Effects of UV-B radiation on terrestrial plants and ecosystems: interaction with CO2 enrichment

Environmental effects on morphology of Acacia tortilis group in the Red Sea Hills, North-Eastern Sudan and South-Eastern Egypt

“…However, the morphological characters may very well be phenotypic expressions of ecological factors (both biotic and abiotic). For example in arid land, the degree of hair density on certain parts of the plant, regulating evapotranspiration (Stebbins, 1952) and radiation budget (Rozema et al, 1997), and the crown shape, may have been altered by browsing, coppicing and age (Kennenni and Vandermaarel, 1990) and the number of trunks, which can be a result of animal browsing at saplings stage or chopping of trunks for wood.…”

Comparison of susceptibility of leaves on short-term UV-B irradiation

“…Damage may occur in many places, including the direct destruction of the DNA, deactivation of protein and enzymes, disruption of membranes and other cell structures and the generation of highly reactive chemical agents known as 'free radicals' (Björn et al, 2002;Caldwell, 1971;Rozema et al, 1997). UV-B can cause damage of cell membranes by photoabsorption and peroxidation of unsaturated fatty acids and changes in the membrane lipid composition.…”

“…Decrease in photosynthesis (3-90%), particularly at higher UV-B doses, was due to both direct (effect on photosystem) and indirect (decrease in pigments and leaf area) effects. Genotypes of crop species exhibited variability in leaf wax layer thickness, loss of chlorophyll, and increase in phenolic compounds as mechanisms of tolerance to enhanced UV-B radiation resulting in changes in biomass or yield (Caldwell et al, 2007;Holosy, 2002;Kakani et al, 2003;Rozema et al, 1997). Generally cereals plant seems to be more tolerant to UV-B than dicotyledon plants due to vertical position of leaves, which are less exposed to harmful radiation (Caldwell et al, 1994;Kakani et al, 2003;Lizana et al, 2009;Skórska, 2000).…”

“…Skórska and Szwarc (2007) showed that special line of triticale with devoiding wax cover was more susceptible to UV-B radiation than the traditional variety. Other way of plant defense against UV-B radiation involves increasing UV-B absorbing pigments such as flavonoids and anthocyanins after the actual entry of UV-B into the outer layer of leaf surface (Jansen et al, 2008;Rozema et al, 1997). Relatively little data concerns herbal plants, while some of them eg peppermint plants are cultivated on plantations.…”

Climate Change and Crops

“…damage to DNA, alterations in transpiration, photosynthesis and respiration potential, growth, development and morphology (Rozema et al 1997;Björn 1999;Gaberščik et al 2002;Jansen 2002). The effects of enhanced UV-B radiation on plants have been widely studied, showing that UV-B radiation can have deleterious effect on plants i.e.…”