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Liu R, Wang WJ, Wang H, Ree RH, Li DZ, Yu WB. Plant species diversification in the Himalaya-Hengduan Mountains region: an example from an endemic lineage of Pedicularis (Orobanchaceae) in the role of floral specializations and rapid range expansions. Cladistics 2024. [PMID: 39258812 DOI: 10.1111/cla.12596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 08/15/2024] [Accepted: 08/18/2024] [Indexed: 09/12/2024] Open
Abstract
The c. 270 endemic species of Pedicularis in the Himalaya-Hengduan Mountains (HHM) region exhibit high diversity in geographic distribution, elevational range and floral morphology. Many of these, including the species with the longest corolla tubes and beaked galeas, are monophyletic and represent a putative in situ radiation. In this study, we focus on the representative Clade 3 within the HHM region. We integrate the plastid phylogeny of this clade with environmental data and species distributions to infer environmental correlates of species diversity. We estimate macroevolutionary rates and reconstructed ancestral states for geographic ranges and corolla traits, and analyse patterns of range overlap and niche evolution to assess drivers of diversification in the HHM region. Our results show that the region from northwest Yunnan to southwest Sichuan is the centre of diversity for this clade of Pedicularis. Rates of diversification are associated with precipitation and multiple environmental factors. Multiple range expansions from the Sanjiang (Three Parallel Rivers) region, followed by allopatric speciation across the HHM region, contributed to early rapid diversification. Corolla traits are not significantly associated with species diversification. This study highlights the importance of integrated evidence for understanding species diversification dynamics and contributes to our understanding of the origins of the remarkable richness of plant species in the HHM region.
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Affiliation(s)
- Rong Liu
- Center for Integrative Conservation and Yunnan Key Laboratory for the Conservation of Tropical Rainforests and Asian Elephants, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
- University of Chinese Academy of Sciences, Huairou District, Beijing, 101408, China
| | - Wei-Jia Wang
- Center for Integrative Conservation and Yunnan Key Laboratory for the Conservation of Tropical Rainforests and Asian Elephants, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Hong Wang
- University of Chinese Academy of Sciences, Huairou District, Beijing, 101408, China
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Richard H Ree
- Negaunee Integrative Research Center, Field Museum, Chicago, Illinois, 60605, USA
| | - De-Zhu Li
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Wen-Bin Yu
- Center for Integrative Conservation and Yunnan Key Laboratory for the Conservation of Tropical Rainforests and Asian Elephants, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
- Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
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Chitchak N, Stewart AB, Traiperm P. Functional Ecology of External Secretory Structures in Rivea ornata (Roxb.) Choisy (Convolvulaceae). PLANTS (BASEL, SWITZERLAND) 2022; 11:2068. [PMID: 35956546 PMCID: PMC9370475 DOI: 10.3390/plants11152068] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/02/2022] [Accepted: 08/05/2022] [Indexed: 11/20/2022]
Abstract
Plants have evolved numerous secretory structures that fulfill diverse roles and shape their interactions with other organisms. Rivea ornata (Roxb.) Choisy (Convolvulaceae) is one species that possesses various external secretory organs hypothesized to be ecologically important. This study, therefore, aimed to investigate five secretory structures (nectary disc, petiolar nectaries, calycinal glands, staminal hairs, and foliar glands) using micromorphology, anatomy, histochemistry, and field observations of plant-animal interactions in order to assess the functional contributions of these structures. Results show that the nectary disc and petiolar nectaries are complex working units consisting of at least epidermis and ground tissue, while the other structures are glandular trichomes. Various groups of metabolites (lipids, phenolic compounds, polysaccharides, terpenoids, flavonoids, and alkaloids) were detected in all structures, while starch grains were only found in the nectary disc, petiolar nectaries, and their adjacent tissues. Integrating preliminary observation of animal visitors with micromorphological, anatomical, and histochemical results, two hypotheses are proposed: (I) nectary disc and staminal hairs are important for pollination as they potentially attract and reward floral visitors, and (II) petiolar nectaries, calycinal glands, and foliar glands contribute to plant defense. Specifically, petiolar nectaries and calycinal glands provide protection from herbivores via guard ants, while calycinal and foliar glands may use plant metabolites to help prevent tissue damage from dehydration and insolation.
