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Zhou H, Zhang X, Liu H, Ma J, Hao F, Ye H, Wang Y, Zhang S, Yue M, Zhao P. Chromosome-level genome assembly of Platycarya strobilacea. Sci Data 2024; 11:269. [PMID: 38443357 PMCID: PMC10914804 DOI: 10.1038/s41597-024-03107-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 02/29/2024] [Indexed: 03/07/2024] Open
Abstract
Platycarya strobilacea belongs to the walnut family (Juglandaceae), is commonly known as species endemic to East Asia, and is an ecologically important, wind pollinated, woody deciduous tree. To facilitate this ancient tree for the ecological value and conservation of this ancient tree, we report a new high-quality genome assembly of P. strobilacea. The genome size was 677.30 Mb, with a scaffold N50 size of 45,791,698 bp, and 98.43% of the assembly was anchored to 15 chromosomes. We annotated 32,246 protein-coding genes in the genome, of which 96.30% were functionally annotated in six databases. This new high-quality assembly of P. strobilacea provide valuable resource for the phylogenetic and evolutionary analysis of the walnut family and angiosperm.
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Affiliation(s)
- Huijuan Zhou
- Xi'an Botanical Garden of Shaanxi Province, Institute of Botany of Shaanxi Province, Shaanxi Academy of Science, Xi'an, Shaanxi, 710061, China
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi, 710069, China
| | - Xuedong Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi, 710069, China
| | - Hengzhao Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi, 710069, China
| | - Jiayu Ma
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi, 710069, China
| | - Fan Hao
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Hang Ye
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi, 710069, China
| | - Yaling Wang
- Xi'an Botanical Garden of Shaanxi Province, Institute of Botany of Shaanxi Province, Shaanxi Academy of Science, Xi'an, Shaanxi, 710061, China
| | - Shuoxin Zhang
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Ming Yue
- Xi'an Botanical Garden of Shaanxi Province, Institute of Botany of Shaanxi Province, Shaanxi Academy of Science, Xi'an, Shaanxi, 710061, China
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi, 710069, China
| | - Peng Zhao
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi, 710069, China.
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Groh JS, Vik DC, Stevens KA, Brown PJ, Langley CH, Coop G. Distinct ancient structural polymorphisms control heterodichogamy in walnuts and hickories. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.23.573205. [PMID: 38187547 PMCID: PMC10769452 DOI: 10.1101/2023.12.23.573205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
The maintenance of stable mating type polymorphisms is a classic example of balancing selection, underlying the nearly ubiquitous 50/50 sex ratio in species with separate sexes. One lesser known but intriguing example of a balanced mating polymorphism in angiosperms is heterodichogamy - polymorphism for opposing directions of dichogamy (temporal separation of male and female function in hermaphrodites) within a flowering season. This mating system is common throughout Juglandaceae, the family that includes globally important and iconic nut and timber crops - walnuts (Juglans), as well as pecan and other hickories (Carya). In both genera, heterodichogamy is controlled by a single dominant allele. We fine-map the locus in each genus, and find two ancient (>50 Mya) structural variants involving different genes that both segregate as genus-wide trans-species polymorphisms. The Juglans locus maps to a ca. 20 kb structural variant adjacent to a probable trehalose phosphate phosphatase (TPPD-1), homologs of which regulate floral development in model systems. TPPD-1 is differentially expressed between morphs in developing male flowers, with increased allele-specific expression of the dominant haplotype copy. Across species, the dominant haplotype contains a tandem array of duplicated sequence motifs, part of which is an inverted copy of the TPPD-1 3' UTR. These repeats generate various distinct small RNAs matching sequences within the 3' UTR and further downstream. In contrast to the single-gene Juglans locus, the Carya heterodichogamy locus maps to a ca. 200-450 kb cluster of tightly linked polymorphisms across 20 genes, some of which have known roles in flowering and are differentially expressed between morphs in developing flowers. The dominant haplotype in pecan, which is nearly always heterozygous and appears to rarely recombine, shows markedly reduced genetic diversity and is over twice as long as its recessive counterpart due to accumulation of various types of transposable elements. We did not detect either genetic system in other heterodichogamous genera within Juglandaceae, suggesting that additional genetic systems for heterodichogamy may yet remain undiscovered.
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Affiliation(s)
- Jeffrey S Groh
- Department of Evolution and Ecology, University of California, Davis
- Center for Population Biology, University of California, Davis
| | - Diane C Vik
- Department of Evolution and Ecology, University of California, Davis
| | - Kristian A Stevens
- Department of Evolution and Ecology, University of California, Davis
- Department of Computer Science, University of California, Davis
| | - Patrick J Brown
- Department of Plant Sciences, University of California, Davis
| | - Charles H Langley
- Department of Evolution and Ecology, University of California, Davis
- Center for Population Biology, University of California, Davis
| | - Graham Coop
- Department of Evolution and Ecology, University of California, Davis
- Center for Population Biology, University of California, Davis
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Pauly G, Larue C, Petit RJ. Adaptive function of duodichogamy: Why do chestnut trees have two pollen emission phases? AMERICAN JOURNAL OF BOTANY 2023; 110:e16204. [PMID: 37342965 DOI: 10.1002/ajb2.16204] [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: 02/03/2023] [Revised: 04/28/2023] [Accepted: 04/28/2023] [Indexed: 06/23/2023]
Abstract
PREMISE Intersexual mating facilitation in flowering plants has been largely underexplored. Duodichogamy is a rare flowering system in which individual plants flower in the sequence male-female-male. We studied the adaptive advantages of this flowering system using chestnuts (Castanea spp., Fagaceae) as models. These insect-pollinated trees produce many unisexual male catkins responsible for a first staminate phase and a few bisexual catkins responsible for a second staminate phase. We hypothesized that duodichogamy increases female mating success by facilitating pollen deposition on stigmas of the rewardless female flowers through their proximity with attractive male flowers responsible for the minor staminate phase. METHODS We monitored insect visits to 11 chestnut trees during the entire flowering period and explored reproductive traits of all known duodichogamous species using published evidence. RESULTS In chestnuts, insects visited trees more frequently during the first staminate phase but visited female flowers more frequently during the second staminate phase. All 21 animal-pollinated duodichogamous species identified are mass-flowering woody plants at high risk of self-pollination. In 20 of 21 cases, gynoecia (female flower parts) are located close to androecia (male flower parts), typically those responsible for the second minor staminate phase, whereas androecia are often distant from gynoecia. CONCLUSIONS Our results suggest that duodichogamy increases female mating success by facilitating pollen deposition on stigmas by means of the attractiveness of the associated male flowers while effectively limiting self-pollination.
