Torres, M.A., Dangl, J.L. & Jones, J.D. Arabidopsis gp91phox homologues AtrbohD and AtrbohF are required for accumulation of reactive oxygen intermediates in the plant defense response. Proc. Natl. Acad. Sci. USA 99, 517-522

Department of Biology and Curriculum in Genetics and Molecular Biology, CB 3280, 108 Coker Hall, University of North Carolina, Chapel Hill, NC 27599-3280, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.67). 02/2002; 99(1):517-22. DOI: 10.1073/pnas.012452499
Source: PubMed


Reactive oxygen intermediates (ROI) are strongly associated with plant defense responses. The origin of these ROI has been controversial. Arabidopsis respiratory burst oxidase homologues (rboh genes) have been proposed to play a role in ROI generation. We analyzed lines carrying dSpm insertions in the highly expressed AtrbohD and AtrbohF genes. Both are required for full ROI production observed during incompatible interactions with the bacterial pathogen Pseudomonas syringae pv. tomato DC3000(avrRpm1) and the oomycete parasite Peronospora parasitica. We also observed reduced cell death, visualized by trypan blue stain and reduced electrolyte leakage, in the Atrboh mutants after DC3000(avrRpm1) inoculation. However, enhanced cell death is observed after infection of mutant lines with P. parasitica. Paradoxically, although atrbohD mutation eliminated the majority of total ROI production, atrbohF mutation exhibited the strongest effect on cell death.

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    • "Rboh genes were first identified to generate ROS in response to biotic stress. Study on mutant and antisense lines of Rboh genes AtrbohD and AtrbohF, gave the proof of production of oxidative burst by RBOH in pathogen infection (Torres et al., 2002). ROS generated by RBOH also impose their role in abiotic signaling and same genes are involved in ROS production in this signaling. "
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    ABSTRACT: Plants encounter a number of environmental stresses throughout their life cycles, most of which activate mitogen activated protein kinase (MAPK) pathway. The MAPKs show crosstalks at several points but the activation and the final response is known to be specific for particular stimuli that in-turn activates specific set of downstream targets. Interestingly, reactive oxygen species (ROS) is an important and common messenger produced in various environmental stresses and is known to activate many of the MAPKs. ROS activates a similar MAPK in different environmental stimuli, showing different downstream targets with different and specific responses. In animals and yeast, the mechanism behind the specific activation of MAPK by different concentration and species of ROS is elaborated, but in plants this aspect is still unclear. This review mainly focuses on the aspect of specificity of ROS mediated MAPK activation. Attempts have been made to review the involvement of ROS in abiotic stress mediated MAPK signaling and how it differentiates with that of biotic stress.
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    • "Wheat plants appeared to be responding to the presence of Ggt as shown by the accumulation of transcripts for several genes involved in the signal transduction following the perception of pathogen-associated molecular patterns (PAMPs). We observed a transcript accumulation of a putative gene coding for a RBOHF protein, which is required for full reactive oxygen intermediate production (Torres et al. 2002) and genes involved in oxidation–reduction processes and proteolysis. Although it was not demonstrated in our study, we speculate that Ggt could induce a hypersensitive response (HR), a defence mechanism which relies on the production of Reactive Oxygen Species (ROS) (Ma and Berkowitz 2011; Mittler 2006; Rejeb et al. 2014). "
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    • "phenotype and reduced fertility ( Pineiro et al . , 2003 ) . EBS encodes a nuclear protein with homeodomain Zn finger that regulate chromatin remodeling and repress the initiation of flowering in short days . Pathogen recognition triggers generation of reactive oxygen intermediates ( ROIs ) , which is required for activation of defense responses ( Torres et al . , 2002 ) . It is also evident that the generation of ROI occurs within hours of pathogen infection ( Alvarez et al . , 1998 ) . Since PAP5 is induced only during the earlier stages ( 6 h . p . i ) of Pst DC3000 infection and the localization of PAP5 in peroxisome ( Figure 4 ) suggests that PAP5 may act as a component of ROI generation . Hence "
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    ABSTRACT: Plants possess an exceedingly complex innate immune system to defend against most pathogens. However, a relative proportion of the pathogens overcome host's innate immunity and impair plant growth and productivity. We previously showed that mutation in purple acid phosphatase (PAP5) lead to enhanced susceptibility of Arabidopsis to the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). Here, we report that an optimal level of PAP5 is crucial for mounting complete basal resistance. Overexpression of PAP5 impaired ICS1, PR1 expression and salicylic acid (SA) accumulation similar to pap5 knockout mutant plants. Moreover, plant overexpressing PAP5 was impaired in H2O2 accumulation in response to Pst DC3000. PAP5 is localized in to peroxisomes, a known site of generation of reactive oxygen species for activation of defense responses. Taken together, our results demonstrate that optimal levels of PAP5 is required for mounting resistance against Pst DC3000 as both knockout and overexpression of PAP5 lead to compromised basal resistance.
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