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Joyce Van Eck - One of the best experts on this subject based on the ideXlab platform.

  • Setaria viridis chlorotic and seedling lethal mutants define critical functions for chloroplast gene expression
    Plant Journal, 2020
    Co-Authors: Leila Feiz, Susan R Strickler, Joyce Van Eck, Linyong Mao, Navid Movahed, Caroline Taylor, Poornima Gourabathini
    Abstract:

    Deep insights into chloroplast biogenesis have been obtained by mutant analysis; however, in C4 plants a relevant mutant collection has only been developed and exploited for maize. Here, we report the initial characterization of an ethyl methyl sulfonate-induced mutant population for the C4 model Setaria viridis. Approximately 1000 M2 families were screened for the segregation of pale-green seedlings in the M3 generation, and a subset of these was identified to be deficient in post-transcriptional steps of chloroplast gene expression. Causative mutations were identified for three lines using deep sequencing-based bulked segregant analysis, and in one case confirmed by transgenic complementation. Using chloroplast RNA-sequencing and other molecular assays, we describe phenotypes of mutants deficient in PSRP7, a plastid-specific ribosomal protein, OTP86, an RNA editing factor, and cpPNP, the chloroplast isozyme of polynucleotide phosphorylase. The psrp mutant is globally defective in chloroplast translation, and has varying deficiencies in the accumulation of chloroplast-encoded proteins. The otp86 mutant, like its Arabidopsis counterpart, is specifically defective in editing of the rps14 mRNA; however, the conditional pale-green mutant phenotype contrasts with the normal growth of the Arabidopsis mutant. The pnp mutant exhibited multiple defects in 3' end maturation as well as other qualitative changes in the chloroplast RNA population. Overall, our collection opens the door to global analysis of photosynthesis and early seedling development in an emerging C4 model.

  • Robust and Reproducible Agrobacterium-Mediated Transformation System of the C4 Genetic Model Species Setaria viridis.
    Frontiers in plant science, 2020
    Co-Authors: Duc Quan Nguyen, Joyce Van Eck, Andrew L. Eamens, Christopher P. L. Grof
    Abstract:

    Setaria viridis (green foxtail) has been identified as a potential experimental model system to genetically and molecularly characterise the C4 monocotyledonous grasses due to its small physical size, short generation time and prolific seed production, together with a sequenced and annotated genome. Setaria viridis is the wild ancestor of the cropping species, foxtail millet (Setaria italica), with both Setaria species sharing a close evolutionary relationship with the agronomically important species, maize, sorghum, and sugarcane, as well as the bioenergy feedstocks, switchgrass, and Miscanthus. However, an efficient and reproducible transformation protocol is required to further advance the use of S. viridis to study the molecular genetics of C4 monocotyledonous grasses. An efficient and reproducible protocol was established for Agrobacterium tumefaciens-mediated transformation of S. viridis (Accession A10) regenerable callus material derived from mature seeds, a protocol that returned an average transformation efficiency of 6.3%. The efficiency of this protocol was the result of the: (i) use of mature embryo derived callus material; (ii) age of the seed used to induce callus formation; (iii) composition of the callus induction media, including the addition of the ethylene inhibitor, silver nitrate; (iv) use of a co-cultivation approach, and; (v) concentration of the selective agent. Our protocol furthers the use of S. viridis as an experimental model system to study the molecular genetics of C4 monocotyledonous grasses for the potential future development of improved C4 cropping species.

  • The Status of Setaria viridis Transformation: Agrobacterium-Mediated to Floral Dip.
    Frontiers in plant science, 2018
    Co-Authors: Joyce Van Eck
    Abstract:

    Setaria viridis has many attributes, including small stature and simple growth requirements, that make it attractive as a model species for monocots. Genetic engineering (transformation) methodology is a key prerequisite for adoption of plant species as models. Various transformation approaches have been reported for S. viridis including tissue culture-based and in planta by Agrobacterium tumefaciens infection of floral organs referred to as the floral dip method. The tissue culture-based method utilizes A. tumefaciens infection of mature seed-derived callus with subsequent recovery of stable transgenic lines. Vectors found to be most effective contain the hygromycin phosphotransferase selectable marker gene driven by either Panicum virgatum or Zea mays ubiquitin promoters. As for the floral dip method, there are two reports based on Agrobacterium infection of young S. viridis inflorescences. Plants were allowed to mature, seeds were collected, and analysis of the progeny verified the presence of transgenes. Each transformation approach, tissue culture-based and floral dip, has advantages and disadvantages depending on the expertise of personnel and resources available. While the tissue culture-based method results in a higher transformation efficiency than floral dip, implementation requires a specific technical skillset that limits availability of experienced personnel to successfully perform transformations. Less technical experience is required for floral dip; however, a lack of high-quality growth chambers or greenhouses that provide the necessary optimum growing conditions would reduce an already low transformation efficiency or would not result in recovery of transgenic lines. An overview of transformation methods reported for S. viridis is presented in this review.

