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Sugarcane leaf development

One of our goals is to generate a public catalogue/atlas of sugarcane transcripts. Currently there are only ~240K EST available in GenBank, and there is not much genomic information publicly available. Here at the CTBE, we have been generating data in the form of transcriptome and genome sequencing and we are commited to release that data, assemblies and annotation, to the public. We are convinced that making large genomics and functional genomics datasets avaiable for the sugarcane cammunity, will aid in the understanding of C4 photosynthesis, complex polyploid genomes and in the adoption of molecular breeding approaches.

One of our first projects, contributing towards the Sugarcane gene catalogue, is a study of the leaf development in Sugarcane, genotype SP80-3280. The leaf of C4 plants, such as sugarcane have a developmental gradient along the leaf. We have studied the sugarcane leaf +1 (First leaf from top to bottom with the delawp fully exposed), examining four different segments, as show in the following figure. More details are available in Mattiello et al., 2015.

 Sugarcane leaf+1 segments

For each region we collected total RNA, from several individuals. RNA was processed with the total mRNA library preparation kit from Illumina (stranded-chemistry) and sequenced on a HiSeq2500 instrument using paired-end reads (2x100bp). The following table has a summary of the sequencing and quality evaluation.

SegmentIndividualQuality trimmed readsrRNAPlastidMitochondriaRemaining paired-end reads
Bo 235Bo 55.209.307 32.42% 0,90% 0,11% 37.042.139
M 235M 22.796.562 37.26% 1,30% 0,13% 14.146.578
T 235P 30.003.751 16,78% 1,11% 0,05% 24.722.651
Bo 234Bo 19.764.755 35,28% 0,46% 0,06% 12.779.105
M 234M 49.018.540 12,72% 0,25% 0,02% 42.721.041
T 234P 34.074.014 19,30% 0,41% 0,04% 27.316.488
B 138B 18.689.034 6,72% 0,11% 0,01% 16.543.744
Bo 138Bo 29.404.833 11,78% 0,16% 0,02% 25.928.715
M 138M 36.072.049 13,14% 0,37% 0,03% 31.261.141
T 138P 58.826.816 34,52% 0,24% 0,02% 50.767.882
B 163B 10.170.698 34,52% 0,42% 0,05% 6.659.348
M 163M 21.348.210 27,48% 0,28% 0,04% 15.476.837
T 163P 39.844.966 16,47% 0,25% 0,03% 33.233.302
B 234B 48.065.788 12,79% 0,18% 0,02% 41.882.487
rRNA was detected using SortMeRNA. Mitochondrial and plastid reads were identifiedy by mapping them to the Sorghum mitrocondrial genome (NC_008360.1) and the sugarcane chloroplast genome (NC_005878.2).
 
In order to increase coverage of the gene space of Sugarcane, we decided to include a sample that resulted from pooling the whole leaf+1 from plants at one and two months of age, as well as the stalk and roots of the same plants. For this sample (DP3) we have 15.513.277 high quality, strand-specific, paired-end sequenced fragments.
 
High quality reads were de novo assembled using Trinity (Excep for reads coming from the individual 235, which has not been sequenced at that time). We mapped this preliminary assembly to the NCBI's nucleotide database, and analysed the result using MEGAN5, which allowed us to detect some contaminants. In order to remove the contamination we mapped all reads (this time including individual 235) against the contaminants and excluded them. The unmmaped reads were used to make a new de novo Trinity assembly. The resulting 250.035 assembled transcripts were annotated with Trinotate.
 
The raw reads can be obtained from the SRA with accession numbers SRR1979656 to SRR1979669 and SRR1974519. The assembled transcriptome was submitted to NCBI's TSA under accession number: GCZX00000000.
 
We have a public BLAST server, where you can search for your favorite genes against our sugarcane transcriptome.
 
Below you can find our transcript assembly and annotation. Remember this is a strand-specific assembly, thus all trancripts are in the correct orientation. If you use this resourse, please do cite our paper Mattiello et al., 2015.
 

Downloads

 

  1. Strand-specific transcript assembly
  2. Transcript annotation
  3. Deduced proteins
  4. Identified Transcription Associated Proteins (Transcription factors and other transcriptional regulator using the methods described in Perez-Rodriguez, et al., 2010)
  5. Identified KEEG metabolic pathways
  6. Orthologous gene groups identified using OrthoMCL and an inflation value of 1.5 (SACC= Saccharum hybrid cultivar SP80-3280, OSAT= Orysa sativa, SBIC= Sorghum bicolor, SITA= Setaria italica, ZMAY= Zea mays)
  7. Accession numbers for transcripts at NCBI
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