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Genetic diversity analysis and marker-trait associations in Amaranthus species. PLoS One 2022; 17:e0267752. [PMID: 35551526 PMCID: PMC9098028 DOI: 10.1371/journal.pone.0267752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 04/15/2022] [Indexed: 11/26/2022] Open
Abstract
Amaranth (Amaranthus spp.) is a highly nutritious, underutilized vegetable and pseudo-cereal crop. It possesses diverse abiotic stress tolerance traits, is genetically diverse and highly phenotypically plastic, making it an ideal crop to thrive in a rapidly changing climate. Despite considerable genetic diversity there is a lack of detailed characterization of germplasm or population structures. The present study utilized the DArTSeq platform to determine the genetic relationships and population structure between 188 amaranth accessions from 18 agronomically important vegetable, grain, and weedy species. A total of 74, 303 SNP alleles were generated of which 63, 821 were physically mapped to the genome of the grain species A. hypochondriacus. Population structure was inferred in two steps. First, all 188 amaranth accessions comprised of 18 species and second, only 120 A. tricolor accessions. After SNP filtering, a total of 8,688 SNPs were generated on 181 amaranth accessions of 16 species and 9,789 SNPs generated on 118 A. tricolor accessions. Both SNP datasets produced three major sub-populations (K = 3) and generate consistent taxonomic classification of the amaranth sub-genera (Amaranthus Amaranthus, Amaranthus Acnida and Amaranthus albersia), although the accessions were poorly demarcated by geographical origin and morphological traits. A. tricolor accessions were well discriminated from other amaranth species. A genome-wide association study (GWAS) of 10 qualitative traits revealed an association between specific phenotypes and genetic variants within the genome and identified 22 marker trait associations (MTAs) and 100 MTAs (P≤0.01, P≤0.001) on 16 amaranth species and 118 A.tricolor datasets, respectively. The release of SNP markers from this panel has produced invaluable preliminary genetic information for phenotyping and cultivar improvement in amaranth species.
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Wheeler LC, Walker JF, Ng J, Deanna R, Dunbar-Wallis A, Backes A, Pezzi PH, Palchetti MV, Robertson HM, Monaghan A, Brandão de Freitas L, Barboza GE, Moyroud E, Smith SD. Transcription factors evolve faster than their structural gene targets in the flavonoid pigment pathway. Mol Biol Evol 2022; 39:6536971. [PMID: 35212724 PMCID: PMC8911815 DOI: 10.1093/molbev/msac044] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Dissecting the relationship between gene function and substitution rates is key to understanding genome-wide patterns of molecular evolution. Biochemical pathways provide powerful systems for investigating this relationship because the functional role of each gene is often well characterized. Here, we investigate the evolution of the flavonoid pigment pathway in the colorful Petunieae clade of the tomato family (Solanaceae). This pathway is broadly conserved in plants, both in terms of its structural elements and its MYB, basic helix–loop–helix, and WD40 transcriptional regulators, and its function has been extensively studied, particularly in model species of petunia. We built a phylotranscriptomic data set for 69 species of Petunieae to infer patterns of molecular evolution across pathway genes and across lineages. We found that transcription factors exhibit faster rates of molecular evolution (dN/dS) than their targets, with the highly specialized MYB genes evolving fastest. Using the largest comparative data set to date, we recovered little support for the hypothesis that upstream enzymes evolve slower than those occupying more downstream positions, although expression levels do predict molecular evolutionary rates. Although shifts in floral pigmentation were only weakly related to changes affecting coding regions, we found a strong relationship with the presence/absence patterns of MYB transcripts. Intensely pigmented species express all three main MYB anthocyanin activators in petals, whereas pale or white species express few or none. Our findings reinforce the notion that pathway regulators have a dynamic history, involving higher rates of molecular evolution than structural components, along with frequent changes in expression during color transitions.