  • the status of Setaria viridis transformation agrobacterium mediated to floral dip
    Frontiers in Plant Science, 2018
    Co-Authors: Joyce Van Eck
    Abstract:

    Setaria viridis has many attributes, including small stature and simple growth requirements, that make it attractive as a model species for monocots. Genetic engineering (transformation) methodology is a key prerequisite for adoption of plant species as models. Various transformation approaches have been reported for S. viridis including tissue culture-based and in planta by Agrobacterium tumefaciens infection of floral organs referred to as the floral dip method. The tissue culture-based method utilizes A. tumefaciens infection of mature seed-derived callus with subsequent recovery of stable transgenic lines. Vectors found to be most effective contain the hygromycin phosphotransferase selectable marker gene driven by either Panicum virgatum or Zea mays ubiquitin promoters. As for the floral dip method, there are two reports based on Agrobacterium infection of young S. viridis inflorescences. Plants were allowed to mature, seeds were collected, and analysis of the progeny verified the presence of transgenes. Each transformation approach, tissue culture based and floral dip, has advantages and disadvantages depending on the expertise of personnel and resources available. While the tissue culture-based method results in a higher transformation efficiency than floral dip, implementation requires a specific technical skillset that limits availability of experienced personnel to successfully perform transformations. Less technical experience is required for floral dip, however, a lack of high quality growth chambers or greenhouses that provide the necessary optimum growing conditions would reduce an already low transformation efficiency or would not result in recovery of transgenic lines. An overview of transformation methods reported for S. viridis are presented in this review.

  • agrobacterium tumefaciens mediated transformation of Setaria viridis
    2017
    Co-Authors: Joyce Van Eck, Kerry Swartwood, Kaitlin Pidgeon, Kimberly Maxsonstein
    Abstract:

    Gene transfer methodology, often referred to as transformation, is an important component of a model system research platform. Availability of transformation methods markedly expand the application of a model. We chose to develop an Agrobacterium tumefaciens-mediated gene transfer method for Setaria viridis A10.1. Regenerable callus was recovered from mature seeds without seed coats that were disinfected and cultured on a Murashige and Skoog-based medium supplemented with 40 g/L maltose, 2 mg/L 2,4-dichlorophenoxyacetic acid, 0.5 mg/L kinetin, and 4 g/L Gelzan. The gelling agents Gelzan and Phytagel were found to be critical for recovery of a high quality callus as compared to agar that resulted in a gelatinous, brown, non-regenerable callus. For transformation, the callus was infected with the A. tumefaciens strain AGL1 that contained binary vectors with the hygromycin phosphotransferase selectable marker gene, which confers resistance to the antibiotic hygromycin. The transformation efficiency, which is defined as the percent of infected callus that gives rise to at least one independent transgenic line ranged from 0.3 to 15 % depending upon the vector backbone used to design constructs and the gene of interest that was either overexpressed or had a knockdown of expression. Transgenic lines were first verified by PCR, then positive plants were moved forward for copy number determination by either Southern or TaqMan® analysis. On average, 42 % of the transgenic lines contained one copy of the introduced transgene. Availability of a transformation methodology has contributed to the adoption of S. viridis as a model species by researchers worldwide.

Elizabeth A. Kellogg - One of the best experts on this subject based on the ideXlab platform.

  • The CLV3 Homolog in Setaria viridis Selectively Controls Inflorescence Meristem Size.
    Frontiers in plant science, 2021
    Co-Authors: Chuanmei Zhu, Thomas P Brutnell, David Jackson, Lei Liu, Olivia Crowell, Hui Zhao, Elizabeth A. Kellogg
    Abstract:

