1 research outputs found
Manipulating Root Water Supply Elicits Major Shifts in the Shoot Proteome
Substantial reductions in yield caused
by drought stress can occur
when parts of the root system experience water deficit even though
other parts have sufficient access to soil water. To identify proteins
associated to drought signaling, rice (<i>Oryza sativa</i> L. cv. IR64.) plants were transplanted into plastic pots with an
internal wall dividing each pot into two equal compartments, allowing
for equal distribution of soil and the root system between these compartments.
The following treatments were applied: either both compartments were
watered daily (“wet” roots), or water was withheld from
both compartments (“dry” roots), or water was withheld
from only one of the two compartments in each pot (“wet”
and “dry” roots). The substantial differences in physiological
parameters of different growth conditions were accompanied by differential
changes in protein abundances. Label-free quantitative shotgun proteomics
have resulted in identification of 1383 reproducible proteins across
all three conditions. Differentially expressed proteins were categorized
within 17 functional groups. The patterns observed were interesting
in that in some categories such as protein metabolism and oxidation–reduction,
substantial numbers of proteins were most abundant when leaves were
receiving signals from “wet” and “dry”
roots. In yet other categories such as transport, several key transporters
were surprisingly abundant in leaves supported by partially or completely
droughted root systems, especially plasma membrane and vacuolar transporters.
Stress-related proteins behaved very consistently by increasing in
droughted plants but notably some proteins were most abundant when
roots of the same plant were growing in both wet and dry soils. Changes
in carbohydrate-processing proteins were consistent with the passive
accumulation of soluble sugars in shoots under drought, with hydrolysis
of sucrose and starch synthesis both enhanced. These results suggest
that drought signals are complex interactions and not simply the additive
effect of water supply to the roots