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Liu X, Peng Y, Zeng Q, Ma Y, Liu J, Huang Y, Yu X, Luo J, Li Y, Li M, Cao F. Transcriptomic profiling and gene network analysis revealed regulatory mechanisms of bract development in Bougainvillea glabra. BMC PLANT BIOLOGY 2024; 24:543. [PMID: 38872082 DOI: 10.1186/s12870-024-05246-7] [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: 04/16/2024] [Accepted: 06/04/2024] [Indexed: 06/15/2024]
Abstract
BACKGROUND Bracts are important for ornamental plants, and their developmental regulation process is complex; however, relatively little research has been conducted on bracts. In this study, physiological, biochemical and morphological changes in Bougainvillea glabra leaves, leaf buds and bracts during seven developmental periods were systematically investigated. Moreover, transcriptomic data of B. glabra bracts were obtained using PacBio and Illumina sequencing technologies, and key genes regulating their development were screened. RESULTS Scanning electron microscopy revealed that the bracts develop via a process involving regression of hairs and a color change from green to white. Transcriptome sequencing revealed 79,130,973 bp of transcript sequences and 45,788 transcripts. Differential gene expression analysis revealed 50 expression patterns across seven developmental periods, with significant variability in transcription factors such as BgAP1, BgFULL, BgCMB1, BgSPL16, BgSPL8, BgDEFA, BgEIL1, and BgBH305. KEGG and GO analyses of growth and development showed the involvement of chlorophyll metabolism and hormone-related metabolic pathways. The chlorophyll metabolism genes included BgPORA, BgSGR, BgPPH, BgPAO and BgRCCR. The growth hormone and abscisic acid signaling pathways involved 44 and 23 homologous genes, and coexpression network analyses revealed that the screened genes BgAPRR5 and BgEXLA1 are involved in the regulation of bract development. CONCLUSIONS These findings improve the understanding of the molecular mechanism of plant bract development and provide important guidance for the molecular regulation and genetic improvement of the growth and development of ornamental plants, mainly ornamental bracts.
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Affiliation(s)
- Xiangdong Liu
- College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Hunan Applied Technology University, Changde, 415000, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
- Hunan Mid-Subtropical Quality Plant Breeding and Utilization Engineering Technology Research Center, Changsha, 410128, China
- Yuelushan Laboratory, Changsha, 410128, China
| | - Yaonan Peng
- College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
- Hunan Mid-Subtropical Quality Plant Breeding and Utilization Engineering Technology Research Center, Changsha, 410128, China
| | - Qinghui Zeng
- College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
- Hunan Mid-Subtropical Quality Plant Breeding and Utilization Engineering Technology Research Center, Changsha, 410128, China
| | - Yuwan Ma
- College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
- Hunan Mid-Subtropical Quality Plant Breeding and Utilization Engineering Technology Research Center, Changsha, 410128, China
| | - Jin Liu
- College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
- Hunan Mid-Subtropical Quality Plant Breeding and Utilization Engineering Technology Research Center, Changsha, 410128, China
| | - Yaqi Huang
- College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
- Hunan Botanical Garden, Changsha, 410128, China
- Hunan Mid-Subtropical Quality Plant Breeding and Utilization Engineering Technology Research Center, Changsha, 410128, China
- Yuelushan Laboratory, Changsha, 410128, China
| | - Xiaoying Yu
- College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
- Hunan Mid-Subtropical Quality Plant Breeding and Utilization Engineering Technology Research Center, Changsha, 410128, China
- Yuelushan Laboratory, Changsha, 410128, China
| | - Jun Luo
- Hunan Botanical Garden, Changsha, 410128, China
| | - Yanlin Li
- College of Horticulture, Hunan Agricultural University, Changsha, 410128, China.
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China.
- Hunan Mid-Subtropical Quality Plant Breeding and Utilization Engineering Technology Research Center, Changsha, 410128, China.
- Yuelushan Laboratory, Changsha, 410128, China.
| | - Meng Li
- College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, China.
| | - Fuxiang Cao
- College of Horticulture, Hunan Agricultural University, Changsha, 410128, China.
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China.
- Hunan Mid-Subtropical Quality Plant Breeding and Utilization Engineering Technology Research Center, Changsha, 410128, China.
- Yuelushan Laboratory, Changsha, 410128, China.
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Song B, Chen J, Lev-Yadun S, Niu Y, Gao Y, Ma R, Armbruster WS, Sun H. Multifunctionality of angiosperm floral bracts: a review. Biol Rev Camb Philos Soc 2024; 99:1100-1120. [PMID: 38291834 DOI: 10.1111/brv.13060] [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: 11/28/2022] [Revised: 01/02/2024] [Accepted: 01/22/2024] [Indexed: 02/01/2024]
Abstract
Floral bracts (bracteoles, cataphylls) are leaf-like organs that subtend flowers or inflorescences but are of non-floral origin; they occur in a wide diversity of species, representing multiple independent origins, and exhibit great variation in form and function. Although much attention has been paid to bracts over the past 150 years, our understanding of their adaptive significance remains remarkably incomplete. This is because most studies of bract function and evolution focus on only one or a few selective factors. It is widely recognised that bracts experience selection mediated by pollinators, particularly for enhancing pollinator attraction through strong visual, olfactory, or echo-acoustic contrast with the background and through signalling the presence of pollinator rewards, either honestly (providing rewards for pollinators), or deceptively (attraction without reward or even trapping pollinators). However, studies in recent decades have demonstrated that bract evolution is also affected by agents other than pollinators. Bracts can protect flowers, fruits, or seeds from herbivores by displaying warning signals, camouflaging conspicuous reproductive organs, or by providing physical barriers or toxic chemicals. Reviews of published studies show that bracts can also promote seed dispersal and ameliorate the effects of abiotic stressors, such as low temperature, strong ultraviolet radiation, heavy rain, drought, and/or mechanical abrasion, on reproductive organs or for the plants' pollinators. In addition, green bracts and greening of colourful bracts after pollination promote photosynthetic activity, providing substantial carbon (photosynthates) for fruit or seed development, especially late in a plant's life cycle or season, when leaves have started to senesce. A further layer of complexity derives from the fact that the agents of selection driving the evolution of bracts vary between species and even between different developmental stages within a species, and selection by one agent can be reinforced or opposed by other agents. In summary, our survey of the literature reveals that bracts are multifunctional and subject to multiple agents of selection. To understand fully the functional and evolutionary significance of bracts, it is necessary to consider multiple selection agents throughout the life of the plant, using integrative approaches to data collection and analysis.
