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Rafińska K, Niedojadło K, Świdziński M, Bednarska-Kozakiewicz E. Distribution of exchangeable Ca 2+ during the process of Larix decidua Mill. pollination and germination. Sci Rep 2024; 14:5639. [PMID: 38454044 PMCID: PMC10920793 DOI: 10.1038/s41598-024-54903-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 02/18/2024] [Indexed: 03/09/2024] Open
Abstract
The involvement of Ca2+ ions in angiosperms sexual processes is well established, while in gymnosperms, such knowledge remains limited and is still a topic of discussion. In this study, we focused on Larix decidua, using Alizarin-red S staining and the pyroantimonate method to examine the tissue and subcellular distribution of free and loosely bound Ca2+ ions at different stages of the male gametophyte's development and its interaction with the ovule. Our findings show that in larch, both the germination of pollen grains and the growth of pollen tubes occur in an environment rich in Ca2+. These ions play a crucial role in the adhesion of the pollen grain to the stigmatic tip and its subsequent movement to the micropylar canal. There is a significant presence of free and loosely bound Ca2+ ions in both the fluid of the micropylar canal and the extracellular matrix of the nucellus. As the pollen tube extends through the nucellus, we observed a notable accumulation of Ca2+ ions just above the entry to the mature archegonium, a region likely crucial for the male gametophyte's directional growth. Meanwhile, the localized presence of free and loosely bound Ca2+ ions within the egg cell cytoplasm may inhibit the pollen tubes growth and rupture, playing an important role in fertilization.
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Affiliation(s)
- Katarzyna Rafińska
- Department of Environmental Chemistry and Bioanalysis, Faculty of Chemistry, Nicolaus Copernicus University, Gagarina 7, 87-100, Toruń, Poland
| | - Katarzyna Niedojadło
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Lwowska 1, 87-100, Toruń, Poland.
| | - Michał Świdziński
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Lwowska 1, 87-100, Toruń, Poland
| | - Elżbieta Bednarska-Kozakiewicz
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Lwowska 1, 87-100, Toruń, Poland
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Duan YF, Zhang C, Zhang M, Ye Y, Zhang KL, Chen MX, Chen L, Wang XR, Zhu FY. SWATH-MS based quantitive proteomics reveal regulatory metabolism and networks of androdioecy breeding system in Osmanthus fragrans. BMC PLANT BIOLOGY 2021; 21:468. [PMID: 34645403 PMCID: PMC8513349 DOI: 10.1186/s12870-021-03243-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 09/30/2021] [Indexed: 05/14/2023]
Abstract
BACKGROUND The fragrant flower plant Osmanthus fragrans has an extremely rare androdioecious breeding system displaying the occurrence of males and hermaphrodites in a single population, which occupies a crucial intermediate stage in the evolutionary transition between hermaphroditism and dioecy. However, the molecular mechanism of androdioecy plant is very limited and still largely unknown. RESULTS Here, we used SWATH-MS-based quantitative approach to study the proteome changes between male and hermaphroditic O. fragrans pistils. A total of 428 proteins of diverse functions were determined to show significant abundance changes including 210 up-regulated and 218 down-regulated proteins in male compared to hermaphroditic pistils. Functional categorization revealed that the differentially expressed proteins (DEPs) primarily distributed in the carbohydrate metabolism, secondary metabolism as well as signaling cascades. Further experimental analysis showed the substantial carbohydrates accumulation associated with promoted net photosynthetic rate and water use efficiency were observed in purplish red pedicel of hermaphroditic flower compared with green pedicel of male flower, implicating glucose metabolism serves as nutritional modulator for the differentiation of male and hermaphroditic flower. Meanwhile, the entire upregulation of secondary metabolism including flavonoids, isoprenoids and lignins seem to protect and maintain the male function in male flowers, well explaining important feature of androdioecy that aborted pistil of a male flower still has a male function. Furthermore, nine selected DEPs were validated via gene expression analysis, suggesting an extra layer of post-transcriptional regulation occurs during O. fragrans floral development. CONCLUSION Taken together, our findings represent the first SWATH-MS-based proteomic report in androdioecy plant O. fragrans, which reveal carbohydrate metabolism, secondary metabolism and post-transcriptional regulation contributing to the androdioecy breeding system and ultimately extend our understanding on genetic basis as well as the industrialization development of O. fragrans.
