Publications - Faculty - Recently Submitted Faculty Publications 2008
<- Back
Wang - Molecular Plant Pathology
Response of sweet orange (Citrus sinensis) to Candidatus Liberibacter asiaticus infection: microscopy and microarray analyses
Jeong-soon Kim, Uma Shankar Sagaram, Jacqueline K. Burns, and Nian Wang
Abstract. Citrus greening or Huanglongbing (HLB) is a devastating disease of citrus. HLB is caused by the phloem-limited fastidious prokaryotic α-proteobacterium Candidatus Liberibacter spp. In this report, we used sweet orange (Citrus sinensis) leaf tissue infected with Candidatus Liberibacter asiaticus and compared this with healthy controls. Investigation of the host response was examined using a citrus microarray hybridization based on 33,879 EST sequences of several citrus species and hybrids. The microarray analysis indicated that HLB infection significantly affected expression of 624 genes whose encoded proteins were categorized according to function. The categories included genes associated with sugar metabolism, plant defense, phytohormone, and cell wall metabolism, as well as 14 other gene categories. The anatomical changes of phloem caused by Candidatus Liberibacter asiaticus was analyzed in Valencia sweet orange (Citrus sinensis) leaves using light and transmission electron microscopy. Analyses indicated that HLB infection caused phloem disruption, sucrose and starch accumulation, and plugged sieve pores.