    The CLAVATA pathway controls meristem size during inflorescence development in both eudicots and grasses, and is initiated by peptide ligands encoded by CLV3/ESR-related (CLE) genes. While CLV3 controls all shoot meristems in Arabidopsis, evidence from cereal grasses indicates that different meristem types are regulated by different CLE peptides. The rice peptide FON2 primarily controls the size of the floral meristem, whereas the orthologous peptides CLE7 and CLE14 in maize have their most dramatic effects on inflorescence and branch meristems, hinting at diversification among CLE responses in the grasses. Setaria viridis is more closely related to maize than to rice, so can be used to test whether the maize CLE network can be generalized to all members of subfamily Panicoideae. We used CRISPR-Cas9 in S. viridis to knock out the SvFON2 gene, the closest homolog to CLV3 and FON2. Svfon2 mutants developed larger inflorescence meristems, as in maize, but had normal floral meristems, unlike Osfon2, suggesting a panicoid-specific CLE network. Vegetative traits such as plant height, tiller number and leaf number were not significantly different between mutant and wild type plants, but time to heading was shorter in the mutants. In situ hybridization showed strong expression of Svfon2 in the inflorescence and branch meristems, consistent with the mutant phenotype. Using bioinformatic analysis, we predicted the co-expression network of SvFON2 and its signaling components, which included genes known to control inflorescence architecture in maize as well as genes of unknown function. The similarity between SvFON2 function in Setaria and maize suggests that its developmental specialization in inflorescence meristem control may be shared among panicoid grasses.

  • Sparse panicle1 is required for inflorescence development in Setaria viridis and maize.
    Nature plants, 2017
    Co-Authors: Pu Huang, Elizabeth A. Kellogg, Chuanmei Zhu, Jerry Jenkins, Kerrie Barry, Hui Jiang, Laura Sandor, Jeremy Schmutz, Mathew S. Box, Thomas P Brutnell
    Abstract:

    Setaria viridis is a rapid-life-cycle model panicoid grass. To identify genes that may contribute to inflorescence architecture and thus have the potential to influence grain yield in related crops such as maize, we conducted an N-nitroso-N-methylurea (NMU) mutagenesis of S. viridis and screened for visible inflorescence mutant phenotypes. Of the approximately 2,700 M2 families screened, we identified four recessive sparse panicle mutants (spp1-spp4) characterized by reduced and uneven branching of the inflorescence. To identify the gene underlying the sparse panicle1 (spp1) phenotype, we performed bulked segregant analysis and deep sequencing to fine map it to an approximately 1 Mb interval. Within this interval, we identified disruptive mutations in two genes. Complementation tests between spp1 and spp3 revealed they were allelic, and deep sequencing of spp3 identified an independent disruptive mutation in SvAUX1 (AUXIN1), one of the two genes in the ∼1 Mb interval and the only gene disruption shared between spp1 and spp3. SvAUX1 was found to affect both inflorescence development and root gravitropism in S. viridis. A search for orthologous mutant alleles in maize confirmed a very similar role of ZmAUX1 in maize, which highlights the utility of S. viridis in accelerating functional genomic studies in maize.

  • Abscission zone development in Setaria viridis and its domesticated relative, Setaria italica
    American journal of botany, 2016
    Co-Authors: John G Hodge, Elizabeth A. Kellogg
    Abstract:

    Premise of the study Development of an abscission zone (AZ) is needed for dispersal of seeds, and AZ loss was a critical early step in plant domestication. The AZ forms in different tissues in different species of plants, but whether the AZ is developmentally similar wherever it occurs is unknown. AZ development in Setaria viridis was studied as a representative of the previously uncharacterized subfamily Panicoideae. Methods One accession of the wild species S. viridis and two of its domesticate, S. italica, were studied. Strength of the AZ was measured with a force gauge. Anatomy of the AZ was studied throughout development using bright field and confocal microscopy. Key results The force required to remove a spikelet of S. viridis from the parent plant dropped steadily during development, whereas that required to remove spikelets of S. italica increased initially before stabilizing at a high level. Despite the clear difference in tensile strength of the AZ, anatomical differences between S. viridis and S. italica were subtle, and the position of the AZ was not easy to determine in cross sections of pedicel apices. Staining with DAPI showed that nuclei were present up to and presumably through abscission in S. viridis, and acridine orange staining showed much less lignification than in other cereals. Conclusions The AZ in Setaria is developmentally and anatomically different from that characterized in rice, barley, and many eudicots. In particular, no set of small, densely cytoplasmic cells is obvious. This difference in anatomy could point to differential genetic control of the structure.

  • population genetics of Setaria viridis a new model system
    Molecular Ecology, 2014
    Co-Authors: Pu Huang, Xianmin Diao, Maximilian Feldman, Stephan Schröder, Bochra A. Bahri, Hui Zhi, Matt C. Estep, Ivan Baxter, Katrien M. Devos, Elizabeth A. Kellogg
    Abstract:

