Project description:Genome assembly and comparative genomic analyses of the soybean pathogens Cercospora cf. flagellaris, C. kikuchii and C. cf. sigesbeckiae.
Project description:Purpose: The aim was to compare the transcriptome (using RNASeq) of a Cercospora zeina-resistant line (RIL387) and a Cercospora zeina susceptible line (RIL165), following inoculation by Cercospora zeina, in order to identify the defense responses associated with each line. Methods: Plants were grown in rows in three randomised blocks. Natural infection with Cercospora zeina was allowed to take place. Infected leves were harvested at the R5-early dent stage. Three leaves (one per plant) were harvested per block and pooled to make up one biological rep. One biological rep was harvested per block for each line. RNA was extracted and sequenced using Illumina. Sequencing reads were mapped to the B73 reference genome and were analysed using the Tuxedo suite of tools (Top hat, Cufflinks, Cuffmerge and Cuffdiff). Results: 5349 genes were differentially expressed between RIL165 and RIL387. In order to dissect responses specific to RIL165 and RIL387, 2394 genes with Log2FC ≤-1 were defined as having higher expression in RIL165 compared to RIL387 and 1393 genes with a Log2FC ≥1 as having increased expression in RIL387 compared to RIL165. Nine genes were validated using RT-qPCR. Four reference genes were included in the RT-qPCR analysis. Differentially expressed genes were further analysed for GO enrichment and pathway representation. Conclusions: Our RNA-Seq results show that a resistant and susceptible line repond differently to infection with Cercospora zeina, as differentially expressed genes were identified between the two lines.
Project description:Gray leaf spot (GLS) disease of maize can be caused by either of two sibling fungal species Cercospora zeina or Cercospora zeae-maydis. These species differ in geographical distribution, for example to date only C. zeina is associated with GLS in Africa. C. zeae-maydis isolates produce the phytotoxin cercosporin in vitro, whereas C. zeina does not. C.zeina was grown in different in vitro conditions to determine if the cercosporin biosynthesis genes were expressed. Furthermore, the choice of a range of different in vitro conditions was aimed at capturing transcript sequences from a broad range of genes to aid in identification of gene models for annotation of the C.zeina genome sequence.
