Browsing by Author "Bombarely, Aureliano"
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- Assessment of Genetic Diversity and Population Structure in Iranian Cannabis GermplasmSoorni, Aboozar; Fatahi, Reza; Haak, David C.; Salami, Seyed Alireza; Bombarely, Aureliano (Nature Publishing Group, 2017-11-15)Cannabis sativa has a complex history reflected in both selection on naturally occurring compounds and historical trade routes among humans. Iran is a rich resource of natural populationswhich hold the promise to characterize historical patterns of population structure and genetic diversity within Cannabis. Recent advances in high-throughput DNA sequencing technologies have dramatically increased our ability to produce information to the point that it is now feasible to inexpensively obtain population level genotype information at a large scale. In the present investigation, we have explored the use of Genotyping-By-Sequencing (GBS) in Iranian cannabis. We genotyped 98 cannabis samples 36 from Iranian locations and 26 accessions from two germplasm collections. In total, 24,710 high-quality Single Nucleotide Polymorphisms (SNP) were identified. Clustering analysis by Principal Component Analysis (PCA) identified two genetic clusters among Iranian populations and fineSTRUCTURE analysis identified 19 populations with some geographic partitioning. We defined Iranian cannabis in two main groups using the results of the PCA and discovered some strong signal to define some locations as population according to fineSTRUCTURE analyses. However, single nucleotide variant analysis uncovered a relatively moderate level of variation among Iranian cannabis.
- Dissecting Tissue-Specific Transcriptomic Responses from Leaf and Roots under Salt Stress in Petunia hybrida MitchellVillarino, Gonzalo H.; Hu, Qiwen; Scanlon, Michael J.; Mueller, Lukas A.; Bombarely, Aureliano; Mattson, Neil S. (MDPI, 2017-08-03)One of the primary objectives of plant biotechnology is to increase resistance to abiotic stresses, such as salinity. Salinity is a major abiotic stress and increasing crop resistant to salt continues to the present day as a major challenge. Salt stress disturbs cellular environment leading to protein misfolding, affecting normal plant growth and causing agricultural losses worldwide. The advent of state-of-the-art technologies such as high throughput mRNA sequencing (RNA-seq) has revolutionized whole-transcriptome analysis by allowing, with high precision, to measure changes in gene expression. In this work, we used tissue-specific RNA-seq to gain insight into the Petunia hybrida transcriptional responses under NaCl stress using a controlled hydroponic system. Roots and leaves samples were taken from a continuum of 48 h of acute 150 mM NaCl. This analysis revealed a set of tissue and time point specific differentially expressed genes, such as genes related to transport, signal transduction, ion homeostasis as well as novel and undescribed genes, such as Peaxi162Scf00003g04130 and Peaxi162Scf00589g00323 expressed only in roots under salt stress. In this work, we identified early and late expressed genes in response to salt stress while providing a core of differentially express genes across all time points and tissues, including the trehalose-6-phosphate synthase 1 (TPS1), a glycosyltransferase reported in salt tolerance in other species. To test the function of the novel petunia TPS1 allele, we cloned and showed that TPS1 is a functional plant gene capable of complementing the trehalose biosynthesis pathway in a yeast tps1 mutant. The list of candidate genes to enhance salt tolerance provided in this work constitutes a major effort to better understand the detrimental effects of salinity in petunia with direct implications for other economically important Solanaceous species.
- ERAMOSA controls lateral branching in snapdragonMizzotti, Chiara; Galliani, Bianca M.; Dreni, Ludovico; Sommer, Hans; Bombarely, Aureliano; Masiero, Simona (Springer Nature, 2017-02-01)Plant forms display a wide variety of architectures, depending on the number of lateral branches, internode elongation and phyllotaxy. These are in turn determined by the number, the position and the fate of the Axillary Meristems (AMs). Mutants that affect AM determination during the vegetative phase have been isolated in several model plants. Among these genes, the GRAS transcription factor LATERAL SUPPRESSOR (Ls) plays a pivotal role in AM determination during the vegetative phase. Hereby we characterize the phylogenetic orthologue of Ls in Antirrhinum, ERAMOSA (ERA). Our data supported ERA control of AM formation during both the vegetative and the reproductive phase in snapdragon. A phylogenetic analysis combined with an analysis of the synteny of Ls in several species strongly supported the hypothesis that ERA is a phylogenetic orthologue of Ls, although it plays a broader role. During the reproductive phase ERA promotes the establishment of the stem niche at the bract axis but, after the reproductive transition, it is antagonized by the MADS box transcription factor SQUAMOSA (SQUA). Surprisingly double mutant era squa plants display a squa phenotype developing axillary meristems, which can eventually turn into inflorescences or flowers.
