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In November, scientists working on P. syringae and related pathogens from some 20 countries convened in Agadir to discuss the latest research into these important disease-causing bacteria. The conference was split into six sessions with themes ranging from taxonomy and epidemiology to pathogenesis and genomics. The opening ceremony was notable due to the presence of the Moroccan Minister for Agriculture and Moroccan television cameras! This highlighted the local significance placed upon our work, with the nearby Souss valley an economically important agricultural area where bacterial plant diseases are increasing.
The identification, taxonomy and epidemiology sessions were very interesting as I had little experience in these areas of study. They introduced to me several different methods, both biochemical and DNA-based, being employed to try to gain accurate identification of and characterisation of Pseudomonas. I particularly enjoyed a talk given by Marco Scortichini (Italy) working on P. avellanae, a pathogen of hazelnut in Greece and Italy. Through a variety of molecular biological and statistical methods he had been able to show that it was likely that, given the absence of exchange of propagative material, the similar environmental conditions in the areas had locally selected for Pseudomonads with similar pathogenic traits.
Of course, no conference on P. syringae would be complete without talks on type III secretion and we were treated to a series of very informative and interesting presentations in the genomics session. The keynote talk by Magdalen Lindeberg (Cornell) on genome comparison and pattern-based searches using bioinformatics was fascinating, demonstrating the tremendous capacity genomics has in identifying genes likely to be important in pathogenesis and virulence. Alan Collmer’s talk (also Cornell) describing lab-based studies prompted by insights from genomics complemented Magdalen’s very well, proving the validity of their findings. Talks by James Alfano and Jens Boch further showed that while the inventory of type III effectors may be approaching its completion, we have much to learn about the way these proteins act once delivered into plant cells.
Cindy Morris (Montana State/INRAAvignon) gave an entertaining presentation exploring P. syringae outside of its traditional agricultural niche. Her group had isolated P. syringae from a variety of niches including non-cultivated fields, river epilithon and new snow. She suggested that there was the potential for P. syringae to be interacting with an array of other organisms found in these habitats, an idea which I have been interested in during my PhD studies. There was some debate about whether such niches would play an important part in the evolution of P. syringae pathovars and it was stimulating to hear the differences in viewpoint between those working at an ‘ecological’ level and those whose mainfocus is ‘molecular’. Interestingly, it was suggested that perhaps the presence of P. syringae in these other niches might be hinted at by some of the genes present, for example putative insecticidal toxins. Special mention should be given to Dawn Arnold (UWE) for standing in for a keynote speaker who was at the last minute unable to attend. In her talk on evolution of bacterial virulence driven by plant resistance, she showed the identification of a genomic island in P. syringae pathovar phaseolicola. When passaged via repeated inoculation and re-isolation through resistant bean cultivars, the genomic island excises from the genome, removing the HR eliciting avr protein and converting the interaction to a susceptible one.
An evening ‘why is there no ecology session’ round table meeting brought much deliberation and highlighted areas of which we still have a poor understanding. It was generally agreed that while we now know much more about the roles that toxins, type III secretion and host resistance have on determining host-bacterial interaction, we still have many unanswered questions regarding why some Pseudomonas cause disease on plants while others in the plant environment thrive without causing disease.
The conference excursion to Marrakech afforded the opportunity to visit one of Morocco’s imperial cities and experience haggling in the souks. Non-scientific skills were also demonstrated on the beach, with a keenly contested ‘shirts v skins’ football match, and at the farewell dinner with some impromptu Moroccan dancing. I would like to thank the conference chairman M’barak Fatmi for such a well organised meeting and the BSPP for making my attendance possible.
Peter Burlinson, Department of Plant Sciences, University of Oxford
…and an alternative view of the same Conference – Dynamo Syringae play Morocco
Picture this. Twenty pairs of legs running in the sand on a large golden beach. A host of onlookers admiring the glistening and writhing bodies. A red sun setting on a watery horizon. No, it’s not the set of Baywatch, but the return of football legends Dynamo Syringae!
