title: Effects of genetic changes to the begomovirus/betasatellite complex causing cotton leaf curl disease in South Asia post-resistance breaking.
abstract: Cotton leaf curl disease (CLCuD) has been a problem for cotton production across Pakistan and north-eastern India since the early 1990s. The appearance of the disease has been attributed to the introduction, and near monoculture of highly susceptible cotton varieties. During the intervening period the genetic make-up of the virus(es) causing the disease has changed dramatically. The most prominent of these changes has been in response to the introduction of CLCuD-resistant cotton varieties in the late 1990s, which provided a brief respite from the losses due to the disease. During the 1990s the disease was shown to be caused by multiple begomoviruses and a single, disease-specific betasatellite. Post-resistance breaking the complex encompassed only a single begomovirus, Cotton leaf curl Burewala virus (CLCuBuV), and a recombinant version of the betasatellite. Surprisingly CLCuBuV lacks an intact transcriptional-activator protein (TrAP) gene. The TrAP gene is found in all begomoviruses and encodes a product of ∼134 amino acids that is important in virus-host interactions; being a suppressor of post-transcriptional gene silencing (host defence) and a transcription factor that modulates host gene expression, including microRNA genes. Recent studies have highlighted the differences between CLCuBuV and the earlier viruses that are part of on-going efforts to define the molecular basis for resistance breaking in cotton.
authors.affiliation: National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad, Pakistan. Electronic address: rob.briddon@gmail.com.
authors.forename: Rob W
authors.initials: RW
authors.lastname: Briddon
authors.affiliation: National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad, Pakistan. Electronic address: mala_442000@yahoo.com.
authors.forename: Fazal
authors.initials: F
authors.lastname: Akbar
authors.affiliation: National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad, Pakistan. Electronic address: zafariqbal2009@gmail.comluq.
authors.forename: Zafar
authors.initials: Z
authors.lastname: Iqbal
authors.affiliation: National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad, Pakistan. Electronic address: raoluqman@gmail.com.
authors.forename: Luqman
authors.initials: L
authors.lastname: Amrao
authors.affiliation: National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad, Pakistan. Electronic address: imranamin1@yahoo.com.
authors.forename: Imran
authors.initials: I
authors.lastname: Amin
authors.affiliation: National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad, Pakistan. Electronic address: saeed_hafeez@yahoo.com.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Saeed
authors.affiliation: National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad, Pakistan. Electronic address: shahidmansoor7@gmail.com.
authors.forename: Shahid
authors.initials: S
authors.lastname: Mansoor
mesh_terms: D000595:Amino Acid Sequence; D053839:Begomovirus / Q000235:genetics* / Q000472:pathogenicity; D001947:Breeding; D002874:Chromosome Mapping; D020868:Gene Silencing; D005814:Genes, Viral; D016679:Genome, Viral; D003368:Gossypium / Q000235:genetics / Q000276:immunology / Q000821:virology*; D054884:Host-Pathogen Interactions; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology / Q000821:virology*; D057865:Plant Immunity / Q000235:genetics; D012526:Satellite Viruses / Q000235:genetics* / Q000472:pathogenicity
chemical_list: D035683:MicroRNAs
keywords: Begomovirus; Betasatellite; Cotton leaf curl disease; Geminivirus; Resistance breaking