Vesicular-arbuscular mycorrhizal fungi can affect the water balance of both amply watered and droughted host plants. This review summarizes these effects and possible causal mechanisms. Also discussed are host drought resistance and the influence of soil drying on the fungi.

Water relations, drought and vesicular-arbuscular mycorrhizal symbiosis

Stomata, the small pores on the surfaces of leaves and stalks, regulate the flow of gases in and out of leaves and thus plants as a whole. They adapt to local and global changes on all timescales from minutes to millennia. Recent data from diverse fields are establishing their central importance to plant physiology, evolution and global ecology. Stomatal morphology, distribution and behaviour respond to a spectrum of signals, from intracellular signalling to global climatic change. Such concerted adaptation results from a web of control systems, reminiscent of a 'scale-free' network, whose untangling requires integrated approaches beyond those currently used.

http://www.bio.bristol.ac.uk/research/HetheringtonLab/pdfs/nature01843.pdf

The role of stomata in sensing and driving environmental change.

Publisher Summary This chapter illustrates the developments in the field of aeration since 1960, which have culminated in the modeling of the oxygen movements within the plant. The chapter collates the mathematical approaches to the aeration process and explains the concepts of modeling in a simplified manner. It is noted that the environment exerts a considerable influence on the directional flow of the respiratory gases within the plant and the directional exchange with the atmosphere. Oxygen can enter the plant body in a variety of ways. In non-aquatic species, the stomata and lenticels provide paths of low resistance for the entry and exit of both oxygen and carbon dioxide. In submerged astomatal aquatics, surface permeabilities are sufficiently high to allow the necessary gas transference. Plants rooted in unsaturated soils are exposed to an oxygen-rich environment over the greater part of their shoot and root surfaces. Oxygen enters the plant in the combined state as water. As water, it is transported from root to shoot in the xylem where a proportion is finally released into the liquid phase within the chloroplasts during the photolysis stage of photosynthesis.

Aeration in Higher Plants

Publisher Summary This chapter discusses the pressure chamber as an instrument for ecological research. It provides the workers with a thorough and useful discussion of the effective use of the pressure chamber technique. It offers a uniform terminology. To assemble, interpret, and evaluate published ecological studies the pressure chamber has been employed. And suggest areas of research where the technique is potentially useful. The chapter discusses some unknowns and problems associated with the pressure chamber. Assembly of the device and its associated components is briefly discussed. The chapter reviews the status of the pressure chamber technique in current ecological and eco-physiological research and suggests what appear to be promising new directions and applications. Four strategies for expressing and interpreting P data were explored. The pressure chamber may also be used effectively in studies of plant pathology, entomology, and pollution effects. Activities of pathogenic agents which disrupt vascular function or cause membrane damage can often be detected. Productive use of the pressure chamber technique in forestry, agriculture, and horticulture in such operations as irrigation, transplanting, and fertilization has proved successful.

The Pressure Chamber as an Instrument for Ecological Research

INTRODUCfION . MEASUREMENTS OF INTRACELLULAR pH . MECHANISMS FOR pH REGULATION .. Intracellular Buffers .

Intracellular PH and its Regulation

Physiology of stomata

Plant material theoretical background gravimetric and potometric methods mass-flow potometer diffusion potometers determining stomatal aperture responses of stomata in leaf pieces and discs epidermal strips protoplasts guard cells and sub-cellular fractions.

Hans Meidner

Papers

Physiology of stomata

Methods in stomatal research

Class Experiments in Plant Physiology