Plant and Water Relations Water Deficits: Plant Responses from Cell to Community J. A. C. Smith H. Griffith

BioScience ◽  
1994 ◽  
Vol 44 (9) ◽  
pp. 628-629
Author(s):  
T. T. Kozlowski
Keyword(s):  
Water Relations ◽  
Plant Responses ◽  
Water Deficits

scholarly journals The Vascular Pathogen Verticillium longisporum Does Not Affect Water Relations and Plant Responses to Drought Stress of Its Host, Brassica napus

2017 ◽  
Vol 107 (4) ◽  
pp. 444-454 ◽  
Author(s):  
Daniel Teshome Lopisso ◽  
Jessica Knüfer ◽  
Birger Koopmann ◽  
Andreas von Tiedemann
Keyword(s):  
Drought Stress ◽  
Brassica Napus ◽  
Plant Growth ◽  
Water Relations ◽  
Growth Parameters ◽  
Molecular Genetic ◽  
Leaf Water Content ◽  
Plant Responses ◽  
Brassica Napus L ◽  
Verticillium Longisporum

Verticillium longisporum is a host-specific vascular pathogen of oilseed rape (Brassica napus L.) that causes economic crop losses by impairing plant growth and inducing premature senescence. This study investigates whether plant damage through Verticillium stem striping is due to impaired plant water relations, whether V. longisporum affects responses of a susceptible B. napus variety to drought stress, and whether drought stress, in turn, affects plant responses to V. longisporum. Two-factorial experiments on a susceptible cultivar of B. napus infected or noninfected with V. longisporum and exposed to three watering levels (30, 60, and 100% field capacity) revealed that drought stress and V. longisporum impaired plant growth by entirely different mechanisms. Although both stresses similarly affected plant growth parameters (plant height, hypocotyl diameter, and shoot and root dry matter), infection of B. napus with V. longisporum did not affect any drought-related physiological or molecular genetic plant parameters, including transpiration rate, stomatal conductance, photosynthesis rate, water use efficiency, relative leaf water content, leaf proline content, or the expression of drought-responsive genes. Thus, this study provides comprehensive physiological and molecular genetic evidence explaining the lack of wilt symptoms in B. napus infected with V. longisporum. Likewise, drought tolerance of B. napus was unaffected by V. longisporum, as was the level of disease by drought conditions, thus excluding a concerted action of both stresses in the field. Although it is evident that drought and vascular infection with V. longisporum impair plant growth by different mechanisms, it remains to be determined by which other factors V. longisporum causes crop loss.

Water Relations in Cowpea and Pearl Millet Under Soil Water Deficits. I. Contrasting Leaf Water Relations

1992 ◽  
Vol 19 (6) ◽  
pp. 577 ◽  
Author(s):  
CL Petrie ◽  
AE Hall
Keyword(s):  
Soil Water ◽  
Pearl Millet ◽  
Water Relations ◽  
Pressure Chamber ◽  
Leaf Water ◽  
Surface Conductance ◽  
Pennisetum Americanum ◽  
Leaf Water Relations ◽  
Water Deficits ◽  
Rooting Media

Cowpea [Vigna unguiculata (L.) Walp.] can survive soil water deficits more effectively than pearl millet [Pennisetum americanum (L.) Leeke]. Cowpea and millet were grown in a glasshouse in different rooting media and different sizes of container, under wet and dry treatments, and as sole crops and intercrops to evaluate any differences in leaf water potential. Millet developed significantly lower predawn leaf water potentials (ΨL) than cowpea under the dry treatment of all of the rooting media and container sizes used, but both millet and cowpea maintained high predawn ΨL in the well-watered treatment. With the dry treatment, the same difference in predawn ΨL between cowpea and millet developed in plants grown either as sole crops or as intercrops in the same pot. These results suggest that plants grown as intercrops were somehow isolated from each other, even though their root systems may have overlapped, and that competition for water was probably not occurring. Differences in predawn ΨL between cowpea and millet were detected with either a pressure chamber or psychrometers, but values of ΨL varied with measurement method. Compared with psychrometer values, pressure chamber values became significantly lower in millet late in the dry treatment but were higher in cowpea. Agreement between the methods for measuring ΨL improved in cowpea when predawn xylem osmotic potential was added to the pressure chamber value. At the end of the experiments, leaf surface conductance to water vapour and leaf area were lower in millet than cowpea. Consequently, it is possible that the significantly lower predawn ΨL in millet was not due to greater water use by millet compared with cowpea.

scholarly journals Interaction of Huanglongbing and Foliar Applications of Copper on Water Relations of Citrus sinensis cv. Valencia

Plants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 298 ◽  
Author(s):  
Said A. Hamido ◽  
Robert C. Ebel ◽  
Kelly T. Morgan
Keyword(s):  
Surface Area ◽  
Water Relations ◽  
Citrus Sinensis ◽  
Fine Sand ◽  
Root Surface ◽  
Root Surface Area ◽  
Plant Water ◽  
Stem Water Potential ◽  
Water Deficits ◽  
The Impact

The following study was conducted to determine the impact of frequent foliar Cu applications on water relations of Huanglongbing (HLB)-affected Citrus sinensis cv. ‘Valencia’. HLB in Florida is putatively caused by Candidatus Liberibacter asiaticus that is vectored by the Asian citrus psyllid. The experiment was conducted in a psyllid-free greenhouse with trees grown in Immokalee fine sand soil with the trees well-maintained to promote health. Cu was applied to the foliage at 0×, 0.5×, 1×, and 2× the commercially recommended rates, which were 0, 46, 92, and 184 mM, respectively, with applications made 3× in both 2016 and 2017. Previous studies indicate that HLB causes roots to decline before the canopy develops symptoms, which increases the ratio between the evaporative surface area of the canopy to the uptake surface area of roots and increases the hydraulic strain within the tree. In the current study, overall growth was suppressed substantially by HLB and Cu treatments but the ratio between evaporative surface area (leaf surface area) and the uptake surface area of roots (feeder root surface area) was not affected by either treatment. Stem water potential (Ψxylem), which was used as a measure of plant water deficits and the hydraulic strain within the tree, was significantly 13% lower for HLB-affected trees than the non-HLB controls but were not affected by Cu treatments. All Ψxylem measurements were in a range typical of well-watered trees conditions. Stomatal conductance (ks) and root and soil resistances (Rr+s) were not affected by HLB and Cu. The results of this experiment suggest that tree leaf area and feeder roots are reduced when the trees are affected by HLB or are treated with foliar Cu applications such that plant water deficits are not significantly different over that of the controls.

Sign in / Sign up

Export Citation Format

Share Document