- Exploring transposable element-based markers to identify allelic variations underlying agronomic traits in riceYan, Haidong; Haak, David C.; Li, Song; Huang, Linkai; Bombarely, Aureliano (Elsevier, 2022-05-09)Transposable elements (TEs) are a major force in the production of new alleles during domestication; nevertheless, their use in association studies has been limited because of their complexity. We have developed a TE genotyping pipeline (TEmarker) and applied it to whole-genome genome-wide association study (GWAS) data from 176 Oryza sativa subsp. japonica accessions to identify genetic elements associated with specific agronomic traits. TE markers recovered a large proportion (69%) of single-nucleotide polymorphism (SNP)-based GWAS peaks, and these TE peaks retained ca. 25% of the SNPs. The use of TEs in GWASs may reduce false positives associated with linkage disequilibrium (LD) among SNP markers. A genome scan revealed positive selection on TEs associated with agronomic traits. We found several cases of insertion and deletion variants that potentially resulted from the direct action of TEs, including an allele of LOC_Os11g08410 associated with plant height and panicle length traits. Together, these findings reveal the utility of TE markers for connecting genotype to phenotype and suggest a potential role for TEs in influencing phenotypic variations in rice that impact agronomic traits.
- Extensive phenotypic diversity in the cultivated Florist’s Gloxinia, Sinningia speciosa (Lodd.) Hiern, is derived from the domestication of a single founder populationHasing, Tomas; Rinaldi, Elijah; Manrique, Silvia; Colombo, Lucia; Haak, David C.; Zaitlin, David; Bombarely, Aureliano (Wiley, 2019-08-19)Domesticated plants are essential for agriculture and human societies. Hence, understanding the processes of domestication will be crucial as we strive for more efficient crops and improvements to plants that benefit humankind in other ways. Here, we study the ornamental plant Sinningia speciosa, and reveal that despite the incredible variety found in domesticated varieties (e.g., in flower colour and form), they are all derived from a single founder population near Rio de Janeiro, Brazil. Knowledge of the domestication of horticultural plants is scarce and given its small, low‐complexity genome, and ease of cultivation, we suggest that S. speciosa is a good model for studying genomic variation during domestication.
- Gene expression atlas of fruit ripening and transcriptome assembly from RNA-seq data in octoploid strawberry (Fragaria x ananassa)Sanchez-Sevilla, José F.; Vallarino, José G.; Osorio, Sonia; Bombarely, Aureliano; Posé, David; Merchante, Catharina; Botella, Miguel A.; Amaya, Iraida; Valpuesta, Victoriano (Nature Publishing Group, 2017-10-23)
- Genome assembly provides insights into the genome evolution and flowering regulation of orchardgrassHuang, Linkai; Feng, Guangyan; Yan, Haidong; Zhang, Zhongren; Bushman, Bradley Shaun; Wang, Jianping; Bombarely, Aureliano; Li, Mingzhou; Yang, Zhongfu; Nie, Gang; Xie, Wengang; Xu, Lei; Chen, Peilin; Zhao, Xinxin; Jiang, Wenkai; Zhang, Xinquan (2020-02)Orchardgrass (Dactylis glomerata L.) is an important forage grass for cultivating livestock worldwide. Here, we report an similar to 1.84-Gb chromosome-scale diploid genome assembly of orchardgrass, with a contig N50 of 0.93 Mb, a scaffold N50 of 6.08 Mb and a super-scaffold N50 of 252.52 Mb, which is the first chromosome-scale assembled genome of a cool-season forage grass. The genome includes 40 088 protein-coding genes, and 69% of the assembled sequences are transposable elements, with long terminal repeats (LTRs) being the most abundant. The LTRretrotransposons may have been activated and expanded in the grass genome in response to environmental changes during the Pleistocene between 0 and 1 million years ago. Phylogenetic analysis reveals that orchardgrass diverged after rice but before three Triticeae species, and evolutionarily conserved chromosomes were detected by analysing ancient chromosome rearrangements in these grass species. We also resequenced the whole genome of 76 orchardgrass accessions and found that germplasm from Northern Europe and East