
TY  - JOUR
A1  - Schmidhalter, U. 
A1  - Burucs, Z. 
A1  - Camp, K.H. 
T1  - Sensitivity of root and leaf water status in maize (<emph type="2">Zea mays</emph>) subjected to mild soil dryness
JF  - Functional Plant Biology
JO  - Functional Plant Biol.
Y1  - 1998
VL  - 25
IS  - 3
SP  - 307
EP  - 316
KW  - 
UR  - https://doi.org/10.1071/PP97047 
N2  - The aim of this work was to test the sensitivity of the water potential (&Psi;w), osmotic potential (&Psi;s) and turgor (&Psi;p) of roots and leaves of maize seedlings (Zea mays L. cv. Carla) subjected to a mild stress in drying soil in a growth chamber. To the best of our knowledge there are no experimental data which describes diurnal courses of &Psi;w in soil, roots, and leaves and the parallel changes in the osmotic potential (&Psi;s) and turgor (&Psi;p) of roots and leaves from plants grown in moist and drying soil. Root and leaf &Psi;w varied diurnally, the amplitude being much more marked in leaves than in roots. Root and leaf &Psi;w did not achieve equilibrium at predawn with the bulk soil matric potential (&Psi;m) but became higher. Our results are at variance with data indicating root &Psi;w is a sensitive indicator of soil dryness. Root &Psi;w in the well-watered and drought-stressed treatments did not differ, whereas daytime leaf &Psi;w in the droughted treatment was lower 6 days after water was withheld. Diurnal changes in &Psi;s and &Psi;p were more marked in leaves than in roots. Withholding water lowered leaf Yp, whereas root &Psi;p substantially increased after only 3 days of withholding water. Early mild stress can be more easily and more quickly identified by changes in root &Psi;s, increases in root &Psi;p, or the divergence in root and leaf &Psi;p than by a lower &Psi;w of root or leaf. Relative water contents of roots and leaves measured in the light period indicated also sensitively falling &Psi;m. 
ER  -