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Affiliation(s)
| | - Clément Larue
- Univ. Bordeaux, INRAE, BIOGECO, 33610, Cestas, France
- INVENIO, Maison Jeannette, 24140, Douville, France
| | - Rémy J Petit
- Univ. Bordeaux, INRAE, BIOGECO, 33610, Cestas, France
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Yao K, Deng M, Lin L, Hu J, Yang X, Li Q, Feng Z. The fertilization process in Lithocarpus dealbatus (Fagaceae) and its implication on the sexual reproduction evolution of Fagales. PLANTA 2023; 258:23. [PMID: 37341801 DOI: 10.1007/s00425-023-04178-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 06/05/2023] [Indexed: 06/22/2023]
Abstract
MAIN CONCLUSION The pistillate flowers of Lithocarpus dealbatus show two pollen tube (PT) arresting sites (the style-joining and micropyle) within the pistil during the postpollination-prezygotic stage. The PT, arrested at the pre-ovule stage, enhanced PT competition allowing the most compatible PTs to enter the ovary to ensure the highest fertilization success. During the shift from animal pollination to wind pollination, plants require a series of changes in reproductive traits. The mode of pollination is striking labile in Fagaceae. Lithocarpus is insect pollinated and is closely related to wind-pollinated Quercus. Little is known about the sexual reproduction of Lithocarpus. This study aimed to reveal the sexual reproduction of Lithocarpus dealbatus and to explore the evolutionary pattern of the key sexual reproduction traits to better understand their possible role in labile pollination. We found that after pollination, L. dealbatus PTs grew slowly in the style reaching style-joining in mid-January of the second year; then PT growth was arrested at style-joining for four months. Only two to three PTs resumed growth in mid-May to reach the micropyle, where PT growth ceased for one month before one PT resumed growth and passed through the micropyle to the embryo sac. Fagaceae showed a generalized mating system. Vast pollen production, small-sized pollen grains, long stigmatic receptive time, and reduced perianth were compatible with beetle pollination syndrome, representing the plesiomorphic status in Fagaceae. A large stigmatic surface and dry pollen grains linked to wind pollination might be independently derived several times in fagaceous lineages. Beetle pollination syndrome can cope with the uncertainty of pollinators to ensure conspecific pollen capture, which represents pre-adaptation status and has a selective advantage when conditions change, favouring wind pollination. The arrest of the PT at style-joining is a unique mechanism in later derived fagaceous lineages to enhance PT competition and promote outcrossing.
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Affiliation(s)
- Kaiping Yao
- School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, China
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Institute of Biodiversity, Yunnan University, Kunming, 650504, Yunnan, China
- The Key Laboratory of Rare and Endangered Forest Plants of National Forestry and Grassland Administration and the Key Laboratory for Silviculture and Forest Resources Development of Yunnan Province, Yunnan, Academy of Forestry and Grassland, Kunming, 650201, Yunnan, China
| | - Min Deng
- School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, China.
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Institute of Biodiversity, Yunnan University, Kunming, 650504, Yunnan, China.
- The Key Laboratory of Rare and Endangered Forest Plants of National Forestry and Grassland Administration and the Key Laboratory for Silviculture and Forest Resources Development of Yunnan Province, Yunnan, Academy of Forestry and Grassland, Kunming, 650201, Yunnan, China.
| | - Lin Lin
- School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, China
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Institute of Biodiversity, Yunnan University, Kunming, 650504, Yunnan, China
- The Key Laboratory of Rare and Endangered Forest Plants of National Forestry and Grassland Administration and the Key Laboratory for Silviculture and Forest Resources Development of Yunnan Province, Yunnan, Academy of Forestry and Grassland, Kunming, 650201, Yunnan, China
| | - Jinjin Hu
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China
| | - Xiaorui Yang
- Shanghai Chenshan Botanical Garden, Shanghai, 201602, China
| | - Qiansheng Li
- Atlanta Botanical Garden, Atlanta, GA, 30309, USA.
| | - Zhuo Feng
- Institute of Palaeontology, Yunnan Key Laboratory of Earth System Science, Yunnan Key Laboratory for Palaeobiology, MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan University, Kunming, 650500, China.
