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Bai SN, Rao GY, Yang J. Origins of the seed: The "golden-trio hypothesis". FRONTIERS IN PLANT SCIENCE 2022; 13:965000. [PMID: 36105705 PMCID: PMC9465013 DOI: 10.3389/fpls.2022.965000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
The seed is an evolutionary innovation in the plant kingdom. While human civilization depends heavily on seed production, how the seed trait emerged remains elusive. In this opinion article, a "golden-trio hypothesis" is proposed based on our investigations of LEC1 gene functions in Adiantum capillus-veneris. This hypothesis posits that a "seed program" arose from spatiotemporal integration of three key components: assimilate flow, ABA-mediated stress responses, and stress-induced LEC1 expression. Thus, the evolutionary innovation of seeds should be considered not a simple event resulting from new genes; rather, it represents the outcome of a series of physiological and morphological innovations that emerged prior to and regardless of the origin of the seed program. This new perspective could help us tackle some long-standing questions around the puzzling origin of seeds.
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Affiliation(s)
- Shu-Nong Bai
- College of Life Sciences, Peking University, Beijing, China
| | - Guang-Yuan Rao
- College of Life Sciences, Peking University, Beijing, China
| | - Ji Yang
- School of Life Sciences, Fudan University, Shanghai, China
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2
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Cao Q, Feng Y, Dai X, Huang L, Li J, Tao P, Crabbe MJC, Zhang T, Qiao Q. Dynamic Changes of DNA Methylation During Wild Strawberry ( Fragaria nilgerrensis) Tissue Culture. FRONTIERS IN PLANT SCIENCE 2021; 12:765383. [PMID: 34917103 PMCID: PMC8669611 DOI: 10.3389/fpls.2021.765383] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 11/09/2021] [Indexed: 06/14/2023]
Abstract
Tissue culture is an important tool for asexual propagation and genetic transformation of strawberry plants. In plant tissue culture, variation of DNA methylation is a potential source of phenotypic variation in regenerated plants. However, the genome wide dynamic methylation patterns of strawberry tissue culture remain unclear. In this study, we used whole-genome bisulfite sequencing (WGBS) to study genomic DNA methylation changes of a wild strawberry Fragaria nilgerrensis at six stages: from explants of shoot tips to outplanting and acclimation. Global methylation levels showed that CG sites exhibited the highest methylation level in all stages with an average of 49.5%, followed by CHG (33.2%) and CHH (12.4%). Although CHH accounted for the lowest proportion of total cytosine methylation, it showed the most obvious methylation change and the most of these changes occurred in the transposable element regions. The overall methylation levels alternately decreased and increased during the entire tissue culture process and the distribution of DNA methylation was non-uniform among different genetic regions. Furthermore, much more differentially methylated regions (DMRs) were detected in dedifferentiation and redifferentiation stages and most of them were transposable elements, suggesting these processes involved activating or silencing of amounts of transposons. The functional enrichment of the DMR-related genes indicated that genes involved in hormone metabolic processes, plant development and the stress response changed methylation throughout the tissue culture process. Finally, the quantitative real-time PCR (qRT-PCR) was conducted to examine the association of methylation and gene expression of a set of different methylated genes. Our findings give deeper insight into the epigenetic regulation of gene expression during the plant tissue cultures process, which will be useful in the efficient control of somaclonal variations and in crop improvement.
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Affiliation(s)
- Qiang Cao
- School of Agriculture, Yunnan University, Kunming, China
| | - Yuxi Feng
- School of Agriculture, Yunnan University, Kunming, China
| | - Xiongwei Dai
- School of Agriculture, Yunnan University, Kunming, China
| | - Lin Huang
- School of Agriculture, Yunnan University, Kunming, China
| | - Jiamin Li
- School of Agriculture, Yunnan University, Kunming, China
| | - Pang Tao
- Horticultural Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, China
| | - M. James C. Crabbe
- Wolfson College, Oxford University, Oxford, United Kingdom
- Institute of Biomedical and Environmental Science and Technology, School of Life Sciences, University of Bedfordshire, Luton, United Kingdom
- School of Life Sciences, Shanxi University, Taiyuan, China
| | - Ticao Zhang
- College of Chinese Material Medica, Yunnan University of Chinese Medicine, Kunming, China
| | - Qin Qiao
- School of Agriculture, Yunnan University, Kunming, China
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Szövényi P, Gunadi A, Li FW. Charting the genomic landscape of seed-free plants. NATURE PLANTS 2021; 7:554-565. [PMID: 33820965 DOI: 10.1038/s41477-021-00888-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 02/25/2021] [Indexed: 05/02/2023]
Abstract
During the past few years several high-quality genomes has been published from Charophyte algae, bryophytes, lycophytes and ferns. These genomes have not only elucidated the origin and evolution of early land plants, but have also provided important insights into the biology of the seed-free lineages. However, critical gaps across the phylogeny remain and many new questions have been raised through comparing seed-free and seed plant genomes. Here, we review the reference genomes available and identify those that are missing in the seed-free lineages. We compare patterns of various levels of genome and epigenomic organization found in seed-free plants to those of seed plants. Some genomic features appear to be fundamentally different. For instance, hornworts, Selaginella and most liverworts are devoid of whole-genome duplication, in stark contrast to other land plants. In addition, the distribution of genes and repeats appear to be less structured in seed-free genomes than in other plants, and the levels of gene body methylation appear to be much lower. Finally, we highlight the currently available (or needed) model systems, which are crucial to further our understanding about how changes in genes translate into evolutionary novelties.
