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bacteria:t3e:avrbs1

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bacteria:t3e:avrbs1 [2025/02/17 22:33] – jfpothierbacteria:t3e:avrbs1 [2025/07/04 23:05] (current) – jfpothier
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 Epitope tagged AvrBs1 proteins were detected in culture supernatants only in the presence of a functional type III apparatus and not in a //hrcV// mutant, showing that the AvrBs1 proteins are secreted by //Xcv// in an //hrp//-dependent manner (Escolar //et al.//, 2001). Epitope tagged AvrBs1 proteins were detected in culture supernatants only in the presence of a functional type III apparatus and not in a //hrcV// mutant, showing that the AvrBs1 proteins are secreted by //Xcv// in an //hrp//-dependent manner (Escolar //et al.//, 2001).
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 === Regulation === === Regulation ===
  
 In 2001, in tests whether //avrBs1// promoter activity depends on the //hrp// regulatory genes, //hrpG// and //hrpX//, promoter constructs containing only //avrBs1// ORF2 were conjugated into wild-type //Xcv// race 2 strains deleted in //hrpX// or //hrpG//. The mutations did not significantly alter the GUS activity, indicating that //avrBs1// expression is not under the control of these //hrp// gene regulators (Escolar //et al.//, 2001). However, gene expression analysis using β-glucuronidase as reporter in another study in 2006 showed 7.3-fold reduction in GUS activity indicating that //avrBs1// was regulated by //hrpG// (Rongqi //et al.//, 2006). In 2010 it was reported that AvrBsT suppresses AvrBs1-elicited HR from //X. campestris// pv. //vesicatoria// in resistant pepper plants. HR suppression occurs inside the plant cell and depends on a conserved predicted catalytic residue of AvrBsT (Szczesny //et al.//, 2010). In 2001, in tests whether //avrBs1// promoter activity depends on the //hrp// regulatory genes, //hrpG// and //hrpX//, promoter constructs containing only //avrBs1// ORF2 were conjugated into wild-type //Xcv// race 2 strains deleted in //hrpX// or //hrpG//. The mutations did not significantly alter the GUS activity, indicating that //avrBs1// expression is not under the control of these //hrp// gene regulators (Escolar //et al.//, 2001). However, gene expression analysis using β-glucuronidase as reporter in another study in 2006 showed 7.3-fold reduction in GUS activity indicating that //avrBs1// was regulated by //hrpG// (Rongqi //et al.//, 2006). In 2010 it was reported that AvrBsT suppresses AvrBs1-elicited HR from //X. campestris// pv. //vesicatoria// in resistant pepper plants. HR suppression occurs inside the plant cell and depends on a conserved predicted catalytic residue of AvrBsT (Szczesny //et al.//, 2010).
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 === Phenotypes === === Phenotypes ===
  
 AvrBs1 specifies avirulence on pepper cultivars containing the resistance gene //Bs1// observed as hypersensitive response (HR) induction (Ronald & Staskawicz, 1988). Transient expression of //avrBs1// and //avrBsT// in resistant host plants using //Agrobacterium tumefaciens//-mediated gene transfer resulted in the induction of a specific HR (Escolar //et al.//, 2001). Studies with expression of //avrBs1// in //N. benthamiana// showed a decrease in the starch content in chloroplasts and an increased number of vesicles, indicating an enlargement of the central vacuole and the cell wall. These changes resulted in a swelling of the upper epidermis and bloating of the palisade cells in the mesophyll, thus changing their shape and leading to a decrease in the intercellular spaces. A significant increase in ion leakage, as well as dead cells in //avrBs1//-expressing tissue were also detected. Macroscopically, chlorosis and weak necrotic reactions in //N. benthamiana// were observed (Gürlebeck //et al.//, 2009). AvrBs1 specifies avirulence on pepper cultivars containing the resistance gene //Bs1// observed as hypersensitive response (HR) induction (Ronald & Staskawicz, 1988). Transient expression of //avrBs1// and //avrBsT// in resistant host plants using //Agrobacterium tumefaciens//-mediated gene transfer resulted in the induction of a specific HR (Escolar //et al.//, 2001). Studies with expression of //avrBs1// in //N. benthamiana// showed a decrease in the starch content in chloroplasts and an increased number of vesicles, indicating an enlargement of the central vacuole and the cell wall. These changes resulted in a swelling of the upper epidermis and bloating of the palisade cells in the mesophyll, thus changing their shape and leading to a decrease in the intercellular spaces. A significant increase in ion leakage, as well as dead cells in //avrBs1//-expressing tissue were also detected. Macroscopically, chlorosis and weak necrotic reactions in //N. benthamiana// were observed (Gürlebeck //et al.//, 2009).
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 === Localization === === Localization ===
  
