- Pathogens Drop the Hint: Don't Forget Phytoalexin Pathways
Cell Host & Microbe, Volume 9, Issue 3, 17 March 2011, Pages 169-170
SummaryMany effectors secreted by pathogenic bacteria suppress host signal transduction pathways that activate host defense responses. In this issue of Cell Host & Microbe, Zhou et al. (2011) now broaden that theme by demonstrating that HopZ1b from Pseudomonas syringae pv. glycinea causes degradation of a host enzyme directly involved in the synthesis of antimicrobial phytoalexin compounds.
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- Catch me if you can: bacterial effectors and plant targets
Trends in Plant Science, Volume 17, Issue 11, 1 November 2012, Pages 644-655
Laurent Deslandes and Susana Rivas
AbstractTo suppress plant defense responses and favor the establishment of disease, phytopathogenic bacteria have gained the ability to deliver effector molecules inside host cells through the type III secretion system. Inside plant cells, bacterial effector proteins may be addressed to different subcellular compartments where they are able to manipulate a variety of host cellular components and molecular functions. Here we review how the recent identification and functional characterization of plant components targeted by bacterial effectors, as well as the discovery of new pathogen recognition capabilities evolved in turn by plant cells, have significantly contributed to further our knowledge about the intricate molecular interactions that are established between plants and their invading bacteria.
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- Facts and fiction of genetically engineered food
Trends in Biotechnology, Volume 27, Issue 5, 1 May 2009, Pages 277-286
Rita Batista and Maria Margarida Oliveira
AbstractThe generation of genetically engineered (GE) foods has been raising several concerns and controversies that divide not only the general public but also the scientific community. The fear and importance of the new technology, as well as commercial interests, have supported many of the ongoing discussions. The recent increase in the number of GE foods approved for import into the European Union and the increasingly global commercial food trades justify revisiting the facts and fiction surrounding this technology with the aim of increasing public awareness for well-informed decisions. Techniques that have recently become available for assessing food quality and its impact on human health, as well as the wealth of scientific data previously generated, clearly support the safety of commercialized GE products.
- Type III secreted effectors (T3SEs), such as Pseudomonas syringae HopZ1, are essential bacterial virulence proteins injected into the host cytosol to facilitate infection. However, few direct targets of T3SEs are known. Investigating the target(s) of HopZ1 in soybean, a natural P. syringae host, we find that HopZ1 physically interacts with the isoflavone biosynthesis enzyme, 2-hydroxyisoflavanone dehydratase (GmHID1). P. syringae infection induces gmhid1 expression and production of daidzein, a major soybean isoflavone. Silencing gmhid1 increases susceptibility to P. syringae infection, supporting a role for GmHID1 in innate immunity. P. syringae expressing active but not the catalytic mutant of HopZ1 inhibits daidzein induction and promotes bacterial multiplication in soybean. HopZ1-enhanced P. syringae multiplication is at least partially dependent on GmHID1. Thus, GmHID1 is a virulence target of HopZ1 to promote P. syringae infection of soybean. This work highlights the isoflavonoid biosynthesis pathway as an antibacterial defense mechanism and a direct T3SE target.