Submitted to: International Research Conference on Huanglongbing
Publication Type: Abstract Only
Publication Acceptance Date: 10/15/2014
Publication Date: 3/30/2015
Citation: Nwugo, C.C., Doud, M.S., Duan, Y., Lin, H. 2015. Proteomics analysis reveals novel host molecular mechanisms that could be associated with heat-induced resistance to ‘Ca. Liberibacter asiaticus’ in lemon plants. J Cit Pathol. 2(1):32. iocv_journalcitruspathology_30222.
Technical Abstract: Sustainable long-term measures to combat HLB via breeding or genetic engineering methods are hampered by the fact that no true genetic resistance has been found in citrus germplasm. All cultivated citrus species or citrus relatives are susceptible to the disease. However, the degree of HLB susceptibility or tolerance varies among citrus species. There have been suggestions toward the identification of innate Las resistance-associated molecular mechanisms in citrus plants for application in breeding or genetic engineering crop development programs. Furthermore, a recent study showed that continuous heat treatment of 40°C to 42°C for a minimum of 48 h was sufficient to significantly reduce Las titer or eliminate Las entirely in HLB-affected citrus seedlings. Plant exposure to one form of stress has been shown to serendipitously induce resistance to other forms of stress. In this study, we conducted proteomics analysis of heat-treated HLB-affected lemon plants, detected proteins that were markedly up-regulated only in plants that were simultaneously exposed to heat and Las. This suggests that heat treatment induces proteins in Las-infected citrus plants that could play an active role in the suppression of Las growth. Hence, this research demonstrates that: (1) the application of a proteomics approach to elucidate the molecular mechanisms involved in heat-induced Las-resistance in citrus plants, (2) the use of the information from proteomics analysis to develop genetically-modified Las-resistant citrus plants by altering host gene expression to mimic heat-induced conditions.