NO: A nitric oxide synthase generated chemical effector of fungal pathogenesis
Lead Research Organisation:
University of Oxford
Department Name: Plant Sciences
Abstract
The world relies heavily on a handful of food crops. Of these, rice forms the staple diet of half of the world's population. However, rice and 50 other known grasses, are vulnerable to attack by the rice blast fungus. Such attack can lead to very significant crop losses. This may have implications for UK cereal crops - if global climate change leads to a rise in ambient temperature, rice blast disease will infiltrate Europe. Currently, disease is moderately well controlled by fungicides or by the use of rice varieties bred to carry extra disease resistance genes. Both are problematic: fungicides are costly, antifungal activity can be lost and inbred disease resistance can be lost due to the emergence of new and aggressive races of the fungus. Whilst we have made great strides towards understanding fungal invasion, much remains to be discovered. Detailed knowledge of the processes underpinning fungal attack will allow us to identify weak links during the early stages of fungal attack. This will empower us with the knowledge to design more environmentally benign modes of crop protection. This project aims to look at signals the fungus uses to drive the formation of its infection structures. More specifically, it will look at the generation and consequence of chemical effectors of fungal disease.
Technical Summary
The research aims to determine whether generation of the transient and simple molecule NO, by nitric oxide synthase, influences germination and appressorium formation in Magnaporthe grisea. The work builds on preliminary data which shows that the transcript level of one of 4 putative NOS genes in M. grisea is highly up-regulated coincident with penetration (NOS3) and one significantly up-regulated coincident with germination (NOS2). Gene knockout showed highly attenuated disease levels in the NOS3 mutant. Appressorium formation and disease levels were restored by exogenous cAMP and by the NO donors SNP and PAPANONOate. These results demonstrate a link between NOS and NO and with signalling cascades. The proposed work is to a) to generate single and double NOS knockout and recomplementation strains b) to determine whether NOS2 and NOS3 synthesise NO, and when and where NO burst is c) to determine the cellular localisation of the proteins d) to unmask links between NO/NOS and signal relay pathways e) to identify both down-stream targets and genes involved in NO/NOS activity.
People |
ORCID iD |
Sarah Gurr (Principal Investigator) | |
Mark Fricker (Co-Investigator) |
Publications
Bagchi R
(2014)
Pathogens and insect herbivores drive rainforest plant diversity and composition.
in Nature
Che Omar S
(2016)
Validation of Reference Genes for Robust qRT-PCR Gene Expression Analysis in the Rice Blast Fungus Magnaporthe oryzae.
in PloS one
Danac R
(2008)
Synthesis of UDP-glucose derivatives modified at the 3-OH as potential chain terminators of beta-glucan biosynthesis.
in Carbohydrate research
Fisher MC
(2012)
Emerging fungal threats to animal, plant and ecosystem health.
in Nature
Geoghegan IA
(2016)
Chitosan Mediates Germling Adhesion in Magnaporthe oryzae and Is Required for Surface Sensing and Germling Morphogenesis.
in PLoS pathogens
Gurr S
(2011)
The rise and rise of emerging infectious fungi challenges food security and ecosystem health
in Fungal Biology Reviews
Petkov V
(2009)
Atomic-scale structure of biogenic materials by total X-ray diffraction: a study of bacterial and fungal MnOx.
in ACS nano
Rodgers CJ
(2010)
Designer laccases: a vogue for high-potential fungal enzymes?
in Trends in biotechnology
Samalova M
(2014)
Robust anti-oxidant defences in the rice blast fungus Magnaporthe oryzae confer tolerance to the host oxidative burst.
in The New phytologist
Description | First evidence of a role for Nitric Oxide in fungal pathogenesis and a description of a new method for ratio imaging. |
Exploitation Route | have driven further research effort and cited by others |
Sectors | Agriculture, Food and Drink |
Description | Antifungals and Puricore |
Organisation | Puricore |
Country | United States |
Sector | Private |
PI Contribution | Mode of action studies |
Collaborator Contribution | Provision of solutions and growth chambers |
Impact | papers |
Start Year | 2009 |