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Affiliation(s)
- Yi-Fan Duan
- College of Biology and the Environment, International Cultivar Registration Center for Osmanthus, Nanjing Forestry University, Nanjing, 210037, China
- College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Cheng Zhang
- College of Biology and the Environment, International Cultivar Registration Center for Osmanthus, Nanjing Forestry University, Nanjing, 210037, China
- College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Min Zhang
- College of Biology and the Environment, International Cultivar Registration Center for Osmanthus, Nanjing Forestry University, Nanjing, 210037, China
- College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Yu Ye
- College of Biology and the Environment, International Cultivar Registration Center for Osmanthus, Nanjing Forestry University, Nanjing, 210037, China
- College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Kai-Lu Zhang
- College of Biology and the Environment, International Cultivar Registration Center for Osmanthus, Nanjing Forestry University, Nanjing, 210037, China
- College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Mo-Xian Chen
- College of Biology and the Environment, International Cultivar Registration Center for Osmanthus, Nanjing Forestry University, Nanjing, 210037, China
- College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Lin Chen
- College of Biology and the Environment, International Cultivar Registration Center for Osmanthus, Nanjing Forestry University, Nanjing, 210037, China
- College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Xian-Rong Wang
- College of Biology and the Environment, International Cultivar Registration Center for Osmanthus, Nanjing Forestry University, Nanjing, 210037, China.
- College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.
| | - Fu-Yuan Zhu
- College of Biology and the Environment, International Cultivar Registration Center for Osmanthus, Nanjing Forestry University, Nanjing, 210037, China.
- College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.
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Candotto Carniel F, Fortuna L, Nepi M, Cai G, Del Casino C, Adami G, Bramini M, Bosi S, Flahaut E, Martín C, Vázquez E, Prato M, Tretiach M. Beyond graphene oxide acidity: Novel insights into graphene related materials effects on the sexual reproduction of seed plants. JOURNAL OF HAZARDOUS MATERIALS 2020; 393:122380. [PMID: 32126426 DOI: 10.1016/j.jhazmat.2020.122380] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/14/2020] [Accepted: 02/21/2020] [Indexed: 06/10/2023]
Abstract
Graphene related materials (GRMs) are currently being used in products and devices of everyday life and this strongly increases the possibility of their ultimate release into the environment as waste items. GRMs have several effects on plants, and graphene oxide (GO) in particular, can affect pollen germination and tube growth due to its acidic properties. Despite the socio-economic importance of sexual reproduction in seed plants, the effect of GRMs on this process is still largely unknown. Here, Corylus avellana L. (common Hazel) pollen was germinated in-vitro with and without 1-100 μg mL-1 few-layer graphene (FLG), GO and reduced GO (rGO) to identify GRMs effects alternative to the acidification damage caused by GO. At 100 μg mL-1 both FLG and GO decreased pollen germination, however only GO negatively affected pollen tube growth. Furthermore, GO adsorbed about 10 % of the initial Ca2+ from germination media accounting for a further decrease in germination of 13 % at the pH created by GO. In addition, both FLG and GO altered the normal tip-focused reactive oxygen species (ROS) distribution along the pollen tube. The results provided here help to understand GRMs effect on the sexual reproduction of seed plants and to address future in-vivo studies.
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Affiliation(s)
- Fabio Candotto Carniel
- Department of Life Sciences, University of Trieste, via L. Giorgieri 10, I-34127, Trieste, Italy.
| | - Lorenzo Fortuna
- Department of Life Sciences, University of Trieste, via L. Giorgieri 10, I-34127, Trieste, Italy.
| | - Massimo Nepi
- Department of Life Sciences, University of Siena, via P. A. Mattioli 4, I-53100, Siena, Italy.
| | - Giampiero Cai
- Department of Life Sciences, University of Siena, via P. A. Mattioli 4, I-53100, Siena, Italy.
| | - Cecilia Del Casino
- Department of Life Sciences, University of Siena, via P. A. Mattioli 4, I-53100, Siena, Italy.
| | - Giampiero Adami
- Department of Chemical and Pharmaceutical Science, University of Trieste, via L. Giorgieri 1, I-34127, Trieste, Italy.
| | - Mattia Bramini
- Center for Synaptic Neuroscience, Italian Institute of Technology, Largo Rosanna Benzi 10, I-16132, Genova, Italy.
| | - Susanna Bosi
- Department of Chemical and Pharmaceutical Science, University of Trieste, via L. Giorgieri 1, I-34127, Trieste, Italy.