Asia clustered together, likely due to the exchange of plants along the 'Silk Road' or other ancient trade routes connecting the East and West. Last, a combined transcriptome, quantitative genetic and bulk segregant analysis provided insights into the genetic network regulating flowering time in orchardgrass and revealed four main candidate genes controlling this trait. This chromosome-scale genome and the online database of orchardgrass developed here will facilitate the discovery of genes controlling agronomically important traits, stimulate genetic improvement of and functional genetic research on orchardgrass and provide comparative genetic resources for other forage grasses.
- Genomics-based diversity analysis of Vanilla species using a Vanilla planifolia draft genome and Genotyping-By-SequencingHu, Ying; Resende Jr., Marcio F. R.; Bombarely, Aureliano; Brym, Maria; Bassil, Elias; Chambers, Alan H. (Springer Nature, 2019-03-04)Demand for all-natural vanilla flavor is increasing, but its botanical source, Vanilla planifolia, faces critical challenges arising from a narrow germplasm base and supply limitations. Genomics tools are the key to overcoming these limitations by enabling advanced genetics and plant breeding for new cultivars with improved yield and quality. The objective of this work was to establish the genomic resources needed to facilitate analysis of diversity among Vanilla accessions and to provide a resource to analyze other Vanilla collections. A V. planifolia draft genome was assembled and used to identify 521,732 single nucleotide polymorphism (SNP) markers using Genotyping-By-Sequencing (GBS). The draft genome had a size of 2.20 Gb representing 97% of the estimated genome size. A filtered set of 5,082 SNPs was used to genotype a living collection of 112 Vanilla accessions from 23 species including native Florida species. Principal component analysis of the genetic distances, population structure, and the maternally inherited rbcL gene identified putative hybrids, misidentified accessions, significant diversity within V. planifolia, and evidence for 12 clusters that separate accessions by species. These results validate the efficiency of genomics-based tools to characterize and identify genetic diversity in Vanilla and provide a significant tool for genomics-assisted plant breeding.
- Identification, characterization, and gene expression analysis of nucleotide binding site (NB)-type resistance gene homologues in switchgrassFrazier, Taylor P.; Palmer, Nathan A.; Xie, Fuliang; Tobias, Christian M.; Donze-Reiner, Teresa J.; Bombarely, Aureliano; Childs, Kevin L.; Shu, Shengqiang; Jenkins, Jerry W.; Schmutz, Jeremy; Zhang, Baohong; Sarath, Gautam; Zhao, Bingyu Y. (2016-11-08)BACKGROUND: Switchgrass (Panicum virgatum L.) is a warm-season perennial grass that can be used as a second generation bioenergy crop. However, foliar fungal pathogens, like switchgrass rust, have the potential to significantly reduce switchgrass biomass yield. Despite its importance as a prominent bioenergy crop, a genome-wide comprehensive analysis of NB-LRR disease resistance genes has yet to be performed in switchgrass. RESULTS: In this study, we used a homology-based computational approach to identify 1011 potential NB-LRR resistance gene homologs (RGHs) in the switchgrass genome (v 1.1). In addition, we identified 40 RGHs that potentially contain unique domains including major sperm protein domain, jacalin-like binding domain, calmodulin-like binding, and thioredoxin. RNA-sequencing analysis of leaf tissue from 'Alamo', a rust-resistant switchgrass cultivar, and 'Dacotah', a rust-susceptible switchgrass cultivar, identified 2634 high quality variants in the RGHs between the two cultivars. RNA-sequencing data from field-grown cultivar 'Summer' plants indicated that the expression of some of these RGHs was developmentally regulated. CONCLUSIONS: Our results provide useful insight into the molecular structure, distribution, and expression patterns of members of the NB-LRR gene family in switchgrass. These results also provide a foundation for future work aimed at elucidating the molecular mechanisms underlying disease resistance in this important bioenergy crop.