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Cao Y, Almeida-Silva F, Zhang WP, Ding YM, Bai D, Bai WN, Zhang BW, Van de Peer Y, Zhang DY. Genomic Insights into Adaptation to Karst Limestone and Incipient Speciation in East Asian Platycarya spp. (Juglandaceae). Mol Biol Evol 2023; 40:msad121. [PMID: 37216901 PMCID: PMC10257982 DOI: 10.1093/molbev/msad121] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 04/06/2023] [Accepted: 05/16/2023] [Indexed: 05/24/2023] Open
Abstract
When challenged by similar environmental conditions, phylogenetically distant taxa often independently evolve similar traits (convergent evolution). Meanwhile, adaptation to extreme habitats might lead to divergence between taxa that are otherwise closely related. These processes have long existed in the conceptual sphere, yet molecular evidence, especially for woody perennials, is scarce. The karst endemic Platycarya longipes and its only congeneric species, Platycarya strobilacea, which is widely distributed in the mountains in East Asia, provide an ideal model for examining the molecular basis of both convergent evolution and speciation. Using chromosome-level genome assemblies of both species, and whole-genome resequencing data from 207 individuals spanning their entire distribution range, we demonstrate that P. longipes and P. strobilacea form two species-specific clades, which diverged around 2.09 million years ago. We find an excess of genomic regions exhibiting extreme interspecific differentiation, potentially due to long-term selection in P. longipes, likely contributing to the incipient speciation of the genus Platycarya. Interestingly, our results unveil underlying karst adaptation in both copies of the calcium influx channel gene TPC1 in P. longipes. TPC1 has previously been identified as a selective target in certain karst-endemic herbs, indicating a convergent adaptation to high calcium stress among karst-endemic species. Our study reveals the genic convergence of TPC1 among karst endemics and the driving forces underneath the incipient speciation of the two Platycarya lineages.
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Affiliation(s)
- Yu Cao
- State Key Laboratory of Earth Surface Process and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Fabricio Almeida-Silva
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Wei-Ping Zhang
- State Key Laboratory of Earth Surface Process and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Ya-Mei Ding
- State Key Laboratory of Earth Surface Process and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Dan Bai
- State Key Laboratory of Earth Surface Process and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Wei-Ning Bai
- State Key Laboratory of Earth Surface Process and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Bo-Wen Zhang
- State Key Laboratory of Earth Surface Process and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Yves Van de Peer
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
- Center for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Da-Yong Zhang
- State Key Laboratory of Earth Surface Process and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
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Jin H, Yang Z, Luo J, Li C, Chen J, Lim KJ, Wang Z. Comprehensive identification and analysis of circRNAs during hickory ( Carya cathayensis Sarg.) flower bud differentiation. FRONTIERS IN PLANT SCIENCE 2023; 13:1000489. [PMID: 36684801 PMCID: PMC9846342 DOI: 10.3389/fpls.2022.1000489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Flower bud differentiation represents a crucial transition from vegetative growth to reproductive development. Carya cathayensis (hickory) is an important economic species in China, with a long juvenile period that hinders its commercial development. In recent years, circular RNAs (circRNAs) have been widely studied and identified as sponges for miRNA regulation of mRNA expression. However, little is known regarding the role of circRNAs in flower buds. In this study, we sequenced circRNAs at three developmental stages (undifferentiated, differentiating, and fully differentiated) in both female and male buds. A total of 6,931 circRNAs were identified in the three developmental stages and 4,449 and 2,209 circRNAs were differentially expressed in female and male buds, respectively. Gene ontology demonstrated that many circRNA host genes participated in various processes, for example, cellular and intracellular pH regulation. Function annotation identified 46 differentially expressed circRNAs involved in flowering regulation, with 28 circRNAs found only in female buds, 4 found only in male buds, and 11 found in both female and male buds. A circRNA-miRNA-mRNA network was predicted based on 13 flowering-related circRNAs and their seven putative interacting miRNAs to describe the regulatory mechanism. Our preliminary results demonstrated a potential involvement of circRNA in bud differentiation. They provided a preliminary theoretical basis for how circRNA might participate in flower development in hickory, perhaps in woody plants.
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Yuan X, Quan S, Liu J, Guo C, Zhang Z, Kang C, Niu J. Evolution of the PEBP gene family in Juglandaceae and their regulation of flowering pathway under the synergistic effect of JrCO and JrNF-Y proteins. Int J Biol Macromol 2022; 223:202-212. [PMID: 36347378 DOI: 10.1016/j.ijbiomac.2022.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/23/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022]
Abstract
Phosphatidyl ethanolamine-binding protein (PEBP) has a conserved PEBP domain and plays an important role in regulating the flowering time and growth of angiosperms. To understand the evolution of PEBP family genes in walnut family and the mechanism of regulating flowering in photoperiod pathway, 53 genes with PEBP domain were identified from 5 Juglandaceae plants. The PEBP gene family of Juglandaceae can be divided into four subgroups, FT-like, TFL-like, MFT-like and PEBP-like subgroups. These genes all show very high homology for motifs and gene structure in Juglandaceae. In addition, the results of gene replication and collinearity analysis showed that the evolution of PEBP genes was mainly purified and selected, and segmental repetition was the main driving force for the evolution of PEBP gene family in walnut family. We found that PEBP gene family played an important role in female flower bud differentiation, and most JrPEBP genes were highly expressed in leaf bud and female flower bud by qRT-PCR. In Arabidopsis, AtCO can not only directly bind to CORE2, but also interact with NF-Y complex to positively regulate the expression of AtFT gene. In this study, we proved that JrCO (the lineal homologue of AtCO) could not directly regulate the expression of JrFT gene, but could enhance the binding of JrNF-YB4/6 protein to the promoter of JrFT gene by forming a heteropolymer with NF-YB4/NF-YB6. We also confirmed that JrNF-YC1/3/7, JrNF-YB4/6 and JrCO can form a trimer structure similar to AtNF-YB-YC-CO of Arabidopsis, and then bind to the promoter of JrFT gene to promote the transcription of JrFT gene. In a word, through identification and analysis of PEBP gene family in Juglandaceae and study on the mechanism of photoperiod pathway regulating flowering in walnut, we have found that nuclear transcription factor NF-YB/YC plays a more important role in the trimer structure of NF-YB-YC-CO in walnut species. Our study has further perfected the flowering regulatory network of walnut species.