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Affiliation(s)
- Lucas C Wheeler
- Department of Ecology and Evolutionary Biology, University of Colorado, 1900 Pleasant Street 334 UCB, Boulder, CO, USA, 80309-0334
| | - Joseph F Walker
- Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, UK.,Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, 60607 U.S.A
| | - Julienne Ng
- Department of Ecology and Evolutionary Biology, University of Colorado, 1900 Pleasant Street 334 UCB, Boulder, CO, USA, 80309-0334
| | - Rocío Deanna
- Department of Ecology and Evolutionary Biology, University of Colorado, 1900 Pleasant Street 334 UCB, Boulder, CO, USA, 80309-0334.,Instituto Multidisciplinario de Biología Vegetal (IMBIV), CONICET and Universidad Nacional de Córdoba, CC 495, CP 5000, Córdoba, Argentina
| | - Amy Dunbar-Wallis
- Department of Ecology and Evolutionary Biology, University of Colorado, 1900 Pleasant Street 334 UCB, Boulder, CO, USA, 80309-0334
| | - Alice Backes
- Laboratory of Molecular Evolution, Department of Genetics, Universidade Federal do Rio Grande do Sul, P.O. Box 15053, 91501-970, Porto Alegre, RS, Brazil
| | - Pedro H Pezzi
- Laboratory of Molecular Evolution, Department of Genetics, Universidade Federal do Rio Grande do Sul, P.O. Box 15053, 91501-970, Porto Alegre, RS, Brazil
| | - M Virginia Palchetti
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), CONICET and Universidad Nacional de Córdoba, CC 495, CP 5000, Córdoba, Argentina
| | - Holly M Robertson
- Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, UK
| | - Andrew Monaghan
- Research Computing,University of Colorado, 3100 Marine Street, 597 UCB Boulder, CO 80303
| | - Loreta Brandão de Freitas
- Laboratory of Molecular Evolution, Department of Genetics, Universidade Federal do Rio Grande do Sul, P.O. Box 15053, 91501-970, Porto Alegre, RS, Brazil
| | - Gloria E Barboza
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), CONICET and Universidad Nacional de Córdoba, CC 495, CP 5000, Córdoba, Argentina.,Facultad de Ciencias Químicas, Universidad Nacional de Córdoba,Haya de la Torre y Medina Allende, Córdoba, Argentina
| | - Edwige Moyroud
- Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, UK
| | - Stacey D Smith
- Department of Ecology and Evolutionary Biology, University of Colorado, 1900 Pleasant Street 334 UCB, Boulder, CO, USA, 80309-0334
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Zeng Q, Liu H, Chu X, Niu Y, Wang C, Markov GV, Teng L. Independent Evolution of the MYB Family in Brown Algae. Front Genet 2022; 12:811993. [PMID: 35186015 PMCID: PMC8854648 DOI: 10.3389/fgene.2021.811993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 12/27/2021] [Indexed: 11/13/2022] Open
Abstract
Myeloblastosis (MYB) proteins represent one of the largest families of eukaryotic transcription factors and regulate important processes in growth and development. Studies on MYBs have mainly focused on animals and plants; however, comprehensive analysis across other supergroups such as SAR (stramenopiles, alveolates, and rhizarians) is lacking. This study characterized the structure, evolution, and expression of MYBs in four brown algae, which comprise the biggest multicellular lineage of SAR. Subfamily 1R-MYB comprised heterogeneous proteins, with fewer conserved motifs found outside the MYB domain. Unlike the SHAQKY subgroup of plant 1R-MYB, THAQKY comprised the largest subgroup of brown algal 1R-MYBs. Unlike the expansion of 2R-MYBs in plants, brown algae harbored more 3R-MYBs than 2R-MYBs. At least ten 2R-MYBs, fifteen 3R-MYBs, and one 6R-MYB orthologs existed in the common ancestor of brown algae. Phylogenetic analysis showed that brown algal MYBs had ancient origins and a diverged evolution. They showed strong affinity with stramenopile species, while not with red algae, green algae, or animals, suggesting that brown algal MYBs did not come from the secondary endosymbiosis of red and green plastids. Sequence comparison among all repeats of the three types of MYB subfamilies revealed that the repeat of 1R-MYBs showed higher sequence identity with the R3 of 2R-MYBs and 3R-MYBs, which supports the idea that 1R-MYB was derived from loss of the first and second repeats of the ancestor MYB. Compared with other species of SAR, brown algal MYB proteins exhibited a higher proportion of intrinsic disordered regions, which might contribute to multicellular evolution. Expression analysis showed that many MYB genes are responsive to different stress conditions and developmental stages. The evolution and expression analyses provided a comprehensive analysis of the phylogeny and functions of MYBs in brown algae.
