Root loss on presymptomatic Huanglongbing affected trees is preceded by Candidatus Liberibacter asiaticus root infection but not phloem plugging

Huanglongbing (HLB) is a systemic disease of citrus caused by phloem-limited bacteria Candidatus Liberibacter spp. with Ca. Liberibacter asiaticus (Las) the most widespread. Phloem-limited bacteria such as Liberibacters and Phytoplasmas are emerging as major pathogens of woody and herbaceous plants. Little is known about their systemic movement within a plant and the disease process in these tissues. Las movement after initial infection was monitored in leaves and roots of greenhouse trees. Root density, storage starch content, and vascular system anatomy in relation to Las presence in symptomatic and asymptomatic field and