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Affiliation(s)
- Péter Szövényi
- Department of Systematic and Evolutionary Botany, University of Zurich and Zurich-Basel Plant Science Center, Zurich, Switzerland.
| | | | - Fay-Wei Li
- Boyce Thompson Institute, Ithaca, NY, USA
- Plant Biology Section, Cornell University, Ithaca, NY, USA
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He C, Si C, Teixeira da Silva JA, Li M, Duan J. Genome-wide identification and classification of MIKC-type MADS-box genes in Streptophyte lineages and expression analyses to reveal their role in seed germination of orchid. BMC PLANT BIOLOGY 2019; 19:223. [PMID: 31138149 PMCID: PMC6540398 DOI: 10.1186/s12870-019-1836-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 05/17/2019] [Indexed: 05/21/2023]
Abstract
BACKGROUND MADS-box genes play crucial roles in plant floral organ formation and plant reproductive development. However, there is still no information on genome-wide identification and classification of MADS-box genes in some representative plant species. A comprehensive investigation of MIKC-type genes in the orchid Dendrobium officinale is still lacking. RESULTS Here we conducted a genome-wide analysis of MADS-box proteins from 29 species. In total, 1689 MADS-box proteins were identified. Two types of MADS-box genes, termed type I and II, were found in land plants, but not in liverwort. The SQUA, DEF/GLO, AG and SEP subfamilies existed in all the tested flowering plants, while SQUA was absent in the gymnosperm Ginkgo biloba, and no genes of the four subfamilies were found in a charophyte, liverwort, mosses, or lycophyte. This strongly corroborates the notion that clades of floral organ identity genes led to the evolution of flower development in flowering plants. Nine subfamilies of MIKCC genes were present in two orchids, D. officinale and Phalaenopsis equestris, while the TM8, FLC, AGL15 and AGL12 subfamilies may be lost. In addition, the four clades of floral organ identity genes in both orchids displayed a conservative and divergent expression pattern. Only three MIKC-type genes were induced by cold stress in D. officinale while 15 MIKC-type genes showed different levels of expression during seed germination. CONCLUSIONS MIKC-type genes were identified from streptophyte lineages, revealing new insights into their evolution and development relationships. Our results show a novel role of MIKC-type genes in seed germination and provide a useful clue for future research on seed germination in orchids.
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Affiliation(s)
- Chunmei He
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Gene Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China
| | - Can Si
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Gene Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China
- University of the Chinese Academy of Sciences, Beijing, 100049 China
| | | | - Mingzhi Li
- Genepioneer Biotechnologies Co. Ltd, Nanjing, 210014 China
| | - Jun Duan
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Gene Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China
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Pais MS. Somatic Embryogenesis Induction in Woody Species: The Future After OMICs Data Assessment. FRONTIERS IN PLANT SCIENCE 2019; 10:240. [PMID: 30984207 PMCID: PMC6447717 DOI: 10.3389/fpls.2019.00240] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 02/12/2019] [Indexed: 05/15/2023]
Abstract
Very early somatic embryogenesis has been recognized as a powerful method to propagate plants in vitro. For some woody species and in particular for some coniferous trees, somatic embryogenesis induction has become a routine procedure. For the majority, the application of this technology presents yet many limitations especially due to the genotype, the induction conditions, the number of embryos produced, maturation, and conversion, among other factors that compromise the systematic use of somatic embryogenesis for commercial purposes especially of woody species and forest trees in particular. The advancements obtained on somatic embryogenesis in Arabidopsis and the development of OMIC technologies allowed the characterization of genes and the corresponding proteins that are conserved in woody species. This knowledge will help in understanding the molecular mechanisms underlying the complex regulatory networks that control somatic embryogenesis in woody plants. In this revision, we report on developments of OMICs (genomics, transcriptomics, metabolomics, and proteomics) applied to somatic embryogenesis induction and its contribution for understanding the change of fate giving rise to the expression of somatic embryogenesis competence.