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Affiliation(s)
| | - Hanyu Liu
- College of Life Sciences, Dezhou University, Dezhou, China
| | - Xiaonan Chu
- College of Life Sciences, Dezhou University, Dezhou, China
| | - Yonggang Niu
- College of Life Sciences, Dezhou University, Dezhou, China
| | - Caili Wang
- College of Life Sciences, Dezhou University, Dezhou, China
| | - Gabriel V. Markov
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), Roscoff, France
| | - Linhong Teng
- College of Life Sciences, Dezhou University, Dezhou, China
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4
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Xie YF, Zhang RX, Qin LJ, Song LL, Zhao DG, Xia ZM. Genome-wide identification and genetic characterization of the CaMYB family and its response to five types of heavy metal stress in hot pepper (Capsicum annuum cv. CM334). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2022; 170:98-109. [PMID: 34863059 DOI: 10.1016/j.plaphy.2021.11.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/11/2021] [Accepted: 11/12/2021] [Indexed: 06/13/2023]
Abstract
MYB proteins play a crucial role in plant growth and development and stress responses. In this study, 160 members of the MYB gene family from the pepper genome database were used to analyze gene structures, chromosome localization, collinearity, genetic affinity and expression in response to heavy metals. The results identified R2R3-MYB members and further phylogenetically classified them into 35 subgroups based on highly conserved gene structures and motifs. Collinearity analysis showed that segmental duplication events played a crucial role in the functional expansion of the CaMYB gene family by intraspecific collinearity, and at least 12 pairs of CaMYB genes existed between species prior to the differentiation between monocots and dicots. Moreover, the upstream CaMYB genes were mainly localized to the phytohormone elements ABRE and transcription factor elements MYB and MYC. Further analysis revealed that MYB transcription factors were closely associated with a variety of abiotic stress-related proteins (e.g., MAC-complex and SKIP). Under the stress of five metal ions, Cd2+, Cu2+, Pb2+, Zn2+, and Fe3+, the expression levels of some CaMYB family genes were upregulated. Of these genes, pairing homologous 1 (PH-1), PH-13, and PH-15 in the roots of Capsicum annuum were upregulated to the greatest extent, indicating that these three MYB family members are particularly sensitive to these five metals. This study provides a theoretical reference for the analysis of the molecular regulatory mechanism of MYB family genes in mediating the response to heavy metals in plants. This study reveals the mode of interaction between MYB and a variety of abiotic stress proteins and clarifies the biological functions of CaMYB family members in the regulation of heavy metal stress.
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Affiliation(s)
- Yu-Feng Xie
- The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Guizhou University, Guiyang, Guizhou Province, PR China; Institute of Agro-Bioengineering and College of Life Sciences, Guizhou University, Guiyang, Guizhou Province, PR China
| | | | - Li-Jun Qin
- The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Guizhou University, Guiyang, Guizhou Province, PR China; Institute of Agro-Bioengineering and College of Life Sciences, Guizhou University, Guiyang, Guizhou Province, PR China.