- K-seq, an affordable, reliable, and open Klenow NGS-based genotyping technologyZiarsolo, Peio; Hasing, Tomas; Hilario, Rebeca; Garcia-Carpintero, Victor; Blanca, Jose; Bombarely, Aureliano; Cañizares, Joaquin (2021-03-25)Background K-seq, a new genotyping methodology based on the amplification of genomic regions using two steps of Klenow amplification with short oligonucleotides, followed by standard PCR and Illumina sequencing, is presented. The protocol was accompanied by software developed to aid with primer set design. Results As the first examples, K-seq in species as diverse as tomato, dog and wheat was developed. K-seq provided genetic distances similar to those based on WGS in dogs. Experiments comparing K-seq and GBS in tomato showed similar genetic results, although K-seq had the advantage of finding more SNPs for the same number of Illumina reads. The technology reproducibility was tested with two independent runs of the tomato samples, and the correlation coefficient of the SNP coverages between samples was 0.8 and the genotype match was above 94%. K-seq also proved to be useful in polyploid species. The wheat samples generated specific markers for all subgenomes, and the SNPs generated from the diploid ancestors were located in the expected subgenome with accuracies greater than 80%. Conclusion K-seq is an open, patent-unencumbered, easy-to-set-up, cost-effective and reliable technology ready to be used by any molecular biology laboratory without special equipment in many genetic studies.
- Modifying Anthocyanins Biosynthesis in Tomato Hairy Roots: A Test Bed for Plant Resistance to Ionizing Radiation and Antioxidant Properties in SpaceMassa, Silvia; Pagliarello, Riccardo; Cemmi, Alessia; Di Sarcina, Ilaria; Bombarely, Aureliano; Demurtas, Olivia Costantina; Diretto, Gianfranco; Paolini, Francesca; Petzold, H. Earl; Bliek, Mattijs; Bennici, Elisabetta; Del Fiore, Antonella; De Rossi, Patrizia; Spelt, Cornelis; Koes, Ronald; Quattrocchio, Francesca; Benvenuto, Eugenio (Frontiers, 2022-02-24)Gene expression manipulation of specific metabolic pathways can be used to obtain bioaccumulation of valuable molecules and desired quality traits in plants. A single-gene approach to impact different traits would be greatly desirable in agrospace applications, where several aspects of plant physiology can be affected, influencing growth. In this work, MicroTom hairy root cultures expressing a MYB-like transcription factor that regulates the biosynthesis of anthocyanins in Petunia hybrida (PhAN4), were considered as a testbed for bio-fortified tomato whole plants aimed at agrospace applications. Ectopic expression of PhAN4 promoted biosynthesis of anthocyanins, allowing to profile 5 major derivatives of delphinidin and petunidin together with pelargonidin and malvidin-based anthocyanins, unusual in tomato. Consistent with PhAN4 features, transcriptomic profiling indicated upregulation of genes correlated to anthocyanin biosynthesis. Interestingly, a transcriptome reprogramming oriented to positive regulation of cell response to biotic, abiotic, and redox stimuli was evidenced. PhAN4 hairy root cultures showed the significant capability to counteract reactive oxygen species (ROS) accumulation and protein misfolding upon high-dose gamma irradiation, which is among the most potent pro-oxidant stress that can be encountered in space. These results may have significance in the engineering of whole tomato plants that can benefit space agriculture.