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Kumar A, Batra R, Gahlaut V, Gautam T, Kumar S, Sharma M, Tyagi S, Singh KP, Balyan HS, Pandey R, Gupta PK. Genome-wide identification and characterization of gene family for RWP-RK transcription factors in wheat (Triticum aestivum L.). PLoS One 2018; 13:e0208409. [PMID: 30540790 PMCID: PMC6291158 DOI: 10.1371/journal.pone.0208409] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 11/17/2018] [Indexed: 02/07/2023] Open
Abstract
RWP-RKs represent a small family of transcription factors (TFs) that are unique to plants and function particularly under conditions of nitrogen starvation. These RWP-RKs have been classified in two sub-families, NLPs (NIN-like proteins) and RKDs (RWP-RK domain proteins). NLPs regulate tissue-specific expression of genes involved in nitrogen use efficiency (NUE) and RKDs regulate expression of genes involved in gametogenesis/embryogenesis. During the present study, using in silico approach, 37 wheat RWP-RK genes were identified, which included 18 TaNLPs (2865 to 7340 bp with 4/5 exons), distributed on 15 chromosomes from 5 homoeologous groups (with two genes each on 4B,4D and 5A) and 19 TaRKDs (1064 to 5768 bp with 1 to 6 exons) distributed on 12 chromosomes from 4 homoeologous groups (except groups 1, 4 and 5); 2–3 splice variants were also available in 9 of the 37 genes. Sixteen (16) of these genes also carried 24 SSRs (simple sequence repeats), while 11 genes had targets for 13 different miRNAs. At the protein level, MD simulation analysis suggested their interaction with nitrate-ions. Significant differences were observed in the expression of only two (TaNLP1 and TaNLP2) of the nine representative genes that were used for in silico expression analysis under varying levels of N at post-anthesis stage (data for other genes was not available for in silico expression analysis). Differences in expression were also observed during qRT-PCR, when expression of four representative genes (TaNLP2, TaNLP7, TaRKD6 and TaRKD9) was examined in roots and shoots of seedlings (under different conditions of N supply) in two contrasting genotypes which differed in NUE (C306 with low NUE and HUW468 with high NUE). These four genes for qRT-PCR were selected on the basis of previous literature, level of homology and the level of expression (in silico study). In particular, the TaNLP7 gene showed significant up-regulation in the roots and shoots of HUW468 (with higher NUE) during N-starvation; this gene has already been characterized in Arabidopsis and tobacco, and is known to be involved in nitrate-signal transduction pathway.
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Affiliation(s)
- Anuj Kumar
- Advance Center for Computational & Applied Biotechnology, Uttarakhand Council for Biotechnology (UCB), Dehradun, India
| | - Ritu Batra
- Department of Genetics and Plant Breeding, CCS University, Meerut, India
| | - Vijay Gahlaut
- Department of Plant Molecular Biology, South Campus, University of Delhi, Delhi, India
| | - Tinku Gautam
- Department of Genetics and Plant Breeding, CCS University, Meerut, India
| | - Sanjay Kumar
- Bioinformatics Centre, Biotech Park, Lucknow, India
| | - Mansi Sharma
- ICMR- National Institute of Cancer Prevention and Research, Noida, India
| | - Sandhya Tyagi
- Division of Plant Physiology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Krishna Pal Singh
- Advance Center for Computational & Applied Biotechnology, Uttarakhand Council for Biotechnology (UCB), Dehradun, India
- Ch. Charan Singh Haryana Agricultural University, Hisar, India
| | | | - Renu Pandey
- Division of Plant Physiology, ICAR-Indian Agricultural Research Institute, New Delhi, India
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Sajeev S, Melo JS, Hegde S. Gamma radiation-induced in vitro hormetic apogamy in the fern Pityrogramma calomelanos (L.) link. Biosystems 2018; 173:221-224. [PMID: 30114432 DOI: 10.1016/j.biosystems.2018.08.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 08/07/2018] [Accepted: 08/09/2018] [Indexed: 10/28/2022]
Abstract
Pityrogramma calomelanos (L.) Link, popularly known as "Silver fern" has significant importance as a medicinal plant used traditionally for its astringent, analgesic, anti-haemorrhagic, anti-hypertensive, anti-pyretic and anthelminthic properties. This fern demonstrates an increased morphogenetic potential towards sporophyte formation, upon exposure to low doses of gamma radiation. Young sporophytic leaf crosier cultures were established in vitro on agar based Knop's media with and without 20 g/l sucrose. The cultures were subjected to 60Co radiations in the range of 2.5-100 Gy. Apospory (production of gametophytes on sporophytic tissue without spores) was observed on leaf tissue cultured on Knops media with and without sucrose in P. calomelanos, at the end of 60 days. 5 Gy treated explants showed high number of aposporous gametophytes and was comparable to the control. Other tested doses reduced the aposporous gametophyte production significantly. In the second phase of the experimentation, the cultures were retained on the gametophyte induction media for a period of 4 weeks. Aposporous gametophytes were observed to proliferate with occasional development of antheridia. At the end of 4 weeks, morphogenetic development on the gametophytic tissue resulted in a significantly higher number of apogamous sporophytes (production of sporophytes without fusion of gametes) were obtained on 5 Gy treated tissue as compared to control and all the other treated explants. Apogamous sporophytes thus produced were successfully grown in the greenhouse and transferred to the field. Thus the use of gamma radiation in vitro not only reduced the need for sucrose for induction of apospory in P.calomelanos, it also exhibited hormesis at 5 Gy for improved sporophyte production.