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Affiliation(s)
- Xing Yuan
- Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, Xinjiang, China; Xinjiang Production and Construction Corps Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization, Shihezi 832003, Xinjiang, China
| | - Shaowen Quan
- Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, Xinjiang, China; Xinjiang Production and Construction Corps Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization, Shihezi 832003, Xinjiang, China
| | - Jinming Liu
- Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, Xinjiang, China; Xinjiang Production and Construction Corps Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization, Shihezi 832003, Xinjiang, China
| | - Caihua Guo
- Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, Xinjiang, China; Xinjiang Production and Construction Corps Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization, Shihezi 832003, Xinjiang, China
| | - Zhongrong Zhang
- Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, Xinjiang, China; Xinjiang Production and Construction Corps Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization, Shihezi 832003, Xinjiang, China
| | - Chao Kang
- Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, Xinjiang, China; Xinjiang Production and Construction Corps Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization, Shihezi 832003, Xinjiang, China
| | - Jianxin Niu
- Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, Xinjiang, China; Xinjiang Production and Construction Corps Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization, Shihezi 832003, Xinjiang, China.
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Qu Y, Chen X, Mao X, Huang P, Fu X. Transcriptome Analysis Reveals the Role of GA 3 in Regulating the Asynchronism of Floral Bud Differentiation and Development in Heterodichogamous Cyclocarya paliurus (Batal.) Iljinskaja. Int J Mol Sci 2022; 23:ijms23126763. [PMID: 35743203 PMCID: PMC9224186 DOI: 10.3390/ijms23126763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/04/2022] [Accepted: 06/11/2022] [Indexed: 12/04/2022] Open
Abstract
Cyclocarya paliurus is an important medical plant owing to the diverse bioactive compounds in its leaves. However, the heterodichogamy with female and male functions segregation within protandry (PA) or protogyny (PG) may greatly affect seed quality and its plantations for medicinal use. To speculate on the factor playing the dominant role in regulating heterodichogamy in C. paliurus, based on phenotypic observations, our study performed a multi comparison transcriptome analysis on female and male buds (PG and PA types) using RNA-seq. For the female and male bud comparisons, a total of 6753 differentially expressed genes (DEGs) were detected. In addition, functional analysis revealed that these DEGs were significantly enriched in floral development, hormone, and GA-related pathways. As the dominant hormones responsible for floral differentiation and development, gibberellins (GAs) in floral buds from PG and PA types were quantified using HPLC-MS. Among the tested GAs, GA3 positively regulated the physiological differentiation (S0) and germination (S2) of floral buds. The dynamic changes of GA3 content and floral morphological features were consistent with the expression levels of GA-related genes. Divergences of GA3 contents at S0 triggered the asynchronism of physiological differentiation between male and female buds of intramorphs (PA-M vs. PA-F and PG-F vs. PG-M). A significant difference in GA3 content enlarged this asynchronism at S2. Thus, we speculate that GA3 plays the dominant role in the formation of heterodichogamy in C. paliurus. Meanwhile, the expression patterns of GA-related DEGs, including CPS, KO, GA20ox, GA2OX, GID1, and DELLA genes, which play central roles in regulating flower development, coincided with heterodichogamous characteristics. These results support our speculations well, which should be further confirmed.
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Schoonderwoerd KM, Friedman WE. Interspecific morphological variation in Juglandoideae resting bud organization: a winter's tale? ANNALS OF BOTANY 2022; 129:679-696. [PMID: 35390122 PMCID: PMC9113150 DOI: 10.1093/aob/mcac050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 04/02/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND AND AIMS Dormant resting buds are frequently regarded as static units, with protective cataphylls on the outside and embryonic foliage leaves on the inside. How the presence of cataphylls influences the dynamic, cyclical, annually repeating sequence of leaf forms that a resting bud gives rise to has rarely been interrogated. To examine the connection between dormant structure and growing-season development, we compare the complete seasonal heteroblastic sequence of leaf forms of six species of temperate Juglandaceae with distinctly different vegetative resting bud structures. These include buds with cataphylls; buds without cataphylls; and buds with caducous cataphylls that are lost before the onset of winter. METHODS In a common garden setting over a 7-month growing season, the dimensions of 2249 individual vegetative metamers were tracked from first exposure to abscission along the shoots of saplings and mature trees. The timing of metamer initiation within terminal buds was investigated using micro-CT scanning. Character state transitions of resting bud types were estimated using a phylogenetic tree of Juglandaceae. KEY RESULTS The presence of cataphylls within a heteroblastic sequence is associated with a single cohort of foliage leaves that flush and abscise synchronously. This growing pattern is highly determinate, with next year's terminal-bud cataphylls already initiated before spring leaf out. In contrast, in sequences without cataphylls, shorter-lived foliage leaves appear and abscise in a staggered fashion. Despite these differences in leaf demography, all examined heteroblastic sequences produce a series of small, caducous leaf forms that precede terminal bud set. CONCLUSIONS The ubiquity of caducous leaf forms in Juglandoideae may point to the importance of shoot tip protection far beyond the dormant season. In addition, the presence or absence of cataphylls in resting buds is indicative of distinct shoot ontogenetic patterns, and functional strategies, in summer.
