Spinach grana appear to be injured by the same mechanism and by the same degree of dehydration and volume reduction that injures animal cells. Winter-hardened or artificially protected grana avoid injury by permitting a reversible influx of solute which forestalls excessive dehydration and shrinkage.

In the foregoing papers of this series (25, 26) we have given an account of our more intensive researches on the physiology of cold resistance, approached always through a study of living cells. We now describe a number of lesser excursions into the same field, and combine with this a survey of the whole problem of hardening in the light of those changes which have been found to accompany it. T...

The release of hydrogen cyanide from Amelanchier alnifolia was monitored at 30 C and -10 C following lethal freezing at both slow and fast rates. Assuming that hydrogen cyanide release indicates membrane damage, it was concluded that during a fatal freeze-thaw cycle membrane damage occurred during cell contraction and, therefore, was not dependent upon membrane area expansion during thawing.

Generally speaking, the literature indicates that the number of bacteria surviving subfreezing temperatures will be functions of: (1) initial numbers of viable cells present when frozen (Record and Taylor, 1953; Kropp, 1950), (2) the rate of the freezing and thawing process (Luyet and Gehenio, 1940), (3) the temperature of storage, with 0 to -20 C being more destructive than the range below -20...

Plasma membrane ATPase has been proposed as a site of functional alteration during early stages of freezing injury. To test this, plasma membrane was purified from Solanum leaflets by a single step partitioning of microsomes in a dextran-polyethylene glycol two phase system. Addition of lysolecithin in the ATPase assay produced up to 10-fold increase in ATPase activity. ATPase activity was spec...

Physiological changes and freezing injury in maturing maize " (1950). Retrospective Theses and Dissertations. Paper 13557. 1980 Signature was redacted for privacy. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleed-through, substandard margins, and improper alignment...

Both the existence and the cause of protection, by nonpenetrating solutes such as sugars, against freezing injury to plant cells have been alternatively and repeatedly proclaimed and questioned for some time. Since theories of the mechanism of frost injury have been both rejected (8) and proposed (2, 3) on the basis of this protection, it is of fundamental importance to understand the reasons f...

SYNOPSIS The effects of nursery practices on freeze tolerance of P taeda and P elliottii seedlings were examined by placing the seedlings in a freezing chamber and lowering the temperature to -10C. Injury was evaluated 10 days after the freeze treatment by examining cambial tissue (browning test). Top-pruning P taeda seedlings (three times) increased freeze tolerance while rootwrenching (six ti...

Freezing injury to the cortical plate at postnatal day (P) 1 initiates a cascade of events that ultimately result in a focal neocortical malformation resembling human 4-layered microgyria. This malformation has been associated with widespread changes in neocortical and thalamic architecture and physiology. It was hypothesized that at least some of these alterations could result from connectiona...

Winter frost injury is a major limiting factor for olive cultivation in temperate regions. The response of shoots to freezing stress can be used selecting genotypes resistant freezing. electrolyte leakage (EL) and tetrazolium tests (TZ) are commonly evaluate dead tissues cold studies. temperature–response curve lethal temperature (LT) measured with models calculate LT50 LT90. In this study, we ...