Proceedings of the National Academy of Sciences,
Journal Year:
2023,
Volume and Issue:
120(32)
Published: July 31, 2023
In
plants,
host-pathogen
coevolution
often
manifests
in
reciprocal,
adaptive
genetic
changes
through
variations
host
nucleotide-binding
leucine-rich
repeat
immune
receptors
(NLRs)
and
virulence-promoting
pathogen
effectors.
grass
powdery
mildew
(PM)
fungi,
an
extreme
expansion
of
a
RNase-like
effector
family,
termed
RALPH,
dominates
the
repertoire,
with
some
members
recognized
as
avirulence
(AVR)
effectors
by
cereal
NLR
receptors.
We
report
structures
sequence-unrelated
barley
PM
AVR
Science Advances,
Journal Year:
2023,
Volume and Issue:
9(11)
Published: March 17, 2023
Toll/interleukin-1
receptor
(TIR)
domain
proteins
function
in
cell
death
and
immunity.
In
plants
bacteria,
TIR
domains
are
often
enzymes
that
produce
isomers
of
cyclic
adenosine
5′-diphosphate–ribose
(cADPR)
as
putative
immune
signaling
molecules.
The
identity
functional
conservation
cADPR
isomer
signals
is
unclear.
A
previous
report
found
a
plant
could
cross-activate
the
prokaryotic
Thoeris
TIR–immune
system,
suggesting
TIR-immune
signals.
Here,
we
generate
autoactive
TIRs
test
converse
hypothesis:
Do
also
immunity?
Using
planta
vitro
assays,
find
overlapping
sets
further
clarify
how
activate
system
via
producing
3′cADPR.
This
study
demonstrates
requirements
for
systems
distinct
across
kingdoms
diversity
small-molecule
products.
Nature,
Journal Year:
2024,
Volume and Issue:
632(8026), P. 869 - 876
Published: June 12, 2024
Abstract
Nucleotide-binding
leucine-rich
repeat
(NLR)
proteins
play
a
pivotal
role
in
plant
immunity
by
recognizing
pathogen
effectors
1,2
.
Maintaining
balanced
immune
response
is
crucial,
as
excessive
NLR
expression
can
lead
to
unintended
autoimmunity
3,4
Unlike
most
NLRs,
the
required
for
cell
death
2
(NRC2)
belongs
small
group
characterized
constitutively
high
without
self-activation
5
The
mechanisms
underlying
NRC2
autoinhibition
and
activation
are
not
yet
understood.
Here
we
show
that
Solanum
lycopersicum
(tomato)
(
Sl
NRC2)
forms
dimers
tetramers
higher-order
oligomers
at
elevated
concentrations.
Cryo-electron
microscopy
shows
an
inactive
conformation
of
these
oligomers.
Dimerization
oligomerization
only
stabilize
state
but
also
sequester
from
assembling
into
active
form.
Mutations
dimeric
or
interdimeric
interfaces
enhance
pathogen-induced
Nicotiana
benthamiana
cryo-electron
structures
unexpectedly
inositol
hexakisphosphate
(IP
6
)
pentakisphosphate
bound
inner
surface
C-terminal
domain
NRC2,
confirmed
mass
spectrometry.
phosphate-binding
site
impair
phosphate
binding
NRC2-mediated
N.
Our
study
indicates
negative
regulatory
mechanism
suggests
phosphates
cofactors
NRCs.
Open Biology,
Journal Year:
2024,
Volume and Issue:
14(1)
Published: Jan. 1, 2024
Plants
deploy
cell-surface
and
intracellular
receptors
to
detect
pathogen
attack
trigger
innate
immune
responses.
Inside
host
cells,
families
of
nucleotide-binding/leucine-rich
repeat
(NLR)
proteins
serve
as
sensors
or
downstream
mediators
defence
outputs
cell
death,
which
prevent
disease.
Established
genetic
underpinnings
NLR-mediated
immunity
revealed
various
strategies
plants
adopt
combat
rapidly
evolving
microbial
pathogens.
The
molecular
mechanisms
NLR
activation
signal
transmission
components
controlling
execution
were
less
clear.
Here,
we
review
recent
protein
structural
biochemical
insights
plant
sensor
signalling
functions.
When
put
together,
the
data
show
how
different
families,
whether
transducers,
converge
on
nucleotide-based
second
messengers
cellular
calcium
confer
immunity.
Although
pathogen-activated
NLRs
in
engage
plant-specific
machineries
promote
defence,
comparisons
with
mammalian
receptor
counterparts
highlight
some
shared
working
principles
for
across
kingdoms.
