Transcriptional Analyses of citrus host defense response repression by feeding of Diaphorina citri transmitting Candidatus Liberibacter asiaticus at early stages of infection
Purpose: We obtained RNA-seq-based differential expression profile of Valencia sweet orange plants challenged against healthy and CLas-infected psyllid infection at 1 dpi and 5 dpi.  The goals of this study are to reveal the interaction between citrus and psyllid/CaLas during the early phase of infection and understand the molecular mechanisms underlying the host-pathogen interactions and the susceptibility of most citrus varieties. Methods: leaf mRNA profiles of in vitro cultured Valencia sweet orange (VAL) budwood (WT) and of VAL fed by healthy and CLas-infected psyllid were generated by RNA-seq, in triplicate (one sample is duplicate), using Illumina HiSeq platform. The sequence reads that passed quality filters were used for gene expression and DEG detection analysis by EBseq algorithms. qRT–PCR validation was performed using SYBR Green assays Results: Using the RNA-seq data analysis workflow, we mapped about 136.80M sequence reads per sample to the reference Citrus clementina v1.0 genome and a total of 32,677 genes were detected. The average total mapping of each library was 71.98%. RNA-seq data were validated with qRT–PCR. Conclusions: Our study obtained the transcriptional profiles of citrus host by feeding of psyllid transmitting Candidatus Liberibacter asiaticus at early stages of infection, with biologic replicates, generated by RNA-seq technology. The RNA-seq data analysis workflows reported here should provide a framework for comparative investigations of expression profiles. We conclude that RNA-seq based transcriptome characterization would expedite genetic network analyses and permit the dissection of complex biologic functions. Overall design: Leaf mRNA profiles of in vitro cultured Valencia sweet orange (VAL) budwood (WT) and of VAL fed by healthy and CLas-infected psyllid