bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2023,
Номер
unknown
Опубликована: Ноя. 16, 2023
ABSTRACT
The
ecologically
and
economically
vital
symbiosis
between
nitrogen-fixing
rhizobia
leguminous
plants
is
often
thought
of
as
a
bi-partite
interaction,
yet
studies
increasingly
show
the
prevalence
non-rhizobial
endophytes
(NREs)
that
occupy
nodules
alongside
rhizobia.
Yet,
what
impact
these
NREs
have
on
plant
or
rhizobium
fitness
remains
unclear.
Here,
we
investigated
four
NRE
strains
found
to
naturally
co-occupy
legume
Medicago
truncatula
Sinorhizobium
meliloti
in
native
soils.
Our
objectives
were
(1)
examine
direct
indirect
effects
M.
S.
fitness,
(2),
determine
whether
can
re-colonize
root
nodule
tissues
upon
reinoculation.
We
identified
one
strain
(522)
novel
Paenibacillus
species,
another
(717A)
Bacillus
other
two
(702A
733B)
Pseudomonas
species.
Additionally,
(Bacillus
717A
reduced
benefits
obtained
from
for
both
partners,
while
(522,
702A)
had
little
effect.
Lastly,
able
co-infect
host
.
This
study
demonstrates
variation
present
natural
populations
must
be
considered
better
understand
legume-rhizobium
dynamics
soil
communities.
PLoS Biology,
Год журнала:
2024,
Номер
22(4), С. e3002304 - e3002304
Опубликована: Апрель 25, 2024
Specialized
host–microbe
symbioses
canonically
show
greater
diversity
than
expected
from
simple
models,
both
at
the
population
level
and
within
individual
hosts.
To
understand
how
this
heterogeneity
arises,
we
utilize
squash
bug,
Anasa
tristis
,
its
bacterial
symbionts
in
genus
Caballeronia
.
We
modulate
symbiont
bottleneck
size
inoculum
composition
during
colonization
to
demonstrate
significance
of
ecological
drift,
noisy
fluctuations
community
due
demographic
stochasticity.
Consistent
with
predictions
neutral
theory
biodiversity,
found
that
drift
alone
can
account
for
between
hosts,
even
when
2
strains
are
nearly
genetically
identical.
When
acting
on
competing
strains,
maintain
genetic
among
different
hosts
by
stochastically
determining
dominant
strain
each
host.
Finally,
mediates
isogenic
populations
a
single
host,
along
consistent
gradient
running
anterior-posterior
axis
symbiotic
organ.
Our
results
structure
across
scales
does
not
necessarily
require
host-mediated
selection,
as
it
emerge
result
unrelated
competitors.
findings
illuminate
processes
might
affect
transmission,
coinfection,
nature,
which
drive
evolution
microbe–microbe
interactions
host-associated
microbiomes.
Frontiers in Microbiology,
Год журнала:
2024,
Номер
15
Опубликована: Авг. 16, 2024
Soil
salinization
seriously
affects
soil
microbial
diversity,
and
crop
yield
quality
worldwide.
Microorganisms
play
a
vital
role
in
the
process
of
quality.
Traditional
Chinese
medicine
Frontiers in Plant Science,
Год журнала:
2023,
Номер
14
Опубликована: Окт. 9, 2023
Rhizobia
are
soil
bacteria
that
can
establish
a
nitrogen-fixing
symbiosis
with
legume
plants.
As
horizontally
transmitted
symbionts,
the
life
cycle
of
rhizobia
includes
free-living
phase
in
and
plant-associated
symbiotic
phase.
Throughout
this
cycle,
exposed
to
myriad
other
microorganisms
interact
them,
modulating
their
fitness
performance.
In
review,
we
describe
diversity
interactions
between
occur
rhizosphere,
during
initiation
nodulation,
within
nodules.
Some
these
rhizobia-microbe
indirect,
when
presence
some
microbes
modifies
plant
physiology
way
feeds
back
on
rhizobial
fitness.
We
further
how
impose
significant
selective
pressures
modify
evolutionary
trajectories.
More
extensive
investigations
eco-evolutionary
dynamics
complex
biotic
environments
will
likely
reveal
fascinating
new
aspects
well-studied
interaction
provide
critical
knowledge
for
future
agronomical
applications.
Proceedings of the Royal Society B Biological Sciences,
Год журнала:
2024,
Номер
291(2027)
Опубликована: Июль 23, 2024
Symbiotic
nitrogen
(N)
fixation
(SNF)
by
legumes
and
their
rhizobial
partners
is
one
of
the
most
important
sources
bioavailable
N
to
terrestrial
ecosystems.
While
work
on
regulation
SNF
has
focussed
abiotic
drivers
such
as
light,
water
soil
nutrients,
diversity
rhizobia
with
which
individual
legume
may
play
an
but
under-recognized
role
in
regulating
inputs
from
SNF.
By
experimentally
manipulating
available
legumes,
we
demonstrate
that
can
increase
average
rates
more
than
90%,
high
induce
increased
even
under
conditions
fertilization.
However,
effects
diversity,
were
strongest,
likely
mechanisms
driving
these
differed
between
two
species
assessed.
These
results
provide
evidence
biodiversity-ecosystem
function
relationships
occur
at
scales
plant
be
long-established
factors,
availability,
via
Abstract
Symbiotic
mutualisms
provide
critical
ecosystem
services
throughout
the
world.
Anthropogenic
stressors,
however,
may
disrupt
mutualistic
interactions
and
impact
health.