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Affiliation(s)
- Bo Song
- Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, 650201, China
| | - Jiaqi Chen
- Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, 650201, China
- School of Life Sciences, Yunnan University, Huannan Road, East of University Town, Chenggong New Area, Kunming, 650500, China
| | - Simcha Lev-Yadun
- Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa at Oranim, Kiryat Tiv'on, 36006, Israel
| | - Yang Niu
- Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, 650201, China
| | - Yongqian Gao
- Yunnan Forestry Technological College, 1 Jindian, Kunming, 650224, China
| | - Rong Ma
- Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, 650201, China
| | - W Scott Armbruster
- School of Biological Sciences, University of Portsmouth, King Henry Building, King Henry I Street, Portsmouth, PO1 2DY, UK
- Institute of Arctic Biology, University of Alaska, PO Box 757000, Fairbanks, AK, 99775, USA
| | - Hang Sun
- Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, 650201, China
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Neves B, Kessous IM, Moura RL, Couto DR, Zanella CM, Antonelli A, Bacon CD, Salgueiro F, Costa AF. Pollinators drive floral evolution in an Atlantic Forest genus. AOB PLANTS 2020; 12:plaa046. [PMID: 33033591 PMCID: PMC7532729 DOI: 10.1093/aobpla/plaa046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 08/19/2020] [Indexed: 06/11/2023]
Abstract
Pollinators are important drivers of angiosperm diversification at both micro- and macroevolutionary scales. Both hummingbirds and bats pollinate the species-rich and morphologically diverse genus Vriesea across its distribution in the Brazilian Atlantic Forest. Here, we (i) determine if floral traits predict functional groups of pollinators as documented, confirming the pollination syndromes in Vriesea and (ii) test if genetic structure in Vriesea is driven by geography (latitudinal and altitudinal heterogeneity) or ecology (pollination syndromes). We analysed 11 floral traits of 58 Vriesea species and performed a literature survey of Vriesea pollination biology. The genealogy of haplotypes was inferred and phylogenetic analyses were performed using chloroplast (rps16-trnk and matK) and nuclear (PHYC) molecular markers. Floral traits accurately predict functional groups of pollinators in Vriesea. Genetic groupings match the different pollination syndromes. Species with intermediate position were found between the groups, which share haplotypes and differ morphologically from the typical hummingbird- and bat-pollinated flowers of Vriesea. The phylogeny revealed moderately to well-supported clades which may be interpreted as species complexes. Our results suggest a role of pollinators driving ecological isolation in Vriesea clades. Incipient speciation and incomplete lineage sorting may explain the overall low genetic divergence within and among morphologically defined species, precluding the identification of clear species boundaries. The intermediate species with mixed floral types likely represent a window into shifts between pollinator syndromes. This study reports the morphological-genetic continuum that may be typical of ongoing pollinator-driven speciation in biodiversity hotspots.
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Affiliation(s)
- Beatriz Neves
- Universidade Federal do Rio de Janeiro, Museu Nacional, Programa de Pós Graduação em Ciências Biológicas (Botânica), São Cristóvão, Rio de Janeiro, RJ, Brazil
- Gothenburg Global Biodiversity Centre, SE Gothenburg, Sweden
| | - Igor M Kessous
- Universidade Federal do Rio de Janeiro, Museu Nacional, Programa de Pós Graduação em Ciências Biológicas (Botânica), São Cristóvão, Rio de Janeiro, RJ, Brazil
| | - Ricardo L Moura
- Universidade Federal do Rio de Janeiro, Museu Nacional, Programa de Pós Graduação em Ciências Biológicas (Botânica), São Cristóvão, Rio de Janeiro, RJ, Brazil
| | - Dayvid R Couto
- Universidade Federal do Rio de Janeiro, Museu Nacional, Programa de Pós Graduação em Ciências Biológicas (Botânica), São Cristóvão, Rio de Janeiro, RJ, Brazil
| | | | - Alexandre Antonelli
- Gothenburg Global Biodiversity Centre, SE Gothenburg, Sweden
- Royal Botanic Gardens, Surrey, UK
- Department of Biological and Environmental Sciences, University of Gothenburg, SE Gothenburg, Sweden
| | - Christine D Bacon
- Gothenburg Global Biodiversity Centre, SE Gothenburg, Sweden
- Department of Biological and Environmental Sciences, University of Gothenburg, SE Gothenburg, Sweden
| | - Fabiano Salgueiro
- Departamento de Botânica, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Andrea F Costa
- Departamento de Botânica, Universidade Federal do Rio de Janeiro, Museu Nacional, São Cristóvão, Rio de Janeiro, RJ, Brazil
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