    An extensive survey of the standing genetic variation in natural populations is among the priority steps in developing a species into a model system. In recent years, green fox-tail (Setaria viridis), along with its domesticated form foxtail millet (S. italica), has rapidly become a promising new model system for C4 grasses and bioenergy crops, due to its rapid life cycle, large amount of seed production and small diploid genome, among other characters. However, remarkably little is known about the genetic diversity in natural populations of this species. In this study, we survey the genetic diversity of a worldwide sample of more than 200 S. viridis accessions, using the genotyping-by-sequencing tech-nique. Two distinct genetic groups in S. viridis and a third group resembling S. italica were identified, with considerable admixture among the three groups. We find the genetic variation of North American S. viridis correlates with both geography and climate and is representative of the total genetic diversity in this species. This pattern may reflect several introduction/dispersal events of S. viridis into North America. We also modelled demo-graphic history and show signal of recent population decline in one subgroup. Finally, we show linkage disequilibrium decay is rapid (<45 kb) in our total sample and slow in genetic subgroups. These results together provide an in-depth understanding of the pat-tern of genetic diversity of this new model species on a broad geographic scale. They also provide key guidelines for on-going and future work including germplasm preservation, local adaptation, crossing designs and genomewide association studies.

  • Population Genetics Of Setaria viridis, A New Model System
    Molecular ecology, 2014
    Co-Authors: Pu Huang, Xianmin Diao, Maximilian Feldman, Stephan Schröder, Bochra A. Bahri, Hui Zhi, Matt C. Estep, Ivan Baxter, Katrien M. Devos, Elizabeth A. Kellogg
    Abstract:

    An extensive survey of the standing genetic variation in natural populations is among the priority steps in developing a species into a model system. In recent years, green fox-tail (Setaria viridis), along with its domesticated form foxtail millet (S. italica), has rapidly become a promising new model system for C4 grasses and bioenergy crops, due to its rapid life cycle, large amount of seed production and small diploid genome, among other characters. However, remarkably little is known about the genetic diversity in natural populations of this species. In this study, we survey the genetic diversity of a worldwide sample of more than 200 S. viridis accessions, using the genotyping-by-sequencing tech-nique. Two distinct genetic groups in S. viridis and a third group resembling S. italica were identified, with considerable admixture among the three groups. We find the genetic variation of North American S. viridis correlates with both geography and climate and is representative of the total genetic diversity in this species. This pattern may reflect several introduction/dispersal events of S. viridis into North America. We also modelled demo-graphic history and show signal of recent population decline in one subgroup. Finally, we show linkage disequilibrium decay is rapid (

Christopher P. L. Grof - One of the best experts on this subject based on the ideXlab platform.

  • Profiling of the Salt Stress Responsive MicroRNA Landscape of C4 Genetic Model Species Setaria viridis (L.) Beauv
    Agronomy, 2020
    Co-Authors: Joseph L. Pegler, Duc Quan Nguyen, Christopher P. L. Grof, Andrew L. Eamens
    Abstract:

    Setaria viridis has recently emerged as an ideal model species to genetically characterize the C4 monocotyledonous grasses via a molecular modification approach. Soil salinization has become a compelling agricultural problem globally with salinity adversely impacting the yield potential of many of the major cereals. Small regulatory molecules of RNA, termed microRNAs (miRNAs), were originally demonstrated crucial for developmental gene expression regulation in plants, however, miRNAs have since been shown to additionally command a central regulatory role in abiotic stress adaptation. Therefore, a small RNA sequencing approach was employed to profile the salt stress responsive miRNA landscapes of the shoot and root tissues of two Setaria viridis accessions (A10 and ME034V) amenable to molecular modification. Small RNA sequencing-identified abundance alterations for miRNAs, miR169, miR395, miR396, miR397, miR398 and miR408, were experimentally validated via RT-qPCR. RT-qPCR was further applied to profile the molecular response of the miR160 and miR167 regulatory modules to salt stress. This analysis revealed accession- and tissue-specific responses for the miR160 and miR167 regulatory modules in A10 and ME034V shoot and root tissues exposed to salt stress. The findings reported here form the first crucial step in the identification of the miRNA regulatory modules to target for molecular manipulation to determine if such modification provides S. viridis with an improved tolerance to salt stress.

  • Robust and Reproducible Agrobacterium-Mediated Transformation System of the C4 Genetic Model Species Setaria viridis.
    Frontiers in plant science, 2020
    Co-Authors: Duc Quan Nguyen, Joyce Van Eck, Andrew L. Eamens, Christopher P. L. Grof
    Abstract:

