scholarly journals A putative LysR-type transcriptional regulator PrhO positively regulates the type III secretion system and contributes to the virulence ofRalstonia solanacearum

2018 ◽  
Vol 19 (8) ◽  
pp. 1808-1819 ◽  
Author(s):  
Yong Zhang ◽  
Jiaman Li ◽  
Weiqi Zhang ◽  
Hualei Shi ◽  
Feng Luo ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Transcriptional Regulator ◽  
Secretion System ◽  
Type Iii

scholarly journals PrhG, a Transcriptional Regulator Responding to Growth Conditions, Is Involved in the Control of the Type III Secretion System Regulon in Ralstonia solanacearum

2009 ◽  
Vol 192 (4) ◽  
pp. 1011-1019 ◽  
Author(s):  
Laure Plener ◽  
Pablo Manfredi ◽  
Marc Valls ◽  
Stéphane Genin
Keyword(s):  
Ralstonia Solanacearum ◽  
Type Iii Secretion ◽  
Minimal Medium ◽  
Type Iii Secretion System ◽  
Transcriptional Regulator ◽  
Secretion System ◽  
Host Cells ◽  
Bacterial Disease ◽  
Type Iii ◽  
Regulatory Cascade

ABSTRACT The ability of Ralstonia solanacearum to cause disease in plants depends on its type III secretion system (T3SS). The expression of the T3SS and its effector substrates is coordinately controlled by a regulatory cascade, at the bottom of which is HrpB. Transcription of the hrpB gene is activated by a plant-responsive regulator named HrpG, which is a master regulator of a wide array of pathogenicity functions in R. solanacearum. We have identified in the genome of strain GMI1000 a close paralog of hrpG (83% overall similarity at the protein level) that we have named prhG. Despite this high similarity, the expression pattern of prhG is remarkably different from that of hrpG: prhG expression is activated after growth of bacteria in minimal medium but not in the presence of host cells, while hrpG expression is specifically induced in response to plant cell signals. We provide genetic evidence that prhG is a transcriptional regulator that, like hrpG, controls the expression of hrpB and the hrpB-regulated genes under minimal medium conditions. However, the regulatory functions of prhG and hrpG are distinct: prhG has no influence on hrpB expression when the bacteria are in the presence of plant cells, and transcriptomic profiling analysis of a prhG mutant revealed that the PrhG and HrpG regulons have only one pathogenicity target in common, hrpB. Functional complementation experiments indicated that PrhG and HrpG are individually sufficient to activate hrpB expression in minimal medium. Rather surprisingly, a prhG disruption mutant had little impact on pathogenicity, which may indicate that prhG has a minor role in the activation of T3SS genes when R. solanacearum grows parasitically inside the plant. The cross talk between pathogenicity regulatory proteins and environmental signals described here denotes that an intricate network is at the basis of the bacterial disease program.

Type III Secretion System–Associated Toxins, Proteases, Serotypes, and Antibiotic Resistance ofPseudomonas aeruginosaIsolates Associated with Keratitis

2006 ◽  
Vol 31 (4) ◽  
pp. 297-306 ◽  
Author(s):  
Hua Zhu ◽  
Tim C.R. Conibear ◽  
Rani Bandara ◽  
Yulina Aliwarga ◽  
Fiona Stapleton ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Type Iii
Sign in / Sign up

Export Citation Format

Share Document