Home About us MoEF Contact us Sitemap Tamil Website  
About Envis
Whats New
Research on Microbes
Microbiology Experts
Online Submission
Access Statistics

Site Visitors

blog tracking

Vol: 75, No: 6, 2009, Pages: 1566–1574

Bacterial Diversity Analysis of Huanglongbing Pathogen-Infected Citrus,
Using PhyloChip Arrays and 16S rRNA Gene Clone Library Sequencing

Uma Shankar Sagaram,1‡ Kristen M. DeAngelis,2‡ Pankaj Trivedi,1 Gary L. Andersen,2 Shi-En Lu,3 and Nian Wang1*

Citrus Research and Education Center, Department of Microbiology and Cell Science, University of Florida/IFAS, 700 Experiment Station Road, Lake Alfred, FL 33850.


The bacterial diversity associated with citrus leaf midribs was characterized for citrus groves that contained the Huanglongbing (HLB) pathogen, which has yet to be cultivated in vitro. We employed a combination of high-density phylogenetic 16S rRNA gene microarrays and 16S rRNA gene clone library sequencing to determine the microbial community composition for symptomatic and asymptomatic citrus midribs. Our results revealed that citrus leaf midribs can support a diversity of microbes. PhyloChip analysis indicated that 47 orders of bacteria in 15 phyla were present in the citrus leaf midribs, while 20 orders in 8 phyla were observed with the cloning and sequencing method. PhyloChip arrays indicated that nine taxa were significantly more abundant in symptomatic midribs than in asymptomatic midribs. “Candidatus Liberibacter asiaticus” was detected at a very low level in asymptomatic plants but was over 200 times more abundant in symptomatic plants. The PhyloChip analysis results were further verified by sequencing 16S rRNA gene clone libraries, which indicated the dominance of “Candidatus Liberibacter asiaticus” in symptomatic leaves. These data implicate “Candidatus Liberibacter asiaticus” as the pathogen responsible for HLB disease.

Keywords:Candidatus Liberobacter spp.,;high-density phylogenetic 16S rRNA gene microarrays;Cuscuta campestris;Catharanthus roseus;16S rRNA gene clone libraries.

Corresponding author: Tel (863) 956-1151, Fax (863) 956-4631.

E-mail: nianwang@crec.ifas.ufl.edu


Copyright © 2005 ENVIS Centre ! All rights reserved
This site is optimized for 1024 x 768 screen resolution