| | - La-la Song
- Guizhou Academy of Agricultural Sciences, Guiyang, 550006, PR China
| | - De-Gang Zhao
- The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Guizhou University, Guiyang, Guizhou Province, PR China; Guizhou Academy of Agricultural Sciences, Guiyang, 550006, PR China
| | - Zhong-Min Xia
- Guizhou Soil and Fertilizer General Station, Guiyang, 550001, PR China
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Wu W, Zhu S, Zhu L, Wang D, Liu Y, Liu S, Zhang J, Hao Z, Lu Y, Cheng T, Shi J, Chen J. Characterization of the Liriodendron Chinense MYB Gene Family and Its Role in Abiotic Stress Response. FRONTIERS IN PLANT SCIENCE 2021; 12:641280. [PMID: 34381467 PMCID: PMC8350534 DOI: 10.3389/fpls.2021.641280] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 06/09/2021] [Indexed: 05/04/2023]
Abstract
Liriodendron chinense (Lchi) is a Magnoliaceae plant, which is a basic angiosperm left behind by the Pleistocene and mainly distributed in the south of the Yangtze River. Liriodendron hybrids has good wood properties and is widely used in furniture and in other fields. It is not clear if they can adapt to different environmental conditions, such as drought and high and low temperatures, and the molecular mechanisms for this adaptation are unknown. Among plant transcription factors (TFs), the MYB gene family is one of the largest and is often involved in stress or adversity response signaling, growth, and development. Therefore, studying the role of MYBTFs in regulating abiotic stress signaling, growth, and development in Lchi is helpful to promote afforestation in different environments. In our research, a genome-wide analysis of the LchiMYB gene family was performed, including the phylogenetic relationship tree, gene exon-intron structure, collinearity, and chromosomal position. According to the evolutionary tree, 190 LchiMYBs were divided into three main branches. LchiMYBs were evenly distributed across 19 chromosomes, with their collinearity, suggesting that segment duplication events may have contributed to LchiMYB gene expansion. Transcriptomes from eight tissues, 11 stages of somatic embryogenesis, and leaves after cold, heat, and drought stress were used to analyze the function of the MYB gene family. The results of tissue expression analysis showed that most LchiMYB genes regulated bark, leaf, bud, sepal, stigma, and stamen development, as well as the four important stages (ES3, ES4, ES9, and PL) of somatic embryogenesis. More than 60 LchiMYBs responded to heat, cold, and drought stress; some of which underwent gene duplication during evolution. LchiMYB3 was highly expressed under all three forms of stress, while LchiMYB121 was strongly induced by both cold and heat stress. Eight genes with different expression patterns were selected and verified by quantitative real-time PCR (qRT-PCR) experiments. The results suggested that these LchiMYBs may regulate Lchi growth development and resistance to abiotic stress. This study shows the cross-regulatory function of LchiMYBs in the growth and development, asexual reproduction, and abiotic resistance of Lchi. This information will prove pivotal to directing further studies on the biological function of Lchi MYBTFs in genetic improvement and abiotic stress response.
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Affiliation(s)
- Weihuang Wu
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education of China, Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Sheng Zhu
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, China
| | - Liming Zhu
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education of China, Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Dandan Wang
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education of China, Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Yang Liu
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education of China, Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Siqin Liu
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education of China, Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Jiaji Zhang
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education of China, Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Zhaodong Hao
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education of China, Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Ye Lu
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education of China, Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Tielong Cheng
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, China
| | - Jisen Shi
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education of China, Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Jinhui Chen
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education of China, Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- *Correspondence: Jinhui Chen,
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Wang J, Liu Y, Tang B, Dai X, Xie L, Liu F, Zou X. Genome-Wide Identification and Capsaicinoid Biosynthesis-Related Expression Analysis of the R2R3-MYB Gene Family in Capsicum annuum L. Front Genet 2020; 11:598183. [PMID: 33408738 PMCID: PMC7779616 DOI: 10.3389/fgene.2020.598183] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/30/2020] [Indexed: 11/13/2022] Open
Abstract
Capsaicinoids are naturally specialized metabolites in pepper and are the main reason that Capsicum fruits have a pungent smell. During the synthesis of capsaicin, MYB transcription factors play key regulatory roles. In particular, R2R3-MYB subfamily genes are the most important members of the MYB family and are critical candidate factors in capsaicinoid biosynthesis. The 108 R2R3-MYB genes in pepper were identified in this study and all are shown to have two highly conserved MYB binding domains. Phylogenetic and structural analyses clustered CaR2R3-MYB genes into seven groups. Interspecies collinearity analysis found that the R2R3-MYB family contains 16 duplicated gene pairs and the highest gene density is on chromosome 00 and 03. The expression levels of CaR2R3-MYB differentially expressed genes (DEGs) and capsaicinoid-biosynthetic genes (CBGs) in fruit development stages were obtained via RNA-seq and quantitative polymerase chain reaction (qRT-PCR). Co-expression analyses reveal that highly expressed CaR2R3-MYB genes are co-expressed with CBGs during early stages of pericarp and placenta development processes. It is speculated that six candidate CaR2R3-MYB genes are involved in regulating the synthesis of capsaicin and dihydrocapsaicin. This study is the first systematic analysis of the CaR2R3-MYB gene family and provided references for studying their molecular functions. At the same time, these results also laid the foundation for further research on the capsaicin characteristics of CaR2R3-MYB genes in pepper.