    Setaria viridis (green foxtail) has been identified as a potential experimental model system to genetically and molecularly characterise the C4 monocotyledonous grasses due to its small physical size, short generation time and prolific seed production, together with a sequenced and annotated genome. Setaria viridis is the wild ancestor of the cropping species, foxtail millet (Setaria italica), with both Setaria species sharing a close evolutionary relationship with the agronomically important species, maize, sorghum, and sugarcane, as well as the bioenergy feedstocks, switchgrass, and Miscanthus. However, an efficient and reproducible transformation protocol is required to further advance the use of S. viridis to study the molecular genetics of C4 monocotyledonous grasses. An efficient and reproducible protocol was established for Agrobacterium tumefaciens-mediated transformation of S. viridis (Accession A10) regenerable callus material derived from mature seeds, a protocol that returned an average transformation efficiency of 6.3%. The efficiency of this protocol was the result of the: (i) use of mature embryo derived callus material; (ii) age of the seed used to induce callus formation; (iii) composition of the callus induction media, including the addition of the ethylene inhibitor, silver nitrate; (iv) use of a co-cultivation approach, and; (v) concentration of the selective agent. Our protocol furthers the use of S. viridis as an experimental model system to study the molecular genetics of C4 monocotyledonous grasses for the potential future development of improved C4 cropping species.

  • Reference gene identification for reliable normalisation of quantitative RT-PCR data in Setaria viridis.
    Plant methods, 2018
    Co-Authors: Duc Quan Nguyen, Andrew L. Eamens, Christopher P. L. Grof
    Abstract:

    Quantitative real-time polymerase chain reaction (RT-qPCR) is the key platform for the quantitative analysis of gene expression in a wide range of experimental systems and conditions. However, the accuracy and reproducibility of gene expression quantification via RT-qPCR is entirely dependent on the identification of reliable reference genes for data normalisation. Green foxtail (Setaria viridis) has recently been proposed as a potential experimental model for the study of C4 photosynthesis and is closely related to many economically important crop species of the Panicoideae subfamily of grasses, including Zea mays (maize), Sorghum bicolor (sorghum) and Sacchurum officinarum (sugarcane). Setaria viridis (Accession 10) possesses a number of key traits as an experimental model, namely; (i) a small sized, sequenced and well annotated genome; (ii) short stature and generation time; (iii) prolific seed production, and; (iv) is amendable to Agrobacterium tumefaciens-mediated transformation. There is currently however, a lack of reference gene expression information for Setaria viridis (S. viridis). We therefore aimed to identify a cohort of suitable S. viridis reference genes for accurate and reliable normalisation of S. viridis RT-qPCR expression data. Eleven putative candidate reference genes were identified and examined across thirteen different S. viridis tissues. Of these, the geNorm and NormFinder analysis software identified SERINE/THERONINE-PROTEIN PHOSPHATASE 2A (PP2A), 5'-ADENYLYLSULFATE REDUCTASE 6 (ASPR6) and DUAL SPECIFICITY PHOSPHATASE (DUSP) as the most suitable combination of reference genes for the accurate and reliable normalisation of S. viridis RT-qPCR expression data. To demonstrate the suitability of the three selected reference genes, PP2A, ASPR6 and DUSP, were used to normalise the expression of CINNAMYL ALCOHOL DEHYDROGENASE (CAD) genes across the same tissues. This approach readily demonstrated the suitably of the three selected reference genes for the accurate and reliable normalisation of S. viridis RT-qPCR expression data. Further, the work reported here forms a highly useful platform for future gene expression quantification in S. viridis and can also be potentially directly translatable to other closely related and agronomically important C4 crop species.

  • MOESM5 of Reference gene identification for reliable normalisation of quantitative RT-PCR data in Setaria viridis
    2018
    Co-Authors: Duc Nguyen, Andrew L. Eamens, Christopher P. L. Grof
    Abstract:

    Additional file 5: Figure S2. Analysis of Setaria viridis CAD gene expression according to the RNA-Seq dataset published in [4]. The transcript abundance of each of the detected members of the S. viridis CAD gene family across the four developmentally distinct zones of the elongating internode, internode 5, according to the dataset published by Martin et al. [4]. Of the six CADs identified from the dataset, the SvCAD2 (Sevir.1G056800) transcript was determined to be the most abundance in internode 5 and further, SvCAD2 returned an expression profile expected of a gene that encodes a protein that plays a functional role in the formation of secondary cell walls, that is; less abundant in young or undifferentiated tissues and with a greatly enhanced abundance in transitioning and/or mature tissues

  • Roles of Aquaporins in Setaria viridis Stem Development and Sugar Storage
    Frontiers in plant science, 2016
    Co-Authors: Samantha A. Mcgaughey, Robert T Furbank, Joseph L. Pegler, Hannah L. Osborn, Lily Chen, Stephen D. Tyerman, Caitlin S. Byrt, Christopher P. L. Grof
    Abstract:

