1
|
Chen K, Wang Q, Yu X, Wang C, Gao J, Zhang S, Cheng S, You S, Zheng H, Lu J, Zhu X, Lei D, Jian A, He X, Yu H, Chen Y, Zhou M, Li K, He L, Tian Y, Liu X, Liu S, Jiang L, Bao Y, Wang H, Zhao Z, Wan J. OsSRF8 interacts with OsINP1 and OsDAF1 to regulate pollen aperture formation in rice. Nat Commun 2024; 15:4512. [PMID: 38802369 PMCID: PMC11130342 DOI: 10.1038/s41467-024-48813-0] [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: 09/11/2023] [Accepted: 05/14/2024] [Indexed: 05/29/2024] Open
Abstract
In higher plants, mature male gametophytes have distinct apertures. After pollination, pollen grains germinate, and a pollen tube grows from the aperture to deliver sperm cells to the embryo sac, completing fertilization. In rice, the pollen aperture has a single-pore structure with a collar-like annulus and a plug-like operculum. A crucial step in aperture development is the formation of aperture plasma membrane protrusion (APMP) at the distal polar region of the microspore during the late tetrad stage. Previous studies identified OsINP1 and OsDAF1 as essential regulators of APMP and pollen aperture formation in rice, but their precise molecular mechanisms remain unclear. We demonstrate that the Poaceae-specific OsSRF8 gene, encoding a STRUBBELIG-receptor family 8 protein, is essential for pollen aperture formation in Oryza sativa. Mutants lacking functional OsSRF8 exhibit defects in APMP and pollen aperture formation, like loss-of-function OsINP1 mutants. OsSRF8 is specifically expressed during early anther development and initially diffusely distributed in the microsporocytes. At the tetrad stage, OsSRF8 is recruited by OsINP1 to the pre-aperture region through direct protein-protein interaction, promoting APMP formation. The OsSRF8-OsINP1 complex then recruits OsDAF1 to the APMP site to co-regulate annulus formation. Our findings provide insights into the mechanisms controlling pollen aperture formation in cereal species.
Collapse
Affiliation(s)
- Keyi Chen
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Qiming Wang
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Xiaowen Yu
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Chaolong Wang
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Junwen Gao
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Shihao Zhang
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Siqi Cheng
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Shimin You
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Hai Zheng
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Jiayu Lu
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Xufei Zhu
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Dekun Lei
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Anqi Jian
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Xiaodong He
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Hao Yu
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Yun Chen
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Mingli Zhou
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Kai Li
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Ling He
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Yunlu Tian
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Xi Liu
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Shijia Liu
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Ling Jiang
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Yiqun Bao
- School of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Haiyang Wang
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Zhigang Zhao
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China.
| | - Jianmin Wan
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China.
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| |
Collapse
|
2
|
Zhong S, Zhao P, Peng X, Li HJ, Duan Q, Cheung AY. From gametes to zygote: Mechanistic advances and emerging possibilities in plant reproduction. PLANT PHYSIOLOGY 2024; 195:4-35. [PMID: 38431529 PMCID: PMC11060694 DOI: 10.1093/plphys/kiae125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 02/13/2024] [Accepted: 02/13/2024] [Indexed: 03/05/2024]
Affiliation(s)
- Sheng Zhong
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, New Cornerstone Science Laboratory, College of Life Sciences, Peking University, Beijing 100871, China
| | - Peng Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Xiongbo Peng
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Hong-Ju Li
- Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Center for Molecular Agrobiology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qiaohong Duan
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Alice Y Cheung
- Department of Biochemistry and Molecular Biology, Molecular and Cellular Biology Program, Plant Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
| |
Collapse
|
3
|
Zhao W, Hou Q, Qi Y, Wu S, Wan X. Structural and molecular basis of pollen germination. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 203:108042. [PMID: 37738868 DOI: 10.1016/j.plaphy.2023.108042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/27/2023] [Accepted: 09/14/2023] [Indexed: 09/24/2023]
Abstract
Pollen germination is a prerequisite for double fertilization of flowering plants. A comprehensive understanding of the structural and molecular basis of pollen germination holds great potential for crop yield improvement. The pollen aperture serves as the foundation for most plant pollen germination and pollen aperture formation involves the establishment of cellular polarity, the formation of distinct membrane domains, and the precise deposition of extracellular substances. Successful pollen germination requires precise material exchange and signal transduction between the pollen grain and the stigma. Recent cytological and mutant analysis of pollen germination process in Arabidopsis and rice has expanded our understanding of this biological process. However, the overall changes in germination site structure and energy-related metabolites during pollen germination remain to be further explored. This review summarizes and compares the recent advances in the processes of pollen aperture formation, pollen adhesion, hydration, and germination between eudicot Arabidopsis and monocot rice, and provides insights into the structural basis and molecular mechanisms underlying pollen germination process.