- Natural variation in stress response gene activity in the allopolyploid Arabidopsis suecicaCarlson, Keisha D.; Fernandez-Pozo, Noe; Bombarely, Aureliano; Pisupati, Rahul; Mueller, Lukas A.; Madlung, Andreas (2017-08-23)Background Allopolyploids contain genomes composed of more than two complete sets of chromosomes that originate from at least two species. Allopolyploidy has been suggested as an important evolutionary mechanism that can lead to instant speciation. Arabidopsis suecica is a relatively recent allopolyploid species, suggesting that its natural accessions might be genetically very similar to each other. Nonetheless, subtle phenotypic differences have been described between different geographic accessions of A. suecica grown in a common garden. Results To determine the degree of genomic similarity between different populations of A. suecica, we obtained transcriptomic sequence, quantified SNP variation within the gene space, and analyzed gene expression levels genome-wide from leaf material grown in controlled lab conditions. Despite their origin from the same progenitor species, the two accessions of A. suecica used in our study show genomic and transcriptomic variation. We report significant gene expression differences between the accessions, mostly in genes with stress-related functions. Among the differentially expressed genes, there are a surprising number of homoeologs coordinately regulated between sister accessions. Conclusions Many of these homoeologous genes and other differentially expressed genes affect transpiration and stomatal regulation, suggesting that they might be involved in the establishment of the phenotypic differences between the two accessions.
- De novo assembly and functional annotation of Myrciaria dubia fruit transcriptome reveals multiple metabolic pathways for L-ascorbic acid biosynthesisCastro, Juan C.; Maddox, J. D.; Cobos, Marianela; Requena, David; Zimic, Mirko; Bombarely, Aureliano; Imán, Sixto A.; Cerdeira, Luis A.; Medina, Andersson E. (2015-11-24)Background Myrciaria dubia is an Amazonian fruit shrub that produces numerous bioactive phytochemicals, but is best known by its high L-ascorbic acid (AsA) content in fruits. Pronounced variation in AsA content has been observed both within and among individuals, but the genetic factors responsible for this variation are largely unknown. The goals of this research, therefore, were to assemble, characterize, and annotate the fruit transcriptome of M. dubia in order to reconstruct metabolic pathways and determine if multiple pathways contribute to AsA biosynthesis. Results In total 24,551,882 high-quality sequence reads were de novo assembled into 70,048 unigenes (mean length = 1150 bp, N50 = 1775 bp). Assembled sequences were annotated using BLASTX against public databases such as TAIR, GR-protein, FB, MGI, RGD, ZFIN, SGN, WB, TIGR_CMR, and JCVI-CMR with 75.2 % of unigenes having annotations. Of the three core GO annotation categories, biological processes comprised 53.6 % of the total assigned annotations, whereas cellular components and molecular functions comprised 23.3 and 23.1 %, respectively. Based on the KEGG pathway assignment of the functionally annotated transcripts, five metabolic pathways for AsA biosynthesis were identified: animal-like pathway, myo-inositol pathway, L-gulose pathway, D-mannose/L-galactose pathway, and uronic acid pathway. All transcripts coding enzymes involved in the ascorbate-glutathione cycle were also identified. Finally, we used the assembly to identified 6314 genic microsatellites and 23,481 high quality SNPs. Conclusions This study describes the first next-generation sequencing effort and transcriptome annotation of a non-model Amazonian plant that is relevant for AsA production and other bioactive phytochemicals. Genes encoding key enzymes were successfully identified and metabolic pathways involved in biosynthesis of AsA, anthocyanins, and other metabolic pathways have been reconstructed. The identification of these genes and pathways is in agreement with the empirically observed capability of M. dubia to synthesize and accumulate AsA and other important molecules, and adds to our current knowledge of the molecular biology and biochemistry of their production in plants. By providing insights into the mechanisms underpinning these metabolic processes, these results can be used to direct efforts to genetically manipulate this organism in order to enhance the production of these bioactive phytochemicals. The accumulation of AsA precursor and discovery of genes associated with their biosynthesis and metabolism in M. dubia is intriguing and worthy of further investigation. The sequences and pathways produced here present the genetic framework required for further studies. Quantitative transcriptomics in concert with studies of the genome, proteome, and metabolome under conditions that stimulate production and accumulation of AsA and their precursors are needed to provide a more comprehensive view of how these pathways for AsA metabolism are regulated and linked in this species.