Four years on from the infamous Maratea tour, and the “7th International Conference on Pseudomonas syringae and related pathogens” conference opened in the Tivoli Hotel in Agadir, Morocco. Three full days of talks were included, with one excursion day. The success of the conference is almost entirely due to Professor M’barek Fatmi and his team, who arranged airport transfers, smooth running of the meeting and excellent food and entertainment. Shukran Professor.
This conference is always highly regarded as it brings a lot of high profile scientists into the mix with the less lofty of us, which allows for an excellent range of presentations at all levels and informal science and social discussions in relaxing settings. Sessions covered diagnostics , epidemiology, pathogenesis, genomics, evolution and newly emerging pathogens. One talk by Cindy Morris described the identification of P. syringae bacteria in non-agricultural niches including clouds and epilithon biofilms, thereby highlighting the potential for these bacteria to live outside of the plant environment and to swap DNA with an array of other bacteria. Alec Forsyth made a very nice presentation on his work identifying plant components involved in basal defence. He indicated that there appears to be a second plant protein, extra to FLS2, which is involved in detecting PAMPs. On a familiar theme, Arantza Rico told us how Agrobacterium suppresses P. syringae-elicited salicylic acid (SA) production in Nicotiana benthamiana leaves. Interestingly, she used an SA biosensor to monitor SA levels. Luiz Rodrego-Moreno provided a nice talk on the use of chlorophyll fluorescence imaging for observing presymptomatic symptoms in plant leaves.
Magdalen Lindeberg described the power of comparative genomics, using three P. syringae genome sequences, to identify virulence factors and genomic islands. Interestingly, a mutant bank of P. syringae with transposons in almost every gene has been generated, which should aid future studies. Alan Collmer described some nice work on creating effector polymutants to study the basis of basal resistance and disease in host and non-host plants. Jens Boch and Jim Alfano identified a group of effectors similar to ADP- ribosyltransferases. Boris Vinatzer described how the P. syringae core genomes are very different in P. syringae, after studying a number of P. syringae isolates closely related to the tomato pathogen DC3000. Matthias Ullrich and other members of his group talked about the role of levan for P. syringae. They suggested that it is used as a food cache that is deposited within biofilms and can be utilized during times of nutrient depletion. Jesus Murillo described how phaseolotoxin gene clusters are not highly conserved through P. syringae, indicating separate acquisition events. A very elegant study of the phaseolotoxin gene cluster expression was given by Selene Aguilera. She provided new insight to the link between temperature regulation, expression and phenotypic analysis. In a talk close to my heart, Cayo Ramos described the curing of plasmids in P. savastanoi, which led to a major reduction in virulence observed as smaller galls on olive plants. Carmen Beuzón described the use of Competitive Index as a way of determining small changes in bacterial fitness during competition experiments. This will be very useful when examining different effector gene knockouts. Norman Schaad reveled as usual in the debate on whether some pathogens should be classified as P. savastanoi or not. Unfortunately, his old adversary John Young was absent, but Charles Manceau picked up the mantle to keep the debate alive and balanced. David Sands was, literally, poetic in joining Cindy Morris as eco-warriors-in arms, by chairing an evening session on the lack of an ecology session. Gail Preston elicited much humour by initializing the session with a role playing account of why P. syringae doesn’t like the soil and root environments. Towards the end of the meeting several non-molecular people commented on how they sensed a shift in the outlook of the molecular community to a broader perspective that considers the eco-evo context.
