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Metabolomic and transcriptomic insights into how cotton fiber transitions to secondary wall synthesis, represses lignification, and prolongs elongation.

Tuttle JR, Nah G, Duke MV, Alexander DC, Guan X, Song Q, Chen ZJ, Scheffler BE, Haigler CH - BMC Genomics (2015)

Bottom Line: Oxidative stress was lower in the fiber of G. barbadense cv Phytogen 800 as compared to G. hirsutum cv Deltapine 90.Correspondingly, the G. barbadense cultivar had enhanced capacity for management of reactive oxygen species during its prolonged elongation period, as indicated by a 138-fold increase in ascorbate concentration at 28 DPA.The data showed how lignification can be transcriptionally repressed during secondary cell wall synthesis, and they implicated enhanced capacity to manage reactive oxygen species through the ascorbate-glutathione cycle as a positive contributor to fiber length.

View Article: PubMed Central - PubMed

Affiliation: Department of Crop Science, North Carolina State University, Raleigh, NC, 27695, USA. jrtuttle@ncsu.edu.

ABSTRACT

Background: The morphogenesis of single-celled cotton fiber includes extreme elongation and staged cell wall differentiation. Designing strategies for improving cotton fiber for textiles and other uses relies on uncovering the related regulatory mechanisms. In this research we compared the transcriptomes and metabolomes of two Gossypium genotypes, Gossypium barbadense cv Phytogen 800 and G. hirsutum cv Deltapine 90. When grown in parallel, the two types of fiber developed similarly except for prolonged fiber elongation in the G. barbadense cultivar. The data were collected from isolated fibers between 10 to 28 days post anthesis (DPA) representing: primary wall synthesis to support elongation; transitional cell wall remodeling; and secondary wall cellulose synthesis, which was accompanied by continuing elongation only in G. barbadense fiber.

Results: Of 206 identified fiber metabolites, 205 were held in common between the two genotypes. Approximately 38,000 transcripts were expressed in the fiber of each genotype, and these were mapped to the reference set and interpreted by homology to known genes. The developmental changes in the transcriptomes and the metabolomes were compared within and across genotypes with several novel implications. Transitional cell wall remodeling is a distinct stable developmental stage lasting at least four days (18 to 21 DPA). Expression of selected cell wall related transcripts was similar between genotypes, but cellulose synthase gene expression patterns were more complex than expected. Lignification was transcriptionally repressed in both genotypes. Oxidative stress was lower in the fiber of G. barbadense cv Phytogen 800 as compared to G. hirsutum cv Deltapine 90. Correspondingly, the G. barbadense cultivar had enhanced capacity for management of reactive oxygen species during its prolonged elongation period, as indicated by a 138-fold increase in ascorbate concentration at 28 DPA.

Conclusions: The parallel data on deep-sequencing transcriptomics and non-targeted metabolomics for two genotypes of single-celled cotton fiber showed that a discrete developmental stage of transitional cell wall remodeling occurs before secondary wall cellulose synthesis begins. The data showed how lignification can be transcriptionally repressed during secondary cell wall synthesis, and they implicated enhanced capacity to manage reactive oxygen species through the ascorbate-glutathione cycle as a positive contributor to fiber length.

No MeSH data available.


Expression of GhRAC13 peaks during transitional cell wall remodeling. (a) The level of expression of GhRAC13 (GenBank: S79308.1) is shown for Gb (grey bars) and Gh (white bars) fiber at 10 to 28 DPA, as derived from the RNA-Seq data. In both fibers, the similar timing of upregulated expression corresponds to the similar timing of the transition stage. (b) Expression of an RBOHC homolog (related to Gorai.001G053300.1) that may contribute to the oxidative burst by producing superoxide. Asterisks indicate a significant difference in the cross-genotype comparison (p ≤ 1E-4). Error bars are standard deviation
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Fig5: Expression of GhRAC13 peaks during transitional cell wall remodeling. (a) The level of expression of GhRAC13 (GenBank: S79308.1) is shown for Gb (grey bars) and Gh (white bars) fiber at 10 to 28 DPA, as derived from the RNA-Seq data. In both fibers, the similar timing of upregulated expression corresponds to the similar timing of the transition stage. (b) Expression of an RBOHC homolog (related to Gorai.001G053300.1) that may contribute to the oxidative burst by producing superoxide. Asterisks indicate a significant difference in the cross-genotype comparison (p ≤ 1E-4). Error bars are standard deviation

Mentions: The data show that transitional cell wall remodeling is a distinct phase of fiber development that remains relatively stable at both the transcriptional and biochemical level for four days (between 18 to 21 DPA) under these experimental conditions. Only 0 or 2 transcripts and 6 or 8 metabolites changed concentrations between 18 and 21 DPA in Gb or Gh fiber, in contrast to substantial differences between 15 and 18 DPA and even greater differences between 21 and 28 DPA (Fig. 1). The expression pattern of the gene encoding a small GTPase-family protein (GhRAC13) [GenBank S79308.1], which is homologous to Gorai.011G031400.2 and AtRAC2 (At5g45970), confirmed the consistency of these results with known aspects of the transition stage in cotton fiber [60]. In the RNA-Seq data, GhRAC13 or its ortholog in Gb fiber were upregulated between 15 to 21 DPA (Fig. 5a). They were also the most highly expressed RAC homologs at 18 DPA (Additional file 17), consistent with the prior data on Gh fiber [34].Fig. 5


Metabolomic and transcriptomic insights into how cotton fiber transitions to secondary wall synthesis, represses lignification, and prolongs elongation.