- Organelle_PBA, a pipeline for assembling chloroplast and mitochondrial genomes from PacBio DNA sequencing dataSoorni, Aboozar; Haak, David C.; Zaitlin, David; Bombarely, Aureliano (Biomed Central, 2017-01-07)Background The development of long-read sequencing technologies, such as single-molecule real-time (SMRT) sequencing by PacBio, has produced a revolution in the sequencing of small genomes. Sequencing organelle genomes using PacBio long-read data is a cost effective, straightforward approach. Nevertheless, the availability of simple-to-use software to perform the assembly from raw reads is limited at present. Results We present Organelle-PBA, a Perl program designed specifically for the assembly of chloroplast and mitochondrial genomes. For chloroplast genomes, the program selects the chloroplast reads from a whole genome sequencing pool, maps the reads to a reference sequence from a closely related species, and then performs read correction and de novo assembly using Sprai. Organelle-PBA completes the assembly process with the additional step of scaffolding by SSPACE-LongRead. The program then detects the chloroplast inverted repeats and reassembles and re-orients the assembly based on the organelle origin of the reference. We have evaluated the performance of the software using PacBio reads from different species, read coverage, and reference genomes. Finally, we present the assembly of two novel chloroplast genomes from the species Picea glauca (Pinaceae) and Sinningia speciosa (Gesneriaceae). Conclusion Organelle-PBA is an easy-to-use Perl-based software pipeline that was written specifically to assemble mitochondrial and chloroplast genomes from whole genome PacBio reads. The program is available at https://github.com/aubombarely/Organelle_PBA
- Pangenomic analysis identifies structural variation associated with heat tolerance in pearl milletYan, Haidong; Sun, Min; Zhang, Zhongren; Jin, Yarong; Zhang, Ailing; Lin, Chuang; Wu, Bingchao; He, Min; Xu, Bin; Wang, Jing; Qin, Peng; Mendieta, John Pablo; Nie, Gang; Wang, Jianping; Jones, Chris S. S.; Feng, Guangyan; Srivastava, Rakesh K. K.; Zhang, Xinquan; Bombarely, Aureliano; Luo, Dan; Jin, Long; Peng, Yuanying; Wang, Xiaoshan; Ji, Yang; Tian, Shilin; Huang, Linkai (Nature Portfolio, 2023-03)Pearl millet is an important cereal crop worldwide and shows superior heat tolerance. Here, we developed a graph-based pan-genome by assembling ten chromosomal genomes with one existing assembly adapted to different climates worldwide and captured 424,085 genomic structural variations (SVs). Comparative genomics and transcriptomics analyses revealed the expansion of the RWP-RK transcription factor family and the involvement of endoplasmic reticulum (ER)-related genes in heat tolerance. The overexpression of one RWP-RK gene led to enhanced plant heat tolerance and transactivated ER-related genes quickly, supporting the important roles of RWP-RK transcription factors and ER system in heat tolerance. Furthermore, we found that some SVs affected the gene expression associated with heat tolerance and SVs surrounding ER-related genes shaped adaptation to heat tolerance during domestication in the population. Our study provides a comprehensive genomic resource revealing insights into heat tolerance and laying a foundation for generating more robust crops under the changing climate. A graph-based pan-genome constructed using de novo genome assemblies of ten pearl millet accessions adapted to different climates worldwide identifies structural variations and their contribution to heat tolerance in pearl millet.