The
plant‐rhizobia
symbiosis
promotes
plant
growth
contributes
to
nitrogen
(N)
cycle.
While
off‐target
herbicide
exposure
is
recognized
as
a
significant
stressor
impacting
wild
plants,
we
lack
knowledge
about
how
it
affects
symbiotic
relationship
between
plants
rhizobia.
Moreover,
do
not
know
whether
of
on
traits
or
fitness
might
be
ameliorated
by
rhizobial
genetic
variation.
To
address
these
gaps,
conducted
greenhouse
study
where
grew
17
full‐sibling
families
red
clover
(
Trifolium
pratense
)
either
alone
(uninoculated)
in
with
one
two
strains
rhizobia
Rhizobium
leguminosarum
exposed
them
concentration
dicamba
that
simulated
“drift”
(i.e.,
atmospheric
movement)
control
solution.
We
recorded
responses
immediate
vegetative
injury,
key
features
mutualism
(nodule
number,
nodule
size,
N
fixation),
outcomes,
(biomass).
In
general,
found
variation
more
than
determined
outcomes
response
exposure.
Herbicide
damage
depended
family,
but
also
were
inoculated
if
so,
which
strain.
Rhizobial
strain
number
this
was
treatment‐dependent.
contrast,
treatment
independently
impacted
fixation.
And
while
significantly
reduced
fitness,
effect
inoculation
state.
Furthermore,
differential
benefits
provided
seemed
diminish
under
herbicidal
conditions.
Altogether,
findings
suggest
low
levels
components
well
partners
determines
magnitude
and/or
direction
effects.
particular,
our
results
highlight
strong
role
identity
driving
both
stress.
Canadian Journal of Microbiology,
Год журнала:
2024,
Номер
70(7), С. 275 - 288
Опубликована: Март 20, 2024
The
ecologically
and
economically
vital
symbiosis
between
nitrogen-fixing
rhizobia
leguminous
plants
is
often
thought
of
as
a
bi-partite
interaction,
yet
studies
increasingly
show
the
prevalence
non-rhizobial
endophytes
(NREs)
that
occupy
nodules
alongside
rhizobia.
Yet,
what
impact
these
NREs
have
on
plant
or
rhizobium
fitness
remains
unclear.
Here,
we
investigated
four
NRE
strains
found
to
naturally
co-occupy
legume
Medicago
truncatula
Sinorhizobium
meliloti
in
native
soils.
Our
objectives
were
(1)
examine
direct
indirect
effects
M.
S.
fitness,
(2)
determine
whether
can
re-colonize
root
nodule
tissues
upon
reinoculation.
We
identified
one
strain
(522)
novel
Paenibacillus
species,
another
(717A)
Bacillus
other
two
(702A
733B)
Pseudomonas
species.
Additionally,
(Bacillus
717A
reduced
benefits
obtained
from
for
both
partners,
while
(522,
702A)
had
little
effect.
Lastly,
able
co-infect
host
meliloti.
This
study
demonstrates
variation
present
natural
populations
must
be
considered
better
understand
legume–rhizobium
dynamics
soil
communities.
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Дек. 12, 2024
Legume-rhizobium
symbiosis
provides
a
sustainable
nitrogen
source
for
agriculture.
Nitrogen
fixation
efficiency
depends
on
both
legume
and
rhizobium
genotypes,
but
the
implications
of
their
interactions
plant
performance
in
environments
with
many
competing
strains
remain
unclear.
Here,
we
let
399
Rhizobium
leguminosarum
complex
sv.
viciae
compete
nodulation
212
faba
bean
genotypes.
We
find
that
can
be
categorised
by
nodule
occupancy
profiles
into
groups
show
distinct
competitive
growth-promoting
effects.
Further,
diversity
occupying
root
nodules
affects
growth
is
under
genetic
control.
These
insights
provide
basis
re-designing
inoculation
breeding
strategies
to
enhance
symbiotic
Optimising
plant-rhizobium
fixation,
improving
sustainability
This
study
identified
four
symbionts
characteristics
whose
across
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2023,
Номер
unknown
Опубликована: Авг. 21, 2023
Abstract
Host-associated
microbiomes
vary
greatly
in
composition
both
within
and
between
host
individuals,
providing
the
raw
material
for
natural
selection
to
act
on
host-microbe
associations.
Nonetheless,
drivers
of
compositional
heterogeneity
host-associated
have
only
rarely
been
examined.
To
understand
how
this
arises,
we
utilize
squash
bug,
Anasa
tristis
,
its
bacterial
symbionts
genus
Caballeronia
.
We
artificially
modulate
symbiont
bottleneck
size
strain
diversity
during
colonization
demonstrate
significance
ecological
drift,
which
causes
stochastic
fluctuations
community
composition.
Consistent
with
predictions
from
neutral
theory
biodiversity,
drift
alone
can
account
hosts,
even
when
two
strains
are
nearly
genetically
identical.
When
acting
competing,
unrelated
strains,
maintain
genetic
among
different
hosts
by
stochastically
determining
dominant
each
host.
Finally,
mediates
isogenic
populations
a
single
host,
along
consistent
gradient
running
anterior-posterior
axis
symbiotic
organ.
Our
results
that
population
structure
across
scales
does
not
necessarily
require
host-mediated
selection,
but
emerges
as
result
competitors.
findings
illuminate
processes
might
affect
transmission,
coinfection,
nature,
drive
evolution
symbiosis
microbe-microbe
interactions
microbiomes.
