Desiccation injury

The free radical damage hypothesis of desiccation injury requires that these various protective mechanisms are unable to detoxify reactive species during dehydration and rehydration. There is evidence that free radicals increase with decreasing moisture content of seeds (Priestley et al., 1985), and, in plants subjected to episodic droughting, increased levels of malon-dialdehyde occur (Price Hendry, 1987). 

Stewart GR. Desiccation injury, anhy.drobiosis and survival. In Jones HG, Flowers TJ, Jones M, editors. Plant under stress. Cambridge Cambridge University Press, 1989 115-130. 

The importance of respiratory heat and water losses is not confined to the respiratory structures. Inspiration of cold, hot, or dry air poses the potential threats of thermal injury or desiccation to the airway epithelium" - T8,69 g challenge to whole-body thermoregulation. 

Although seen only occasional during the first half of this century, winter injury of first-year red spruce needles has become an annual event in the coniferous montane forest area, resulting in the formation of red-brown first year needles that subsequently desiccate and are shed 20, 21). The loss of foliage reduces photosynthesis and the obligatory accumulation of carbohydrate in the twigs and root systems. There is some evidence that this phenomenon involves both natural and anthropogenic causal factors. 

Injuries from desiccation are likely to arise from a combination of physical damage to cellular components following water removal, structural and metabolic consequences of increased solute concentration and chemical damage resulting from metabolic disfunction induced by dehydration. 

Desiccation tolerance and injury avoidance The remarkable tolerance to prolonged anhydrobiosis in resurrection plants suggests they are able to maintain essential structure and physiological integrity in the dry state or are able to repair dehydration-induced damage rapidly following rehydration. 

Senaratna, T. McKenzie, B.D. (1986). Loss of desiccation tolerance during seed germination A free radical mechanism of injury. In Membranes, Metabolism and Dry Organisms, ed. A.C. Leopold, pp. 85-101. Ithaca, N.Y. Comstock Publishing Associates. 

Many other compounds have been included in studies on sucrose response. Most of these have been herbicides or enzyme poisons. None of the common herbicides had any positive effect on sucrose at rates up to that causing severe foliar injury. Earlier reports of response from 2-(2,4,5-trichlorophenoxy)propionic acid and 2,2-dichloropropionic acid could not be substantiated in British Guiana and Queensland. 27 Some compounds, such as 3-(p-chlorophenyl)-l,l-dimethylurea (monuron), (2,4-dichloro-phenoxy) acetic acid in soil, ethylenediaminetetraacetic acid, and leaf desiccants decreased sucrose and juice solids content. 20 Field trials with several chemicals in Trinidad showed enhanced sucrose at 14 to 28 days before harvest resulting from the application of 8 and 12 lb. (per acre) of... 

Sulphite is known to cause growth inhibition and injuries to plants (Garsed, 1981). The toxicity to Zea mays of root applied sulphite has been investigated by Bertelsen and Gissel-Nielsen (1987). Sulphite toxicity produced greyness of the leaves with flabbiness and desiccation. The symptoms were more pronounced at low pH and in non-aerated solutions at higher pH values. The toxicity was found to decrease in the order S02(aq) > HSOf > SOj. ... 

Uses Technical diquat dibromide is more than 95% pure and forms white to yellow crystals. It is used to desiccate potato vines and seed crops, to control flowering of sugarcane, and for industrial and aquatic weed control. It is not residual (i.e., it does not leave any trace of herbicide on or in plants, soil, or water). Diquat dibromide is a nonselective, quick-acting herbicide and plant growth regulator, causing injury only to the parts of the plant to which it is applied. Diquat dibromide is referred to as a desiccant because it causes a leaf or entire plant to dry out quickly. 

Place the lid on the desiccator and open the tap and cover the desiccator with an appropriately sized safety cage (Fig. 5.19) to prevent injury from flying glass in the case of an implosion. 

Sevoflurane (ULTANE Figure 13-3) is a clear, colorless, volatile liquid at room temperature and must be stored in a sealed bottle. It is nonflammable and nonexplosive in mixtures of air or oxygen. Sevoflurane can undergo an exothermic reaction with desiccated CO absorbent (BARA-lyme) to produce airway bums or spontaneous ignition, explosion, and fire. Care must be taken to ensure that sevoflurane is not used with an anesthesia machine in which the COj absorbent has been dried by prolonged gas flow through the absorbent. Sevoflurane reaction with desiccated CO absorbent also can produce CO, which can result in serious patient injury. 

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