Transcriptome Analysis of Citrus Cultivars Infected by Xac at Different Time Points. Citrus

Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (Xac), is one of the most devastating diseases of citrus plants, and responsible for citriculture damage around the world. There are different levels of susceptibility to the disease, with Tangerine ‘Ponkan’ (Citrus reticulata) and Sweet Orange ‘Bahia’ (Citrus sinensis) being considered resistant and susceptible, respectively. Additionaly, another citrus cultivars have intermediate susceptibility to Xac, such as Limao Galego, Satsuma, Valencia, Kunquat, Pera Rio and Hanlim. The identification of genes that are induced or repressed during the infection process by Xac, through the technique of RNA-Seq, is an important tool for the understanding of genetic and molecular mechanisms that confer different levels of susceptibility to plant citrus against Xac pathogen. To detect genetic modifications underlying Citrus Canker disease, leaves of these 8 citrus cultivars were inoculated with a suspension of Xac isolate (treatment) or sterile water (control). At 24, 48 and 72 hours after inoculation leaves were collected and immediately stored in liquid nitrogen. mRNA was isolated for cDNA synthesis, and in vitro cloning (clustering) was performed in a flow cell using cBOT (Illumina, Ca, USA). Samples were then multiplexed and sequenced in HiScanSQ high throughput sequencing machine (Illumina, Ca, USA).