| | - Emmanuel Flahaut
- CIRIMAT, Université de Toulouse, CNRS, INPT, UPS, UMR CNRS-UPS-INP N° 5085, Université Toulouse 3 Paul Sabatier, Bât. CIRIMAT, 118, route de Narbonne, F-31062, Toulouse cedex 9, France.
| | - Cristina Martín
- Department of Organic Chemistry, Faculty of Chemical Science and Technology, University of Castilla-La Mancha, Av. Camilo José Cela, s/n, E-13005, Ciudad Real, Spain.
| | - Ester Vázquez
- Department of Organic Chemistry, Faculty of Chemical Science and Technology, University of Castilla-La Mancha, Av. Camilo José Cela, s/n, E-13005, Ciudad Real, Spain; Instituto Regional de Investigación Científica Aplicada (IRICA), Universidad de Castilla-La Mancha, E-13071, Ciudad Real, Spain.
| | - Maurizio Prato
- Department of Chemical and Pharmaceutical Science, University of Trieste, via L. Giorgieri 1, I-34127, Trieste, Italy; Carbon Nanobiotechnology Laboratory CIC BiomaGUNE, Paseo de Miramón 182, E-20009, Donostia-San Sebastian, Spain.
| | - Mauro Tretiach
- Department of Life Sciences, University of Trieste, via L. Giorgieri 10, I-34127, Trieste, Italy.
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Li W, Yang Q, Gu Z, Wu C, Meng D, Yu J, Chen Q, Li Y, Yuan H, Wang D, Li T. Molecular and genetic characterization of a self-compatible apple cultivar, 'CAU-1'. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2016; 252:162-175. [PMID: 27717452 DOI: 10.1016/j.plantsci.2016.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 07/16/2016] [Accepted: 07/18/2016] [Indexed: 06/06/2023]
Abstract
In this study, we characterized a naturally occurring self-compatible apple cultivar, 'CAU-1' (S1S9), and studied the underlying mechanism that causes its compatibility. Analyses of both fruit set rate and seed number after self-pollination or cross-pollination with 'Fuji' (S1S9), and of pollen tube growth, demonstrated that 'CAU-1' is self-compatible. Genetic analysis by S-RNase PCR-typing of selfed progeny of 'CAU-1' revealed the presence of all progeny classes (S1S1, S1S9, and S9S9). Moreover, no evidence of S-allele duplication was found. These findings support the hypothesis that loss of function of an S-locus unlinked pollen-part mutation (PPM) expressed in pollen, rather than a natural mutation in the pollen-S gene (S1- and S9- haplotype), leads to SI breakdown in 'CAU-1'. In addition, there were no significant differences in pollen morphology or fertility between 'Fuji' and 'CAU-1'. However, we found that the effect of S1- and S9-RNase on the SI behavior of pollen could not be addressed better in 'CAU-1' than in 'Fuji'. Furthermore, we found that a pollen-expressed hexose transporter, MdHT1, interacted with S-RNases and showed significantly less expression in 'CAU-1' than in 'Fuji' pollen tubes. These findings support the hypothesis that MdHT1 may participate in S-RNase internalization during the SI process, and decrease of MdHT1 expression in 'CAU-1' hindered the release of self S-RNase into the cytoplasm of pollen tubes, thereby protecting pollen from the cytotoxicity of S-RNase, finally probably resulting in self-compatibility. Together, these findings indicate that S-locus external factors are required for gametophytic SI in the Rosaceae subtribe Pyrinae.
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Affiliation(s)
- Wei Li
- Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Qing Yang
- Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Zhaoyu Gu
- Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Chuanbao Wu
- Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Dong Meng
- Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Jie Yu
- Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Qiuju Chen
- Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Yang Li
- Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Hui Yuan
- College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China
| | - Dongmei Wang
- Institute of Pomology, Liaoning Academy of Agricultural Sciences, Yingkou 115009, China
| | - Tianzhong Li
- Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing 100193, China.