Nature,
Journal Year:
2024,
Volume and Issue:
627(8005), P. 847 - 853
Published: March 13, 2024
Abstract
Plant
nucleotide-binding
leucine-rich
repeat
(NLR)
immune
receptors
with
an
N-terminal
Toll/interleukin-1
receptor
(TIR)
domain
mediate
recognition
of
strain-specific
pathogen
effectors,
typically
via
their
C-terminal
ligand-sensing
domains
1
.
Effector
binding
enables
TIR-encoded
enzymatic
activities
that
are
required
for
TIR–NLR
(TNL)-mediated
immunity
2,3
Many
truncated
TNL
proteins
lack
effector-sensing
but
retain
similar
and
4,5
The
mechanism
underlying
the
activation
these
TIR
remain
unclear.
Here
we
show
substrates
NAD
+
ATP
induces
phase
separation
in
vitro.
A
condensation
occurs
a
protein
expressed
its
native
promoter
response
to
inoculation
planta.
formation
condensates
is
mediated
by
conserved
self-association
interfaces
predicted
intrinsically
disordered
loop
region
TIRs.
Mutations
disrupt
impair
cell
death
activity
proteins.
Our
data
reveal
as
provide
insight
into
substrate-induced
autonomous
signalling
confer
plant
immunity.
Science,
Journal Year:
2025,
Volume and Issue:
387(6733), P. 510 - 516
Published: Jan. 30, 2025
Caspase
family
proteases
and
Toll/interleukin-1
receptor
(TIR)-domain
proteins
have
central
roles
in
innate
immunity
regulated
cell
death
humans.
We
describe
a
bacterial
immune
system
comprising
both
caspase-like
protease
TIR-domain
protein.
found
that
the
TIR
protein,
once
it
recognizes
phage
invasion,
produces
previously
unknown
signaling
molecule
adenosine
5′-diphosphate-cyclo[N7:1′′]-ribose
(N7-cADPR).
This
specifically
activates
protease,
which
then
indiscriminately
degrades
cellular
to
halt
replication.
The
TIR-caspase
defense
system,
we
denote
as
type
IV
Thoeris,
is
abundant
bacteria
efficiently
protects
against
propagation.
Our
study
highlights
diversity
of
TIR-produced
molecules
demonstrates
by
caspase
an
ancient
mechanism
immunity.
Nature,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 8, 2025
Abstract
Plants
lack
specialized
and
mobile
immune
cells.
Consequently,
any
cell
type
that
encounters
pathogens
must
mount
responses
communicate
with
surrounding
cells
for
successful
defence.
However,
the
diversity,
spatial
organization
function
of
cellular
states
in
pathogen-infected
plants
are
poorly
understood
1
.
Here
we
infect
Arabidopsis
thaliana
leaves
bacterial
trigger
or
supress
integrate
time-resolved
single-cell
transcriptomic,
epigenomic
transcriptomic
data
to
identify
states.
We
describe
cell-state-specific
gene-regulatory
logic
involves
transcription
factors,
putative
cis
-regulatory
elements
target
genes
associated
disease
immunity.
show
a
rare
population
emerges
at
nexus
immune-active
hotspots,
which
designate
as
primary
responder
(PRIMER)
PRIMER
have
non-canonical
signatures,
exemplified
by
expression
genome
accessibility
previously
uncharacterized
factor,
GT-3A,
contributes
plant
immunity
against
pathogens.
surrounded
another
state
(bystander)
activates
long-distance
cell-to-cell
signalling.
Together,
our
findings
suggest
interactions
between
these
propagate
across
leaf.
Our
molecularly
defined
spatiotemporal
atlas
provides
functional
regulatory
insights
into
plants.
Science,
Journal Year:
2025,
Volume and Issue:
387(6737), P. 955 - 962
Published: Feb. 27, 2025
Inorganic
phosphate
(Pi)
is
essential
for
life,
and
plant
cells
monitor
Pi
availability
by
sensing
inositol
pyrophosphate
(PP-InsP)
levels.
In
this
work,
we
describe
the
hijacking
of
a
conserved
family
Nudix
hydrolase
effectors
from
pathogenic
Magnaporthe
Colletotrichum
fungi.
Structural
enzymatic
analyses
effector
demonstrate
that
they
selectively
hydrolyze
PP-InsP.
Gene
deletion
experiments
in
oryzae,
higginsianum,
graminicola
indicate
PP-InsP
hydrolysis
substantially
enhances
disease
symptoms
diverse
pathosystems.
Further,
show
induces
starvation
signaling
plants.
Our
study
elucidates
molecular
mechanism,
used
multiple
phytopathogenic
fungi,
manipulates
highly
pathway
to
exacerbate
disease.