Acta Physiol Plant (2007) 29 (Suppl 1):S5 DOI 10.1007/s11738-007-0077-7 © Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków 2007

Preface Since 1995, every two years, the Institute of Plant Physiology, Polish Academy of Sciences in co-operate with the Slovak University of Agriculture in Nitra, Constantine the Philosopher University in Nitra, Warsaw and Cracow Agricultural Universities and Cracow Pedagogical Academy organize an International Conference entitled “Ecophysiological Aspects of Plant Responses to Stress Factors”. Till now in conferences were attended by about 1 100 participants from 18 countries. Colloquially word “stress” is given various meanings and due to this it is very hard to define it precisely. Stress has a strictly defined physical scientific definition describing it as the force per unit of area acting upon a material, inducing strain and leading to dimensional change. In the biological sense, stress can be any factor that may produce an adverse effect in individual organisms or communities. Biologically stress has been defined as the overpowering pressure that affects the normal functions and structure of an individual life or the conditions in which plants are prevented from full expression of their genetic potential for the growth and development. In agricultural context, stress has been defined as a phenomenon that limits crop production or injures of biomass. The study of plant responses to stress has been a main feature of plant researches attempts to explain how plants function in natural and managed environments. Traditionally, stresses experienced by plants are divided by physiologists, ecologists and agronomists into two groups: abiotic and biotic. Generally abiotic stress is related to impact on plants of physical and chemical environmental factors and biotic stresses originate from the interactions between organisms and the outer environment. Strictly, biotic stress results from competition between organisms for resources, from predation and parasitism, and from the actions of allelopathic chemicals released by one organism and affecting another. Stressfull environments are often characterized by the simultaneous occurrence of more than one stress. For example, soil drought is often a companioned by high temperature, salinity stress, associated with drought stress or flooding by the see water. All of these factors complicate the management of stress in agriculture situation and make research of physiologists, ecologists and breeders more difficult as they attempts to understand the physiological base of stress response and stress tolerance as a part of crop improvement. Some abiotic stresses such as water stress (drought or waterlogging), metal toxicity, salinity, mineral nutrient deficiency, adverse pH are soil-based and amenable to improvement by drainage, irrigation and chemical amelioration. Other abiotic stresses, principally low or high temperature, UV exposure and photoinhibition are more difficult to measure by physical means and demand a biological approach. Investigations in stress biology are multidisciplinary and cover various aspects of plant physiology, ecology, biochemistry, genetics and breeding. Over the past few decades plant physiologists and plant breeders has proved highly effective selection for describe plant traits for stress tolerance in crop species through the exploitation of genetic variability. The source of stress tolerance in plant breeding has been the natural variation that exists among present varieties and land race. Many desirable traits are controlled by several genes and conventional breeding possibilities are limited by reproductive barriers between more distantly related plant groups. Molecular biology has been used to research the structure and action of plant genomes and to begin to assemble an understanding of the genetic basis of stress tolerance. Also plant biotechnology has provided a range of methods to increase the genetic variation include for plant stress tolerance at the level of the individual cell, tissue, whole plant, plant canopy and ecosystem. There are many reasons why progress in this area is necessary, due to the fact that only about 10 percent of the land surface being used for agricultural purposes offer optimal conditions for plant cultivation. Aiming in popularization of the plant stress biology are scientific meetings, where a present state of research is discussed. We hope this year conference will be interesting for a wide range of plant scientists including physiologists, agriculturalists, ecologists, plant breeders and molecular biologists concerned with stressful environments. Also we hope that this meeting will be interest for undergraduate’s students seeking an introduction in the area of plant stress physiology. We would like to take opportunities to thank for the help all those involved in preparing of this year conference. Particularly we gratefully acknowledge financial support of the Polish Botanical Society, Plant Physiology and Biochemistry Branch and Committee of Physiology, Genetics and Breeding of Plant, Polish Academy of Sciences.

Editorial Board

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