Transposon mutagenesis reveals differential pathogenesis of Ralstonia solanacearum on tomato and Arabidopsis.
Ralstonia solanacearum causes a deadly wilting disease on a wide range of crops. To elucidate pathogenesis of this bacterium in different host plants, we set out to identify R. solanacearum genes involved in pathogenesis by screening random transposon insertion mutants of a highly virulent strain, Pss190, on tomato and Arabidopsis thaliana. Mutants exhibiting various decreased virulence levels on these two hosts were identified. Sequence analysis showed that most, but not all, of the identified pathogenesis genes are conserved among distinct R. solanacearum strains. A few of the disrupted loci were not reported previously as being involved in R. solanacearum pathogenesis. Notably, a group of mutants exhibited differential pathogenesis on tomato and Arabidopsis. These results were confirmed by characterizing allelic mutants in one other R. solanacearum strain of the same phylotype. The significantly decreased mutants' colonization in Arabidopsis was found to be correlated with differential pathogenesis on these two plants. Differential requirement of virulence genes suggests adaptation of this bacterium in different host environments. Together, this study reveals commonalities and differences of R. solanacearum pathogenesis on single solanaceous and nonsolanaceous hosts, and provides important new insights into interactions between R. solanacearum and different host plants.
Lin
Yu-Mei
YM
Graduate Institute of Plant Biology, Department of Life Science, National Taiwan University, Taipei, Taiwan. Republic of China.
Chou
I-Chun
IC
Wang
Jaw-Fen
JF
Ho
Fang-I
FI
Chu
Yu-Ju
YJ
Huang
Pei-Cheng
PC
Lu
Der-Kang
DK
Shen
Hwei-Ling
HL
Elbaz
Mounira
M
Huang
Shu-Mei
SM
Cheng
Chiu-Ping
CP
D017360:Arabidopsis / Q000382:microbiology*; D004251:DNA Transposable Elements / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics; D018551:Solanum lycopersicum / Q000382:microbiology*; D008957:Models, Genetic; D016254:Mutagenesis, Insertional; D009154:Mutation; D043368:Ralstonia solanacearum / Q000235:genetics* / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
D004251:DNA Transposable Elements; D037521:Virulence Factors