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Affiliation(s)
| | | | - Paweena Traiperm
- Department of Plant Science, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
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Chen T, Zhou Y, Zhang J, Peng Y, Yang X, Hao Z, Lu Y, Wu W, Cheng T, Shi J, Chen J. Integrative analysis of transcriptome and proteome revealed nectary and nectar traits in the plant-pollinator interaction of Nitraria tangutorum Bobrov. BMC PLANT BIOLOGY 2021; 21:230. [PMID: 34022807 PMCID: PMC8140516 DOI: 10.1186/s12870-021-03002-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 04/27/2021] [Indexed: 05/05/2023]
Abstract
BACKGROUND Nitraria tangutorum is an important desert shrub that shows resistance to drought, salt and wind erosion stresses. It is a central ecological species in its area. Here, we have studied how N. tangutorum has adapted to achieve a successful reproduction strategy. RESULTS We found that N. tangutorum is mainly pollinated by insects of the Hymenoptera, Diptera and Coleoptera orders. Nitraria tangutorum has very small flowers, with the nectary composed of secretive epidermal cells from which nectar is secreted, located within the inner petals. In addition, analyzing the transcriptome of four successive flower developmental stages revealed that mainly differentially expressed genes associated with flower and nectary development, nectar biosynthesis and secretion, flavonoid biosynthesis, plant hormone signal transduction and plant-pathogen interaction show dynamic expression. From the nectar, we could identify seven important proteins, of which the L-ascorbate oxidase protein was first found in plant nectar. Based on the physiological functions of these proteins, we predict that floral nectar proteins of N. tangutorum play an important role in defending against microbial infestation and scavenging active oxygen. CONCLUSIONS This study revealed that N. tangutorum is an insect-pollinated plant and its nectary is composed of secretive epidermal cells that specialized into secretive trichomes. We identified a large number of differentially expressed genes controlling flower and nectary development, nectar biosynthesis and secretion, flavonoid biosynthesis, plant hormone signal transduction and plant-pathogen interaction. We suggest that proteins present in N. tangutorum nectar may have both an antibacterial and oxygen scavenging effect. These results provide a scientific basis for exploring how the reproductive system of N. tangutorum and other arid-desert plants functions.
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Affiliation(s)
- Tingting Chen
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Longpan Rd, Xuanwu Nanjing, 210037 China
| | - Yanwei Zhou
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Longpan Rd, Xuanwu Nanjing, 210037 China
| | - Jingbo Zhang
- Experimental Center of Desert Forestry, Chinese Academy of Forestry, Dengkou, Inner Mongolia China
| | - Ye Peng
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037 China
| | - Xiuyan Yang
- Research center of saline and alkali land of National Forestry and Grassland Administration, Chinese Academy of Forestry, Beijing, 100091 China
| | - Zhaodong Hao
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Longpan Rd, Xuanwu Nanjing, 210037 China
| | - Ye Lu
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Longpan Rd, Xuanwu Nanjing, 210037 China
| | - Weihuang Wu
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Longpan Rd, Xuanwu Nanjing, 210037 China
| | - Tielong Cheng
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037 China
| | - Jisen Shi
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Longpan Rd, Xuanwu Nanjing, 210037 China
| | - Jinhui Chen
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Longpan Rd, Xuanwu Nanjing, 210037 China
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Tong ZY, Wang XP, Wu LY, Huang SQ. Nectar supplementation changes pollinator behaviour and pollination mode in Pedicularis dichotoma: implications for evolutionary transitions. ANNALS OF BOTANY 2019; 123:373-380. [PMID: 29878060 PMCID: PMC6344217 DOI: 10.1093/aob/mcy102] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 05/17/2018] [Indexed: 05/26/2023]
Abstract
BACKGROUNDS AND AIMS Gain or loss of floral nectar, an innovation in floral traits, has occurred in diverse lineages of flowering plants, but the causes of reverse transitions (gain of nectar) remain unclear. Phylogenetic studies show multiple gains and losses of floral nectar in the species-rich genus Pedicularis. Here we explore how experimental addition of nectar to a supposedly nectarless species, P. dichotoma, influences pollinator foraging behaviour. METHODS The liquid (nectar) at the base of the corolla tube in P. dichotoma was investigated during anthesis. Sugar components were measured by high-performance liquid chromatography. To understand evolutionary transitions of nectar, artificial nectar was added to corolla tubes and the reactions of bumble-bee pollinators to extra nectar were examined. KEY RESULTS A quarter of unmanipulated P. dichotoma plants contained measurable nectar, with 0.01-0.49 μL per flower and sugar concentrations ranging from 4 to 39 %. The liquid surrounding the ovaries in the corolla tubes was sucrose-dominant nectar, as in two sympatric nectariferous Pedicularis species. Bumble-bees collected only pollen from control (unmanipulated) flowers of P. dichotoma, adopting a sternotribic pollination mode, but switched to foraging for nectar in manipulated (nectar-supplemented) flowers, adopting a nototribic pollination mode as in nectariferous species. This altered foraging behaviour did not place pollen on the ventral side of the bees, and sternotribic pollination also decreased. CONCLUSION Our study is the first to quantify variation in nectar production in a supposedly 'nectarless' Pedicularis species. Flower manipulations by adding nectar suggested that gain (or loss) of nectar would quickly result in an adaptive behavioural shift in the pollinator, producing a new location for pollen deposition and stigma contact without a shift to other pollinators. Frequent gains of nectar in Pedicularis species would be beneficial by enhancing pollinator attraction in unpredictable pollination environments.
