Impact of elevated CO(2) and O(3) on gas exchange parameters and epidermal characteristics in potato (Solanum tuberosum L.).

Potato plants (Solanum tuberosum L. cv. Bintje) were grown in open-top chambers (OTCs) under three CO(2) levels (ambient and 24 h d(-1) seasonal mean concentrations of 550 and 680 micromol mol(-1)) and two O(3) levels (ambient and a seasonal mean 8 h d(-1) concentration of 50 nmol mol(-1)).

Plant hormones and the control of physiological processes.

This review examines contemporary views of the role of plant hormones in the control of physiological processes. Past and present difficulties with nomenclature encapsulate the problems inherent in using the 'classic' hormone concept in plants, with their distinctive multicellular organization. Chemical control may be a more relevant notion.

Relative control potential of abscisic acid, carbon dioxide and light in responses of Phaseolus vulgaris stomata.

We outline a theoretical framework for comparing the relative effectiveness of hormonal and other factors in the control of physiological responses. This involves determining a 'baseline' set of conditions, then adjusting each factor in turn with the others held constant. The initial rate of response to each change in condition is estimated and compared among factors to arrive at a quantitative indication of control potential under the specified baseline conditions - the control coefficient.

ACCURATE ESTIMATION OF STOMATAL APERTURE FROM SILICONE RUBBER IMPRESSIONS.

The potential of low viscosity silicone-based impression material for measuring stomatal aperture on intact leaves was investigated. It was found that the probability of successful replication of Commelina communis L. stomata depended on the width of the stomatal pores.