    Setaria viridis is a C4 grass used as a model for bioenergy feedstocks. The elongating internodes in developing S. viridis stems grow from an intercalary meristem at the base, and progress acropetally toward fully expanded cells that store sugar. During stem development and maturation, water flow is a driver of cell expansion and sugar delivery. As aquaporin proteins are implicated in regulating water flow, we analyzed elongating and mature internode transcriptomes to identify putative aquaporin encoding genes that had particularly high transcript levels during the distinct stages of internode cell expansion and maturation. We observed that SvPIP2;1 was highly expressed in internode regions undergoing cell expansion, and SvNIP2;2 was highly expressed in mature sugar accumulating regions. Gene co-expression analysis revealed SvNIP2;2 expression was highly correlated with the expression of five putative sugar transporters expressed in the S. viridis internode. To explore the function of the proteins encoded by SvPIP2;1 and SvNIP2;2, we expressed them in Xenopus laevis oocytes and tested their permeability to water. SvPIP2;1 and SvNIP2;2 functioned as water channels in X. laevis oocytes and their permeability was gated by pH. Our results indicate that SvPIP2;1 may function as a water channel in developing stems undergoing cell expansion and SvNIP2;2 is a candidate for retrieving water and possibly a yet to be determined solute from mature internodes. Future research will investigate whether changing the function of these proteins influences stem growth and sugar yield in S. viridis.

Fernanda Reinert - One of the best experts on this subject based on the ideXlab platform.

  • Physiological and molecular responses of Setaria viridis to osmotic stress.
    Plant physiology and biochemistry : PPB, 2020
    Co-Authors: David Da Cunha Valença, Bianca Ortiz-silva, Marcio Alves-ferreira, Stéfanie Menezes De Moura, João Travassos-lins, Leonardo Oliveira Medici, Andrew Macrae, Fernanda Reinert
    Abstract:

    Drought-tolerant species, such as Setaria viridis, a C4 model plant, make physiological and biochemical adjustments water limitation and recover from the stress upon its release. We investigated S. viridis (A10.1 accession) responses to continuing osmotic stress. The osmotic stress was imposed using polyethylene glycol (PEG) 8000 (7.5%) for 10 days. Morphological traits and stomatal conductance were measured daily for the 10 days. On days 6 and 10, the following traits were measured separately for root and shoot: relative water content (RWC), osmotic potential (OP), electrolytic leakage (EL), and proline content. qPCR analysis was used to evaluate the expression of five selected genes in roots (SvLEA, SvDREB1C, SvPIP2-1, SvHSP20, and SvP5CS2), and chlorophyll a fluorescence was measured on three key days. The morphological data demonstrated a drastic reduction in shoot biomass as an effect of water deficit caused by the osmotic stress. Shoot biomass reduction could be associated with putative ABA-dependent signaling involved in SvDREB1C expression. Stomatal conductance and photosynthesis were severely affected up until day 6, however, stomatal conductance and some photosynthetic parameters such as FV/FM, ABS/RC, and DI0/RC showed total or slight recovery on day 10. Root EL decreased in treated plants suggesting an investment in membrane protection by osmoregulator expression such as dehydrin (SvLEA) and proline (SvP5CS2) genes. Our data suggest that S. viridis exhibited a partial recovery from an imposed and constant osmotic stress within 10 days.

  • Phenology of the genetic model Setaria viridis (Poaceae) according to the BBCH-scale of development
    Botanical Journal of the Linnean Society, 2019
    Co-Authors: Nicia E G Junqueira, Bianca Ortiz-silva, Marcio Alves-ferreira, Leonardo Oliveira Medici, Andrew Macrae, Ana Carolina Mendes Bezerra, Marcus Vinicius Cattem, Fernanda Reinert
    Abstract:

    Abstract Setaria viridis, a genetic model for C4 monocots, has potential to provide information of relevance for plant biotechnology, contributing to an understanding of how genetic engineering can affect phenotype and agricultural production. The BBCH growth scale for the A10.1 accession of S. viridis consists of a detailed phenotypic analysis process, based on defined growth stages. Measurements of morphological attributes complementing the scale were also made, supporting the identification of growth and development stages. Phenotypic stages were grouped into three major stages of development: vegetative (BBCH 0 to 4), reproductive (BBCH 5 to 8) and senescence (BBCH 9). Observation and interpretation of the growth and development data of accessions A10.1 and Ast-1 showed that the former presents phenotypic homogeneity, which makes it suitable for the construction of the BBCH-scale and improves our understanding of the phenology of this model plant. This methodological framework facilitates the comparison of genotypes and phenotypes among natural accessions and future mutants and the study of the evolution of tolerance to abiotic stress.

