Project description:Gossypium barbadense is widely cultivated because of its extra-long staple cotton with superior luster, silkiness and high yield. These economically important traits were selected during initial domestication of an agronomically inferior wild ancestor, followed by millennia of human- mediated selection. To reveal the effects of this history on the cotton fiber transcriptome, we conducted comparative expression profiling on mechanically isolated fiber cells at three different stages encompassing early, mid, and late fiber elongation in wild (K101) and domesticated (Pima S-7) accessions, using a microarray platform that interrogates 42,429 unigenes. The distribution of differentially expressed genes across developmental stages was different in the two accessions, with a shift toward greater change earlier in cultivated than in wild G. barbadense. Approximately 4200 genes were differentially expressed between wild and domesticated accessions at one or more of the stages studied. Domestication appears to have led to enhanced modulation of cellular redox levels and the avoidance or delay of stress-like processes. Prolonged fiber growth in cultivated relative to wild G. barbadense is associated with upregulation of signal transduction and hormone signaling genes and down-regulation of cell wall maturation genes. Clues are provided into the processes and genes that may unwittingly have been selected by humans during domestication and development of modern elite lines. Several of the transcriptomic differences between wild and domesticated G. barbadense described here appear to have parallels in a second domesticated cotton species, Gossypium hirsutum, suggesting that replicated domestication of two different species has resulted in overlapping, parallel, metabolic transformations. Two accessions of G. barbadense were studied, the elite cultivar, Pima S-7, and a wild accession from Bolivia, K101. Seeds of both accessions were sown in sterilized potting mix in the Pohl Conservatory at Iowa State University, Ames, IA, and three biological replicates were grown for 3-5 months. Flowers were tagged at anthesis and harvested at three time points, 2, 10, and 20 days postanthesis. For each of three biological replicates, ovules were excised, frozen in liquid nitrogen, and stored at -80C.
Project description:Gossypium barbadense is widely cultivated because of its extra-long staple cotton with superior luster, silkiness and high yield. These economically important traits were selected during initial domestication of an agronomically inferior wild ancestor, followed by millennia of human- mediated selection. To reveal the effects of this history on the cotton fiber transcriptome, we conducted comparative expression profiling on mechanically isolated fiber cells at three different stages encompassing early, mid, and late fiber elongation in wild (K101) and domesticated (Pima S-7) accessions, using a microarray platform that interrogates 42,429 unigenes. The distribution of differentially expressed genes across developmental stages was different in the two accessions, with a shift toward greater change earlier in cultivated than in wild G. barbadense. Approximately 4200 genes were differentially expressed between wild and domesticated accessions at one or more of the stages studied. Domestication appears to have led to enhanced modulation of cellular redox levels and the avoidance or delay of stress-like processes. Prolonged fiber growth in cultivated relative to wild G. barbadense is associated with upregulation of signal transduction and hormone signaling genes and down-regulation of cell wall maturation genes. Clues are provided into the processes and genes that may unwittingly have been selected by humans during domestication and development of modern elite lines. Several of the transcriptomic differences between wild and domesticated G. barbadense described here appear to have parallels in a second domesticated cotton species, Gossypium hirsutum, suggesting that replicated domestication of two different species has resulted in overlapping, parallel, metabolic transformations.
Project description:We performed RNA-seq analysis of the root transcriptional response to Fusarium oxysporum f.sp. vasinfectum (FOV) race 4 (FOV4) infection in Gossypium barbadense, also known as Pima cotton. Susceptible Gossypium barbadense inbred lines Pima S-7 (PI 560140) and Pima 3-79 susceptible to Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV)] race 4 (FOV4), and Pima S-6 (PI 608346) which is resistant to FOV4 infection, were used for the preparation of cDNA libraries and further RNA-seq analyses. An isolate of FOV4 (FOV CA-14) from a naturally infested field in Fresno County in the San Joaquin Valley, California was used in this study.
Project description:Purpose: The goal of this experiment was to use RNA-seq to compare the two commercial cotton species Gossypium hirsutum and Gossypium barbadense and determine what transcripts may account for the better fiber quality in the latter. Methods: RNA was extracted from Gossypium barbadense or Gossypium hirsutum fibers at 10, 15, 18, 21, and 28 days post anthesis. Paired-end, 100-bp RNA-seq was performed on an Illumina HiSeq2000 and the reads were mapped to the Gossypium raimondii genome at www.phytozome.net and non-homologous contig assemblies from Gossypium arboreum. Results from RNA-seq were combined with non-targeted metabolomics. Results: Approximately 38,000 transcripts were expressed (RPKM>2) in each fiber type and approximately 2,000 of these transcripts were differentially expressed in a cross-species comparison at each timepoint. Enriched Gene Ontology biological processes in differentially expressed transcripts suggested that Gh fibers were more stressed. Conclusions: Both metabolomic and transcriptomic data suggest that better mechanisms for managing reactive oxygen species contribute to the increased fiber length in Gossypium barbadense. This appears to result from enhanced ascorbate biosynthesis via gulono-1,4-lactone oxidase and ascorbate recycling via dehydroascorbate reductase. See Bioproject PRJNA263926 and SRA accession SRP049330 for study design and raw sequencing data and Bioproject PRJNA269608 and TSA accession GBYK00000000 for Gossypium arboreum assembled contig sequences used for transcriptome mapping - Cotton fiber mRNA from 10,15,18,21 and 28 day post anthesis fiber from either Gossypium hirusutm or Gossypium barbadense was sequenced and differential gene expression analysis was conducted between species for each timepoint and between adjacent timepoints. Each timepoint was representative of fiber from 9 individual plants processed as 3 biological replicate pools (material from 3 individual plants per pool).