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Affiliation(s)
- Jin Wang
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, China
| | - Yi Liu
- Longping Branch, Graduate School of Hunan University, Changsha, China
| | - Bingqian Tang
- Longping Branch, Graduate School of Hunan University, Changsha, China
| | - Xiongze Dai
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, China
- College of Horticulture, Hunan Agricultural University, Changsha, China
| | - Lingling Xie
- Hunan Vegetable Research Institute, Changsha, China
| | - Feng Liu
- College of Horticulture, Hunan Agricultural University, Changsha, China
- Hunan Vegetable Research Institute, Changsha, China
| | - Xuexiao Zou
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, China
- College of Horticulture, Hunan Agricultural University, Changsha, China
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7
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Larter M, Dunbar-Wallis A, Berardi AE, Smith SD. Convergent Evolution at the Pathway Level: Predictable Regulatory Changes during Flower Color Transitions. Mol Biol Evol 2020; 35:2159-2169. [PMID: 29878153 DOI: 10.1093/molbev/msy117] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The predictability of evolution, or whether lineages repeatedly follow the same evolutionary trajectories during phenotypic convergence remains an open question of evolutionary biology. In this study, we investigate evolutionary convergence at the biochemical pathway level and test the predictability of evolution using floral anthocyanin pigmentation, a trait with a well-understood genetic and regulatory basis. We reconstructed the evolution of floral anthocyanin content across 28 species of the Andean clade Iochrominae (Solanaceae) and investigated how shifts in pigmentation are related to changes in expression of seven key anthocyanin pathway genes. We used phylogenetic multivariate analysis of gene expression to test for phenotypic and developmental convergence at a macroevolutionary scale. Our results show that the four independent losses of the ancestral pigment delphinidin involved convergent losses of expression of the three late pathway genes (F3'5'h, Dfr, and Ans). Transitions between pigment types affecting floral hue (e.g., blue to red) involve changes to the expression of branching genes F3'h and F3'5'h, while the expression levels of early steps of the pathway are strongly conserved in all species. These patterns support the idea that the macroevolution of floral pigmentation follows predictable evolutionary trajectories to reach convergent phenotype space, repeatedly involving regulatory changes. This is likely driven by constraints at the pathway level, such as pleiotropy and regulatory structure.