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Affiliation(s)
- Kristel M Schoonderwoerd
- Harvard University, Organismic and Evolutionary Biology, 26 Oxford Street, Cambridge, MA 02138, USA
- The Arnold Arboretum of Harvard University, 1300 Centre Street, Boston, MA 02131, USA
| | - William E Friedman
- Harvard University, Organismic and Evolutionary Biology, 26 Oxford Street, Cambridge, MA 02138, USA
- The Arnold Arboretum of Harvard University, 1300 Centre Street, Boston, MA 02131, USA
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Qin B, Lu X, Sun X, Cui J, Deng J, Zhang L. Transcriptome-based analysis of the hormone regulation mechanism of gender differentiation in Juglans mandshurica Maxim. PeerJ 2021; 9:e12328. [PMID: 34820167 PMCID: PMC8588858 DOI: 10.7717/peerj.12328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 09/27/2021] [Indexed: 12/03/2022] Open
Abstract
Juglans mandshurica Maxim is a hermaphroditic plant belonging to the genus Juglans in the family Juglandaceae. The pollination period of female flowers is different from the loose powder period of male flowers on the same tree. In several trees, female flowers bloom first, whereas in others, male flowers bloom first. In this study, male and female flower buds of J. mandshurica at the physiological differentiation stage were used. Illumina-based transcriptome sequencing was performed, and the quality of the sequencing results was evaluated and analyzed. A total of 138,138 unigenes with an average length of 788 bp were obtained. There were 8,116 differentially expressed genes (DEGs); 2,840 genes were upregulated, and 5,276 genes were downregulated. The DEGs were classified by Gene Ontology and analyzed by Kyoto Encyclopedia of Genes and Genomes. The signal transduction factors involved in phytohormone synthesis were selected. The results displayed that ARF and SAUR were expressed differently in the auxin signaling pathway. Additionally, DELLA protein (a negative regulator of gibberellin), the cytokinin synthesis pathway, and A-ARR were downregulated. On April 2nd, the contents of IAA, GA, CTK, ETH and SA in male and female flower buds of two types of J. mandshurica were opposite, and there were obvious genes regulating gender differentiation. Overall, we found that the sex differentiation of J. mandshurica was related to various hormone signal transduction pathways, and hormone signal transduction plays a leading role in regulation.
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Affiliation(s)
- Baiting Qin
- College of Forestry, Shenyang Agricultural University, Shenyang, China.,Key Laboratory of Forest Tree Genetics, Breeding and Cultivation of Liaoning Province, Shenyang, China
| | - Xiujun Lu
- College of Forestry, Shenyang Agricultural University, Shenyang, China
| | - Xiaomei Sun
- College of Forestry, Shenyang Agricultural University, Shenyang, China
| | - Jianguo Cui
- College of Forestry, Shenyang Agricultural University, Shenyang, China.,Key Laboratory of Forest Tree Genetics, Breeding and Cultivation of Liaoning Province, Shenyang, China
| | - Jifeng Deng
- College of Forestry, Shenyang Agricultural University, Shenyang, China.,Key Laboratory of Forest Tree Genetics, Breeding and Cultivation of Liaoning Province, Shenyang, China
| | - Lijie Zhang
- College of Forestry, Shenyang Agricultural University, Shenyang, China.,Key Laboratory of Forest Tree Genetics, Breeding and Cultivation of Liaoning Province, Shenyang, China
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11
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Zhang L, Guo C, Lu X, Sun X, Liu C, Zhou Q, Deng J. Flower Development of Heterodichogamous Juglans mandshurica (Juglandaceae). FRONTIERS IN PLANT SCIENCE 2021; 12:541163. [PMID: 33859656 PMCID: PMC8042317 DOI: 10.3389/fpls.2021.541163] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 03/08/2021] [Indexed: 06/12/2023]
Abstract
Juglans mandshurica is a monoecious heterodichogamous species with protogynous and protandrous mating strategies that occur at a 1:1 ratio and are randomly distributed in the population. The inconsistent male and female flowering periods of the same mating type result in an imbalance of the ratio of male and female flowers, contributing to the low yield of this species. However, little more is known about its floral development. Following three consecutive years of observations, histological analysis, and scanning electron microscopy, we found that the morphological and anatomical development of the male and female flowers were synchronous. The male floral morphological development of J. mandshurica was divided into seven phases, while that of the female flower was nine. Four stages were shared between the male and female flower's anatomical development. Our findings indicate that there was minimal overlap between sexual functions within the same mating type, guaranteeing synchronization, mutual non-interference, outcrossing, and avoidance of self-fertilization. These results provide a theoretical basis for the improvement of fruit yield and quality through the reasonable allocation of protogynous and protandrous individuals in a population, and for artificial pollination control. Further, these findings lay a foundation for further research on the genetic mechanisms and environmental effects on flower development of heterodichogamous J. mandshurica.
