Molecular and genetic interactions between Diaphorina citri and Candidatus Liberibacter asiaticus
M. CILIA (1) (1) USDA ARS, U.S.A.

The Asian citrus psyllid (ACP, Diaphorina citri) is the primary insect vector capable of transmitting ‘Candidatus Liberibacter asiaticus’ (CLas), the bacterial pathogen associated with citrus greening disease. Transmission of CLas to a healthy citrus tree depends on the ability of CLas to circulate within the insect vector. CLas is transmitted to a healthy citrus plant when pathogen-containing saliva is injected into a sieve tube element cell through the insect stylet bundle, and as the pathogen replicates in the plant, its distribution is restricted to the phloem. After emergence from eggs, D. citri nymphs begin feeding from the phloem tissue that has been inoculated with CLas by their mother or other D. citri and ingest the bacterium, The bacterium crosses the first barrier to circulative transmission by entering the cells of the insect gut. Acquisition of CLas by nymphs during feeding occurs at a much higher rate than during transovarial transmission, and also at a higher rate than during feeding by adults. This presentation will highlight the efforts of our multidisciplinary team to use a variety of approaches, including advanced proteomics and protein interaction technologies, insect genetics, cell biology and biochemistry to explore the dynamic pathogen-vector interface as a function of infection status and developmental stage. Several examples of proteomics, molecular and genetic data will be discussed to illustrate the power of these approaches, when used in combination, to further our basic understanding of the dynamic molecular pathways involved in CLas transmission by D. citri. The excellent agreement of our data with previously published studies on the biology of D. citri and CLas will be highlighted. Finally, intriguing parallels with other vector-plant pathogen pathosystems and the use of these approaches to develop novel targeted strategies for citrus greening control will also be presented.

Abstract Number: S1-6
Session Type: Special Session