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Affiliation(s)
- Maximilian Larter
- Department of Ecology and Evolutionary Biology, University of Colorado-Boulder, Boulder, CO
| | - Amy Dunbar-Wallis
- Department of Ecology and Evolutionary Biology, University of Colorado-Boulder, Boulder, CO
| | - Andrea E Berardi
- Department of Ecology and Evolutionary Biology, University of Colorado-Boulder, Boulder, CO.,Department of Biology, Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - Stacey D Smith
- Department of Ecology and Evolutionary Biology, University of Colorado-Boulder, Boulder, CO
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Stetter MG, Vidal-Villarejo M, Schmid KJ. Parallel Seed Color Adaptation during Multiple Domestication Attempts of an Ancient New World Grain. Mol Biol Evol 2019; 37:1407-1419. [DOI: 10.1093/molbev/msz304] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
AbstractThousands of plants have been selected as crops; yet, only a few are fully domesticated. The lack of adaptation to agroecological environments of many crop plants with few characteristic domestication traits potentially has genetic causes. Here, we investigate the incomplete domestication of an ancient grain from the Americas, amaranth. Although three grain amaranth species have been cultivated as crop for millennia, all three lack key domestication traits. We sequenced 121 crop and wild individuals to investigate the genomic signature of repeated incomplete adaptation. Our analysis shows that grain amaranth has been domesticated three times from a single wild ancestor. One trait that has been selected during domestication in all three grain species is the seed color, which changed from dark seeds to white seeds. We were able to map the genetic control of the seed color adaptation to two genomic regions on chromosomes 3 and 9, employing three independent mapping populations. Within the locus on chromosome 9, we identify an MYB-like transcription factor gene, a known regulator for seed color variation in other plant species. We identify a soft selective sweep in this genomic region in one of the crop species but not in the other two species. The demographic analysis of wild and domesticated amaranths revealed a population bottleneck predating the domestication of grain amaranth. Our results indicate that a reduced level of ancestral genetic variation did not prevent the selection of traits with a simple genetic architecture but may have limited the adaptation of complex domestication traits.
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Affiliation(s)
- Markus G Stetter
- Botanical Institute, University of Cologne, Cologne, Germany
- Department of Plant Breeding, Population Genetics and Seed Science, University of Hohenheim, Stuttgart, Germany
| | - Mireia Vidal-Villarejo
- Department of Plant Breeding, Population Genetics and Seed Science, University of Hohenheim, Stuttgart, Germany
| | - Karl J Schmid
- Department of Plant Breeding, Population Genetics and Seed Science, University of Hohenheim, Stuttgart, Germany
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Gates DJ, Pilson D, Smith SD. Filtering of target sequence capture individuals facilitates species tree construction in the plant subtribe Iochrominae (Solanaceae). Mol Phylogenet Evol 2018; 123:26-34. [DOI: 10.1016/j.ympev.2018.02.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 01/30/2018] [Accepted: 02/01/2018] [Indexed: 10/18/2022]
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10
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Gates DJ, Olson BJSC, Clemente TE, Smith SD. A novel R3 MYB transcriptional repressor associated with the loss of floral pigmentation in Iochroma. THE NEW PHYTOLOGIST 2018; 217:1346-1356. [PMID: 29023752 DOI: 10.1111/nph.14830] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 08/31/2017] [Indexed: 05/23/2023]
Abstract
Losses of floral pigmentation represent one of the most common evolutionary transitions in flower color, yet the genetic basis for these changes has been elucidated in only a handful of cases. Here we used crossing studies, bulk-segregant RNA sequencing, phylogenetic analyses and functional tests to identify the gene(s) responsible for the transition to white flowers in Iochroma loxense. Crosses between I. loxense and its blue-flowered sister species, I. cyaneum, suggested that a single locus controls the flower color difference and that the white allele causes a nearly complete loss of pigmentation. Examining sequence variation across phenotypic pools from the crosses, we found that alleles at a novel R3 MYB transcription factor were tightly associated with flower color variation. This gene, which we term MYBL1, falls into a class of MYB transcriptional repressors and, accordingly, higher expression of this gene is associated with downregulation of multiple anthocyanin pigment pathway genes. We confirmed the repressive function of MYBL1 through stable transformation of Nicotiana. The mechanism underlying the evolution of white flowers in I. loxense differs from that uncovered in previous studies, pointing to multiple mechanisms for achieving fixed transitions in flower color intensity.
