Maintenanance of Viability of Carrot Tissue Slices in Washing Solutions After Cutting

Abstract

In studies of the characteristics of the uptake of boric acid by plant tissues (Wildes and Neales, unpublished data) we used disks cut from carrot roots. Bacon, MacDonald, and Knight (1965) have emphasized the necessity of using storage tissue free of bacteria for such physiological studies. In the course of our experiments we therefore investigated the extent of bacterial contamination in carrot disks immediately after cutting, and also examined the effects of chloramphenicol and calcium chloride in the washing solution on the extent of the development of bacterial contamination in the disks. We also made measurements of various properties that gave evidence of their normal biological activity. The loss of this activity, in our experience, was characterized by a final loss of turgor, browning of both tissue and washing solutions, and a failure to respond in respiration rate to both the addition of salts and 2,4-dinitrophenol.The inclusion of 50 /Lg/ml of chloramphenicol has been shown (Edelman and Hall 1965;Leaver and Edelman 1965;Atkinson et al. 1966) to prevent the multiplication of bacteria in disks of storage tissue. Also Marinos (1962) and Jones and Lunt (1967) have shown that the maintenance of cell membrane structure requires a supply of calcium. In its absence there is a loss of cell contents (Skou 1963;Van Steveninck 1965a;Garrard and Humphreys 1967; van Goor 1968) and also an impairment in the ability of barley roots to absorb potassium (Epstein 1961). Therefore we investigated: (1) the extent of bacterial contamination with washing time; (2) the effellt of the inclusion of chloramphenicol in the washing solution and the effect of a spectrum of antibiotics on the growth of the contaminating bacteria; and (3) the effect of calcium chloride in the washing solution on the deterioration of carrot disks. MethodsCarrot disks were cut from the phloem tissue of intact roots, obtained periodically from the local market. The roots were thickly peeled and cut into slices 1 mm thick. Disks 10 mm in diameter were then cut from these slices with a sterilized cork-borer, and placed into 4 litres of washing solution maintained at room temperature (c. 18°C). This washing solution was changed several times in the first 3-4 hr, and then daily until the disks were used.

Relationship Between Ion Accumulation and Growth in Two Spring Wheat Lines Differing in Salt Tolerance at Different Growth Stages

“…which is evident from the results for Ca versus Na selectivity and Ca/Na ratios of S24. The high degree of salt tolerance of S24 can be partially related to its higher accumulation of Ca""û nder saline conditions, since it is known that Ca plays an important role in increasing salt tolerance of plants by maintaining proper functioning of biological membranes and their permeability (Wildes and Neales, 1971;Kent and Lauchli. 1985).…”

Salt tolerance of pigeon pea (Cajanus cajan (L.) Millsp.) at three growth stages

“…Calcium plays an important role in regulating ion transfer into plant cells growing in saline medium (Epstein, 1961;Rains, 1972: Ashraf & Naqvi, 1992. Ca2+ can also affect membrane stability (Wildes & Neales, 1971), and ion translocation (LaHaye & Epstein, 1971). Ca2+ was also shown to inhibit Na+ absorption in beans (LaHaye & Epstein, 1971) and soybeans (Wieneke & Lauchli, 1980) and thus may be an important factor in controlling the salinity response of legumes.…”

Wall‐bound Invertase Activity in Convolvulus Callus: Increase after Subculturing, and Paradoxical Effects of Actinomycin D, Cycloheximide, and Thienylalanine

“…This system provides the opportunity to study the mechanism(s) which control the formation and degradation of invertase (Edelman and Hall 1964, Imaseki et al 1968, Bradshaw et al 1970. A major objection against the system used is, however, that bacterial contamination is difficult to avoid (Bacon et al 1965, Wildes andNeales 1971). This necessitates to investigate in how far microbial infection influences the results (e.g.…”