Collapse
Affiliation(s)
- Wei Zhao
- Research Institute of Biology and Agriculture, Shunde Innovation School, University of Science and Technology Beijing (USTB), Beijing, 100083, China
| | - Quancan Hou
- Research Institute of Biology and Agriculture, Shunde Innovation School, University of Science and Technology Beijing (USTB), Beijing, 100083, China; Zhongzhi International Institute of Agricultural Biosciences, Beijing, 100083, China
| | - Yuchen Qi
- Research Institute of Biology and Agriculture, Shunde Innovation School, University of Science and Technology Beijing (USTB), Beijing, 100083, China
| | - Suowei Wu
- Research Institute of Biology and Agriculture, Shunde Innovation School, University of Science and Technology Beijing (USTB), Beijing, 100083, China; Zhongzhi International Institute of Agricultural Biosciences, Beijing, 100083, China; Beijing Engineering Laboratory of Main Crop Bio-Tech Breeding, Beijing Solidwill Sci-Tech Co. Ltd., Beijing, 100192, China.
| | - Xiangyuan Wan
- Research Institute of Biology and Agriculture, Shunde Innovation School, University of Science and Technology Beijing (USTB), Beijing, 100083, China; Zhongzhi International Institute of Agricultural Biosciences, Beijing, 100083, China; Beijing Engineering Laboratory of Main Crop Bio-Tech Breeding, Beijing Solidwill Sci-Tech Co. Ltd., Beijing, 100192, China.
| |
Collapse
|
4
|
Mazuecos-Aguilera I, Suárez-Santiago VN. Identification of Candidate Genes Involved in the Determinism of Pollen Grain Aperture Morphology by Comparative Transcriptome Analysis in Papaveraceae. PLANTS (BASEL, SWITZERLAND) 2023; 12:1570. [PMID: 37050196 PMCID: PMC10096813 DOI: 10.3390/plants12071570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 04/03/2023] [Accepted: 04/05/2023] [Indexed: 06/19/2023]
Abstract
In the last decade, certain genes involved in pollen aperture formation have been discovered. However, those involved in pollen aperture shape remain largely unknown. In Arabidopsis, the interaction during the tetrad development stage of one member of the ELMOD protein family, ELMOD_E, with two others, MCR/ELMOD_B and ELMOD_A, can change the morphology of apertures from colpus (elongated) to pore (round). Here, comparative transcriptome analysis is used to identify candidate genes involved in the determination of pollen aperture morphology in Papaveraceae (order Ranunculales). Furthermore, the role of ELMOD genes in the genetic determinism of aperture shape was tested by comparative analysis of their expression levels using RNA-seq data and RT-qPCR. Two pairs of species belonging to two different subfamilies were used. Within each pair, one species has colpate pollen and the other porate (Fumarioideae-Dactylicapnos torulosa, 6-colpate, and Fumaria bracteosa, pantoporate; Papaveroideae-Eschsholzia californica, 5-7 colpate, and Roemeria refracta, 6-porate). The transcriptomes were obtained at the tetrad stage of pollen development. A total of 531 DEGs were found between the colpate and porate pollen species groups. The results from RNA-seq and RT-qPCR indicate that pollen aperture shape is not determined by the relative expression levels of ELMOD family genes in Papaveraceae. However, genes related to callose wall formation or cytoskeleton organisation were found, these processes being involved in pollen aperture formation. In addition, transcriptomes from anthers with pollen during the tetrad stage of three species (D. torulosa, R. refracta, and F. bracteosa) were obtained for the first time. These data will be available for further studies in the field of floral evolution and development.
Collapse
|
5
|
Zhou D, Zou T, Zhang K, Xiong P, Zhou F, Chen H, Li G, Zheng K, Han Y, Peng K, Zhang X, Yang S, Deng Q, Wang S, Zhu J, Liang Y, Sun C, Yu X, Liu H, Wang L, Li P, Li S. DEAP1 encodes a fasciclin-like arabinogalactan protein required for male fertility in rice. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:1430-1447. [PMID: 35485235 DOI: 10.1111/jipb.13271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 04/26/2022] [Indexed: 06/14/2023]
Abstract
Arabinogalactan proteins (AGPs) are widely distributed in plant cells. Fasciclin-like AGPs (FLAs) belong to a subclass of AGPs that play important roles in plant growth and development. However, little is known about the biological functions of rice FLA. Herein, we report the identification of a male-sterile mutant of DEFECTIVE EXINE AND APERTURE PATTERNING1 (DEAP1) in rice. The deap1 mutant anthers produced aberrant pollen grains with defective exine formation and a flattened aperture annulus and exhibited slightly delayed tapetum degradation. DEAP1 encodes a plasma membrane-associated member of group III plant FLAs and is specifically and temporally expressed in reproductive cells and the tapetum layer during male development. Gene expression studies revealed reduced transcript accumulation of genes related to exine formation, aperture patterning, and tapetum development in deap1 mutants. Moreover, DEAP1 may interact with two rice D6 PROTEIN KINASE-LIKE3s (OsD6PKL3s), homologs of a known Arabidopsis aperture protein, to affect rice pollen aperture development. Our findings suggested that DEAP1 is involved in male reproductive development and may affect exine formation and aperture patterning, thereby providing new insights into the molecular functions of plant FLAs in male fertility.
