Project description:MicroRNAs (miRNAs) are non-coding, short, single-stranded RNAs with essential roles in gene regulation in various organisms including higher plants. In contrast to the vast information on miRNAs from many economically important plants, almost nothing has been reported on the identification or analysis of miRNAs from rubber tree (Hevea brasiliensis L.), the most important natural rubber-producing crop. To identify miRNAs and their target genes in rubber tree, high throughput sequencing combined with a computational approach was performed. Four small RNA libraries were constructed for deep sequencing from mature and young leaves of two rubber tree clones, PB 260 and PB 217, which provide high and low latex yield, respectively. 237 miRNAs belonging to 37 known miRNA families were identified, and northern hybridization validated miRNA expression and revealed developmental stage-dependent and clone-specific expression for some miRNAs. We took advantage of the newly released rubber tree genome assembly as well as the genomic databases from leafy spurge and cassava, two species related to rubber tree, and predicted 15 novel miRNAs.
Project description:MicroRNAs (miRNAs) are non-coding, short, single-stranded RNAs with essential roles in gene regulation in various organisms including higher plants. In contrast to the vast information on miRNAs from many economically important plants, almost nothing has been reported on the identification or analysis of miRNAs from rubber tree (Hevea brasiliensis L.), the most important natural rubber-producing crop. To identify miRNAs and their target genes in rubber tree, high throughput sequencing combined with a computational approach was performed. Four small RNA libraries were constructed for deep sequencing from mature and young leaves of two rubber tree clones, PB 260 and PB 217, which provide high and low latex yield, respectively. 237 miRNAs belonging to 37 known miRNA families were identified, and northern hybridization validated miRNA expression and revealed developmental stage-dependent and clone-specific expression for some miRNAs. We took advantage of the newly released rubber tree genome assembly as well as the genomic databases from leafy spurge and cassava, two species related to rubber tree, and predicted 15 novel miRNAs. 4 samples examined: PB260 mature leaves, PB260 young leaves, PB217 mature leaves, and PB217 young leaves.
Project description:We first report the use of next-generation massively parallel sequencing technologies and de novo transcriptome assembly to gain insight into the wide range of transcriptome of Hevea brasiliensis. The output of sequenced data showed that more than 12 million sequence reads with average length of 90nt were generated. Totally 48,768 unigenes (mean size = 488 bp) were assembled through transcriptome de novo assembly, which represent more than 3-fold of all the sequences of Hevea brasiliensis deposited in the GenBank. Assembled sequences were annotated with gene descriptions, gene ontology and clusters of orthologous group terms. Total 37,373 unigenes were successfully annotated and more than 10% of unigenes were aligned to known proteins of Euphorbiaceae. The unigenes contain nearly complete collection of known rubber-synthesis-related genes. Our data provides the most comprehensive sequence resource available for study rubber tree and demonstrates the availability of Illumina sequencing and de novo transcriptome assembly in a species lacking genome information.
Project description:We first report the use of next-generation massively parallel sequencing technologies and de novo transcriptome assembly to gain insight into the wide range of transcriptome of Hevea brasiliensis. The output of sequenced data showed that more than 12 million sequence reads with average length of 90nt were generated. Totally 48,768 unigenes (mean size = 488 bp) were assembled through transcriptome de novo assembly, which represent more than 3-fold of all the sequences of Hevea brasiliensis deposited in the GenBank. Assembled sequences were annotated with gene descriptions, gene ontology and clusters of orthologous group terms. Total 37,373 unigenes were successfully annotated and more than 10% of unigenes were aligned to known proteins of Euphorbiaceae. The unigenes contain nearly complete collection of known rubber-synthesis-related genes. Our data provides the most comprehensive sequence resource available for study rubber tree and demonstrates the availability of Illumina sequencing and de novo transcriptome assembly in a species lacking genome information. The transcriptome of latex and leaf in Hevea brasiliensis
Project description:Nutural rubber (NR) production, latex is harvested by periodical tapping of the trunk bark. Ethylene enhances and prolongs latex flow and latex regeneration. Ethephon, which is an ethylene-releasing compound, applied to the trunk before tapping usually results in a 1.5- to 2-fold increase in latex yield. We investigated gene expression in response to ethephon treatment using Pará rubber tree seedlings as a model system. After ethephon treatment, 3,270 genes showed significant differences in expression compared with the mock treatment. Genes associated with carotenoids, flavonoids, and abscisic acid biosynthesis were significantly upregulated by ethephon treatment, which might contribute to an increase in latex flow. Genes associated with secondary cell wall formation were downregulated, which might be because of the reduced sugar supply. Given that sucrose is an important molecule for NR production, a trade-off may arise between NR production and cell wall formation for plant growth and for wound healing at the tapping panel.
Project description:We report transcriptome data of four kinds of bark samples from the Hevea brasiliensis clone CATAS7-33-97 by use of next-generation massively parallel sequencing technologies and de novo transcriptome assembly. The output of sequenced data showed that a total of 323,842,182 clean reads with average length of 90 nt were generated in four samples. Totally 67,873 uingenes with an average length of 750 nt and a N50 of 1,222 nt were assembled through transcriptome de novo assembly. The all assembled sequences were annotated with gene descriptions, gene ontology and clusters of orthologous group terms. The comparative analysis of the transcriptome data performed with the criteria of FDR ≤ 0.001 and |log2 Ratio| ≥ 1. As a result, 15,780 different expression unigenes (8,646 up and 7,134 down ) were detected in early libraries (Control-A versus COR-A) upon coronatine treatment, and 19,824 different expression unigenes (7,711 up and 12,113 down) were detected in late libraries (Control-B versus COR-B) upon coronatine treatment. Functional analysis of different expression unigenes showed that mass of unigenes were annotated in multiple signaling pathways. Comparative transcriptome analysis of inner bark in response to coronatine reveals a new insight into the signal networks for the secondary laticifer differentiation from vascular cambia in rubber tree.