The global population is predicted to reach >9 billion by 2050, putting unprecedented pressure on already scarce natural resources. To tackle the population increase and the associated increased consumption there is an urgent need to increase food production in a sustainable manner. One important pressure on global food security that is often overlooked is that posed by plant pathogens, which cause devastating losses in staple crops including rice and wheat each year. This special Focus issue of Nature Reviews Microbiology on Plant–Microbe Interactions presents five Reviews from leading experts discussing the latest advances in our understanding of the relationship between bacterial, viral and eukaryotic filamentous pathogens and their plant hosts.
Editorial
Editorial: Two branches intertwined
doi:10.1038/nrmicro3152
Nature Reviews Microbiology 11, 737 (2013)
Research highlights
Microbial ecology: A bacterial decoy skews plant defences
Christina Tobin Kåhrström
doi:10.1038/nrmicro3142
Nature Reviews Microbiology 11, 740–741 (2013)
A new study shows that the larvae of a herbivorous insect exploits its bacterial symbionts to evade plant defences.
Symbiosis: Non-legumes answer the rhizobial call
Rachel David
doi:10.1038/nrmicro3137
Nature Reviews Microbiology 11, 740–741 (2013)
This study provides evidence that non-legumes can respond to rhizobial symbiotic signals.
Reviews
RNA silencing suppression by plant pathogens: defence, counter-defence and counter-counter-defence
Nathan Pumplin & Olivier Voinnet
doi:10.1038/nrmicro3120
Nature Reviews Microbiology 11, 745–760 (2013)
In plants, RNA silencing targets viral RNA for degradation, and viruses have evolved mechanisms to avoid silencing, most notably by expressing silencing suppressors. The recent identification of silencing suppressors in plant pathogenic bacteria and oomycetes suggests that RNA silencing functions in plant defence against a broad range of pathogens, not just viruses. There is also increasing evidence that plants have evolved counter-counter-defence responses to pathogen-mediated RNA-silencing suppression.
On the front line: structural insights into plant–pathogen interactions
Lennart Wirthmueller, Abbas Maqbool & Mark J. Banfield
doi:10.1038/nrmicro3118
Nature Reviews Microbiology 11, 761–776 (2013)
Structural biology studies of proteins involved in plant pathogen–host interactions are crucial to understanding the molecular mechanisms of both pathogen virulence and host defence. Banfield and colleagues review the current developments in the structural biology of plant–pathogen interactions, highlighting examples in which structural studies have had the biggest effect on our understanding of molecular function.
Geminiviruses: masters at redirecting and reprogramming plant processes
Linda Hanley-Bowdoin, Eduardo R. Bejarano, Dominique Robertson & Shahid Mansoor
doi:10.1038/nrmicro3117
Nature Reviews Microbiology 11, 777–788 (2013)
Geminiviruses are important plant pathogens that cause devastating crop losses worldwide. Here, Hanley-Bowdoin and colleagues review how viral proteins interact with cellular machineries and reprogramme cellular control pathways in their plant host to support viral DNA replication, gene expression and trafficking, and to interfere with host defences.
Going back to the roots: the microbial ecology of the rhizosphere
Laurent Philippot, Jos M. Raaijmakers, Philippe Lemanceau & Wim H. van der Putten
doi:10.1038/nrmicro3109
Nature Reviews Microbiology 11, 789–799 (2013)
The rhizosphere – the interface between plant roots and soil – is an intriguingly complex and dynamic niche. Laurent Philippot and colleagues review recent progress in rhizosphere research and suggest that going back to the roots could be crucial to further improve the sustainability of crop production.
Filamentous plant pathogen effectors in action
Martha C. Giraldo & Barbara Valent
doi:10.1038/nrmicro3119
Nature Reviews Microbiology 11, 800–813 (2013)
Giraldo and Valent review the latest research into the molecular and cellular biology of the effectors that are secreted during biotrophic invasion of plant cells by eukaryotic filamentous pathogens, with an emphasis on results obtained by live-cell imaging of effector dynamics during natural plant invasions.