Foliar dehydration tolerance of twelve deciduous tree species

Abstract

Plants have evolved many physiological, morphological, The potential for foliar dehydration tolerance and maxanatomical, and phenological characteristics for imum capacity for osmotic adjustment were compared responding to and resisting drought stress. Certain characamong 12 temperate, deciduous tree species, under teristics and responses to drought do not occur at random standardized soil and atmospheric conditions. but appear to coincide, leading to the sometimes loose Dehydration tolerance was operationally defined as but useful categories of perennial plants as drought lethal leaf water potential (y): the y of the last avoiders or drought tolerators (Ludlow et al., 1983). remaining leaves surviving a continuous, lethal soil Drought avoiders have tissues that are very sensitive to drying episode. Nyssa sylvatica Marsh., and dehydration. They tend to have characteristics that allow Liriodendron tulipifera L. were most sensitive to them to avoid tissue water deficits when soil moisture dehydration, having lethal leaf y of −2.04 and limitation occurs: e.g. deep roots to maximize water −2.38 MPa, respectively. Chionanthus virginicus L., uptake and sensitive stomates to minimize leaf water loss. Quercus prinus L., Acer saccharum Marsh., and Drought tolerators have leaves that can tolerate dehydra-Quercus acutissima Carruthers withstood the most tion, and they tend to have poorly developed responses dehydration, with leaves not dying until leaf y dropped for avoiding dehydration. Tolerators rely on osmotic to −5.63 MPa or below. Lethal leaf y (in MPa) of other, adjustment to survive drought (Ludlow et al., 1985). intermediate species were: Quercus rubra L. (−3.34), Ludlow (1989) has profiled the mechanistically linked Oxydendrum arboreum (L.) D.C. (−3.98), Halesia characteristics that classify these two drought resistance carolina L. (−4.11), Acer rubrum L. (−4.43), Quercus strategies. alba L. (−4.60), and Cornus florida L. (−4.88). In the spectrum of responses ranging from extreme Decreasing lethal leaf y was significantly correlated drought avoidance to extreme tolerance, perhaps the with increasing capacity for osmotic adjustment. C. single most important determinant of drought resistance virginicus and Q. acutissima showed the most osmotic strategy is the dehydration tolerance of the species, which adjustment during the lethal soil drying episode, with is a measure of tissue capacity for withstanding desiccaosmotic potential at full turgor declining by 1.73 and tion (Ludlow, 1989). Dehydration tolerance has been 1.44 MPa, respectively. Other species having reducoperationally defined as the water potential (y) or relative tions in osmotic potential at full turgor exceeding water content (RWC) of the last surviving leaves (called 0.50 MPa were (in MPa) Q. prinus (0.89), A. saccharum the lethal value) on a plant subjected to a slow, continuous (0.71), Q. alba (0.68), H. carolina (0.67), Q. rubra (0.60), soil drying episode (Ludlow, 1989). Drought avoidance, and C. florida (0.52). a strategy possessed by both annual...

Drought‐induced shoot dieback starts with massive root xylem embolism and variable depletion of nonstructural carbohydrates in seedlings of two tree species

“…) contributed to faster soil desiccation for seedlings of U. minor than Q. ilex . The faster soil drying could contribute to greater reductions in g s in response to drought in U. minor via limitations to leaf osmotic adjustment (Turner & Jones, ; but see Augé et al ., ), and accelerate the loss of hydraulic conductivity (Anderegg & Anderegg, ).…”

-Aminobutyric acid increases abscisic acid accumulation and desiccation tolerance and decreases water use but fails to improve grain yield in two spring wheat cultivars under soil drying

“…The effect of BABA on the desiccation tolerance of the two wheat cultivars was assessed by measuring the lethal leaf water potential (Ψ) ( Augé et al , 1998 ). Experiment 2 used the same cultivars and treatments as Experiment 1, but the soil drying treatments was continued for longer than 20 d. The Ψ of the plants was measured between 08.30h and 10.30h using a pressure chamber (PMS Instrument Company, Albany, OR, USA) and following the precautions recommended by Turner (1988 ).…”

Review. Use of psychrometers in field measurements of plant material: accuracy and handling difficulties

“…Machado and Paulsen (2001) measured water potential in leaves of wheat (Triticum aestivum) and sorghum (Sorghum bicolor) to study the effects of drought and high temperatures as yield limiting factors. Auge et al (1998) observed the foliar dehydration tolerance and Liu et al (2003) measured, among other factors, stomatal conductance and leaf water potential in sand rice (Agriphyllum squarrosum) using a WAM, and observed that the increase in soil water content significantly affected the physiological traits analyzed, while the change in the photosynthesis was delayed as compared to changes in water potential. Starting the current trend for the use of WAM, Niu et al (2004) studied other aspects such as gas exchange and chlorophyll fluorescence response to simulated rainfall in plants under water stress by measuring leaf water potential.…”