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Affiliation(s)
- Ze-Yu Tong
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Xiang-Ping Wang
- South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Ling-Yun Wu
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Shuang-Quan Huang
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, China
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Resolving interspecific relationships within evolutionarily young lineages using RNA-seq data: An example from Pedicularis section Cyathophora (Orobanchaceae). Mol Phylogenet Evol 2017; 107:345-355. [DOI: 10.1016/j.ympev.2016.11.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 11/19/2016] [Accepted: 11/27/2016] [Indexed: 11/17/2022]
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Wang XP, Yu WB, Sun SG, Huang SQ. Pollen size strongly correlates with stigma depth among Pedicularis species. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2016; 58:818-821. [PMID: 26990321 DOI: 10.1111/jipb.12477] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 03/14/2016] [Indexed: 06/05/2023]
Abstract
Darwin proposed that pollen size should be positively correlated with stigma depth rather than style length among species given that pollen tubes first enter the stigma autotrophically, then grow through the style heterotrophically. However, studies often show a positive relationship between pollen size and style length. Five floral traits were observed to be correlated among 42 bumblebee-pollinated Pedicularis species (Orobanchaceae) in which stigmas are distinct from styles. The phylogenetic independent contrast analysis revealed that pollen grain volume was more strongly correlated with stigma depth than with style length, consistent with Darwin's functional hypothesis between pollen size and stigma depth.
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Affiliation(s)
- Xiang-Ping Wang
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Wen-Bin Yu
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China
| | - Shi-Guo Sun
- School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Shuang-Quan Huang
- School of Life Sciences, Central China Normal University, Wuhan 430079, China.
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Sun SG, Armbruster WS, Huang SQ. Geographic consistency and variation in conflicting selection generated by pollinators and seed predators. ANNALS OF BOTANY 2016; 118:227-37. [PMID: 27325896 PMCID: PMC4970362 DOI: 10.1093/aob/mcw097] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 04/05/2016] [Indexed: 05/13/2023]
Abstract
BACKGROUNDS AND AIMS Floral traits that attract pollinators may also attract seed predators, which, in turn, may generate conflicting natural selection on such traits. Although such selection trade-offs are expected to vary geographically, few studies have investigated selection mediated by pollinators and seed predators across a geographic mosaic of environments and floral variation. METHODS Floral traits were investigated in 14 populations of the bumble-bee-pollinated herb, Pedicularis rex, in which tubular flowers are subtended by cupular bracts holding rain water. To study potentially conflicting selection on floral traits generated by pollinators and florivores, stigmatic pollen loads, initial seed set, pre-dispersal seed predation and final viable seed production were measured in 12-14 populations in the field. KEY RESULTS Generalized Linear Model (GLM) analyses indicated that the pollen load on stigmas was positively related to the exsertion of the corolla beyond the cupular bracts and size of the lower corolla lip, but so too was the rate of seed predation, creating conflicting selection on both floral traits. A geographic mosaic of selection mediated by seed predators, but not pollinators, was indicated by significant variation in levels of seed predation and the inclusion of two-, three- and four-way interaction terms between population and seed predation in the best model [lowest corrected Akaike Information Criterion (AICc)] explaining final seed production. CONCLUSIONS These results indicate opposing selection in operation: pollinators generated selection for greater floral exsertion beyond the bracts, but seed predators generated selection for reduced exsertion above the protective pools of water, although the strength of the latter varied across populations.
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Affiliation(s)
- Shi-Guo Sun
- School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - W Scott Armbruster
- School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK Institute of Arctic Biology, University of Alaska, Fairbanks AK 99775-7000, USA
| | - Shuang-Quan Huang
- School of Life Sciences, Central China Normal University, Wuhan 430079, China
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Huang SQ, Wang XP, Sun SG. Are long corolla tubes in Pedicularis driven by pollinator selection? JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2016; 58:698-700. [PMID: 26714618 DOI: 10.1111/jipb.12460] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 12/24/2015] [Indexed: 06/05/2023]
Abstract
The evolution of long corolla tubes has been hypothesized to be driven by long-tongued pollinators. Corolla tubes in Pedicularis species can be longer than 10 cm which may function as flower stalks to increase visual attractiveness to pollinators because these species provide no nectar and are pollinated by bumblebees. The corolla tube length was manipulated (shorter or longer) in two Pedicularis species in field to examine whether longer tubes are more attractive to pollinators and produce more seeds than short tubes. Our results did not support the pollinator attraction hypothesis, leaving the evolution of long tubes in Pedicularis remains mysterious.
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Affiliation(s)
- Shuang-Quan Huang
- School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Xiang-Ping Wang
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Shi-Guo Sun
- School of Life Sciences, Central China Normal University, Wuhan 430079, China
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