Collapse
Affiliation(s)
- Dan Zhou
- State Key Laboratory of Hybrid Rice, Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Ting Zou
- State Key Laboratory of Hybrid Rice, Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Kaixuan Zhang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Pingping Xiong
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Fuxing Zhou
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Hao Chen
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Gongwen Li
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Kaiyou Zheng
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yuhao Han
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Kun Peng
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xu Zhang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Shangyu Yang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Qiming Deng
- State Key Laboratory of Hybrid Rice, Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Shiquan Wang
- State Key Laboratory of Hybrid Rice, Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jun Zhu
- State Key Laboratory of Hybrid Rice, Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yueyang Liang
- State Key Laboratory of Hybrid Rice, Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Changhui Sun
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xiumei Yu
- College of Resource, Sichuan Agricultural University, Chengdu, 611130, China
| | - Huainian Liu
- State Key Laboratory of Hybrid Rice, Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Lingxia Wang
- State Key Laboratory of Hybrid Rice, Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Ping Li
- State Key Laboratory of Hybrid Rice, Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Shuangcheng Li
- State Key Laboratory of Hybrid Rice, Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| |
Collapse
|
6
|
Severova EE, Rudall PJ, Macfarlane TD, Krasnova ED, Sokoloff DD. Pollen in water of unstable salinity: Evolution and function of dynamic apertures in monocot aquatics. AMERICAN JOURNAL OF BOTANY 2022; 109:500-513. [PMID: 35244214 DOI: 10.1002/ajb2.1835] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 02/15/2022] [Indexed: 06/14/2023]
Abstract
PREMISE The sporoderm of seed-plant pollen grains typically has apertures in which the outer sporopollenin-bearing layer is relatively sparse. The apertures allow regulation of the internal volume of the pollen grain during desiccation and rehydration (harmomegathy) and also serve as sites of pollen germination. A small fraction of angiosperms undergo pollination in water or at the water surface, where desiccation is unlikely. Their pollen grains commonly lack apertures, though with some notable exceptions. We tested a hypothesis that in some angiosperm aquatics that inhabit water of unstable salinity, the pollen apertures accommodate osmotic effects that occur during pollination in such conditions. METHODS Pollen grains of the tepaloid clade of the monocot order Alismatales, which contains ecologically diverse aquatic and marshy plants, were examined using light microscopy and scanning electron microscopy. We used Ruppia as a model to test pollen grain response in water of various salinities. Pollen aperture evolution was also analyzed using molecular tree topologies. RESULTS Phylogenetic optimizations demonstrated an evolutionary loss and two subsequent regains of the aperturate condition in the tepaloid clade of Alismatales. Both of the taxa that have reverted to aperturate pollen (Ruppia, Ruppiaceae; Althenia, Potamogetonaceae) are adapted to changeable water salinity. Direct experiments with Ruppia showed that the pollen apertures have a role in a harmomegathic response to differences in water salinity. CONCLUSIONS Our results showed that the inferred regain of pollen apertures represents an adaptation to changeable water salinity. We invoke a loss-and-regain scenario, prompting questions that are testable using developmental genetics and plant physiology.
Collapse
Affiliation(s)
- Elena E Severova
- Faculty of Biology, M.V. Lomonosov Moscow State University, 1, 12, Leninskie Gory, Moscow, 119234, Russia
| | - Paula J Rudall
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
| | - Terry D Macfarlane
- Western Australian Herbarium, Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Locked Bag 104, Bentley Delivery Centre, WA, 6983, Australia
| | - Elena D Krasnova
- Faculty of Biology, M.V. Lomonosov Moscow State University, 1, 12, Leninskie Gory, Moscow, 119234, Russia
| | - Dmitry D Sokoloff
- Faculty of Biology, M.V. Lomonosov Moscow State University, 1, 12, Leninskie Gory, Moscow, 119234, Russia
| |
Collapse
|
7
|
A Review of the Developmental Processes and Selective Pressures Shaping Aperture Pattern in Angiosperms. PLANTS 2022; 11:plants11030357. [PMID: 35161338 PMCID: PMC8840023 DOI: 10.3390/plants11030357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 11/25/2022]
Abstract
Pollen grains of flowering plants display a fascinating diversity of forms. The observed diversity is determined by the developmental mechanisms involved in the establishment of pollen morphological features. Pollen grains are generally surrounded by an extremely resistant wall displaying apertures that play a key role in reproduction, being the places at which pollen tube growth is initiated. Aperture number, structure, and position (collectively termed ‘aperture pattern’) are determined during microsporogenesis, which is the earliest step of pollen ontogeny. Here, we review current knowledge about aperture pattern developmental mechanisms and adaptive significance with respect to plant reproduction and how advances in these fields shed light on our understanding of aperture pattern evolution in angiosperms.
