Hydraulic conductance in aspen (Populus tremuloides) seedlings exposed to low root temperatures

Abstract

Low root temperatures significantly reduced root hydraulic conductivity and increased resistance to water flow through the roots of aspen (Populus tremuloides Michx.) seedlings. Increased resistance to water flow could not be fully explained by the corresponding increase in water viscosity at low temperatures. The shapes of Arrhenius plots of root water flow and the activation energies were dependent on the direction, sequence and extent of temperature change. The Arrhenius plots suggested that the effect of low root temperature on root water flow was mediated by an effect on root metabolism. The low root temperatures tested did not induce root electrolyte leakage normally associated with cell membrane injury. Although a decrease in root temperatures to 7 or 4 degrees C induced a reduction in stomatal conductance, this reduction lagged the decline in root water flow by several hours. In contrast, when soil temperatures were raised from 4 or 7 degrees C to 25 degrees C, root water flow presumably increased, and stomatal conductance responded rapidly and was temporarily higher than before the cold treatment was imposed.

Water relations and an expression analysis of plasma membrane intrinsic proteins in sensitive and tolerant rice during chilling and recovery

“…Many reports have emphasized the changes in water relations because water homeostasis is essential for plant survival under this stress condition, and a significant symptom of chilling injury is shoot water deficit resulting from imbalance between water transport and transpiration [2]. It has been well documented that root water transport is sharply suppressed by exposure to low temperature in a number of species, including maize [3][4][5][6], rice [7], bean [8], spinach [9], aspen [10], cucumber and figleaf gourd [11,12]. Some studies have also demonstrated that a decrease in transpiration follows the reduction in root water flow [5,10].…”

Overexpression of PIP2;5 Aquaporin Alleviates Effects of Low Root Temperature on Cell Hydraulic Conductivity and Growth in Arabidopsis

“…Low soil temperature is often a major factor restricting the growth and yield of plants even if the soil is not frozen (Bonan, 1992;Wan and Zwiazek, 1999;Wan et al, 2001). In plants that are sensitive to cold soils, growth reduction is accompanied by the reduction of water uptake, which usually starts within a few minutes after the temperature decrease (Bigot and Boucaud, 1996;Lee et al, 2005a).…”

Effect of Temperature on the Uptake of Na+ , K+ , Ca2+and Mg2+ By the Various Anatomical Parts of the Vegetable Amaranth Gangeticus

“…[35]. The increased viscosity at low temperatures is known to decrease rates of water uptake by roots and transport within the plant [36][37][38], and therefore reduces the rate of nutrient transport to the plants via roots in mass flow. Similarly, the transport of nutrient ions from areas of high to low concentration by the process of diffusion is directly influenced by soil temperature.…”