A Loss in the Plasma Membrane ATPase Activity and Its Recovery Coincides with Incipient Freeze-Thaw Injury and Postthaw Recovery in Onion Bulb Scale Tissue

Abstract

Plasma membrane ATPase has been proposed to be functionally altered during early stages of injury caused by a freeze-thaw stress. Complete recovery from freezing injury in onion cells during the postthaw period provided evidence in support of this proposal. During recovery, a simultaneous decrease in ion leakage and disappearance of water soaking (symptoms of freezethaw injury) has been noted. Since reabsorption of ions during recovery must be an active process, recovery of plasma membrane ATPase (active transport system) functions has been implicated. In the present study, onion (Allium cepa L. cv Downing Yellow Globe) bulbs were subjected to a freeze-thaw stress which resulted in a reversible (recoverable) injury. Plasma membrane ATPase activity in the microsomes (isolated from the bulb scales) and ion leakage rate (efflux/hour) from the same scale tissue were measured immediately following thawing and after complete recovery. In injured tissue (30-40% water soaking), plasma membrane ATPase activity was reduced by about 30% and this was paralleled by about 25% higher ion leakage rate. As water soaking disappeared during recovery, the plasma membrane ATPase activity and the ion leakage rate returned to about the same level as the respective controls. Treatment of freeze-thaw injured tissue with vanadate, a specific inhibitor of plasma membrane ATPase, during postthaw prevented the recovery process. These results indicate that recovery of freeze-injured tissue depends on the functional activity of plasma membrane ATPase.In nature, herbaceous plants experience slow cooling rates (1-2°C/h) during freezing event (9,24). This results in extracellular freezing when ice first forms in the dilute apoplastic solution. Such freezing, depending on the degree and duration of low temperature and subsequent thawing, result in increased efflux of ions and organic solutes. The tissue also takes on a water-soaked appearance. The major cation that leaks out ofthe cell is known to be K+ (17, 22). This enhanced efflux of ions results from a higher efflux than the influx rates.

Assessment of frost damage in mycorrhizal and non-mycorrhizal roots of Scots pine seedlings using classification analysis of their electrical impedance spectra

“…In detached samples (roots, needles and stems), apoplastic electrical resistance and relaxation time (inverse of characteristic frequency) decreased with an increase in freezing injuries (Zhang and Willison 1992;Repo et al 1994;Ryyppö et al 1998). Those changes were connected with changes in cell membranes that are known to be the primary targets of freezing injuries (Steponkus 1984;Hellergren et al 1984;Arora and Palta 1991;Palta and Weiss 1993), and lead to enhanced leaching of symplastic ions to apoplast with a consequent change in the current carrying properties of the tissue. In our study, similar changes as those observed previously, such as an increase in characteristic frequency with damage, were observed for the whole roots systems.…”

Effects of Low Temperature on Leaf Anatomy and Photosynthetic Performance in Different Genotypes of Wheat Following a Rice Crop

“…Under low temperature stress, the arrangement of mesophyll cells in wheat line with poor cold tolerance had been reported more irregular than cultivar with strong cold tolerance (Arora and Palta, 1991). For wheat with strong cold tolerance, the mesophyll cells were small and arranged closely, with many layers advantageous to the arrangement of chloroplast on the mesophyll cell surface (Miao et al, 2006).…”

Metabolomic evaluation of pulsed electric field-induced stress on potato tissue

“…After resealing, the cell membrane recovers its properties in a long-term physiological process that may take from several hours to days (Teissié et al 2005). This process might involve ATPase activity, which uses the chemical energy of ATP, helping the cells to take up the leaked ions against the concentration gradient (Arora and Palta 1991). This hypothesis of the high metabolic energy requirements during the recovery process is supported by our results suggesting that the wounded tissue subjected to PEF is actively mobilizing its carbon energy sources that might involve starch and ascorbic acid degradation, contributing to the hexose pool.…”