ABSTRACT
Defense Mechanisms in Higher Plants Stanislaw Karpinski, Gunnar Wingsle, Barbara Karpinska and Jan-Erik
Hällgren
INTRODUCTION
Temperature is a major abiotic factor that limits agricultural and forestry production and the natural distribution of plants. In many habitats, plants are subjected to large seasonal and diurnal variations in temperature. The general effects are fairly well understood. However, the primary effects of low temperature appear at the molecular level and are not well known. The consequences of low temperature for the whole plant, for example on growth, are more complex and the literature has presented a number of interpretations dealing with both structural and metabolic functions (Levitt, 1980; Steponkus, 1984; Sakai and Larcher, 1987; Kacperska, 1989; Guy, 1990; Hällgren and Öquist, 1990; Hällgren et al., 1991). More recently, comprehensive review articles also give mechanistic explanations for growth impairment or developmental processes, phenotypic modifications, or changes based on alterations of physiological, biochemical, and molecular processes (Thomashow, 1990, 1994, 1998; Alberdi and Corcuera, 1991; Bowler et al., 1992; Palva, 1994; Wise, 1995; Bohnert et al., 1995; Hughes and Dunn, 1996; Nishida and Murata, 1996; Gilmour et al., 1998; Huner et al., 1998).