  • anatomy and ultrastructure of embryonic leaves of the c4 species Setaria viridis
    Annals of Botany, 2018
    Co-Authors: Nicia E G Junqueira, Hugh G. Dickinson, Jane A. Langdale, Bianca Ortizsilva, Marcos Vinicius Lealcosta, Marcio Alvesferreira, Fernanda Reinert
    Abstract:

    Background and Aims Setaria viridis is being promoted as a model C4 photosynthetic plant because it has a small genome (~515 Mb), a short life cycle (~60 d) and it can be transformed. Unlike other C4 grasses such as maize, however, there is very little information about how C4 leaf anatomy (Kranz anatomy) develops in S. viridis. As a foundation for future developmental genetic studies, we provide an anatomical and ultrastructural framework of early shoot development in S. viridis, focusing on the initiation of Kranz anatomy in seed leaves. Methods Setaria viridis seeds were germinated and divided into five stages covering development from the dry seed (stage S0) to 36 h after germination (stage S4). Material at each of these stages was examined using conventional light, scanning and transmission electron microscopy. Key Results Dry seeds contained three embryonic leaf primordia at different developmental stages (plastochron 1-3 primordia). The oldest (P3) leaf primordium possessed several procambial centres whereas P2 displayed only ground meristem. At the tip of P3 primordia at stage S4, C4 leaf anatomy typical of the malate dehydrogenase-dependent nicotinamide dinucleotide phosphate (NADP-ME) subtype was evident in that vascular bundles lacked a mestome layer and were surrounded by a single layer of bundle sheath cells that contained large, centrifugally located chloroplasts. Two to three mesophyll cells separated adjacent vascular bundles and one mesophyll cell layer on each of the abaxial and adaxial sides delimited vascular bundles from the epidermis. Conclusions The morphological trajectory reported here provides a foundation for studies of gene regulation during early leaf development in S. viridis and a framework for comparative analyses with other C4 grasses.

  • Anatomy and ultrastructure of embryonic leaves of the C4 species Setaria viridis.
    Annals of botany, 2018
    Co-Authors: Nicia E G Junqueira, Bianca Ortiz-silva, Marcos Vinicius Leal-costa, Marcio Alves-ferreira, Hugh G. Dickinson, Jane A. Langdale, Fernanda Reinert
    Abstract:

    Setaria viridis is being promoted as a model C4 photosynthetic plant because it has a small genome (~515 Mb), a short life cycle (~60 d) and it can be transformed. Unlike other C4 grasses such as maize, however, there is very little information about how C4 leaf anatomy (Kranz anatomy) develops in S. viridis. As a foundation for future developmental genetic studies, we provide an anatomical and ultrastructural framework of early shoot development in S. viridis, focusing on the initiation of Kranz anatomy in seed leaves. Setaria viridis seeds were germinated and divided into five stages covering development from the dry seed (stage S0) to 36 h after germination (stage S4). Material at each of these stages was examined using conventional light, scanning and transmission electron microscopy. Dry seeds contained three embryonic leaf primordia at different developmental stages (plastochron 1-3 primordia). The oldest (P3) leaf primordium possessed several procambial centres whereas P2 displayed only ground meristem. At the tip of P3 primordia at stage S4, C4 leaf anatomy typical of the malate dehydrogenase-dependent nicotinamide dinucleotide phosphate (NADP-ME) subtype was evident in that vascular bundles lacked a mestome layer and were surrounded by a single layer of bundle sheath cells that contained large, centrifugally located chloroplasts. Two to three mesophyll cells separated adjacent vascular bundles and one mesophyll cell layer on each of the abaxial and adaxial sides delimited vascular bundles from the epidermis. The morphological trajectory reported here provides a foundation for studies of gene regulation during early leaf development in S. viridis and a framework for comparative analyses with other C4 grasses.

Hugo Bruno Correa Molinari - One of the best experts on this subject based on the ideXlab platform.

  • Setaria viridis as a Model Plant for Functional Genomic Studies in C4 Crops
    Transgenic Plants, 2019
    Co-Authors: Polyana Kelly Martins, Bárbara Andrade Dias Brito Cunha, Adilson Kenji Kobayshi, Hugo Bruno Correa Molinari
    Abstract:

    Setaria viridis is an emerging model for C4 species, and it is an important model to validate some genes for further C4 crop transformation, such as sugarcane, maize, and wheat. Here, we describe two protocols for stable transformation of S. viridis mediated by Agrobacterium tumefaciens with three different reporter genes and two selectable markers. Routine transformation efficiency reaching 29% was achieved using embryogenic callus in S. viridis (accession A10.1). Alternatively, we developed a transformation method by floral dip with 0.6% efficiency. The developed protocols could be useful for genetic and genomics studies of important food-feed-fiber-fuel C4 crops.