 AvrBs1-GFP localizes exclusively to the cytoplasm of the plant cells (Gürlebeck //et al.//, 2009). AvrBs1-GFP localizes exclusively to the cytoplasm of the plant cells (Gürlebeck //et al.//, 2009).
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 === Enzymatic function === === Enzymatic function ===
  
 Unknown. It was found that AvrBs1 suppresses the activation of the high osmolarity glycerol (HOG) MAP kinase pathway in yeast, suggesting that this effector targets a signaling component that is conserved in eukaryotic organisms (Teper //et al.//, 2015). Unknown. It was found that AvrBs1 suppresses the activation of the high osmolarity glycerol (HOG) MAP kinase pathway in yeast, suggesting that this effector targets a signaling component that is conserved in eukaryotic organisms (Teper //et al.//, 2015).
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 === Interaction partners === === Interaction partners ===
  
 Gene silencing experiments revealed that SNF1-related kinase 1 (SnRK1) is required for the induction of the AvrBs1-specific HR. It was speculated that SnRK1 is involved in the AvrBsT-mediated suppression of the AvrBs1-specific HR (Szczesny //et al.//, 2010). Gene silencing experiments revealed that SNF1-related kinase 1 (SnRK1) is required for the induction of the AvrBs1-specific HR. It was speculated that SnRK1 is involved in the AvrBsT-mediated suppression of the AvrBs1-specific HR (Szczesny //et al.//, 2010).
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 ===== Conservation ===== ===== Conservation =====
  
 === In xanthomonads: === === In xanthomonads: ===
  
-Yes (//X//. //campestris// pv. //campestris// (Ronald & Staskawicz, 1988), //X//. //campestris// pv. //vitians// (Ronald & Staskawicz, 1988), //X//. //arboricola// pv. //juglandis// <sup>[Acc.No: [[https://www.ncbi.nlm.nih.gov/protein/SYZ61276.1|SYZ61276.1]]]</sup> )+Yes (//X//. //campestris// pv. //campestris// (Ronald & Staskawicz, 1988), //X//. //campestris// pv. //vitians// (Ronald & Staskawicz, 1988), //X//. //arboricola// pv. //juglandis// <sup>[Acc.No: [[https://www.ncbi.nlm.nih.gov/protein/SYZ61276.1|SYZ61276.1]]]</sup>)
  
 === In other plant pathogens/symbionts: === === In other plant pathogens/symbionts: ===
  
-//Acidovorax citrulli//, //Pseudomonas amygdali// <sup>[Acc.No: [[https://www.ncbi.nlm.nih.gov/protein/EGH05685.1|EGH05685.1]]]</sup> , homolog of AvrA from //Pseudomonas syringae// pv. //glycinea// (Napoli & Staskawicz, 1987; Ronald & Staskawicz, 1988), //Xylophilus ampelinus// (Nyembe, 2014).+//Acidovorax citrulli//, //Pseudomonas amygdali// <sup>[Acc.No: [[https://www.ncbi.nlm.nih.gov/protein/EGH05685.1|EGH05685.1]]]</sup>, homolog of AvrA from //Pseudomonas syringae// pv. //glycinea// (Napoli & Staskawicz, 1987; Ronald & Staskawicz, 1988), //Xylophilus ampelinus// (Nyembe, 2014). 
 ===== References ===== ===== References =====
  
bacteria/t3e/avrbs1.1739831635.txt.gz · Last modified: 2025/02/17 22:33 by jfpothier

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