Extracellular virulence factors of Pseudomonas solanacearum: role in disease and regulation of expression

Schell, Mark A.; Denny, Timothy P.; Huang, Jianzhong

doi:10.1007/978-94-011-0746-4_22

Cited by 20 publications

(25 citation statements)

References 28 publications

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“…Subsequently, bacteria spread into the aerial parts of the infected plants (Vasse et al, 1995). The massive production of exopolysaccharides leads to the obstruction of the vascular system that causes wilting symptoms resulting from strong reduction of water flow (Schell et al, 1994). R. solanacearum encodes up to 80 putative TTSS effectors (Salanoubat et al, 2002;Cunnac et al, 2004;Occhialini et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

RD19, anArabidopsisCysteine Protease Required for RRS1-R–Mediated Resistance, Is Relocalized to the Nucleus by theRalstonia solanacearumPopP2 Effector

et al. 2008

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Bacterial wilt, a disease impacting cultivated crops worldwide, is caused by the pathogenic bacterium Ralstonia solanacearum. PopP2 (for Pseudomonas outer protein P2) is an R. solanacearum type III effector that belongs to the YopJ/AvrRxv protein family and interacts with the Arabidopsis thaliana RESISTANT TO RALSTONIA SOLANACEARUM 1-R (RRS1-R) resistance protein. RRS1-R contains the Toll/Interleukin1 receptor-nucleotide binding site-Leu-rich repeat domains found in several cytoplasmic R proteins and a C-terminal WRKY DNA binding domain. In this study, we identified the Arabidopsis Cys protease RESPONSIVE TO DEHYDRATION19 (RD19) as being a PopP2-interacting protein whose expression is induced during infection by R. solanacearum. An Arabidopsis rd19 mutant in an RRS1-R genetic background is compromised in resistance to the bacterium, indicating that RD19 is required for RRS1-R-mediated resistance. RD19 normally localizes in mobile vacuole-associated compartments and, upon coexpression with PopP2, is specifically relocalized to the plant nucleus, where the two proteins physically interact. No direct physical interaction between RRS1-R and RD19 in the presence of PopP2 was detected in the nucleus as determined by Fö rster resonance energy transfer. We propose that RD19 associates with PopP2 to form a nuclear complex that is required for activation of the RRS1-R-mediated resistance response.

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Section: Introductionmentioning

confidence: 99%

RD19, anArabidopsisCysteine Protease Required for RRS1-R–Mediated Resistance, Is Relocalized to the Nucleus by theRalstonia solanacearumPopP2 Effector

et al. 2008

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“…Previous studies (5,6,47) showed that the LysR-type transcriptional regulatory PhcA controls production of EPS and many other known and potential virulence determinants (e.g., Egl, PglA, and Pme). Consistent with this, inactivation of phcA caused a 50-fold reduction in eps transcription as measured with an eps::lacZ reporter (Table 3).…”

Section: Resultsmentioning

confidence: 99%

“…Each of these regulators appears to additionally and differentially control production of some EXPs and other virulence factors in an independent fashion (6,47). Here we report identification of three new eps regulatory genes: vsrC and vsrD, encoding distinct response regulators for VsrB and VsrA, respectively, and xpsR, encoding a unique basic protein.…”

mentioning

confidence: 88%

“…R, position of retarded fragment. (47); in the case of egl (and likely others), PhcA directly binds to and activates its promoter (23,25). (ii) VsrA and VsrD are the only components that appear to regulate genes required for efficient, rapid growth in planta and negatively control production of some EXPs (Fig.…”

Section: Figmentioning

confidence: 99%

“…solanacearum also produces many extracellular proteins (EXPs) that are likely or proven virulence factors; some are plant cell wall-degrading enzymes such as endoglucanase Egl (44), polygalacturonases PglA and PglB (47,50), and pectin methylesterase Pme (53). Studies of mutants lacking Egl or PglA (12,47) suggest that once inside the stem, P. solanacearum does not absolutely require these individual enzymes for wilting; more likely, they function in root invasion or acceleration of disease development. Mutants defective in export of most major EXPs outside of the cell (but not EPS) poorly infect plants via the roots and do not wilt or kill, even when large numbers are injected directly into the stem (28).…”

mentioning

confidence: 99%

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A complex network regulates expression of eps and other virulence genes of Pseudomonas solanacearum

et al. 1995

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We have discovered an unusual and complex regulatory network used by the phytopathogen Pseudomonas solanacearum to control transcription of eps, which encodes for production of its primary virulence factor, the exopolysaccharide EPS I. The major modules of this network were shown to be three separate signal transduction systems: PhcA, a LysR-type transcriptional regulator, and dual two-component regulatory systems, VsrA/VsrD and VsrB/VsrC. Using lacZ fusions and RNA analysis, we found that both PhcA and VsrA/VsrD control transcription of another network component, xpsR, which in turn acts in conjunction with vsrB/vsrC to increase transcription of the eps promoter by >25-fold. Moreover, gel shift DNA binding assays showed that PhcA specifically binds to the xpsR promoter region. Thus, the unique XpsR protein interconnects the three signal transduction systems, forming a network for convergent control of EPS I in simultaneous response to multiple environmental inputs. In addition, we demonstrate that each individual signaling system of the network also acts independently to divergently regulate other unique sets of virulence factors. The purpose of this complex network may be to allow this phytopathogen to both coordinately or independently regulate diverse virulence factors in order to cope with the dynamic situations and conditions encountered during interactions with plants.

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Pectinase in Degradation of Lignocellulosic Wastes

Gunjal¹,

Patil²,

Shinde³

2020

Enzymes in Degradation of the Lignocellulosic Wastes

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Extracellular virulence factors of Pseudomonas solanacearum: role in disease and regulation of expression

Cited by 20 publications

References 28 publications

RD19, anArabidopsisCysteine Protease Required for RRS1-R–Mediated Resistance, Is Relocalized to the Nucleus by theRalstonia solanacearumPopP2 Effector

RD19, anArabidopsisCysteine Protease Required for RRS1-R–Mediated Resistance, Is Relocalized to the Nucleus by theRalstonia solanacearumPopP2 Effector

A complex network regulates expression of eps and other virulence genes of Pseudomonas solanacearum

Pectinase in Degradation of Lignocellulosic Wastes

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