Location: Foreign Disease-Weed Science ResearchTitle: Alterations of phloem translatome gene expression during Candidatus Liberibacter asiaticus infection in tolerant and susceptible citrus cultivars
Submitted to: International Congress on Molecular Plant-Microbe Interactions
Publication Type: Abstract Only
Publication Acceptance Date: 4/11/2023
Publication Date: N/A
Technical Abstract: Huanglongbing (HLB) is a devastating disease of citrus worldwide associated with the phloem-restricted bacterium Candidatus Liberibacter asiaticus (CLas). CLas is spread by phloem feeding Asian citrus psyllids or through grafting. Molecular interactions between CLas and the plant are required for accumulation and spread of CLas in phloem tissues. However, many of these interactions are not well characterized. We have adapted translating ribosome affinity purification (TRAP) methodologies to analyze phloem specific responses to CLas in citrus trees. This method uses tissue specific promoters to express FLAG-tagged ribosomal proteins for immuno-capture of cell-specific mRNAs. HLB-susceptible sweet orange and HLB-tolerant Carrizo were transformed to express the FLAG-tagged ribosome protein L18 (RPL18) under the control of two phloem-specific promoters (pSULTR2;2 and p396ss), as well as the constitutive CaMV 35S promoter. Tagged ribosome complexes were purified from citrus leaves using anti-FLAG conjugated magnetic beads. High quality translatome RNA was recovered from citrus expressing FLAG-RPL18 but not from non-transformed control plants. TRAP citrus lines have been infected with CLas using no-choice Asian citrus psyllid feeding, and efforts are underway to identify phloem genes that are altered during infection. Identified genes will represent unique phloem specific targets for disrupting the CLas life cycle.