- A reference genome for Nicotiana tabacum enables map-based cloning of homeologous loci implicated in nitrogen utilization efficiencyEdwards, Kieron D.; Fernandez-Pozo, Noe; Drake-Stowe, Katherine; Humphry, Matthew Edward; Evans, Andy D.; Bombarely, Aureliano; Allen, Fraser; Hurst, R.; White, B.; Kernodle, Sheri P.; Bromley, Jennifer R.; Sanchez-Tamburrino, Juan Pablo; Lewis, Ramsey S.; Mueller, Lukas A. (2017-06-19)Background Tobacco (Nicotiana tabacum) is an important plant model system that has played a key role in the early development of molecular plant biology. The tobacco genome is large and its characterisation challenging because it is an allotetraploid, likely arising from hybridisation between diploid N. sylvestris and N. tomentosiformis ancestors. A draft assembly was recently published for N. tabacum, but because of the aforementioned genome complexities it was of limited utility due to a high level of fragmentation. Results Here we report an improved tobacco genome assembly, which, aided by the application of optical mapping, achieves an N50 size of 2.17 Mb and enables anchoring of 64% of the genome to pseudomolecules; a significant increase from the previous value of 19%. We use this assembly to identify two homeologous genes that explain the differentiation of the burley tobacco market class, with potential for greater understanding of Nitrogen Utilization Efficiency and Nitrogen Use Efficiency in plants; an important trait for future sustainability of agricultural production. Conclusions Development of an improved genome assembly for N. tabacum enables what we believe to be the first successful map-based gene discovery for the species, and demonstrates the value of an improved assembly for future research in this model and commercially-important species.
- siRNAs regulate DNA methylation and interfere with gene and lncRNA expression in the heterozygous polyploid switchgrassYan, Haidong; Bombarely, Aureliano; Xu, Bin; Frazier, Taylor P.; Wang, Chengran; Chen, Peilin; Chen, Jing; Hasing, Tomas; Cui, Chenming; Zhang, Xinquan; Zhao, Bingyu Y.; Huang, Linkai (2018-07-24)Background Understanding the DNA methylome and its relationship with non-coding RNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), is essential for elucidating the molecular mechanisms underlying key biological processes in plants. Few studies have examined the functional roles of the DNA methylome in grass species with highly heterozygous polyploid genomes. Results We performed genome-wide DNA methylation profiling in the tetraploid switchgrass (Panicum virgatum L.) cultivar ‘Alamo’ using bisulfite sequencing. Single-base-resolution methylation patterns were observed in switchgrass leaf and root tissues, which allowed for characterization of the relationship between DNA methylation and mRNA, miRNA, and lncRNA populations. The results of this study revealed that siRNAs positively regulate DNA methylation of the mCHH sites surrounding genes, and that DNA methylation interferes with gene and lncRNA expression in switchgrass. Ninety-six genes covered by differentially methylated regions (DMRs) were annotated by GO analysis as being involved in stimulus-related processes. Functionally, 82% (79/96) of these genes were found to be hypomethylated in switchgrass root tissue. Sequencing analysis of lncRNAs identified two lncRNAs that are potential precursors of miRNAs, which are predicted to target genes that function in cellulose biosynthesis, stress regulation, and stem and root development. Conclusions This study characterized the DNA methylome in switchgrass and elucidated its relevance to gene and non-coding RNAs. These results provide valuable genomic resources and references that will aid further epigenetic research in this important biofuel crop.
- The Sol Genomics Network (SGN)-from genotype to phenotype to breedingFernandez-Pozo, Noe; Menda, Naama; Edwards, Jeremy D.; Saha, Surya; Tecle, Isaak Y.; Strickler, Susan R.; Bombarely, Aureliano; Fisher-York, Thomas; Pujar, Anuradha; Foerster, Hartmut; Yan, Aimin; Mueller, Lukas A. (2015-01-28)The Sol Genomics Network (SGN, http://solgenomics.net) is a web portal with genomic and phenotypic data, and analysis tools for the Solanaceae family and close relatives. SGN hosts whole genome data for an increasing number of Solanaceae family members including tomato, potato, pepper, eggplant, tobacco and Nicotiana benthamiana. The database also stores loci and phenotype data, which researchers can upload and edit with user-friendly web interfaces. Tools such as BLAST, GBrowse and JBrowse for browsing genomes, expression and map data viewers, a locus community annotation system and a QTL analysis tools are available. A new tool was recently implemented to improve Virus-Induced Gene Silencing (VIGS) constructs called the SGN VIGS tool. With the growing genomic and phenotypic data in the database, SGN is now advancing to develop new web-based breeding tools and implement the code and database structure for other species or clade-specific databases.
