Year: 2021
Type: article
Abstract: Candidatus Liberibacter asiaticus ( C Las), the bacteria responsible for citrus greening disease [huanglongbing (HLB)], has become a worldwide threat to citrus ( Citrus sp.) production. HLB has proven difficult to study and treat because of the complex interactions between C Las, the citrus host, and insect vectors. We have selected for single chain fragment variable (scFv) antibodies from a specialized bacteriophage library for binding activity against C Las proteins InvA and TolC. Portions of each protein were chosen as antigens based on predicted binding availability and theorized necessary functions in pathogenicity. Binding affinity for individual scFv-expressing clones was confirmed by phage enzyme-linked immunosorbent assay (ELISA). The scFv sequences were stably transformed under the control of a tandem Cauliflower mosaic virus 35S (CaMV 2x35S) promoter by Agrobacterium tumefacien –mediated transformation into ‘Carrizo’ citrange ( Citrus sinensis × Poncirus trifoliate ), a citrus rootstock cultivar. Replicated plants of single transformations were inoculated by infestation with C Las positive asian citrus psyllid ( Diaphorina citri ), a C Las vector. Inoculation and disease progression was monitored through quantitative real-time polymerase chain reaction. Inoculated transgenic plants showed significantly reduced C Las titer compared with wild types. A subpopulation of transgenic plants displayed no measurable surviving bacteria after 12 months. Interestingly, individual replicated plants from the same transgenic events strongly segregated into two populations by resistance phenotype: a minority that were indistinguishable from wild-type plants and a majority that were highly resistant. Our results are the first step in developing a novel protection strategy for HLB.
Authors: Joseph Krystel, Huawei Liu, John Hartung, Ed Stover
Language: English
Subfield: Plant Science
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,500
OpenAlex ID: W3198531637