Changes in Variable Number of Tandem Repeats in 'Candidatus Liberibacter asiaticus' through Insect Transmission

• Published in: PloS one Vol. 10; no. 9; p. e0138699
• Main Authors: Katoh, Hiroshi, Inoue, Hiromitsu, Iwanami, Toru
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 24.09.2015; Public Library of Science (PLoS)
• Subjects: Analysis; Animals; Candidatus Liberibacter asiaticus; Causes of; Change detection; Citrus; Citrus - microbiology; Citrus - parasitology; Citrus fruits; Citrus greening; Citrus jambhiri; Deoxyribonucleic acid; Diaphorina citri; Disease; Disease transmission; Diseases and pests; DNA; DNA Primers - metabolism; Genetic aspects; Genetic Loci; Genome, Bacterial; Genomes; Hemiptera - physiology; Inoculation; Insects; Larva; Minisatellite Repeats - genetics; Models, Biological; Rhizobiaceae - genetics; Science; Stability analysis; Trees; Trioza erytreae; Japan; Africa; Taiwan; Brazil; Mexico; Florida; Indonesia; India
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0138699

Citrus greening (huanglongbing) is the most destructive citrus disease worldwide. The disease is associated with three species of 'Candidatus Liberibacter' among which 'Ca. Liberibacter asiaticus' has the widest distribution. 'Ca. L. asiaticus' is commonly transmitted by a phloem-feeding insect vector, the Asian citrus psyllid Diaphorina citri. A previous study showed that isolates of 'Ca. L. asiaticus' were clearly differentiated by variable number of tandem repeat (VNTR) profiles at four loci in the genome. In this study, the VNTR analysis was further validated by assessing the stability of these repeats after multiplication of the pathogen upon host-to-host transmission using a 'Ca. L. asiaticus' strain from Japan. The results showed that some tandem repeats showed detectable changes after insect transmission. To our knowledge, this is the first report to demonstrate that the repeat numbers VNTR 002 and 077 of 'Ca. L. asiaticus' change through psyllid transmission. VNTRs in the recipient plant were apparently unrelated to the growing phase of the vector. In contrast, changes in the number of tandem repeats increased with longer acquisition and inoculation access periods, whereas changes were not observed through psyllid transmission after relatively short acquisition and inoculation access periods, up to 20 and 19 days, respectively.