Survival and recovery of perennial forage grasses under prolonged Mediterranean drought: II. Water status, solute accumulation, abscisic acid concentration and accumulation of dehydrin transcripts in bases of immature leaves

1998 ◽  
Vol 140 (3) ◽  
pp. 451-460 ◽  
Author(s):  
FLORENCE VOLAIRE ◽  
HENRY THOMAS ◽  
NADIA BERTAGNE ◽  
EMMANUELLE BOURGEOIS ◽  
MARIE-FRANCOISE GAUTIER ◽  
...  
2013 ◽  
Vol 48 (9) ◽  
pp. 1210-1219 ◽  
Author(s):  
Muhammad Iqbal ◽  
Muhammad Ashraf

The objective of this work was to assess the regulatory effects of auxin-priming on gas exchange and hormonal homeostasis in spring wheat subjected to saline conditions. Seeds of MH-97 (salt-intolerant) and Inqlab-91 (salt-tolerant) cultivars were subjected to 11 priming treatments (three hormones x three concentrations + two controls) and evaluated under saline (15 dS m-1) and nonsaline (2.84 dS m-1) conditions. The priming treatments consisted of: 5.71, 8.56, and 11.42 × 10-4 mol L-1 indoleacetic acid; 4.92, 7.38, and 9.84 × 10-4 mol L-1 indolebutyric acid; 4.89, 7.34, and 9.79 × 10-4 mol L-1 tryptophan; and a control with hydroprimed seeds. A negative control with nonprimed seeds was also evaluated. All priming agents diminished the effects of salinity on endogenous abscisic acid concentration in the salt-intolerant cultivar. Grain yield was positively correlated with net CO2 assimilation rate and endogenous indoleacetic acid concentration, and it was negatively correlated with abscisic acid and free polyamine concentrations. In general, the priming treatment with tryptophan at 4.89 × 10-4 mol L-1 was the most effective in minimizing yield losses and reductions in net CO2 assimilation rate, under salt stress conditions. Hormonal homeostasis increases net CO2 assimilation rate and confers tolerance to salinity on spring wheat.


1981 ◽  
Vol 8 (5) ◽  
pp. 443 ◽  
Author(s):  
WJS Downton ◽  
BR Loveys

Changes in abscisic acid, phaseic acid, stomatal resistance, water potential, osmotic potential, turgor potential, proline, reducing sugars and ion content (Na+, K+, Cl-) in leaves from grapevines (Vitis vinifera L.) subjected to 0, 25, 50 or 100 mM NaCl (osmotic potentials of 0, - 0.1, - 0.2 and - 0.4 MPa, respectively) were monitored over a 3-week period. Abscisic acid concentration increased within 6 h for the 50 and 100 mM NaCl-treated vines. Proline did not accumulate until the next day for the 100 mM NaCl-treated plants and continued to accumulate for the duration of the experiment. Phaseic acid showed kinetics consistent with its being derived from abscisic acid. Stomatal resistance to water vapour exchange increased in the salt-treated plants over the course of the experiment despite a decline in abscisic acid concentration after the initial upsurge. Reducing sugar concentration showed an early upsurge, its contribution to osmotic readjustment being at least equal to that of accumulated Na+, K+ and Cl- the day after stress began. Potassium was preferentially accumulated over sodium into leaves during the first 8 days of the experiment and the sum of these two cations generally balanced accumulating chloride. Except for an initial loss of turgor in vines given 100 mM NaCl, turgor potential was maintained within 0.1 MPa of control plants for all of the treatments throughout the experiment.


2018 ◽  
Vol 24 (2) ◽  
pp. 103-108
Author(s):  
Tania Pires Da Silva ◽  
Fernanda Ferreira Araujo ◽  
Fernando Luiz Finger

The objective of this study was to evaluate the growth regulators action on the senescence of wild pansy flowers. In the first experiment, floral stems were treated with ethylene for 24 hours at concentrations of 0.1, 1.0, 10, 100 and 1000 μL L-1 and control without the hormone. In a second experiment, the flowers were immersed in solutions of abscisic acid (ABA) containing 5, 20, 50 and 100 μM for one minute and control with water. In a third experiment, 1-methylcyclopropene (1-MCP) was applied at concentrations of 0.5, 1.0 and 1.5 μL L-1 and control without the chemical. In a fourth experiment, 1-MCP and ethylene were applied, where 1-MCP was first applied followed by ethylene. After the treatments with 1-MCP and ethylene, the floral stems were removed from the hermetic chambers and kept in a vessel containing distilled water at 25 °C, 10 μmol m-2 s- 1 white fluorescent light and 50-70% relative humidity as for the ABA treatment. Flowers treated with ethylene did not present significant differences among the concentrations for visual senescence, showing evidence that this flower is not sensitive to ethylene. Treatment with 1000 μL L-1 of ethylene led to a slightly higher fresh weight loss than other treatments, which had a loss of about 33% at end of the experiment. For the ABA treatment, the flowers showed similar fresh weight loss among the different treatments; however, higher concentrations induced slight senescence of flowers. The use of 1-MCP increased the longevity of wild pansy flowers. These results show that 1-MCP is beneficial in maintaining the flower water status, even in the presence of exogenous ethylene, although ethylene may not be directly involved in the senescence of wild pansy flowers.


2014 ◽  
Author(s):  
Rainer Waadt ◽  
Kenichi Hitomi ◽  
Noriyuki Nishimura ◽  
Chiharu Hitomi ◽  
Stephen R Adams ◽  
...  

1992 ◽  
Vol 43 (5) ◽  
pp. 671-679 ◽  
Author(s):  
W. E. FINCH-SAVAGE ◽  
H A. CLAY ◽  
P S. BLAKE ◽  
G. BROWNING

2009 ◽  
Vol 183 (4) ◽  
pp. 1030-1042 ◽  
Author(s):  
Yinggao Liu ◽  
Lin Shi ◽  
Nenghui Ye ◽  
Rui Liu ◽  
Wensuo Jia ◽  
...  

1991 ◽  
Vol 18 (1) ◽  
pp. 17 ◽  
Author(s):  
Z Kefu ◽  
R Munns ◽  
RW King

Exposing barley and cotton plants to 75 mol m-3 NaCl reduced transpiration and increased abscisic acid (ABA) levels in leaves, roots and xylem sap. Exposing saltbush (Atriplex spongiosa) plants to 75 mol m-3 NaCI, at which concentration they grow best, did not affect transpiration or ABA levels but when the NaCl was increased to 150 mol m-3 transpiration fell and ABA levels rose. ABA levels in leaves were high in salt-treated barley and saltbush even when the leaf water status was raised by pressurising the roots. These responses indicate that an increased leaf ABA level was not triggered by leaf water deficit, but by the root's response to the salinity. The flux of ABA in the xylem sap of the three species was more than enough to account for the amount of ABA in leaves, in the presence and absence of salinity. This suggests that the roots may be the source of at least part of the ABA found in leaves.


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