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Affiliation(s)
- Daniel J Gates
- School of Biological Sciences, University of Nebraska, Lincoln, NE, 68588, USA
| | | | - Tom E Clemente
- Department of Agronomy and Horticulture and Center for Plant Science Innovation, University of Nebraska, Lincoln, NE, 68588, USA
| | - Stacey D Smith
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80305, USA
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11
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Identification and Characterization of the Diverse Stress-Responsive R2R3-RMYB Transcription Factor from Hibiscus sabdariffa L. Int J Genomics 2017; 2017:2763259. [PMID: 29181384 PMCID: PMC5664376 DOI: 10.1155/2017/2763259] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 08/11/2017] [Accepted: 09/06/2017] [Indexed: 12/12/2022] Open
Abstract
Various regulatory proteins play a fundamental role to manage the healthy plant growth under stress conditions. Differential display reverse transcriptase PCR and random amplification of cDNA ends (RACE) was used to explore the osmotic stress-responsive transcripts. We identified and characterized the salt stress-responsive R2R3 type RMYB transcription factor from Hibiscus sabdariffa which has an open reading frame of 690 bp, encoding 229 long chain amino acids. In silico analysis confirmed the conserved R2 and R3 domain as well as an NLS-1 localization site. The deduced amino acids of RMYB shared 83, 81, 80, 79, 72, 71, and 66% homology with Arabidopsis thaliana, Glycine max, Oryza sativa, Zea maize, Malus domestica, Populus tremula × Populus alba, and Medicago sativa specific MYB family, respectively. We observed the gene upregulation in stem, leaf, and root tissue in response to abiotic stress. Furthermore, RMYB gene was cloned into plant expression vector under CaMV35S promoter and transformed to Gossypium hirsutum: a local cotton cultivar. Overexpression of RMYB was observed in transgenic plants under abiotic stresses which further suggests its regulatory role in response to stressful conditions. The RMYB transcription factor-overexpressing in transgenic cotton plants may be used as potential agent for the development of stress tolerant crop cultivars.
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Wang F, Li X. Genome-wide characterization and expression analysis of MYB transcription factors in Lotus japonicas and Medicago truncatula. Genes Genomics 2017. [DOI: 10.1007/s13258-017-0544-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Sheshadri SA, Nishanth MJ, Simon B. Stress-Mediated cis-Element Transcription Factor Interactions Interconnecting Primary and Specialized Metabolism in planta. FRONTIERS IN PLANT SCIENCE 2016; 7:1725. [PMID: 27933071 PMCID: PMC5122738 DOI: 10.3389/fpls.2016.01725] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 11/02/2016] [Indexed: 05/07/2023]
Abstract
Plant specialized metabolites are being used worldwide as therapeutic agents against several diseases. Since the precursors for specialized metabolites come through primary metabolism, extensive investigations have been carried out to understand the detailed connection between primary and specialized metabolism at various levels. Stress regulates the expression of primary and specialized metabolism genes at the transcriptional level via transcription factors binding to specific cis-elements. The presence of varied cis-element signatures upstream to different stress-responsive genes and their transcription factor binding patterns provide a prospective molecular link among diverse metabolic pathways. The pattern of occurrence of these cis-elements (overrepresentation/common) decipher the mechanism of stress-responsive upregulation of downstream genes, simultaneously forming a molecular bridge between primary and specialized metabolisms. Though many studies have been conducted on the transcriptional regulation of stress-mediated primary or specialized metabolism genes, but not much data is available with regard to cis-element signatures and transcription factors that simultaneously modulate both pathway genes. Hence, our major focus would be to present a comprehensive analysis of the stress-mediated interconnection between primary and specialized metabolism genes via the interaction between different transcription factors and their corresponding cis-elements. In future, this study could be further utilized for the overexpression of the specific transcription factors that upregulate both primary and specialized metabolism, thereby simultaneously improving the yield and therapeutic content of plants.
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Affiliation(s)
| | | | - Bindu Simon
- School of Chemical and Biotechnology, SASTRA UniversityThanjavur, India
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