Tuttle JR, Nah G, Duke MV, Alexander DC, Guan X, Song Q, Chen ZJ, Scheffler BE, Haigler CH - BMC Genomics (2015)

Expression of GhRAC13 peaks during transitional cell wall remodeling. (a) The level of expression of GhRAC13 (GenBank: S79308.1) is shown for Gb (grey bars) and Gh (white bars) fiber at 10 to 28 DPA, as derived from the RNA-Seq data. In both fibers, the similar timing of upregulated expression corresponds to the similar timing of the transition stage. (b) Expression of an RBOHC homolog (related to Gorai.001G053300.1) that may contribute to the oxidative burst by producing superoxide. Asterisks indicate a significant difference in the cross-genotype comparison (p ≤ 1E-4). Error bars are standard deviation
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4482290&req=5

Fig5: Expression of GhRAC13 peaks during transitional cell wall remodeling. (a) The level of expression of GhRAC13 (GenBank: S79308.1) is shown for Gb (grey bars) and Gh (white bars) fiber at 10 to 28 DPA, as derived from the RNA-Seq data. In both fibers, the similar timing of upregulated expression corresponds to the similar timing of the transition stage. (b) Expression of an RBOHC homolog (related to Gorai.001G053300.1) that may contribute to the oxidative burst by producing superoxide. Asterisks indicate a significant difference in the cross-genotype comparison (p ≤ 1E-4). Error bars are standard deviation
Mentions: The data show that transitional cell wall remodeling is a distinct phase of fiber development that remains relatively stable at both the transcriptional and biochemical level for four days (between 18 to 21 DPA) under these experimental conditions. Only 0 or 2 transcripts and 6 or 8 metabolites changed concentrations between 18 and 21 DPA in Gb or Gh fiber, in contrast to substantial differences between 15 and 18 DPA and even greater differences between 21 and 28 DPA (Fig. 1). The expression pattern of the gene encoding a small GTPase-family protein (GhRAC13) [GenBank S79308.1], which is homologous to Gorai.011G031400.2 and AtRAC2 (At5g45970), confirmed the consistency of these results with known aspects of the transition stage in cotton fiber [60]. In the RNA-Seq data, GhRAC13 or its ortholog in Gb fiber were upregulated between 15 to 21 DPA (Fig. 5a). They were also the most highly expressed RAC homologs at 18 DPA (Additional file 17), consistent with the prior data on Gh fiber [34].Fig. 5

Bottom Line: Oxidative stress was lower in the fiber of G. barbadense cv Phytogen 800 as compared to G. hirsutum cv Deltapine 90.Correspondingly, the G. barbadense cultivar had enhanced capacity for management of reactive oxygen species during its prolonged elongation period, as indicated by a 138-fold increase in ascorbate concentration at 28 DPA.The data showed how lignification can be transcriptionally repressed during secondary cell wall synthesis, and they implicated enhanced capacity to manage reactive oxygen species through the ascorbate-glutathione cycle as a positive contributor to fiber length.

View Article: PubMed Central - PubMed

Affiliation: Department of Crop Science, North Carolina State University, Raleigh, NC, 27695, USA. jrtuttle@ncsu.edu.

ABSTRACT

Background: The morphogenesis of single-celled cotton fiber includes extreme elongation and staged cell wall differentiation. Designing strategies for improving cotton fiber for textiles and other uses relies on uncovering the related regulatory mechanisms. In this research we compared the transcriptomes and metabolomes of two Gossypium genotypes, Gossypium barbadense cv Phytogen 800 and G. hirsutum cv Deltapine 90. When grown in parallel, the two types of fiber developed similarly except for prolonged fiber elongation in the G. barbadense cultivar. The data were collected from isolated fibers between 10 to 28 days post anthesis (DPA) representing: primary wall synthesis to support elongation; transitional cell wall remodeling; and secondary wall cellulose synthesis, which was accompanied by continuing elongation only in G. barbadense fiber.

Results: Of 206 identified fiber metabolites, 205 were held in common between the two genotypes. Approximately 38,000 transcripts were expressed in the fiber of each genotype, and these were mapped to the reference set and interpreted by homology to known genes. The developmental changes in the transcriptomes and the metabolomes were compared within and across genotypes with several novel implications. Transitional cell wall remodeling is a distinct stable developmental stage lasting at least four days (18 to 21 DPA). Expression of selected cell wall related transcripts was similar between genotypes, but cellulose synthase gene expression patterns were more complex than expected. Lignification was transcriptionally repressed in both genotypes. Oxidative stress was lower in the fiber of G. barbadense cv Phytogen 800 as compared to G. hirsutum cv Deltapine 90. Correspondingly, the G. barbadense cultivar had enhanced capacity for management of reactive oxygen species during its prolonged elongation period, as indicated by a 138-fold increase in ascorbate concentration at 28 DPA.

Conclusions: The parallel data on deep-sequencing transcriptomics and non-targeted metabolomics for two genotypes of single-celled cotton fiber showed that a discrete developmental stage of transitional cell wall remodeling occurs before secondary wall cellulose synthesis begins. The data showed how lignification can be transcriptionally repressed during secondary cell wall synthesis, and they implicated enhanced capacity to manage reactive oxygen species through the ascorbate-glutathione cycle as a positive contributor to fiber length.

No MeSH data available.