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Affiliation(s)
- Lijie Zhang
- College of Forestry, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Forest Tree Genetics and Breeding of Liaoning Province, Shenyang, China
| | - Chong Guo
- College of Forestry, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Forest Tree Genetics and Breeding of Liaoning Province, Shenyang, China
| | - Xiujun Lu
- College of Forestry, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Forest Tree Genetics and Breeding of Liaoning Province, Shenyang, China
| | - Xiaomei Sun
- College of Forestry, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Forest Tree Genetics and Breeding of Liaoning Province, Shenyang, China
| | - Chunping Liu
- College of Forestry, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Forest Tree Genetics and Breeding of Liaoning Province, Shenyang, China
| | - Qiang Zhou
- Liaoning Forestry and Grassland Administration, Shenyang, China
| | - Jifeng Deng
- College of Forestry, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Forest Tree Genetics and Breeding of Liaoning Province, Shenyang, China
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12
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Tel-Zur N, Keasar T. Intraspecific Seasonal Variation of Flowering Synchronization in a Heterodichogamous Tree. PLANTS 2020; 9:plants9111509. [PMID: 33171790 PMCID: PMC7694992 DOI: 10.3390/plants9111509] [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: 10/05/2020] [Revised: 10/28/2020] [Accepted: 11/04/2020] [Indexed: 11/16/2022]
Abstract
Heterodichogamous reproduction in plants involves two flowering morphs, reciprocal in their timing of male and female sexual functions. The degree of synchrony in floral sex phase, within and between individuals of each morph, determines the flowers’ potential fertilization partners. Complete within-morph synchrony enables across-morph mating alone, whereas unsynchronized floral sex phases may allow fertilization within a plant individual (geitonogamy) or within a morph. We documented the disruption of flowering synchrony in the heterodichogamous Ziziphus spina-christi towards the end of its seven-month flowering season. This desert tree has self-incompatible, protandrous, short-lived (2-day) flowers that open before dawn (‘Early’ morph) or around noon (‘Late’ morph). We counted flowers in the male and female phase on flowering branches that were sampled monthly during the 2016–2018 flowering seasons. In 2018, we also tagged flowers and followed their sex-phase distributions over two days at the start, middle, and end of the season. The switch to the female phase was delayed at the end-season (November-December), and 74% of the flowers did not develop beyond their male phase. Differences in male-phase duration resulted in asynchrony among flowers within each tree and among trees of both flowering morphs. Consequently, fertilization between trees of the same morph becomes potentially possible during the end-season. In controlled hand-pollination assays, some within-morph fertilizations set fruit. The end-season breakdown of synchronous flowering generates variability within morphs and populations. We suggest that this variability may potentially enable new mating combinations in a population and enhance its genetic diversity.
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Affiliation(s)
- Noemi Tel-Zur
- French Associates Institutes for Agriculture and Biotechnology of Drylands, J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde-Boqer Campus, Sde Boqer 8499000, Israel;
| | - Tamar Keasar
- Department of Biology, University of Haifa—Oranim, Tivon 36006, Israel
- Correspondence: ; Tel.: +972-52-871-8860
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Shigeta K, Suetsugu K. Contribution of thrips to seed production in Habenaria radiata, an orchid morphologically adapted to hawkmoths. JOURNAL OF PLANT RESEARCH 2020; 133:499-506. [PMID: 32468497 DOI: 10.1007/s10265-020-01205-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 05/21/2020] [Indexed: 06/11/2023]
Abstract
The very high floral diversity of Orchidaceae has often been attributed to the intricate relationships between orchids and their pollinators. In particular, the interaction between long-spurred orchids and hawkmoths has been well-studied. However, several recent studies suggest that pollination is driven by complex factors, including floral syndromes and local pollinator availability. Here, we investigated contributions of thrips to seed production in the presumably hawkmoth-pollinated long-spurred orchid Habenaria radiata, using pollination experiments and floral visitor observations. These experiments and observations showed that H. radiata is pollinated by both hawkmoths and thrips. Thrips intrude into the pollen sac, causing several massulae to be shed onto the stigma of the same flower, which is located just below the pollen sac. The fruit set and seed set of flowers enclosed in mesh bags (which allow thrips in) and in flowers enclosed together with thrips in paper bags, were much higher than in flowers enclosed in paper bags without thrips. This suggests that thrips partially contribute to fruit and seed production in this species. It provides evidence that thrips can contribute to seed production in a long-spurred orchid that is morphologically adapted to lepidopteran visitors. Unlike the compact pollinia of typical orchid species, those of H. radiata are mealy and friable, and thrips can therefore dislodge the pollen grains in small clumps. We suggest that secondary pollination by thrips may be more common than previously recognized in orchids with granular pollinia.
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Affiliation(s)
- Koji Shigeta
- Food Technology Research Center, Hiroshima Prefectural Technology Research Institute, 12-70 Hijiyama-honmachi, Minami-ku, Hiroshima, 732-0816, Japan.
| | - Kenji Suetsugu
- Department of Biology, Graduate School of Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501, Japan.
