Some Morphological and Biochemical Characteristics of C₃ and C₄ Plants Irradiated with UV‐B

Abstract

Abstract Four C 3 and two C 4 plants were subjected for 350 h to an enhanced UV‐B radiation (280 to 310 nm) regime simulating a 0.18 atm. cm ozone level (solar angle 55°) in growth chamber. Different degrees of response among plant species were observed. UV‐B radiation reduced plant height, fresh and dry weight, protein content, total chlorophyll, inhibited net CO 2 uptake and the Hill reaction activity. Some broad‐leaved species with C 3 type of carbon assimilation were more susceptible to UV‐B alterations of morphological and biochemical characteristics than the narrowleaved species with C 4 type photosynthesis.