Influence of Environmental Factors on Composition and Function of the Photo-Synthetic Apparatus

Abstract

Growing plants respond to changes in their environment with particular changes and adaptations in the morphology, physiology, composition and ultrastructure of their leaves and chloroplasts. Though the environmental factors, which will change, can be quite different (e.g. water stress, high light or low light exposure, treatment with growth regulators, availability of minerals, level of air pollutants, salt stress etc) a group of qualitatively similar or identical responses can be found. The largest response signals (in a quantitative sense) a plant can exhibit are those found under extreme high light (HL) or low light (LL) growth-conditions: The high-light induced growth and adaptation responses of leaves and plants, as found in full sunlight and in plants grown at high quanta fluence-rates, can be seen in the formation of sun leaves (HL-leaves), which possess sun or HL-chloroplasts (Lichtenthaler 1981; — et al. 1981; Meier, Lichtenthaler 1981). The latter are characterised by a particular pigment composition and ultrastructure which is quite different from that of shade type or low light chloroplasts (Fig. 1 and Table 1).