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Li W, Xu F, Chen S, Zhang Z, Zhao Y, Jin Y, Li M, Zhu Y, Liu Y, Yang Y, Deng X. A comparative study on Ca content and distribution in two Gesneriaceae species reveals distinctive mechanisms to cope with high rhizospheric soluble calcium. FRONTIERS IN PLANT SCIENCE 2014; 5:647. [PMID: 25477893 PMCID: PMC4238373 DOI: 10.3389/fpls.2014.00647] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 11/02/2014] [Indexed: 05/09/2023]
Abstract
Excessive Ca is toxic to plants thus significantly affects plant growth and species distribution in Ca-rich karst areas. To understand how plants survive high Ca soil, laboratory experiments were established to compare the physiological responses and internal Ca distribution in organ, tissue, cell, and intracellular levels under different Ca levels for Lysionotus pauciflorus and Boea hygrometrica, two karst habitant Gesneriaceae species in Southwest China. In the controlled condition, L. pauciflorus could survive as high as 200 mM rhizospheric soluble Ca, attributed to a series of physiological responses and preferential storage that limited Ca accumulation in chloroplasts of palisade cells. In contrast, B. hygrometrica could survive only 20 mM rhizospheric soluble Ca, but accumulated a high level of internal Ca in both palisade and spongy cells without disturbance on photosynthetic activity. By phenotype screening of transgenic plants expressing high Ca-inducible genes from B. hygrometrica, the expression of BhDNAJC2 in A. thaliana was found to enhance plant growth and photosynthesis under high soluble Ca stress. BhDNAJC2 encodes a recently reported heat shock protein (HSP) 40 family DnaJ-domain protein. The Ca-resistant phenotype of BhDNAJC2 highlights the important role of chaperone-mediated protein quality control in Ca tolerance in B. hygrometrica. Taken together, our results revealed that distinctive mechanisms were employed in the two Gesneriaceae karst habitants to cope with a high Ca environment.
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Affiliation(s)
- Wenlong Li
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, The Chinese Academy of SciencesBeijing, China
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of SciencesBeijing, China
- College of Life Sciences, University of Chinese Academy of SciencesBeijing, China
| | - Falun Xu
- Key Laboratory of Bio-Resource and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan UniversityChengdu, China
| | - Shixuan Chen
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, The Chinese Academy of SciencesBeijing, China
| | - Zhennan Zhang
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, The Chinese Academy of SciencesBeijing, China
| | - Yan Zhao
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, The Chinese Academy of SciencesBeijing, China
| | - Yukuan Jin
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, The Chinese Academy of SciencesBeijing, China
| | - Meijing Li
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, The Chinese Academy of SciencesBeijing, China
| | - Yan Zhu
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, The Chinese Academy of SciencesBeijing, China
| | - Yongxiu Liu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of SciencesBeijing, China
| | - Yi Yang
- Key Laboratory of Bio-Resource and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan UniversityChengdu, China
| | - Xin Deng
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, The Chinese Academy of SciencesBeijing, China
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Rejón JD, Delalande F, Schaeffer-Reiss C, Carapito C, Zienkiewicz K, Alché JDD, Rodríguez-García MI, Van Dorsselaer A, Castro AJ. The plant stigma exudate: a biochemically active extracellular environment for pollen germination? PLANT SIGNALING & BEHAVIOR 2014; 9:e28274. [PMID: 24589550 PMCID: PMC4091586 DOI: 10.4161/psb.28274] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
During sexual reproduction, pollen performance is greatly influenced by the female tissues. The stigma exudate, i.e., the extracellular secretion that covers the stigma outermost surface, has been usually regarded as a reservoir of water, secondary metabolites, cell wall precursors and compounds that serve as energy supply for rapid pollen tube growth. In an attempt to identify the proteins present in the stigma secretome, we performed a large-scale analysis in two species (Lilium longiflorum and Olea europaea) following a proteomic-based approach. The resulting data strongly suggest that the stigma exudate is not a mere storage site but also a biochemically active environment with a markedly catabolic nature. Thus, this secretion may modulate early pollen tube growth and contribute to the senescence of stigma after pollination. In addition, a putative cross-talk between genetic programs that regulate stress/defense and pollination responses in the stigma is also suggested. The stigma exudate might also functionally diverge between species on the basis on their ecology and the biochemical, morphological and anatomical features of their stigmas. Unexpectedly, we identified in both exudates some intracellular proteins, suggesting that a mechanism other than the canonical ER-Golgi exocytic pathway may exist in the stigma and contribute to exudate secretion.
