Assessment of acclimation of Pinus sibirica mountain ecotypes ex situ on CO2 -gas exchange parameters

Carbon dioxide gas exchange of vegetative scion Siberian stone pine ecotypes (Pinus sibirica Du Tour)from the West Sayan mountains altitudinal transect grown on the geographical grafting plantation in the south of theTomsk Region were studied. The altitudinal transect was represented by two ecotypes: low mountain zone and alpine zone.The age of the grafted trees was 20 years. It was shown that the photosynthesis intensity did not differ between ecotypessignificantly, and respiratory activity increased significantly along altitudinal transect and the differences were 40 %between ecotypes. The results of the experiment revealed that the respiration / photosynthesis ratio was 1.5 times higher inalpine ecotype than in low mountain ecotype, which indicates a lower plant productivity of the alpine ecotype. The resultsof measuring stomatal and mesophyll conductance showed that these values differ between ecotypes significantly. Alpineecotype was characterized with more high values of stomatal conductance, but low values of mesophyll conductancerelatively low-mountain ecotype. Alpine ecotype had more high values of CO2 in chloroplasts and electronic transportrates. The obtained data indicate the photosynthetic acclimation when ecotypes were moved to the warmer climate. Therespiratory activity are largely regulated by hereditary factors.

Features of gas exchange and use of reserve substances in pumpkin seedlings in conditions of skoto- and photomorphogenesis under the influence of gibberellin and chlormequat-chloride

We investigated the effect of gibberellin and the antigibberellic agent chlormequat-chloride on gas exchange and use of reserve substances in pumpkin seedlings during germination in the light and in the dark. We established that an artificial strengthening or growth inhibition of pumpkin seedlings in conditions of skotomorphogenesis caused an increase in of respiration intensity. Gibberellin treatment increased the proportion of assimilation processes in carbon dioxide gas exchange of seedlings, and growth inhibition by retardant caused an increase in respiratory costs when the nutrition type switches in the light from heterotrophic to autotrophic. The formation by seedlings of the demand for reserve assimilates from cotyledons was largely determined by change of activity of subapical meristems, which is manifested in the acceleration of seed germination, enhancing of histogenesis for the actions of gibberellin and in the weakening of these processes under the influence of retardants. Reserve substances used both oil and nitrogen-containing compounds. The content of protein nitrogen in pumpkin cotyledons decreased more in the light than in the dark, moreover growth inhibition by the retardant slowed down and growth increase by gibberellin accelerated this process both in conditions of photomorphogenesis and skotomorphogenesis.

Liquid Ventilation: It’s Not Science Fiction Anymore

Liquid ventilation is, by all initial considerations, an unconventional concept. Decades of research, however, have found that by using perfluorocarbons, which are capable of holding high concentrations of critical gases such as oxygen and carbon dioxide, gas exchange optimal enough to support life is possible with no known toxic effects. The earliest method of liquid ventilation, tidal liquid breathing, involved infusion and active removal of tidal volumes of perfluorocarbons by a liquid ventilator for gas exchange. Recently, a new method of partial liquid breathing, called perfluorocarbon-associated gas exchange, makes the process of liquid ventilation simpler by using conventional gas ventilators. Current research is showing great promise in the use of liquid ventilation for patients with pulmonary pathology. Critical care nurses should become knowledgeable of this new mode of ventilation and be prepared to meet the special needs of this unique population

Relation between photorespiration and glycolate oxidase activity in sunflower and red kidney bean leaves

Infrared gas analyzer techniques were used and the carbon dioxide gas exchange of attached red kidney bean and sunflower leaves was measured in an open gas stream. The glycolate oxidase activity of the leaf homogenates was manometrically determined. It was concluded that the maximal rates of photorespiration and glycolate oxidase activity have the same order of magnitude.