CITRUS GENOME SEQUENCE RESOURCES: DEVELOPMENT AND UTILIZATION TO CREATE HLB RESISTANT CULTIVARS

The goal of this project is to develop the highest quality citrus genome sequence assembly resources for commercially and biologically important citrus cultivars and accessions using breakthrough sequencing and assembly technologies, and to utilize these resources to tools to support development of HLB-resistant cultivars by genome editing or other techniques. The specific objectives of this proposed project are:Sequence appropriate citrus genomes using the PacBio platform and produce chromosome scale assemblies through proximity ligation technology. Because of the commercial significance and great potential value of engineered HLB resistance, the work will focus on citrus cultivars that are HLB-susceptible but of great commercial value, such as sweet orange and grapefruit, as well as other cultivars or accessions that are HLB-tolerant, to produce contrasting genome assemblies.Sequence RNA transcript libraries from the same genomes using PacBio or other evolving state of the art technologies that can yield full-length RNA sequences, to aid annotation, assembly, etc.Resulting genome assemblies will be annotated, haplotypes phased, structural genomics among the genomes will be compared, to develop a set of genomics-based tools to effectively utilize sequence resources for gene discovery, gene sequence retrieval, genome editing, and ultimately the creation of HLB-tolerant or -resistant citrus cultivars.Identify full length, putative HLB-responsive gene sequences; compare sequences, transcripts and protein structures that may relate to host-pathogen interactions and disease development or its suppression, and predict sites for guide RNA designing and gene editing.