/seed). Of the 40 species with desiccation-sensitive seeds, 45% belong to the MS category, almost similar (approx. 47%) to woody plants with desiccation-sensitive seeds in evergreen rain forests. Seed mass differed significantly as per seed desiccation behavior and successional stage. No relationship of seed mass was found with altitude alone and on the basis of seed desiccation behavior. However, seed mass trend along the altitude differed among monsoon synchronization strategies. Based on our findings, we conclude that in the predicted climate change (warming and uncertain precipitation pattern) scenario, a delay or prolonged break-spell of monsoon may adversely affect the regeneration ecology of desiccation-sensitive seed-bearing species dominant over large forest areas of monsoonal climate.
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Affiliation(s)
- Surendra P. Singh
- Central Himalayan Environment Association (CHEA)06 Waldorf CompoundNainitalUttarakhandIndia
| | - Shyam S. Phartyal
- Department of Forestry and Natural ResourceHNB Garhwal UniversitySrinagar‐GarhwalUttarakhandIndia
| | - Sergey Rosbakh
- Chair of Ecology and Conservation BiologyUniversity of RegensburgRegensburgGermany
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17
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Chamorro D, Luna B, Ourcival JM, Kavgacı A, Sirca C, Mouillot F, Arianoutsou M, Moreno JM. Germination sensitivity to water stress in four shrubby species across the Mediterranean Basin. PLANT BIOLOGY (STUTTGART, GERMANY) 2017; 19:23-31. [PMID: 26998911 DOI: 10.1111/plb.12450] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 03/14/2016] [Indexed: 06/05/2023]
Abstract
Mediterranean shrublands are generally water-limited and fire-driven ecosystems. Seed-based post-fire regeneration may be affected by varying rainfall patterns, depending on species sensitivity to germinate under water stress. In our study, we considered the germination response to water stress in four species from several sites across the Mediterranean Basin. Seeds of species with a hard coat (Cistus monspeliensis, C. salviifolius, Cistaceae, Calicotome villosa, Fabaceae) or soft coat (Erica arborea, Ericaceae), which were exposed or not to a heat shock and smoke (fire cues), were made to germinate under water stress. Final germination percentage, germination speed and viability of seeds were recorded. Germination was modelled using hydrotime analysis and correlated to the water balance characteristics of seed provenance. Water stress was found to decrease final germination in the three hard-seeded species, as well as reduce germination speed. Moreover, an interaction between fire cues and water stress was found, whereby fire cues increased sensitivity to water stress. Seed viability after germination under water stress also declined in two hard-seeded species. Conversely, E. arborea showed little sensitivity to water stress, independent of fire cues. Germination responses varied among populations of all species, and hydrotime parameters were not correlated to site water balance, except in E. arborea when not exposed to fire cues. In conclusion, the species studied differed in germination sensitivity to water stress; furthermore, fire cues increased this sensitivity in the three hard-seeded species, but not in E. arborea. Moreover, populations within species consistently differed among themselves, but these differences could only be related to the provenance locality in E. arborea in seeds not exposed to fire cues.