Project description:Sea-island cotton (Gossypium barbadense L.) has superior fiber quality properties such as length, fineness and strength, while Upland cotton (Gossypium hirsutum L.) is characterized by high yield. To reveal features of Upland cotton and Sea-island cotton fiber cells, differential genes expression profiles during fiber cell elongation and in secondary wall deposits were established using cDNA microarray technology. This research provides a valuable genomic resource to deepen our understanding of the molecular mechanisms of cotton fiber development, and may ultimately lead to improvements in cotton fiber quality and yield.
Project description:Purpose: The goal of this experiment was to use RNA-seq to compare the two commercial cotton species Gossypium hirsutum and Gossypium barbadense and determine what transcripts may account for the better fiber quality in the latter. Methods: RNA was extracted from Gossypium barbadense or Gossypium hirsutum fibers at 10, 15, 18, 21, and 28 days post anthesis. Paired-end, 100-bp RNA-seq was performed on an Illumina HiSeq2000 and the reads were mapped to the Gossypium raimondii genome at www.phytozome.net and non-homologous contig assemblies from Gossypium arboreum. Results from RNA-seq were combined with non-targeted metabolomics. Results: Approximately 38,000 transcripts were expressed (RPKM>2) in each fiber type and approximately 2,000 of these transcripts were differentially expressed in a cross-species comparison at each timepoint. Enriched Gene Ontology biological processes in differentially expressed transcripts suggested that Gh fibers were more stressed. Conclusions: Both metabolomic and transcriptomic data suggest that better mechanisms for managing reactive oxygen species contribute to the increased fiber length in Gossypium barbadense. This appears to result from enhanced ascorbate biosynthesis via gulono-1,4-lactone oxidase and ascorbate recycling via dehydroascorbate reductase.
Project description:Sea-island cotton (Gossypium barbadense L.) has superior fiber quality properties such as length, fineness and strength, while Upland cotton (Gossypium hirsutum L.) is characterized by high yield. To reveal features of Upland cotton and Sea-island cotton fiber cells, differential genes expression profiles during fiber cell elongation and in secondary wall deposits were established using cDNA microarray technology. This research provides a valuable genomic resource to deepen our understanding of the molecular mechanisms of cotton fiber development, and may ultimately lead to improvements in cotton fiber quality and yield. 15 samples were prepared for microarray slides hybridized with three biological replicate samples including a swap-dye experiment for each growth stage. Each spot had a repeat in the microarray slideM-oM-<M-^Ltherefore, data for six replicate experiments performed with biologically independent samples.
Project description:We compared different days post-anthesis (5DPA, 10DPA, 15DPA and 25DPA) differentially expressed genes (DEGs) in fiber development between G. hirsutum and G. barbadense. In addition, we analysis the differentially expressed genes (DEGs) function using the database for annotation, visualization and integrated discovery (DAVID). Overall, gene expression pattern have significantly difference between G. hirsutum and G. barbadense. In this study, G. barbadense DEGS in different two DPA are significantly more than G. hirsutum. In addation, there are 18937 DEGs were identified in fruit development and postembryonic development pathways and only upregulated in G. barbadense only. Taken together, these findings suggest that there are considerable differences of gene expression between G. hirsutum and G. barbadense in cotton fiber development different stages.
Project description:Sea Island cotton (Gossypium barbadense) is the source of the world’s finest fiber-quality cotton, yet relatively little is understood about the genetic variation among diverse germplasm, the genes underlying important traits, and the effects of pedigree selection. Here, we resequenced 336 G. barbadense accessions and identified 16 million SNPs. Phylogenetic and population structure analyses revealed two major gene pools and a third admixed subgroup derived from geographical dissemination and interbreeding. We conducted a genome-wide association study (GWAS) of 15 traits including fiber quality, yield, disease resistance, maturity, and plant architecture. The highest number of associated loci was for fiber quality, followed by disease resistance and yield. Using gene expression analyses and VIGS transgenic experiments we confirmed the role of five candidate genes regulating four key traits, i.e., disease resistance, fiber length, fiber strength, and lint percentage. Geographical and temporal considerations demonstrate selection for the superior fiber quality (fiber length and fiber strength), and high lint-percentage in improving G. barbadense in China. Pedigree selection breeding wholly increased Fusarium wilt disease resistance, and separately improved fiber-quality and yield. Our work provides a foundation for understanding genomic variation in and selective breeding of Sea Island cotton.
Project description:To gain novel insights into the molecular mechanisms underlying Pima cotton fiber quality, expression profiling of the Pima fiber transcriptome was performed as a function of development. The profiling was performed at 6 developmental time points: 8, 11, 14, 17, 21, and 24dpa. The expression profiling using long oligonucleotide microarray showed dynamic changes to the fiber transcriptome that correlate to morphogenesis, and biological cellular processes. Differentially expressed genes were identified by being differentially regulated at various stages of fiber development, and they were used to develop stage-specific regulation patterns that correlate the dynamics of gene expression to fiber morphogenesis.