Collapse
|
8
|
Zhou Y, Amom P, Reeder SH, Lee BH, Helton A, Dobritsa AA. Members of the ELMOD protein family specify formation of distinct aperture domains on the Arabidopsis pollen surface. eLife 2021; 10:71061. [PMID: 34591014 PMCID: PMC8483735 DOI: 10.7554/elife.71061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 09/01/2021] [Indexed: 01/30/2023] Open
Abstract
Pollen apertures, the characteristic gaps in pollen wall exine, have emerged as a model for studying the formation of distinct plasma membrane domains. In each species, aperture number, position, and morphology are typically fixed; across species they vary widely. During pollen development, certain plasma membrane domains attract specific proteins and lipids and become protected from exine deposition, developing into apertures. However, how these aperture domains are selected is unknown. Here, we demonstrate that patterns of aperture domains in Arabidopsis are controlled by the members of the ancient ELMOD protein family, which, although important in animals, has not been studied in plants. We show that two members of this family, MACARON (MCR) and ELMOD_A, act upstream of the previously discovered aperture proteins and that their expression levels influence the number of aperture domains that form on the surface of developing pollen grains. We also show that a third ELMOD family member, ELMOD_E, can interfere with MCR and ELMOD_A activities, changing aperture morphology and producing new aperture patterns. Our findings reveal key players controlling early steps in aperture domain formation, identify residues important for their function, and open new avenues for investigating how diversity of aperture patterns in nature is achieved. Zooming in on cells reveals patterns on their outer surfaces. These patterns are actually a collection of distinct areas of the cell surface, each containing specific combinations of molecules. The outer layers of pollen grains consist of a cell wall, and a softer cell membrane that sits underneath. As a pollen grain develops, it recruits certain fats and proteins to specific areas of the cell membrane, known as ‘aperture domains’. The composition of these domains blocks the cell wall from forming over them, leading to gaps in the wall called ‘pollen apertures’. Pollen apertures can open and close, aiding reproduction and protecting pollen grains from dehydration. The number, location, and shape of pollen apertures vary between different plant species, but are consistent within the same species. In the plant species Arabidopsis thaliana, pollen normally develops three long and narrow, equally spaced apertures, but it remains unclear how pollen grains control the number and location of aperture domains. Zhou et al. found that mutations in two closely related A. thaliana proteins – ELMOD_A and MCR – alter the number and positions of pollen apertures. When A. thaliana plants were genetically modified so that they would produce different levels of ELMOD_A and MCR, Zhou et al. observed that when more of these proteins were present in a pollen grain, more apertures were generated on the pollen surface. This finding suggests that the levels of these proteins must be tightly regulated to control pollen aperture numbers. Further tests revealed that another related protein, called ELMOD_E, also has a role in domain formation. When artificially produced in developing pollen grains, it interfered with the activity of ELMOD_A and MCR, changing pollen aperture shape, number, and location. Zhou et al. identified a group of proteins that help control the formation of domains in the cell membranes of A. thaliana pollen grains. Further research will be required to determine what exactly these proteins do to promote formation of aperture domains and whether similar proteins control domain development in other organisms.
Collapse
Affiliation(s)
- Yuan Zhou
- Department of Molecular Genetics and Center for Applied Plant Sciences, Ohio State University, Columbus, United States
| | - Prativa Amom
- Department of Molecular Genetics and Center for Applied Plant Sciences, Ohio State University, Columbus, United States
| | - Sarah H Reeder
- Department of Molecular Genetics and Center for Applied Plant Sciences, Ohio State University, Columbus, United States
| | - Byung Ha Lee
- Department of Molecular Genetics and Center for Applied Plant Sciences, Ohio State University, Columbus, United States
| | - Adam Helton
- Department of Molecular Genetics and Center for Applied Plant Sciences, Ohio State University, Columbus, United States
| | - Anna A Dobritsa
- Department of Molecular Genetics and Center for Applied Plant Sciences, Ohio State University, Columbus, United States
| |
Collapse
|