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Affiliation(s)
- D Chamorro
- Departamento de Ciencias Ambientales, Universidad de Castilla-La Mancha, Toledo, Spain
| | - B Luna
- Departamento de Ciencias Ambientales, Universidad de Castilla-La Mancha, Toledo, Spain
| | - J-M Ourcival
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175 CNRS/Université de Montpellier/Université Paul Valery Montpellier/EPHE, Montpellier, France
| | - A Kavgacı
- Batı Akdeniz Ormancılık Arastirma Enstitüsü, Southwest Anatolia Forest Research Institute, Antalya, Turkey
| | - C Sirca
- DIPNET, Dipartimento di Scienze della Natura e del Territorio, University of Sassari, Sassari, Italy
- IAFES Division of the CMCC, Euro-Mediterranean Centre on Climate Change, Sassari, Italy
| | - F Mouillot
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175 CNRS/Université de Montpellier/Université Paul Valery Montpellier/EPHE/IRD, Montpellier, France
| | - M Arianoutsou
- Department of Ecology and Systematics, Faculty of Biology, University of Athens, Athens, Greece
| | - J M Moreno
- Departamento de Ciencias Ambientales, Universidad de Castilla-La Mancha, Toledo, Spain
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Obroucheva N, Sinkevich I, Lityagina S. Physiological aspects of seed recalcitrance: a case study on the tree Aesculus hippocastanum. TREE PHYSIOLOGY 2016; 36:1127-1150. [PMID: 27259638 DOI: 10.1093/treephys/tpw037] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 04/03/2016] [Indexed: 06/05/2023]
Abstract
Recalcitrant seeds are typical of some tropical and subtropical trees. Their post-shedding life activity proceeds in humid air and wet litter. They are desiccation sensitive and, for this reason, have a short life span and need some special procedures for cryopreservation. This review is devoted to the post-shedding life strategy of recalcitrant seeds, which includes the maintenance of high hydration status, metabolic readiness and ability to rapidly germinate before desiccation-induced damage exerts a lethal effect. The main physiological aspects of recalcitrant seeds are considered starting from mature seeds, followed during dormancy if occurs and resulting in germination. The collected data embrace the metabolic processes in embryonic axes and whole seeds. The up-to-date results are integrated covering the main metabolic processes, namely water status and transport, protein and carbohydrate metabolism, antioxidant defense, axis-cotyledon relations, hormonal control and germination. Among the representatives of various taxa, the seeds of which exhibit recalcitrance, attention was given to horse chestnut seeds as one of most studied recalcitrants.
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Affiliation(s)
- Natalie Obroucheva
- Institute of Plant Physiology of Russian Academy of Sciences, Botanicheskaya str. 35, Moscow 127276, Russia
| | - Irina Sinkevich
- Institute of Plant Physiology of Russian Academy of Sciences, Botanicheskaya str. 35, Moscow 127276, Russia
| | - Snejana Lityagina
- Institute of Plant Physiology of Russian Academy of Sciences, Botanicheskaya str. 35, Moscow 127276, Russia
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Joët T, Ourcival JM, Capelli M, Dussert S, Morin X. Explanatory ecological factors for the persistence of desiccation-sensitive seeds in transient soil seed banks: Quercus ilex as a case study. ANNALS OF BOTANY 2016; 117:165-76. [PMID: 26420203 PMCID: PMC4701143 DOI: 10.1093/aob/mcv139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 07/28/2015] [Indexed: 05/06/2023]
Abstract
BACKGROUND AND AIMS Dominant tree species in northern temperate forests, for example oak and beech, produce desiccation-sensitive seeds. Despite the potentially major influence of this functional trait on the regeneration and distribution of species under climate change, little is currently known about the ecological determinants of the persistence of desiccation-sensitive seeds in transient soil seed banks. Knowing which key climatic and microsite factors favour seed survival will help define the regeneration niche for species whose seeds display extreme sensitivity to environmental stress METHODS Using the Mediterranean Holm oak (Quercus ilex) forest as a model system, an in situ time-course monitoring of seed water status and viability was performed during the unfavourable winter season in two years with contrasting rainfall, at an instrumented site with detailed climate records. In parallel, the characteristics of the microhabitat and their influence on the post-winter water status and viability of seeds were investigated in a regional survey of 33 woodlands representative of the French distribution of the species. KEY RESULTS Time-course monitoring of seed water status in natural conditions confirmed that in situ desiccation is the main abiotic cause of mortality in winter. Critical water contents could be reached in a few days during drought spells. Seed dehydration rates were satisfactorily estimated using integrative climate proxies including vapour pressure deficit and potential evapotranspiration. Seed water status was therefore determined by the balance between water uptake after a rainfall event and water loss during dry periods. Structural equation modelling of microhabitat factors highlighted the major influence of canopy openness and resulting incident radiation on the ground. CONCLUSIONS This study provides part of the knowledge required to implement species distribution models which incorporate their regeneration niche. It is an important step forward in evaluating the ecological consequences of increasing winter drought and environmental filtering due to climate change on the regeneration of the most dominant Mediterranean tree species.
