Is there any crosstalk between the chemotaxis and virulence induction signaling in Agrobacterium tumefaciens?
Agrobacterium tumefaciens, a soil-born phytopathogenic bacterium, is well known as a nature's engineer due to its ability to genetically transform the host by transferring a DNA fragment (called T-DNA) from its Ti plasmid to host-cell genome. To combat the harsh soil environment and seek the appropriate host, A. tumefaciens can sense and be attracted by a large number of chemical compounds released by wounded host. As a member of α-proteobacterium, A. tumefaciens has a chemotaxis system different from that found in Escherichia coli, since many chemoattractants for A. tumefaciens chemotaxis are virulence (vir) inducers. However, advances in the study of the chemotaxis paradigm, E. coli chemotaxis system, have provided enough information to analyze the A. tumefaciens chemotaxis. At low concentration, chemoattractants elicit A. tumefaciens chemotaxis and attract the species to the wound sites of the host. At high concentration, chemoattractants induce the expression of virulence genes and trigger T-DNA transfer. Recent studies on the VirA and ChvE of the vir-induction system provide some evidences to support the crosstalk between chemotaxis and vir-induction. This review compares the core components of chemotaxis signaling system of A. tumefaciens with those observed in other species, discusses the connection between chemotaxis and vir-induction in A. tumefaciens, and proposes a model depicting the signaling crosstalk between chemotaxis and vir-induction.
College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, Jiangsu 225009, China. Electronic address: guoml@yzu.edu.cn.
Minliang
M
Guo
College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, Jiangsu 225009, China.
Zhiwei
Z
Huang
College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, Jiangsu 225009, China.
Jing
J
Yang
D016960:Agrobacterium tumefaciens; D002633:Chemotaxis; D015398:Signal Transduction; D014774:Virulence
Agrobacterium tumefaciens; Chemoreceptor; Chemotaxis; Histidine autokinase; Response regulator; Signal transduction; Signaling crosstalk; Two-component system; Virulence induction