Hydraulic plasticity and water use regulation act to maintain the hydraulic safety margins of Mediterranean trees in rainfall exclusion experiments
Plant Cell & Environment,
Journal Year:
2024,
Volume and Issue:
47(12), P. 4741 - 4753
Published: July 30, 2024
Hydraulic
failure
due
to
xylem
embolism
has
been
identified
as
one
of
the
main
mechanisms
involved
in
drought-induced
forest
decline.
Trees
vulnerability
hydraulic
depends
on
their
safety
margin
(HSM).
While
it
shown
that
HSM
globally
converges
between
tree
species
and
biomes,
there
is
still
limited
knowledge
regarding
how
can
adjust
locally
varying
drought
conditions
within
species.
In
this
study,
we
relied
three
long-term
partial
rainfall
exclusion
experiments
investigate
plasticity
traits
for
Mediterranean
(Quercus
ilex
L.,
Quercus
pubescens
Willd.,
Pinus
halepensis
Mill.).
For
all
species,
a
homeostasis
response
reduction
was
found,
achieved
through
different
mechanisms.
Q.
ilex,
convergence
attributed
adjustment
both
turgor
loss
point
(Ψtlp)
water
potential
at
which
50%
conductivity
lost
(P50).
contrast,
maintenance
P.
related
its
isohydric
behavior
first
leaf
area
latter.
It
remains
be
seen
whether
generalized
if
will
sufficient
withstand
extreme
droughts
expected
region.
Language: Английский
Within‐leaf variation in embolism resistance is not a rule for compound‐leaved angiosperms
American Journal of Botany,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Dec. 16, 2024
Abstract
Premise
Hydraulic
segmentation,
caused
by
the
difference
in
embolism
resistance
across
plant
organs,
provides
a
sacrificial
layer
of
cheaper
like
leaves,
to
protect
more
costly
such
as
stems,
during
drought.
Within‐leaf
hydraulic
segmentation
has
been
observed
two
compound‐leaved
tree
species,
with
leaflets
being
vulnerable
than
rachis
or
petiole.
Many
herbaceous
species
have
compound
and
some
that
are
associated
pulvini
at
base
lamina,
which
could
provide
an
anatomical
means
preventing
from
spreading
within
leaf
because
higher
number
vessel
endings
pulvinus.
Methods
We
used
optical
vulnerability
method
investigate
whether
differences
were
tissues
six
one
deciduous
leaves.
Our
selection
included
both
palmately
pinnately‐compound
leaved
each
pulvinus
leaflets.
Results
found
considerable
variation
measured,
but
no
evidence
leaf.
In
pulvini,
we
major
events
crossing
pulvinus,
petiole
into
embolizing
same
water
potential.
Conclusions
conclude
within‐leaf
resistance,
is
not
universal
phenomenon
presence
does
barrier
spread
Language: Английский
Better safe than sorry: the unexpected drought tolerance of a wetland plant (Cyperus alternifolius L.)
Physiologia Plantarum,
Journal Year:
2024,
Volume and Issue:
177(1)
Published: Dec. 26, 2024
Abstract
A
common
assumption
of
plant
hydraulic
physiology
is
that
high
efficiency
must
come
at
the
cost
safety,
generating
a
trade‐off
raises
doubts
about
possibility
selecting
both
productive
and
drought‐tolerant
herbaceous
crops.
Wetland
plants
typically
display
productivity,
which
requires
to
sustain
transpiration
rates
coupled
CO
2
uptake.
Previous
studies
have
suggested
vulnerability
xylem
embolism
different
wetland
plants,
in
line
with
expected
trade‐offs.
However,
some
hygrophytes
like
Cyperus
alternifolius
L.
can
also
experience
prolonged
periods
low
water
levels
leading
substantial
drought
stress.
We
conducted
an
in‐depth
investigation
this
species'
safety
by
combining
gas
exchange
measurements,
measurements
leaf
optical
embolism,
determination
cell
turgor
changes
under
drought.
Our
data
confirm
species,
but
same
time,
reveal
its
surprising
tolerance
terms
loss
point
critical
potential
values
inducing
failure,
were
well
below
full
stomatal
closure.
C.
emerges
as
highly
well‐equipped
tolerate
via
combination
early
closure
delayed
onset
damage.
The
species
might
represent
model
develop
crops
two
most
desirable
traits
cultivated
i.e.,
yield
significant
tolerance.
Language: Английский