- The ‘Tommy Atkins’ mango genome reveals candidate genes for fruit qualityBally, Ian S. E.; Bombarely, Aureliano; Chambers, Alan H.; Cohen, Yuval; Dillon, Natalie L.; Innes, David J.; Islas-Osuna, María A.; Kuhn, David N.; Mueller, Lukas A.; Ophir, Ron; Rambani, Aditi; Sherman, Amir; Yan, Haidong (2021-02-22)Background Mango, Mangifera indica L., an important tropical fruit crop, is grown for its sweet and aromatic fruits. Past improvement of this species has predominantly relied on chance seedlings derived from over 1000 cultivars in the Indian sub-continent with a large variation for fruit size, yield, biotic and abiotic stress resistance, and fruit quality among other traits. Historically, mango has been an orphan crop with very limited molecular information. Only recently have molecular and genomics-based analyses enabled the creation of linkage maps, transcriptomes, and diversity analysis of large collections. Additionally, the combined analysis of genomic and phenotypic information is poised to improve mango breeding efficiency. Results This study sequenced, de novo assembled, analyzed, and annotated the genome of the monoembryonic mango cultivar ‘Tommy Atkins’. The draft genome sequence was generated using NRGene de-novo Magic on high molecular weight DNA of ‘Tommy Atkins’, supplemented by 10X Genomics long read sequencing to improve the initial assembly. A hybrid population between ‘Tommy Atkins’ x ‘Kensington Pride’ was used to generate phased haplotype chromosomes and a highly resolved phased SNP map. The final ‘Tommy Atkins’ genome assembly was a consensus sequence that included 20 pseudomolecules representing the 20 chromosomes of mango and included ~ 86% of the ~ 439 Mb haploid mango genome. Skim sequencing identified ~ 3.3 M SNPs using the ‘Tommy Atkins’ x ‘Kensington Pride’ mapping population. Repeat masking identified 26,616 genes with a median length of 3348 bp. A whole genome duplication analysis revealed an ancestral 65 MYA polyploidization event shared with Anacardium occidentale. Two regions, one on LG4 and one on LG7 containing 28 candidate genes, were associated with the commercially important fruit size characteristic in the mapping population. Conclusions The availability of the complete ‘Tommy Atkins’ mango genome will aid global initiatives to study mango genetics.
- Whole-Genome Resequencing of Seven Eggplant (Solanum melongena) and One Wild Relative (S. incanum) Accessions Provides New Insights and Breeding Tools for Eggplant EnhancementGramazio, Pietro; Yan, Haidong; Hasing, Tomas; Vilanova, Santiago; Prohens, Jaime; Bombarely, Aureliano (2019-10-08)Whole-genome resequencing provides information of great relevance for crop genetics, evolution, and breeding. Here, we present the first whole-genome resequencing study using seven eggplant (Solanum melongena) and one wild relative (Solanum incanum) accessions. These eight accessions were selected for displaying a high phenotypic and genetic diversity and for being the founder parents of an eggplant multiparent advanced generation intercrosses population. By resequencing at an average depth of 19.8x and comparing to the high-quality reference genome "67/3" over 10 million high-reliable polymorphisms were discovered, of which over 9 million (84.5%) were single nucleotide polymorphisms and more than 700,000 (6.5%) InDels. However, while for the S. melongena accessions, the variants identified ranged from 0.8 to 1.3 million, over 9 million were detected for the wild S. incanum. This confirms the narrow genetic diversity of the domesticated eggplant and suggests that introgression breeding using wild relatives can efficiently contribute to broadening the genetic basis of this crop. Differences were observed among accessions for the enrichment in genes regulating important biological processes. By analyzing the distribution of the variants, we identified the potential footprints of old introgressions from wild relatives that can help to unravel the unclear domestication and breeding history. The comprehensive annotation of these eight genomes and the information provided in this study represents a landmark in eggplant genomics and allows the development of tools for eggplant genetics and breeding.