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Affiliation(s)
- Juan David Rejón
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas; Estación Experimental del Zaidín; Consejo Superior de Investigaciones Científicas; Granada, Spain
| | - François Delalande
- Laboratoire de Spectrométrie de Masse Bio-Organique; IPHC-DSA; Université de Strasbourg-CNRS UMR 7178; Strasbourg, France
| | - Christine Schaeffer-Reiss
- Laboratoire de Spectrométrie de Masse Bio-Organique; IPHC-DSA; Université de Strasbourg-CNRS UMR 7178; Strasbourg, France
| | - Christine Carapito
- Laboratoire de Spectrométrie de Masse Bio-Organique; IPHC-DSA; Université de Strasbourg-CNRS UMR 7178; Strasbourg, France
| | - Krzysztof Zienkiewicz
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas; Estación Experimental del Zaidín; Consejo Superior de Investigaciones Científicas; Granada, Spain
- Department of Cell Biology; Institute of General and Molecular Biology; Nicolaus Copernicus University; Toruń, Poland
| | - Juan de Dios Alché
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas; Estación Experimental del Zaidín; Consejo Superior de Investigaciones Científicas; Granada, Spain
| | - María Isabel Rodríguez-García
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas; Estación Experimental del Zaidín; Consejo Superior de Investigaciones Científicas; Granada, Spain
| | - Alain Van Dorsselaer
- Laboratoire de Spectrométrie de Masse Bio-Organique; IPHC-DSA; Université de Strasbourg-CNRS UMR 7178; Strasbourg, France
| | - Antonio J Castro
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas; Estación Experimental del Zaidín; Consejo Superior de Investigaciones Científicas; Granada, Spain
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Xu XH, Chen H, Sang YL, Wang F, Ma JP, Gao XQ, Zhang XS. Identification of genes specifically or preferentially expressed in maize silk reveals similarity and diversity in transcript abundance of different dry stigmas. BMC Genomics 2012; 13:294. [PMID: 22748054 PMCID: PMC3416702 DOI: 10.1186/1471-2164-13-294] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 07/02/2012] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND In plants, pollination is a critical step in reproduction. During pollination, constant communication between male pollen and the female stigma is required for pollen adhesion, germination, and tube growth. The detailed mechanisms of stigma-mediated reproductive processes, however, remain largely unknown. Maize (Zea mays L.), one of the world's most important crops, has been extensively used as a model species to study molecular mechanisms of pollen and stigma interaction. A comprehensive analysis of maize silk transcriptome may provide valuable information for investigating stigma functionality. A comparative analysis of expression profiles between maize silk and dry stigmas of other species might reveal conserved and diverse mechanisms that underlie stigma-mediated reproductive processes in various plant species. RESULTS Transcript abundance profiles of mature silk, mature pollen, mature ovary, and seedling were investigated using RNA-seq. By comparing the transcriptomes of these tissues, we identified 1,427 genes specifically or preferentially expressed in maize silk. Bioinformatic analyses of these genes revealed many genes with known functions in plant reproduction as well as novel candidate genes that encode amino acid transporters, peptide and oligopeptide transporters, and cysteine-rich receptor-like kinases. In addition, comparison of gene sets specifically or preferentially expressed in stigmas of maize, rice (Oryza sativa L.), and Arabidopsis (Arabidopsis thaliana [L.] Heynh.) identified a number of homologous genes involved either in pollen adhesion, hydration, and germination or in initial growth and penetration of pollen tubes into the stigma surface. The comparison also indicated that maize shares a more similar profile and larger number of conserved genes with rice than with Arabidopsis, and that amino acid and lipid transport-related genes are distinctively overrepresented in maize. CONCLUSIONS Many of the novel genes uncovered in this study are potentially involved in stigma-mediated reproductive processes, including genes encoding amino acid transporters, peptide and oligopeptide transporters, and cysteine-rich receptor-like kinases. The data also suggest that dry stigmas share similar mechanisms at early stages of pollen-stigma interaction. Compared with Arabidopsis, maize and rice appear to have more conserved functional mechanisms. Genes involved in amino acid and lipid transport may be responsible for mechanisms in the reproductive process that are unique to maize silk.
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Affiliation(s)
- Xiao Hui Xu
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong, China
| | - Hao Chen
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong, China
| | - Ya Lin Sang
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong, China
- College of Forestry, Shandong Agricultural University, Tai’an, Shandong, China
| | - Fang Wang
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong, China
| | - Jun Ping Ma
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong, China
| | - Xin-Qi Gao
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong, China
| | - Xian Sheng Zhang
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong, China
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