الصفحة 1
الصفحة 1
Root Physiology : From Gene to Function
The classical boundaries between physiology, biochemistry and molecular biology have vanished. There has been a strong focus on a limited number of model species, including Arabidopsis thaliana. That focus has allowed greater insight into the significance of specific genes for plant development and functioning. However, many species are very different from A. thaliana, in that they are mycorrhizal, develop a symbiosis with N2-fixing microsymbionts, or have other specialised root structures. Also, some have a much greater capacity to resist extreme environments, such as soil acidity, salinity, flooding or heavy-metal toxicities, due to specific adaptations. Research on species other than A. thaliana is therefore pivotal, to develop new knowledge in plant sciences in a comprehensive manner. This fundamental new knowledge can be the basis for important applications in, e.g., agriculture and plant conservation. Although significant progress has been made, much remains to be learnt. It is envisaged that discoveries made in the recent past will likely lead to major breakthroughs in the next decade.
Plant Respiration : From Cell to Ecosystem
Respiration in plants, as in all living organisms, is essential to provide metabolic energy and carbon skeletons for growth and maintenance. As such, respiration is an essential component of a plant’s carbon budget. Depending on species and environmental conditions, it consumes 25-75% of all the carbohydrates produced in photosynthesis – even more at extremely slow growth rates. Respiration in plants can also proceed in a manner that produces neither metabolic energy nor carbon skeletons, but heat. This type of respiration involves the cyanide-resistant, alternative oxidase; it is unique to plants, and resides in the mitochondria. The activity of this alternative pathway can be measured based on a difference in fractionation of oxygen isotopes between the cytochrome and the alternative oxidase. Heat production is important in some flowers to attract pollinators; however, the alternative oxidase also plays a major role in leaves and roots of most plants. A common thread throughout this volume is to link respiration, including alternative oxidase activity, to plant functioning in different environments.
Plant Physiological Ecology
Plant Physiological Ecology, Second Edition is significantly updated, with full color illustrations and begins with the primary processes of carbon metabolism and transport, plant water relations, and energy balance. After considering individual leaves and whole plants, these physiological processes are then scaled up to the level of the canopy. Subsequent chapters discuss mineral nutrition and the ways in which plants cope with nutrient-deficient or toxic soils. The book then looks at patterns of growth and allocation, life-history traits, and interactions between plants and other organisms. Later chapters deal with traits that affect decomposition of plant material and with the consequences of plant physiological ecology at ecosystem and global levels.Plant Physiological Ecology, Second Edition features numerous boxed entries that extend the discussions of selected issues, a glossary, and numerous references to the primary and review literature. This significant new text is suitable for use in plant ecology courses, as well as classes ranging from plant physiology to plant molecular biology.
