Posts Tagged ‘nematodes’

Effectors in Plant-Microbe Interactions

November 17th, 2011

Just got a copy of our book on Effectors in Plant-Microbe Interactions by Sophien Kamoun and I. It looks georgious … although the photo on the cover page is reminiscent of ‘The Eye of Sauron‘ as portrayed in Peter Jackson’s Lord of the Ringsmovie  trilogy.

Search inside this book at Amazon.com:

 

A Sneak Preview: ‘Effectors in Plant-Microbe Interactions’ book

September 17th, 2011

The book ‘Effectors in Plant-Microbe Interactions’

Edited by Sophien Kamoun and I, will be released by Wiley-Blackwell on January 2012:

A sneak preview …

Effectors are defined as molecules produced by bio-aggressors/pathogens/symbionts to manipulate their host plants, thereby facilitating infection (virulence or symbiotic factors, toxins, inhibitors) and/or triggering defense responses (avirulence factors, elicitors). This dual (and conflicting) activity of effectors has been broadly reported in many plant–microbial interactions. This research topic is actively investigated using a combination of approaches (genetics, molecular biology, biochemistry, physiology and developmental biology) and benefits from the recent advances in plant and microbial functional genomics and genome-wide evolutionary analyses. Tremendous progress has been made in recent years but many questions remain unanswered. The book aims to act as a catalyst for future research by bringing together a collection of contributions on plant–microbe interactions across a range of organisms (viruses, bacteria, fungi and nematodes) to identify and focus on these important questions. A book on this topic will be timely. It combines chapters by researchers involved in a diversity of plant-microbe systems that use biochemical, physiological, and developmental approaches as well as comparative genomics. Such a broad-ranging approach is providing a unique insight and a better understanding of the functions of this new class of proteins. Authors have been encouraged to discuss far reaching extensions of their current or past work and to propose cross-cutting research questions whenever possible.

Image: A great, arty photo from Sebastian Schornack (TSL) showing red fluorescent Phytophthora infestans colonizing its host. The central necrotrophic zone (in black) is surrounded by the biotrophic area (in fluo green).  The biotropic zone was caused by the action of effectors that suppressed the host responses.

 

How to Crunch Plant Walls? … by Gene Transfer

October 2nd, 2010

11752Lateral gene transfer (LGT) between bacteria has largely been documented. The transmission of genes between fungi (e.g., Supernumerary chromosomes in a root-rot fungus, In Vino Veritas, Next-Generation Sequencing of Sordaria Genome), and between fungi and insects, such as aphids (see Tap the Vein that Bleeds), have also been reported. In contrast, data on LGT in animals is scarce. In the last issue of PNAS, Pierre Abad’s group from INRA is publishing their study of LGT in plant-parasitic nematodes. Their phylogenetic analysis of  genes coding for degrading enzymes acting on plant cell walls  (e.g., GH28 polygalacturonase, PL3 pectate lyase, GH43 arabinase, …)  from root-knot nematodes (such as Meloidogyne incognita and M. hapla) shows that these nematode enzymes were likely acquired from several independent bacterial sources. The authors hypothesized a series of acquisition through soil bacteria feeding or gene transfers from endosymbiotic bacteria. The  observed abundance of multigenic families (cellulases, pectate lyases, and expansins) in these plant-parasitic nematodes is likely due to a series of duplications that started after acquisition by LGT events. Selective advantage associated with transfer of these CAZyme genes probably has driven their duplications and facilitated fixation in the different populations and species of plant-parasitic nematodes.

In brief, when ‘worms gobble up genes from bugs’ (S. Kamoun) they were able to get access to the largest store of carbon in soil — is this fast-track evolution?

Danchin et al. (2010) Multiple lateral gene transfers and duplications have promoted plant parasitism ability in nematodes. Proc. Ntl. Acad. Sci., published online before print September 27, 2010, doi: 10.1073/pnas.1008486107.

Photo: Root-knot nematode © www.minlnv.nl

August 24th, 2009

22nps_logo

The 22nd New Phytologist Symposium entitled ‘Effectors in plant–microbe interactions’ will be held at INRA Versailles Research Centre, Paris, France from 13 to 16 September 2009. For full details about the meeting, see The New Phytologist web site.

“Effectors are defined as molecules produced by bio-aggressors/pathogens/symbionts to manipulate their host plants, thereby facilitating infection (virulence or symbiotic factors, toxins, inhibitors) and/or triggering defense responses (avirulence factors, elicitors). This dual (and conflicting) activity of effectors has been broadly reported in many plant–microbial interactions. This research topic is actively investigated using a combination of approaches and benefits from the recent advances in plant and microbial functional genomics and genome-wide evolutionary analyses. The 22nd New Phytologist Symposium aims to bring together scientists working on plant–microbe interactions across a range of organisms (viruses, bacteria, fungi and nematodes) to identify and focus on these important questions.” from H. Slater.