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Mu XY, Tong L, Sun M, Zhu YX, Wen J, Lin QW, Liu B. Phylogeny and divergence time estimation of the walnut family (Juglandaceae) based on nuclear RAD-Seq and chloroplast genome data. Mol Phylogenet Evol 2020; 147:106802. [DOI: 10.1016/j.ympev.2020.106802] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 03/18/2020] [Accepted: 03/18/2020] [Indexed: 11/25/2022]
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15
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Chen X, Mao X, Huang P, Fang S. Morphological Characterization of Flower Buds Development and Related Gene Expression Profiling at Bud Break Stage in Heterodichogamous Cyclocarya paliurus (Batal.) lljinskaja. Genes (Basel) 2019; 10:genes10100818. [PMID: 31627470 PMCID: PMC6827045 DOI: 10.3390/genes10100818] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 10/10/2019] [Accepted: 10/15/2019] [Indexed: 12/11/2022] Open
Abstract
Cyclocarya paliurus (Batal.) Iljinskaja, a unique species growing in southern China, is a multi-function tree species with medicinal, healthcare, material, and ornamental values. So far, sexual reproduction is the main method for extensive cultivation of C. paliurus plantations, but this is limited by low seed plumpness resulted from the character of heterodichogamy. Phenological observations have revealed the asynchronism of flower development in this species. However, its molecular mechanism remains largely unknown. To reveal molecular mechanism of heterodichogamy in C. paliurus, transcriptome of female (F) and male (M) buds from two mating types (protandry, PA; protogyny, PG) at bud break stage were sequenced using Illumina Hiseq 4000 platform. The expression patterns of both 32 genes related to flowering and 58 differentially expressed transcription factors (DETFs) selected from 6 families were divided four groups (PG-F, PG-M, PA-F, and PA-M) into two categories: first flowers (PG-F and PA-M) and later flowers (PA-F and PG-M). The results indicated that genes related to plant hormones (IAA, ABA, and GA) synthesis and response, glucose metabolism, and transcription factors (especially in MIKC family) played significant roles in regulating asynchronism of male and female flowers in the same mating type. The expression of DETFs showed two patterns. One contained DETFs up-regulated in first flowers in comparison to later flowers, and the other was the reverse. Nine genes related to flowering were selected for qRT-PCR to confirm the accuracy of RNA-seq, and generally, the RPKM values of these genes were consistent with the result of qRT-PCR. The results of this work could improve our understanding in asynchronism of floral development within one mating type in C. paliurus at transcriptional level, as well as lay a foundation for further study in heterodichogamous plants.
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Affiliation(s)
- Xiaoling Chen
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China
| | - Xia Mao
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China
| | - Peng Huang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China
| | - Shengzuo Fang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China.
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16
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Scott-Brown AS, Arnold SEJ, Kite GC, Farrell IW, Farman DI, Collins DW, Stevenson PC. Mechanisms in mutualisms: a chemically mediated thrips pollination strategy in common elder. PLANTA 2019; 250:367-379. [PMID: 31069523 DOI: 10.1007/s00425-019-03176-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 04/26/2019] [Indexed: 06/09/2023]
Abstract
This study provides first evidence of a thrips species pollinating Sambucus nigra and describes how interactions are driven by plant biochemical signalling and moderated by temporal changes in floral chemistry. The concept of flower-feeding thrips as pollinating insects in temperate regions is rarely considered as they are more frequently regarded to be destructive florivores feeding on pollen and surrounding plant tissue. Combining laboratory and field-based studies we examined interactions between Sambucus nigra (elderflower) and Thrips major within their native range to ascertain the role of thrips in the pollination of this species and to determine if floral chemicals mediated flower visits. If thrips provide a pollination service to S. nigra, then this will likely manifest in traits that attract the pollinating taxa at temporally critical points in floral development. T. major were highly abundant in inflorescences of S. nigra, entering flowers when stigmas were pollen-receptive and anthers were immature. When thrips were excluded from the inflorescences, fruit-set failed. Linalool was the major component of the inflorescence headspace with peak abundance coinciding with the highest number of adult thrips visiting flowers. Thrips were absent in buds and their numbers declined again in senescing flowers inversely correlating with the concentration of cyanogenic glycosides recorded in the floral tissue. Our data show that S. nigra floral chemistry mediates the behaviour of pollen-feeding thrips by attracting adults in high numbers to the flowers at pre-anthesis stage, while producing deterrent compounds prior to fruit development. Taking an integrative approach to studying thrips behaviour and floral biology we provide a new insight into the previously ambiguously defined pollination strategies of S. nigra and provide evidence suggesting that the relationship between T. major and S. nigra is mutualistic.
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Affiliation(s)
| | - Sarah E J Arnold
- Natural Resources Institute, University of Greenwich, Chatham Maritime, ME4 4TB, UK
| | | | | | - Dudley I Farman
- Natural Resources Institute, University of Greenwich, Chatham Maritime, ME4 4TB, UK
| | | | - Philip C Stevenson
- Royal Botanic Gardens Kew, Richmond, TW9 3AB, UK
- Natural Resources Institute, University of Greenwich, Chatham Maritime, ME4 4TB, UK
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Heterodichogamy, Pollen Viability, and Seed Set in a Population of Polyploidy Cyclocarya Paliurus (Batal) Iljinskaja (Juglandaceae). FORESTS 2019. [DOI: 10.3390/f10040347] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Research Highlights: Cyclocarya paliurus, native to the subtropical region of China, is a monoecious species with a heterodichogamous mating system. Its flowering phenology and low seed success characteristics differ from other typical heterodichogamous Juglandaceae species. This could be caused by the existence of polyploidy in the population. Background and Objectives: C. paliurus has been attracting more attention as a result of its medicinal value. To meet the needs for leaf harvest, cultivation expansion is required, but this is limited by a shortage of seeds. This study aims to profile the flowering phenology and the efficacy of pollen dispersal as well as elucidate on the mechanism of low seed success in the population. Materials and Methods: The flowering phenology pattern of C. paliurus was observed in a juvenile plantation containing 835 individuals of 53 families from 8 provenances at the individual (protandry, PA and protogyny, PG) and population levels for 5 consecutive years (2014–2018). Slides with a culture medium of 10% sucrose and 0.01% boric acid were used to estimate pollen density and viability in the population, and seeds were collected from 20 randomly selected PA and PG individuals to assess seed success during 2017–2018. Results: Four flowering phenotypes and strongly skewed ratios of PA/PG and male/female occurred in the juvenile population. Sexual type and ratio changed significantly with the growth of the population over the years, showing an increasing monoecious group (11.1% to 57.2%) and a decreasing unisexual group (33.6% to 16.3%), as well as a tendency for the sexual ratio to move towards equilibrium (5.42:1 to 1.39:1 for PG:PA). Two flowering phases and bimodality in gender were displayed, as in other heterodichogamous species. However, the high overlap of inter-phases and within individuals was quite different from many previous reports. Owing to the low pollen viability of C. paliurus (~30%), low seed success was monitored in the plantation, as well as in the investigated natural populations. Conclusions: Female-bias (PG and F) and a skewed ratio of mating types corresponded to nutrient accumulation in the juvenile population. Heterodichogamy in C. paliurus was verified, but was shown to be different from other documented species in Juglandaceae. The latest finding of major tetraploidy in a natural population could explain the characteristics of the flowering phenology and seed set of C. paliurus and also give rise to more questions to be answered.