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Affiliation(s)
- Thierry Joët
- IRD, UMR DIADE, BP 64501, 34394 Montpellier, France and
| | - Jean-Marc Ourcival
- CEFE UMR 5175, CNRS-Université de Montpellier-Université Paul-Valéry Montpellier-EPHE, BP 5051, 34293 Montpellier, France
| | | | | | - Xavier Morin
- CEFE UMR 5175, CNRS-Université de Montpellier-Université Paul-Valéry Montpellier-EPHE, BP 5051, 34293 Montpellier, France
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Culot L, Huynen M, Heymann EW. Partitioning the relative contribution of one‐phase and two‐phase seed dispersal when evaluating seed dispersal effectiveness. Methods Ecol Evol 2014. [DOI: 10.1111/2041-210x.12317] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Laurence Culot
- Departamento de Zoologia Universidade Estadual Paulista Avenida 24A 1515 CP199 Rio Claro SP Brazil
- Primatology Research Group Behavioral Biology Unit University of Liège Quai van Beneden 22 Bât. I1 4020 Liège Belgium
- Abteilung Verhaltensökologie & Soziobiologie Deutsches Primatenzentrum (DPZ) Kellnerweg 4 37077 Göttingen Germany
| | - Marie‐Claude Huynen
- Primatology Research Group Behavioral Biology Unit University of Liège Quai van Beneden 22 Bât. I1 4020 Liège Belgium
| | - Eckhard W. Heymann
- Abteilung Verhaltensökologie & Soziobiologie Deutsches Primatenzentrum (DPZ) Kellnerweg 4 37077 Göttingen Germany
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Xia K, Hill LM, Li DZ, Walters C. Factors affecting stress tolerance in recalcitrant embryonic axes from seeds of four Quercus (Fagaceae) species native to the USA or China. ANNALS OF BOTANY 2014; 114:1747-59. [PMID: 25326139 PMCID: PMC4649694 DOI: 10.1093/aob/mcu193] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 08/20/2014] [Indexed: 05/27/2023]
Abstract
BACKGROUND AND AIMS Quercus species are often considered 'foundation' components of several temperate and/or subtropical forest ecosystems. However, the populations of some species are declining and there is considerable urgency to develop ex situ conservation strategies. In this study, the storage physiology of seeds within Quercus was explored in order to determine factors that affect survival during cryopreservation and to provide a quantitative assessment of seed recalcitrance to support future studies of this complex trait. METHODS Water relations and survival of excised axes in response to water loss and cryo-exposure were compared for four Quercus species from subtropical China (Q. franchetii, Q. schottkyana) and temperate USA (Q. gambelii, Q. rubra). KEY RESULTS Seed tissues initially had high water contents and water potentials. Desiccation tolerance of the embryonic axis was not correlated with the post-shedding rainfall patterns where the samples originated. Instead, higher desiccation tolerance was observed in samples growing in areas with colder winters. Survival following cryo-exposure correlated with desiccation tolerance. Among species, plumule tissues were more sensitive than radicles to excision, desiccation and cryo-exposure, and this led to a higher proportion of abnormally developing embryos during recovery following stress. CONCLUSIONS Quercus species adapted to arid and semi-humid climates still produce recalcitrant seeds. The ability to avoid freezing rather than drought may be a more important selection factor to increase desiccation tolerance. Cryopreservation of recalcitrant germplasm from temperate species is currently feasible, whilst additional protective treatments are needed for ex situ conservation of Quercus from tropical and subtropical areas.
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Affiliation(s)
- Ke Xia
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China USDA-ARS National Center for Genetic Resources Preservation, Fort Collins, CO 80524, USA
| | - Lisa M Hill
- USDA-ARS National Center for Genetic Resources Preservation, Fort Collins, CO 80524, USA
| | - De-Zhu Li
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Christina Walters
- USDA-ARS National Center for Genetic Resources Preservation, Fort Collins, CO 80524, USA
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