title: In-Depth Transcriptome Sequencing of Mexican Lime Trees Infected with Candidatus Phytoplasma aurantifolia.
abstract: Witches' broom disease of acid lime greatly affects the production of Mexican lime in Iran. It is caused by a phytoplasma (Candidatus Phytoplasma aurantifolia). However, the molecular mechanisms that underlie phytoplasma pathogenicity and the mode of interactions with host plants are largely unknown. Here, high-throughput transcriptome sequencing was conducted to explore gene expression signatures associated with phytoplasma infection in Mexican lime trees. We assembled 78,185 unique transcript sequences (unigenes) with an average length of 530 nt. Of these, 41,805 (53.4%) were annotated against the NCBI non-redundant (nr) protein database using a BLASTx search (e-value ≤ 1e-5). When the abundances of unigenes in healthy and infected plants were compared, 2,805 transcripts showed significant differences (false discovery rate ≤ 0.001 and log2 ratio ≥ 1.5). These differentially expressed genes (DEGs) were significantly enriched in 43 KEGG metabolic and regulatory pathways. The up-regulated DEGs were mainly categorized into pathways with possible implication in plant-pathogen interaction, including cell wall biogenesis and degradation, sucrose metabolism, secondary metabolism, hormone biosynthesis and signalling, amino acid and lipid metabolism, while down-regulated DEGs were predominantly enriched in ubiquitin proteolysis and oxidative phosphorylation pathways. Our analysis provides novel insight into the molecular pathways that are deregulated during the host-pathogen interaction in Mexican lime trees infected by phytoplasma. The findings can be valuable for unravelling the molecular mechanisms of plant-phytoplasma interactions and can pave the way for engineering lime trees with resistance to witches' broom disease.
authors.affiliation: Department of Systems Biology, Agricultural Biotechnology Research Institute of Iran, Karaj, Tehran, Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Mardi
authors.affiliation: Department of Systems Biology, Agricultural Biotechnology Research Institute of Iran, Karaj, Tehran, Iran.
authors.forename: Laleh
authors.initials: L
authors.lastname: Karimi Farsad
authors.affiliation: Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Javad
authors.initials: J
authors.lastname: Gharechahi
authors.affiliation: Department of Systems Biology, Agricultural Biotechnology Research Institute of Iran, Karaj, Tehran, Iran; Department of Molecular Systems Biology at Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran.
authors.forename: Ghasem Hosseini
authors.initials: GH
authors.lastname: Salekdeh
mesh_terms: D032082:Citrus aurantiifolia / Q000235:genetics* / Q000382:microbiology; D053263:Gene Regulatory Networks; D045582:Phytoplasma / Q000472:pathogenicity*; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D059467:Transcriptome