Acquisition For a circulative pathogen like “Ca. Liberibacter” spp., passage of ingested pathogens through the gut epithelial cells into the vector haemocoele.
Agrobacterium A bacterium that normally causes crown gall disease in a variety of plants.
Agrobacterium-mediated transformation A method of genetic engineering that involves the use of a plasmid (called Ti plasmid) from Agrobacterium. This plasmid has been made incapable of causing disease but can carry foreign DNA into susceptible plant cells.
Anti-bacterial peptide A compound composed of two or more amino acids that can destroy bacteria or suppress its growth.
Apomictic Not requiring the union of male and female gametes (i.e. fertilization) during reproduction.
BAC library (bacterial artificial chromosome) A cloning vector (i.e. small piece of DNA into which a foreign gene can be inserted) that is propagated in a bacterial host and is used in large scale genome sequencing projects.
Best management practices Methods or techniques that have been shown to be the most practical and the most efficacious.
Biomarker A substance that is used as an indicator of disease or a biological state.
Box Tax Tax paid by the grower for each box of harvested citrus, used to fund the Florida Department of Citrus activities.
Budwood A stem used as source of bud for grafting.
Citrus tristeza virus (CTV) A single stranded RNA virus from the group Closterovirus, which is known to cause economically important plant diseases. The causal organism of the citrus tristeza disease.
Genetic engineering A technology that is employed to alter the genetic material of living cells for the purpose of making them produce new substances or perform new functions.
Genome annotation The process of determining the locations of genes and coding regions in a genome and their functions.
Genome sequencing The process of determining the DNA sequence of an organism’s genome (i.e. total hereditary material).
Graft To unite a shoot or bud (i.e. scion) to an established plant (i.e. stock) by insertion or by attachment.
Graft inoculation Introduction of a pathogen to a healthy plant by inserting a bud which is infected with the pathogen (i.e. grafting).
Gram-negative bacteria Bacteria that turn red or pink when subjected to Gram staining protocol, a reaction due to the structural composition of their cell walls.
Haemocele The blood-filled body cavity of arthropods.
Inoculation…For “Ca. Liberibacter” spp. is the passage of pathogens in saliva from the salivary glands into phloem sieve elements via salivation.
Heterozygosity The condition wherein dissimilar alleles (forms of a gene) are present at one or more loci on homologous chromosomes.
Latent period (plant) Time in the plant from pathogen inoculation by vector, graft or mechanical transmission to the time of pathogen expression by symptoms or detection by diagnosis (e.g. serology, PCR, TEM).
Homoptera An insect sub-order comprised of plant-feeding insects with sucking mouthparts. Its members include aphids, leafhoppers, cicadas, and scale insects.
Phytoplasma Formerly known as 'Mycoplasma-like organisms' or MLOs, are bacteria that lack cell wall which thrive in plant phloem tissues and some insects.
Polymerase chain reaction (PCR) A technique used to increase the amount of a specific DNA sequence or DNA region by separating the DNA strand into two and incubating it with oligonucleotide primers and DNA polymerase.
Pure culture In vitro growth of only one type of microorganism.
Pyrosequencing A DNA sequencing technique that depends on the detection of pyrophosphate release during DNA synthesis.
Retention For “Ca. Liberibacter” spp. is the act of pathogen moving through haemocoele and infecting various organs including the salivary glands.
RNAi (RNA interference) A defense mechanism in plants, fungi, and animals against foreign double-stranded RNA, such as viruses. The process is characterized by the prevention of messenger RNA (mRNA) translation by specialized protein complexes in the host.
Rootstock A root or part of a root that is used as the base in plant propagation (i.e. grafting).
Scion A twig or shoot with buds that is attached to the rootstock during grafting.
Systemic acquired resistance (SAR) Resistance to disease exhibited by the whole plant after inoculation with a pathogen that causes a localized response or after the application of certain chemical agents.
Transformation Change in the genetic structure of an organism by the incorporation of DNA from another organism, not necessarily of the same species.
Transmission For Ca. Liberibacter spp. is the acquisition, retention (over a latent period), and inoculation of the pathogen by the vector.
Transgenic An organism formed by the insertion of a gene obtained from another organism using recombinant DNA techniques.
Vector An agent, such as plasmid or virus, used to carry DNA into a cell; an insect that transmits a pathogen.
Vertical transmission Transfer of an infectious agent from parent to offspring via transovarial transmission and eliminates need for traditional acquisition by feeding on a pathogen-infected host.