At the end of the last session on thursday, most of the delegates made the 5 min walk to the beach where we marked out a pitch. Supporters took their seats while the rest of us entered into an Immodium-driven frenzy of kicking and chopping – 10-aside on a 7- aside pitch with huge sand divots. The locals clearly thought this was the latest Monty Python film, funny walks and all. Pseuds United made a great start and only due to some incredible Oliver Kahn-like shot stopping by Matthias Ullrich did Dynamo Syringae survive the onslaught. That was until Charlie “Zine” Manceau scored a curler, bottom corner, to put PSU 1-up. A Bultreys special kept DyS in the match until PSU’s Yuki Ichinose scored the goal of the match with a belting dipping volley. Just to prove that these guys are at the top of the game, we saw amazing basal resistance from PSU’s Alan “The Guard” Collmer in defence and John “The Cat” Mansfield in goal. It felt like PSU had half the Moroccan national team playing, with Hicham Fatmi and friends showing us excellent ball control skills. Arantza Rico (PSU) and Isabelle Justalfre (DyS) exhibited their skills brought from womens rugby – fearless tackling and the kidney punch. DyS defence was legendary also. Matthias Ullrich demonstrated why he likes bacterial levan so much – every time he saved a shot the ball was nicely resisted as if by a solid biofilm. Jim “BigFoot” Alfano demonstrated his skill in defence and attack – like any good effector he made rapid attacks out of defence into the heart of enemy territory with theaim of suppression (usually by leveling someone!). Fortunately he didn’t take “The Guard” out or there could have been a rapid collapse! After goals from Milan Ivanovic and Luiz Rodrego- Moreno, DyS were poised to win 3-2 until a deflected clearance shot bounced back into goal: 3-3.
Enter my only useful contribution to the match – 10 seconds to go and one PSU player had delusions of Ronaldinho – what a cross, oh no, it’s going in. Only after a full stretch, backward dive did I palm the ball off the line and over the crossbar. Well, the referee agreed it was over! Two minutes later and Dynamo Syringae won the game through a Luiz Rodrego-Moreno goal. The shot was completely covered by The Cat, but an unfortunate roll over a sand divot scuppered any thoughts of replacing Paul Robinson in goal for England. This game, like the last one, was enjoyed by all, and after a quick swim in the sea, we retired for a beer and a good chat.
I was asked if the UK might be ready to host the conference for the first time. I wasn’t sure I could manage it entirely myself, but after consultation with some of the other British scientists, we decided that good old Blighty was up to the task if called on. I’m pleased to say that the International Committee voted for the UK to host the next conference in 2010! Our ageless figurehead John Mansfield (no retirement for at least another 4 years, sir) kindly accepted the challenge and we look forward to providing an exciting and stimulating meeting. We are wondering how we will cope for the rematch and we do wonder at the motivation of the International Committee – do they really want to visit our wonderful academic society, drink Pimms and eat cucumber sandwiches? Or perhaps, in reality, they actually have their eyes on the new Wembley!
I thank the BSPP and the Royal Society for providing me with funding. I learnt a lot at the conference and was able to give a talk. I thank Prof Fatmi and his colleagues for arranging such a good conference and also the Moroccan people I met, including Ahmed, who were so friendly and accommodating. Finally, I thank the P. syringae international committee for selecting the UK for the next conference.
Referee: David Sands Scores after full time (2 x 25 min): Dynamo Syringae 3-3 Pseuds United Dynamo Syringae won 4-3 with a golden goal in extra time by Luiz Rodrego-Moreno.
Dynamo Syringae: Rob Jackson (UK, Cap), Jim Alfano (US), Matthias Ullrich (Ger), Isabelle Justafre (Fra), Franco Valentini (Ita), Mohamed Bouabdallah (Mor), Abhishek Srivastava (Ind/Ger), Alain Bultreys (Fra; 1), Milan Ivanovic (Serb; 1), Luiz Rodrego-Moreno (Esp; 2).
Pseuds United: John Mansfield (UK, Cap), Alan Collmer (US), Arantza Rico (Esp/UK), Jens Boch (Ger), Charles Manceau (Fra; 1), Hicham Fatmi (Mor), Marco Scortichini (Ita), Joel Vanneste (Fra/NZ), Mouao Hjiej (Mor), Yuki Ichinose (Jpn; 1), Taha Hosni (Mor), Youness Idrissi-Khamlichi (Mor), Alberto Macho (Esp).
Local organizers for 2010: Robert Jackson (Reading), Dawn Arnold (UWE, Bristol), Gail Preston (Oxford), Richard Thwaites (CSL, York) and Alec Forsyth (Imperial College).
Robert Jackson, University of Reading
