TEDGlobal 2017
Mennat El Ghalid: How fungi recognize (and infect) plants
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Each year, the world loses enough food to feed half a billion people to fungi, the most destructive pathogens of plants. Mycologist and TED Fellow Mennat El Ghalid explains how a breakthrough in our understanding of the molecular signals fungi use to attack plants could disrupt this interaction -- and save our crops.
Mennat El Ghalid - Mycologist
Mennat El Ghalid research aims to understand the molecular mechanisms underlying fungal biology and pathogenicity. Full bio
Mennat El Ghalid research aims to understand the molecular mechanisms underlying fungal biology and pathogenicity. Full bio
Double-click the English transcript below to play the video.
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"Will the blight end the chestnut?
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The farmers rather guess not.
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It keeps smouldering at the roots
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And sending up new shoots
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Till another parasite
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Shall come to end the blight."
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At the beginning of the 20th century,
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the eastern American chestnut population,
counting nearly four billion trees,
counting nearly four billion trees,
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was completely decimated
by a fungal infection.
by a fungal infection.
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Fungi are the most destructive
pathogens of plants,
pathogens of plants,
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including crops of major
economic importance.
economic importance.
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Can you imagine that today,
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crop losses associated
with fungal infection
with fungal infection
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are estimated at billions of dollars
per year, worldwide?
per year, worldwide?
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That represents enough food calories
to feed half a billion people.
to feed half a billion people.
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And this leads to severe repercussions,
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including episodes of famine
in developing countries,
in developing countries,
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large reduction of income
for farmers and distributors,
for farmers and distributors,
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high prices for consumers
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and risk of exposure to mycotoxin,
poison produced by fungi.
poison produced by fungi.
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The problems that we face
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is that the current method
used to prevent and treat
used to prevent and treat
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those dreadful diseases,
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such as genetic control,
exploiting natural sources of resistance,
exploiting natural sources of resistance,
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crop rotation or seed
treatment, among others,
treatment, among others,
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are still limited or ephemeral.
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They have to be constantly renewed.
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Therefore, we urgently need
to develop more efficient strategies
to develop more efficient strategies
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and for this, research is required
to identify biological mechanisms
to identify biological mechanisms
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that can be targeted
by novel antifungal treatments.
by novel antifungal treatments.
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One feature of fungi
is that they cannot move
is that they cannot move
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and only grow by extension
to form a sophisticated network,
to form a sophisticated network,
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the mycelium.
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In 1884, Anton de Bary,
the father of plant pathology,
the father of plant pathology,
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was the first to presume
that fungi are guided by signals
that fungi are guided by signals
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sent out from the host plant,
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meaning a plant upon which
it can lodge and subsist,
it can lodge and subsist,
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so signals act as a lighthouse
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for fungi to locate, grow toward, reach
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and finally invade and colonize a plant.
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He knew that the identification
of such signals
of such signals
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would unlock a great knowledge
that then serves to elaborate strategy
that then serves to elaborate strategy
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to block the interaction
between the fungus and the plant.
between the fungus and the plant.
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However, the lack of an appropriate
method at that moment
method at that moment
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prevented him from identifying
this mechanism at the molecular level.
this mechanism at the molecular level.
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Using purification and mutational
genomic approaches,
genomic approaches,
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as well as a technique
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allowing the measurement
of directed hyphal growth,
of directed hyphal growth,
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today I'm glad to tell you
that after 130 years,
that after 130 years,
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my former team and I
could finally identify such plant signals
could finally identify such plant signals
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by studying the interaction
between a pathogenic fungus
between a pathogenic fungus
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called Fusarium oxysporum
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and one of its host plants,
the tomato plant.
the tomato plant.
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As well, we could characterize
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the fungal receptor
receiving those signals
receiving those signals
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and part of the underlying reaction
occurring within the fungus
occurring within the fungus
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and leading to its direct growth
toward the plant.
toward the plant.
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(Applause)
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Thank you.
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(Applause)
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The understanding
of such molecular processes
of such molecular processes
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offers a panel of potential molecules
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that can be used to create
novel antifungal treatments.
novel antifungal treatments.
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And those treatments would disrupt
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the interaction between
the fungus and the plant
the fungus and the plant
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either by blocking the plant signal
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or the fungal reception system
which receives those signals.
which receives those signals.
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Fungal infections have devastated
agriculture crops.
agriculture crops.
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Moreover, we are now in an era
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where the demand of crop production
is increasing significantly.
is increasing significantly.
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And this is due to population growth,
economic development,
economic development,
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climate change and demand for bio fuels.
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Our understanding
of the molecular mechanism
of the molecular mechanism
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of interaction between
a fungus and its host plant,
a fungus and its host plant,
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such as the tomato plant,
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potentially represents a major step
towards developing more efficient strategy
towards developing more efficient strategy
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to combat plant fungal diseases
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and therefore solving of problems
that affect people's lives,
that affect people's lives,
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food security and economic growth.
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Thank you.
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(Applause)
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ABOUT THE SPEAKER
Mennat El Ghalid - MycologistMennat El Ghalid research aims to understand the molecular mechanisms underlying fungal biology and pathogenicity.
Why you should listen
Mycologist Mennat El Ghalid received an Initial Training Networks - Marie Skłodowska-Curie fellowship to pursue her PhD project in the Molecular Genetics of Fungal Pathogenicity Unit and the International Campus of Excellence in Agrifood CeiA3 at the Universidad de Cordoba (Spain). During her PhD, her former team and herself identified the compounds secreted from the plant roots attracting Fusarium oxysporum, a soilborne plant pathogenic fungus and characterized the underlying mechanisms of attraction. Such compounds were tracked since the 19th century. The discovery was published in the Nature Journal.
El Ghalid became a TED Fellow in 2017 and have been selected as one of the 100 women honorees for OkayAfrica's 2018 #OKAY100Women list for her dedicated work and for being a promising talent within the field of STEM. She is currently working at Institut Pasteur (France) in the Biology and Pathogenicity Unit to study Candida albicans, an opportunistic pathogenic fungus and the main cause of fungal infections in immunocompromised humans.
Mennat El Ghalid | Speaker | TED.com