Response of Chloroplast Structure to Photodynamic Herbicides and High Oxygen

Agnieszka Mostowska Warsaw University, Department of Cytology and Anatomy of Plants, Krakowskie Przedmiescie 26/28, PL-00-927 Warsaw, Poland. Fax: (+48-22) 826-10-67. E-mail: [email protected] Z. Naturforsch. 54c, 621-628 (1999); received November 4, 1998/February 18, 1999 Chloroplast Ultrastructure, Environmental Factors, Oxidative Stress. Photodynamic Herbi­ cides, Senescence Response of chloroplast on the structural level to photodynamic herbicides and high oxy­ gen concentration was compared with symptoms of chloroplast senescence. Based on the present results and those known from the literature a general pattern of response was pro­ posed: the action of most of environmental factors induces the oxidative stress and often gives similar symptoms of structural damage and dysfunctions independent of the primary stressing factor. These alterations consist mostly in swelling of thylakoids, disruption of chlo­ roplast membranes, intensive plastoglobuli accumulation, photodestruction of pigments and inhibition of photosynthesis.