Effect of washing on the plasma membrane and on stress reactions of cultured rose cells

Abstract

Cultured cells of Rosa damascena have been used as a model for studies of responses of plant cells tovarious stresses, including UV radiation, protein-synthesis inhibitors, and elicitors from pathogens. Many of the responses involve reactions at the plasma membrane: efflux of K +, changes in the acid balance between cytoplasm and external medium, synthesis of H202, and inhibition of ferricyanide reduction. In previous studies, the cells have typically been washed with a solution of low ionic strength. We now show that this washing procedure results in changes in the protein composition of the plasma membrane, in the labeling of the proteins in the plasma membrane, and in the specific activity of ATPase in purified plasma membrane vesicles. Also, compared to the unwashed cells, the washed cells show less net K + efflux after UV-C and Phytophthora elicitor treatments; more synthesis of H202 after UV-C and a pattern of accumulation of H202 after elicitor treatment that shows a delayed but higher peak; and more inhibition of ferricyanide reduction after UV-C, but not after elicitor treatment. The results suggest that washing has differential effects on the mechanisms by which cultured plant cells perceive or respond to two stresses, UV-C and elicitor.

Comparative Biochemistry of the Oxidative Burst Produced by Rose and French Bean Cells Reveals Two Distinct Mechanisms1

“…In rose cells the appearance of H 2 O 2 was increased by an initial washing of the cells three times with a solution containing 1 mm CaCl 2 and 0.1 mm KCl (Qian et al, 1993). The increase was ascribed to the loss of peroxidases (or catalase) that consumed the H 2 O 2 .…”

Elicitor induced defence responses in medicago sativa

“…1) suggests that the peroxidase activity in the medium of lucerne cultures (180 mmol H 2 O 2 mg protein −1 min −1 ) contributed to the decline in concentration of H 2 O 2 , which occurred during phase I. A similar increase in accumulation of H 2 O 2 was observed in prewashed cultured rose cells (Qian et al. , 1993; Bolwell et al.…”

“…1) suggests that the peroxidase activity in the medium of lucerne cultures (180 mmol H 2 O 2 mg protein −1 min −1 ) contributed to the decline in concentration of H 2 O 2 , which occurred during phase I. A similar increase in accumulation of H 2 O 2 was observed in prewashed cultured rose cells (Qian et al, 1993;Bolwell et al, 1998), the increase being ascribed to loss of peroxidase or catalase from the medium. However, degradation of H 2 O 2 , by peroxidase, catalase, or any other antioxidant system located solely in the medium, could not alone have accounted for the observed transient decrease in its concentration since the decline was still evident in washed cells (Fig.…”

Sources and Effects of Reactive Oxygen Species in Plants

“…These can be liberated from plant cell walls by pectin-degrading enzymes secreted by pathogens (Bateman and Bashman, 1976;Davis et al, 1984). Plant cells are also sensitive to changes in medium osmolarity and mechanical perturbation of cells and both can result in the production of ROS (Glazener et al, 1991;Qian et al, 1993;Yahraus et al, 1995).…”