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Watanabe S, Takakura KI, Kaneko Y, Noma N, Nishida T. Skewed male reproductive success and pollen transfer in a small fragmented population of the heterodichogamous tree Machilus thunbergii. JOURNAL OF PLANT RESEARCH 2018; 131:623-631. [PMID: 29468326 DOI: 10.1007/s10265-018-1018-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 02/01/2018] [Indexed: 06/08/2023]
Abstract
Heterodichogamy is defined as the presence of two flower morphs that exhibit the male and female functions at different times among individuals within a population. Heterodichogamy is regarded as an adaptation to promote outcrossing through enhanced inter-morph mating, together with a 1:1 morph ratio. However, in highly fragmented populations, the morph ratio may be more likely to be biased by stochastic events. In such a situation, individuals of a minority morph within a population are expected to have higher reproductive success than those of a majority morph, which may suffer from pollen shortages of the minority morph. In this paper, we evaluated mating patterns and male reproductive success in a highly fragmented population of Machilus thunbergii, a putative heterodichogamous evergreen laurel tree. Results of paternity analysis indicated that the selfing rate was not clearly different between the two morphs. In contrast, the proportion of intra-morph mating was higher in the majority-morph (MM) mother trees than in the minority-morph (MF) mother trees. Bayesian estimated male reproductive success indicated that male reproductive success was higher in minority-morph (MF) than in majority-morph (MM) mother trees. These findings indicate that (1) the majority morph mothers, suffering a shortage of the opposite morph pollen, could partly compensate for the reduced reproductive success by intra-morph mating rather than by selfing, and (2) negative-frequency dependent selection may be involved in the maintenance of the two morphs.
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Affiliation(s)
- Shuntaro Watanabe
- Field Science Education and Research Centre (FSERC), Kyoto University, Kitashirakawaoiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan.
| | - Koh-Ichi Takakura
- School of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga, 522-8533, Japan
| | - Yuko Kaneko
- Natural Science Laboratory, Toyo University, 5-28-20, Hakusan, Bunkyo-ku, Tokyo, 112-8606, Japan
| | - Naohiko Noma
- School of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga, 522-8533, Japan
| | - Takayoshi Nishida
- School of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga, 522-8533, Japan
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20
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Renner SS. The relative and absolute frequencies of angiosperm sexual systems: dioecy, monoecy, gynodioecy, and an updated online database. AMERICAN JOURNAL OF BOTANY 2014; 101:1588-96. [PMID: 25326608 DOI: 10.3732/ajb.1400196] [Citation(s) in RCA: 323] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
UNLABELLED • PREMISE OF THE STUDY Separating sexual function between different individuals carries risks, especially for sedentary organisms. Nevertheless, many land plants have unisexual gametophytes or sporophytes. This study brings together data and theoretical insights from research over the past 20 yr on the occurrence and frequency of plant sexual systems, focusing on the flowering plants.• METHODS A list of genera with dioecious species, along with other information, is made available (http://www.umsl.edu/∼renners/). Frequencies of other sexual systems are tabulated, and data on the genetic regulation, ecological context, and theoretical benefits of dioecy reviewed.• KEY RESULTS There are 15600 dioecious angiosperms in 987 genera and 175 families, or 5-6% of the total species (7% of genera, 43% of families), with somewhere between 871 to 5000 independent origins of dioecy. Some 43% of all dioecious angiosperms are in just 34 entirely dioecious clades, arguing against a consistent negative influence of dioecy on diversification. About 31.6% of the dioecious species are wind-pollinated, compared with 5.5-6.4% of nondioecious angiosperms. Also, 1.4% of all angiosperm genera contain dioecious and monoecious species, while 0.4% contain dioecious and gynodioecious species. All remaining angiosperm sexual systems are rare. Chromosomal sex determination is known from 40 species; environmentally modulated sex allocation is common. Few phylogenetic studies have focused on the evolution of dioecy.• CONCLUSIONS The current focus is on the genetic mechanisms underlying unisexual flowers and individuals. Mixed strategies of sexual and vegetative dispersal, together with plants' sedentary life style, may often favor polygamous systems in which sexually inconstant individuals can persist. Nevertheless, there are huge entirely dioecious clades of tropical woody plants.
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Affiliation(s)
- Susanne S Renner
- Systematic Botany and Mycology, University of Munich, 80638 Munich, Germany
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