A two-genome microarray for the rice pathogens Xanthomonas oryzae pv. oryzae and X. oryzae pv. oryzicola and its use in the discovery of a difference in their regulation of hrp genes

Seo, Young-Su; Sriariyanun, Malinee; Wang, Li; Pfeiff, Janice; Phetsom, Jirapa; Ye, Lin; Jung, Ki‐Hong; Chou, Hui Hsien; Bogdanove, Adam J.; Ronald, Pamela C.

doi:10.1186/1471-2180-8-99

Cited by 42 publications

(43 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Genes that were differentially expressed more than 1.75 fold (log 2 ratio >0.8 or <–0.8) and have an FDR less than 5% were selected as described in our previous work [29]. To annotate the functions of the Ax21-regulated genes, COG terms (Clusters of Orthologous Groups of proteins: http://www.ncbi.nlm.nih.gov/COG/) of Xoo PXO99 were assigned.…”

Section: Methodsmentioning

confidence: 99%

Small Protein-Mediated Quorum Sensing in a Gram-Negative Bacterium

et al. 2011

Self Cite

View full text Add to dashboard Cite

The rice XA21 pattern recognition receptor binds a type I secreted sulfated peptide, called axYS22, derived from the Ax21 (activator of XA21-mediated immunity) protein. The conservation of Ax21 in all sequenced Xanthomonas spp. and closely related genera suggests that Ax21 serves a key biological function. Here we show that the predicted N-terminal sequence of Ax21 is cleaved prior to secretion outside the cell and that mature Ax21 serves as a quorum sensing (QS) factor in Xanthomonas oryzae pv. oryzae. Ax21-mediated QS controls motility, biofilm formation and virulence. We provide genetic evidence that the Xoo RaxH histidine kinase serves as the bacterial receptor for Ax21. This work establishes a critical role for small protein-mediated QS in a Gram-negative bacterium.

show abstract

Section: Methodsmentioning

confidence: 99%

Small Protein-Mediated Quorum Sensing in a Gram-Negative Bacterium

et al. 2011

Self Cite

View full text Add to dashboard Cite

show abstract

“…This regulation is very complex and varies substantially between different Xanthomonas -plant pathosystems and in some cases even between closely related bacteria within the same pathosystem [61]. In this study, we found that different carbohydrates have different influences on expression of hrpG and hrpX .…”

Section: Discussionmentioning

confidence: 59%

Fructose-Bisphophate Aldolase Exhibits Functional Roles between Carbon Metabolism and the hrp System in Rice Pathogen Xanthomonas oryzae pv. oryzicola

Guo

Zou

et al. 2012

PLoS ONE

View full text Add to dashboard Cite

Fructose-bisphophate aldolase (FbaB), is an enzyme in glycolysis and gluconeogenesis in living organisms. The mutagenesis in a unique fbaB gene of Xanthomonas oryzae pv. oryzicola, the causal agent of rice bacterial leaf streak, led the pathogen not only unable to use pyruvate and malate for growth and delayed its growth when fructose was used as the sole carbon source, but also reduced extracellular polysaccharide (EPS) production and impaired bacterial virulence and growth in rice. Intriguingly, the fbaB promoter contains an imperfect PIP-box (plant-inducible promoter) (TTCGT-N9-TTCGT). The expression of fbaB was negatively regulated by a key hrp regulatory HrpG and HrpX cascade. Base substitution in the PIP-box altered the regulation of fbaB with the cascade. Furthermore, the expression of fbaB in X. oryzae pv. oryzicola RS105 strain was inducible in planta rather than in a nutrient-rich medium. Except other hrp-hrc-hpa genes, the expression of hrpG and hrpX was repressed and the transcripts of hrcC, hrpE and hpa3 were enhanced when fbaB was deleted. The mutation in hrcC, hrpE or hpa3 reduced the ability of the pathogen to acquire pyruvate and malate. In addition, bacterial virulence and growth in planta and EPS production in RΔfbaB mutant were completely restored to the wild-type level by the presence of fbaB in trans. This is the first report to demonstrate that carbohydrates, assimilated by X. oryzae pv. oryzicola, play critical roles in coordinating hrp gene expression through a yet unknown regulator.

show abstract

“…But also synthetic culture media have been established for different xanthomonas patovars, which induce the synthesis of virulence factors including the TTSS. These media mimic the situation inside the host plant by regarding carbon sources, iron concentration, osmolarity, pH values and amino acids just to name a few (Wengelnik et al, 1996a;Seo et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

“…The genes encoding these virulence determinants are carefully regulated in order to prevent dissipative or premature expression. This regulation is very complex and varies substantially between different pathosystems and in some cases even between closely related bacteria within the same pathosystem (Seo et al, 2008). However, one regulative entity is ubiquitous among pathogenic bacteria the so-called quorum sensing, which permits bacterial cultures to sense their density.…”

Section: Introductionmentioning

confidence: 99%