AvrPtoB: A bacterial type III effector that both elicits and suppresses programmed cell death associated with plant immunity

Abramovitch, Robert B.; Martin, Gregory B.

doi:10.1016/j.femsle.2005.02.025

Cited by 63 publications

(41 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Data sets marked with an asterisk are significantly different from the control (water-treated leaves followed by 8004 infection and water-pretreated leaves followed by 8397 or 8396 infections) as assessed by the Student's t test. Martin, 2004Martin, , 2005Alfano and Collmer, 2004;Nomura et al, 2005). It has recently been shown that the P. syringae type III secretion system down-regulates the expression of a set of Arabidopsis genes encoding putatively secreted cell wall and defense proteins in a salicylic acid-independent manner (Hauck et al, 2003).…”

Section: Discussionmentioning

confidence: 99%

Xanthan Induces Plant Susceptibility by Suppressing Callose Deposition

et al. 2006

View full text Add to dashboard Cite

Xanthan is the major exopolysaccharide secreted by Xanthomonas spp. Despite its diverse roles in bacterial pathogenesis of plants, little is known about the real implication of this molecule in Xanthomonas pathogenesis. In this study we show that in contrast to Xanthomonas campestris pv campestris strain 8004 (wild type), the xanthan minus mutant (strain 8397) and the mutant strain 8396, which is producing truncated xanthan, fail to cause disease in both Nicotiana benthamiana and Arabidopsis (Arabidopsis thaliana) plants. In contrast to wild type, 8397 and 8396 strains induce callose deposition in N. benthamiana and Arabidopsis plants. Interestingly, treatment with xanthan but not truncated xanthan, suppresses the accumulation of callose and enhances the susceptibility of both N. benthamiana and Arabidopsis plants to 8397 and 8396 mutant strains. Finally, in concordance, we also show that treatment with an inhibitor of callose deposition previous to infection induces susceptibility to 8397 and 8396 strains. Thus, xanthan suppression effect on callose deposition seems to be important for Xanthomonas infectivity.

show abstract

Section: Discussionmentioning

confidence: 99%

Xanthan Induces Plant Susceptibility by Suppressing Callose Deposition

et al. 2006

View full text Add to dashboard Cite

show abstract

“…It is possible that an unidentified activity that suppresses basal defences is present in the AvrPtoB N terminus. Some homologues of AvrPtoB only have similarity to the N terminus of AvrPtoB 100,101 , indicating that the N terminus of AvrPtoB has a virulence activity that is independent of the C-terminal anti-PCD activity 102 .…”

Section: Bacterial Suppression Of Hr-based Pcdmentioning

confidence: 99%

Bacterial elicitation and evasion of plant innate immunity

Abramovitch

Anderson

Martin

2006

Nat Rev Mol Cell Biol

Self Cite

377

285

View full text Add to dashboard Cite

Recent research on plant responses to bacterial attack has identified extracellular and intracellular host receptors that recognize conserved pathogen-associated molecular patterns and more specialized virulence proteins, respectively. These findings have shed light on our understanding of the molecular mechanisms by which bacteria elicit host defences and how pathogens have evolved to evade or suppress these defences.Plants are a rich source of nutrients and water for microbes, and they are infected by many bacterial pathogens from both the Proteobacteria and Actinobacteria phyla (Supplementary information 1 (table)). Because of their broad host range, serious economic consequences and experimental tractability, the most intensively studied bacteria are members of the Proteobacteria phylum (such as Agrobacterium, Erwinia, Pseudomonas, Ralstonia and Xanthomonas) [1][2][3][4] . These pathogens are spread by wind, rain, insects or cultivation practices. They enter plant tissues either by wounds or through natural openings such as lenticels, hydathodes or stomata 5 , and they occupy the inter cellular spaces (apoplast) of various plant tissues or the xylem.Plant-pathogenic members of the Proteobacteria cause diverse disease symptoms, including specks, spots, blights, wilts, galls and cankers, and they can cause host-cell death in roots, leaves, flowers, fruits, stems and tubers (FIG. 1). These symptoms affect both yield and quality of agricultural crops and bacterial diseases can have serious economic, social and even political consequences [6][7][8] . Control of bacterial diseases is only partially effective and consists of copper-based sprays, antibiotics, biocontrol strategies, large-scale removal of infected plants and, most importantly, host genetic resistance 5 . Therefore, research on bacterial diseases of plants helps to elucidate fundamental aspects of microbial pathogenesis and associated host responses and also to develop more effective and sustainable disease-control methods.Correspondence to G.B.M. gbm7@cornell.edu. Competing interests statementThe authors declare no competing financial interests. DATABASES NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptPlant-pathogenic bacteria use virulence strategies that are either specialized to plant tissues or are broadly conserved among pathogens of both plants and animals (FIG. 1). Bacterial virulence is manifested as increases in the rate of growth or final population size, as well as by enhanced disease symptoms, which promote the spread of the pathogen through the plant or the broader environment.Unlike mammals, plants have a complex cell wall that bacteria must surmount to gain access to water and nutrients. Bacteria attack this barrier with extracellular virulence factors, such as cell wall degrading enzymes, and bypass it by the secretion of cell wall-permeable toxins 5 . However, perhaps the most effective virulence strategy, and one shared with animal bacterial pathogens, is to breach the wall by use of the type III s...

show abstract

“…Prf is monomorphic, at least in the tomato species analysed to date. Pto is the direct target of two unrelated P. syringae effectors, AvrPto and AvrPtoB, each of which contributes to pathogen virulence in pto mutants 102 . It is thus likely that Prf guards Pto (refs 101, 103).…”

mentioning

confidence: 99%

The plant immune system

Jones

Dangl

2006

Nature

11,149

9,959

View full text Add to dashboard Cite

Many plant-associated microbes are pathogens that impair plant growth and reproduction. Plants respond to infection using a two-branched innate immune system. The first branch recognizes and responds to molecules common to many classes of microbes, including non-pathogens. The second responds to pathogen virulence factors, either directly or through their effects on host targets. These plant immune systems, and the pathogen molecules to which they respond, provide extraordinary insights into molecular recognition, cell biology and evolution across biological kingdoms. A detailed understanding of plant immune function will underpin crop improvement for food, fibre and biofuels production.

show abstract

AvrPtoB: A bacterial type III effector that both elicits and suppresses programmed cell death associated with plant immunity

Cited by 63 publications

References 49 publications

Xanthan Induces Plant Susceptibility by Suppressing Callose Deposition

Xanthan Induces Plant Susceptibility by Suppressing Callose Deposition

Bacterial elicitation and evasion of plant innate immunity

The plant immune system

Contact Info

Product

Resources

About