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Affiliation(s)
- Sudha Sajeev
- Rondano Biodiversity Research Laboratory, Department for Post Graduate Studies and Research in Biotechnology, St Aloysius College (Autonomous), Mangalore, 575 003, India
| | - Jose Savio Melo
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India
| | - Smitha Hegde
- Nitte University Centre for Science Education and Research, Nitte University, Paneer Campus, Derelakatte, Mangalore 575018, India.
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Shu Y, Wan-Ting J, Ya-Ning Y, Yu-Han F. An Optimized CTAB Method for Genomic DNA Extraction from Freshly-picked Pinnae of Fern, Adiantum capillus-veneris L. Bio Protoc 2018; 8:e2906. [PMID: 34395738 DOI: 10.21769/bioprotoc.2906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 06/06/2018] [Accepted: 06/11/2018] [Indexed: 11/02/2022] Open
Abstract
As the sister clade of seed plants, ferns are significant materials for plant phylogeny research. However, the genomic DNA extraction protocol for fern samples like modified CTAB method still lacks robustness. Here, we found that the amount and condition of the pinnae samples are critical for gDNA extraction in fern, Adiantum capillus-veneris L. In 500 μl CTAB solution, the recommended amount of pinnae is about 10-20 mg (2-3 pieces). The condition of the pinnae must be instantly-picked from a plant cultivated in a suitable environment. With these factors under control, it is highly reproducible to get the high-quality gDNA with low degradation rate.
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Affiliation(s)
- Yi Shu
- Yuanpei School, Peking University, Beijing, China
| | - Jin Wan-Ting
- School of Life Sciences, Peking University, Beijing, China
| | - Yuan Ya-Ning
- Yuanpei School, Peking University, Beijing, China
| | - Fang Yu-Han
- Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
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Fang YH, Li X, Bai SN, Rao GY. Sugar Treatments Can Induce AcLEAFY COTYLEDON1 Expression and Trigger the Accumulation of Storage Products during Prothallus Development of Adiantum capillus-veneris. FRONTIERS IN PLANT SCIENCE 2017; 8:541. [PMID: 28484470 PMCID: PMC5399092 DOI: 10.3389/fpls.2017.00541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 03/27/2017] [Indexed: 05/20/2023]
Abstract
A seed is an intricate structure. Of the two development processes involved in seed formation, seed maturation, or seed program includes accumulation of storage products, acquisition of desiccation tolerance, and induction of dormancy. Little is known about how these processes were originated and integrated into the life cycle of seed plants. While previous investigation on seed origin was almost exclusively through fossil comparison in paleobotany, a wealth of information about the key role of LEAFY COTYLEDON1 (LEC1) in seed formation of spermatophyte inspired a new approach to investigating the seed origin mystery. Here, we examined the expression pattern of AcLEC1 during the entire life cycle of Adiantum capillus-veneris, a non-seed plant, confirmed no AcLEC1 gene expression detectable in prothalli, demonstrated inductive expressed by both sucrose and glucose in prothalli. As expected, we found that sugar treatments delayed prothallus development, promoted differentiation of reproductive organs, and triggered accumulation of storage products. These findings demonstrated links between the sugar treatments and the induction of AcLEC1 expression, as well as the sugar treatments and the events such as accumulation of storage products, which is similar to those considered as seed maturation process in seed plants. These links support a modified hypothesis that inductive expression of LEC1 homologs during embryogenesis might be a key innovation for the origin of the seed program.
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Affiliation(s)
- Yu-Han Fang
- College of Life Sciences, Peking UniversityBeijing, China
| | - Xia Li
- RDFZ XiShan SchoolBeijing, China
| | - Shu-Nong Bai
- College of Life Sciences, Peking UniversityBeijing, China
- *Correspondence: Shu-Nong Bai,
| | - Guang-Yuan Rao
- College of Life Sciences, Peking UniversityBeijing, China
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