Immunity gene fusions uncovered in plants

19 February 2016
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Dr Ksenia Krasileva, Group Leader at the Earlham Institute (EI) and Fellow at The Sainsbury Laboratory (TSL) in collaboration with her TSL colleagues, Professor Jonathan Jones and Dr Panagiotis Sarris, have surveyed immune genes across flowering plants to uncover the molecular ‘traps’ that plants use to detect pathogens.

Plant health and interaction with microbes is maintained by intricate antennas – plant immune receptors. A certain class of receptors is turning out to be highly informative about plant disease resistance.

A few of such Nucleotide-binding Leucine-Rich Repeat receptors (NLRs) with additional integrated domains that act as ‘baits’ for the pathogen were previously identified in rice and thale cress and experimentally shown to be involved in disease resistance. Krasileva and her TSL colleagues searched for these genes across plant species, including the key UK crops: wheat, potatoes, and rapeseed.

NLRs are found within the cells, rather than at the cell membrane or in cell walls. When activated by an invasive pathogen or foreign organism, NLRs activate cellular self-destruction – they are sensors of attack. Once a pathogen has infected a plant cell and bound these targets, the cell is likely to self-destruct, blocking pathogen growth before it can reach other cells.

By scanning 40 available plant genome sequences including 19 crop species for the full spectrum of NLRs fused to other plant proteins, the team of scientists evaluated the diversity of such integrations of potential sensor domains across flowering plants. Additional manual analysis of wheat and brassicas validated a subset of fusions in wild and cultivated varieties.

Examining NLR fusions that occur in multiple plant families, the scientists identified that some were prevalent across lineages. The fact that these fusions are common to the majority of surveyed flowering plants is an important discovery in combatting plant disease. The corresponding domains that have been integrated into NLR proteins during evolution likely reveal previously unsuspected targets of pathogen effectors.

Dr Ksenia Krasileva, Lead author of the study and Group Leader at EI/TSL, said: “Our method for detecting variations in immune receptors across flowering plants revealed exciting new genes that might be important for plant health. Our findings provide very rich information for scientists who are working to understand how plant immunity works. Similarly, plant breeders might be able to deploy our discoveries to improve sustainable production of each of the crops we analysed. We hope that the NLR-fusions we uncovered will provide clues to the host proteins targeted by pathogens and that this information can be deployed to discover new sources of disease resistance.”

Dr Jonathan Jones from TSL, Co-author of the study, said: In the last year, we and others showed that plant NLR immune receptors can carry integrated domains that mimic authentic host targets of pathogen effectors. Interestingly, the identity of such NLR-fusions overlaps significantly with effector targets revealed by other methods and thus reveal some important new host components that might be targeted by effectors to promote susceptibility. This work this has been a wonderfully productive collaboration between EI and TSL, and between the Krasileva and Jones groups.”

Dr Panagiotis Sarris from TSL and Exeter University, First author of the study, added: “The latest breakthrough discovery in the evolutionary battle between plants and pathogens is that plant immune receptors carry additional built-in protein areas, which enable them to detect pathogens and activate defence. Our study revealed a great number of extraneous domains. These findings can help us to obtain a better overview of the virulence strategies that pathogenic microbes use to promote susceptibility.

This research, entitled: “Comparative analysis of plant immune receptor architectures uncovers host proteins likely targeted by pathogens” is published in BMC Biology.1

The project was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and The Gatsby Charitable Foundation.

EI is strategically funded by BBSRC and operates a National Capability to promote the application of genomics and bioinformatics to advance bioscience research and innovation.

 

Notes to editors.

Notes to editors.

For more information, please contact:

Hayley London

Marketing & Communications Officer, Earlham Institute (EI)

  • +44 (0)1603 450 107

hayley.london@earlham.ac.uk

About Earlham Institute

The Earlham Institute (EI) is a world-class research institute focusing on the development of genomics and computational biology. EI is based within the Norwich Research Park and receives strategic funding from the Biotechnology and Biological Science Research Council (BBSRC) - £7.4M in 2013/14 - as well as support from other research funders. EI is one of eight institutes that receive strategic funding from BBSRC. EI operates a National Capability to promote the application of genomics and bioinformatics to advance bioscience research and innovation.

EI offers state of the art DNA sequencing facility, unique by its operation of multiple complementary technologies for data generation. The Institute is a UK hub for innovative Bioinformatics through research, analysis and interpretation of multiple, complex data sets. It hosts one of the largest computing hardware facilities dedicated to life science research in Europe. It is also actively involved in developing novel platforms to provide access to computational tools and processing capacity for multiple academic and industrial users and promoting applications of computational Bioscience. Additionally, the Institute offers a Training programme through courses and workshops, and an Outreach programme targeting schools, teachers and the general public through dialogue and science communication activities.

www.earlham.ac.uk

About The Sainsbury Laboratory

The Sainsbury Laboratory (TSL) is a world-leading research centre focusing on making fundamental discoveries about plants and how they interact with microbes. TSL not only provides fundamental biological insights into plant-pathogen interactions, but is also delivering novel, genomics-based, solutions which will significantly reduce losses from major diseases of food crops, especially in developing countries. TSL is an independent charitable company and receives strategic funding from the Gatsby Charitable Foundation with the balance coming from competitive grants and contracts from a range of public and private bodies, including the European Union (EU), Biotechnology and Biological Sciences Research Council (BBSRC) and commercial and charitable organisations www.tsl.ac.uk

About BBSRC

The Biotechnology and Biological Sciences Research Council (BBSRC) invests in world-class bioscience research and training on behalf of the UK public. Our aim is to further scientific knowledge, to promote economic growth, wealth and job creation and to improve quality of life in the UK and beyond.

Funded by Government, BBSRC invested over £509M in world-class bioscience in 2014-15 and is the leading funder of wheat research in the UK (over £100M investment on UK wheat research in the last 10 years). We support research and training in universities and strategically funded institutes. BBSRC research and the people we fund are helping society to meet major challenges, including food security, green energy and healthier, longer lives. Our investments underpin important UK economic sectors, such as farming, food, industrial biotechnology and pharmaceuticals.

For more information about BBSRC, our science and our impact see: http://www.bbsrc.ac.uk For more information about BBSRC strategically funded institutes see: http://www.bbsrc.ac.uk/institutes