  • a simple and highly efficient agrobacterium mediated transformation protocol for Setaria viridis
    Biotechnology Reports, 2015
    Co-Authors: Polyana Kelly Martins, Bárbara Andrade Dias Brito Cunha, Ana Paula Ribeiro, Adilson Kenji Kobayashi, Hugo Bruno Correa Molinari
    Abstract:

    The production and use of sugarcane in Brazil is very important for bioenergy production and is recognized as one of the most efficient in the world. In our laboratory, Setaria viridis is being tested as a model plant for sugarcane. S. viridis has biological attributes (rapid life cycle, small genome, diploid, short stature and simple growth requirements) that make it suitable for use as a model system. We report a highly efficient protocol for Agrobacterium-mediated genetic transformation of S. viridis. The optimization of several steps in tissue culture allowed the rapid regeneration of plants and increased the rate of transformation up to 29%. This protocol could become a powerful tool for functional genomics in sugarcane.

  • Setaria viridis floral-dip: A simple and rapid Agrobacterium-mediated transformation method.
    Biotechnology reports (Amsterdam Netherlands), 2015
    Co-Authors: Polyana Kelly Martins, Bárbara Andrade Dias Brito Cunha, Ana Paula Ribeiro, Adilson Kenji Kobayashi, Thiago Jonas Nakayama, Alexandre Lima Nepomuceno, Frank G. Harmon, Hugo Bruno Correa Molinari
    Abstract:

    Setaria viridis was recently described as a new monocotyledonous model species for C4 photosynthesis research and genetic transformation. It has biological attributes (rapid life cycle, small genome, diploid, short stature and simple growth requirements) that make it suitable for use as a model plant. We report an alternative method of S. viridis transformation using floral dip to circumvent the necessity of tissue culture phase for transgenic plant regeneration. S. viridis spikes at boot stage were selected to be immersed in Agrobacterium suspension. T1 seeds could be identified in 1.5-2 months after floral dipping. We demonstrated through molecular analysis and RFP expression that seeds and resulting plants from dipped inflorescences were transformed. Our results suggest the feasibility of S. viridis floral dip transformation as a time-saving and cost-effective compared with traditional methods. To our knowledge, this is the first report using floral dip in S. viridis as an Agrobacterium-mediated transformation method.

  • A simple and highly efficient Agrobacterium-mediated transformation protocol for Setaria viridis ☆
    Biotechnology reports (Amsterdam Netherlands), 2015
    Co-Authors: Polyana Kelly Martins, Bárbara Andrade Dias Brito Cunha, Ana Paula Ribeiro, Adilson Kenji Kobayashi, Hugo Bruno Correa Molinari
    Abstract:

    The production and use of sugarcane in Brazil is very important for bioenergy production and is recognized as one of the most efficient in the world. In our laboratory, Setaria viridis is being tested as a model plant for sugarcane. S. viridis has biological attributes (rapid life cycle, small genome, diploid, short stature and simple growth requirements) that make it suitable for use as a model system. We report a highly efficient protocol for Agrobacterium-mediated genetic transformation of S. viridis. The optimization of several steps in tissue culture allowed the rapid regeneration of plants and increased the rate of transformation up to 29%. This protocol could become a powerful tool for functional genomics in sugarcane.

  • Genetic transformation of Setaria viridis with CcUNK8 for enhanced drought tolerance
    2015
    Co-Authors: Karoline Estefani Duarte, Polyana Kelly Martins, Hugo Bruno Correa Molinari, Ana Paula Ribeiro, Adilson Kenji Kobayashi, Natalia Gomes Vieira, Barbara A.b.d. Cunha, Pierre Marraccini, Alan Carvalho Andrade
    Abstract:

    Our work is focused on the identification and functional characterization of orphan genes from coffee, which may have a high potential for innovation and biotechnological applications. This study presents data obtained for one of these orphan genes, called CcUNK8 (UNK for Unknown), previously identified as a candidate gene for drought tolerance in coffee. Aiming to identify the functions of CcUNK8 protein, the cDNA of this gene was cloned in an expression vector used to transformed embryogenic callus of Setaria viridis by Agrobacterium tumefaciens. Thirteen T0transformed plants of S. viridis were selected and the presence of the inserted T-DNA was confirmed by PCR. Leaf CcUNK8gene expression was analyzed by RT-qPCR and presented a variation between transformed plants. Physiological and phenological analyses (with or without drought) were performed in order to see if CcUNK8expression enhanced drought tolerance in S. viridis. (Resume d'auteur)