Effect of ultraviolet radiation on chlorophyll, carotenoid, protein and proline contents of some annual desert plants

Abstract

Investigation was carried out to find whether enhanced ultraviolet radiation influences the Malva parviflora L., Plantago major L., Rumex vesicarius L. and Sismbrium erysimoids Desf. of some annual desert plants. The seeds were grown in plastic pots equally filled with a pre-sieved normal sandy soil for 1 month. The planted pots from each species were randomly divided into equal groups (three groups). Plants of the first group exposed to white-light tubes (400-700 nm) 60 w and UV (365 nm) 8 w tubes. The second group was exposed to white-light tubes (400-700 nm) 60 w and UV (302 nm) 8 w tubes. The third group was exposed to white-light tubes (400-700 nm) 60 w and UV (254 nm) 8 w tubes, respectively, for six days. The results indicated that the chlorophyll contents were affected by enhanced UV radiation. The chlorophyll a, b, and total contents were decreased compared with the control values and reduced with the enhanced UV radiation, but the carotenoid was increased compared with the control and also reduced with the enhanced UV radiation. So, the contents of chlorophylls varied considerably. M. parviflora showed the highest constitutive levels of accumulated chlorophyll a, b, and total chlorophyll (0.463, 0.307 and 0.774 mg g(-1) f w) among the investigated plant species. P. major showed the lowest constitutive levels of the chloroplast pigments, 0.0036, 0.0038 and 0.0075 mg g(-1) f w for chlorophyll a, b, and total chlorophyll at UV-365 nm, respectively. The protein content was decreased significantly in both root and shoot systems compared with the control values but, it was increased with increasing wave lengths of UV-radiation of all tested plants. R. vesicarius showed the highest protein contents among the investigated plants; its content was 3.8 mg g(-1) f w at UV-365 nm in shoot system. On the other hand, decreasing ultraviolet wave length induced a highly significant increase in the level of proline in both root and shoot of all tested plants. From the results obtained, it is suggested that proline can protect cells against damage induced by ultraviolet radiation. Statistically, the variations of the studied metabolic activities were significant due to UV radiation treatment in shoot and root system of all investigated plant species.

UVA + B treatment affects antioxidant system and phytochemicals of parsley plant under different concentrations of Zn

“…According to results obtained from this study, parsley plant could effectively protects its own chlorophyll content against the enhanced UVA + B radiation by increasing the carotenoids content in both levels of Zn. Similar to this study, Salama et al (2011) reported that in Rumex vesicarius L. the chlorophyll content of plant was not affected notably by UV treatment. The carotenoids are involved in the photosynthetic structures protection against the destructive effects of UV radiation (Nasibi and Kalantari, 2005).…”

“…At normal condition there was no main difference in these parameters between two levels of applied Zn ( Table 2). The reductive effect of UV radiation on protein content is related to direct DNA injury, amino acid destruction and proteins and enzymes inactivation induced by UV radiation (Salama et al, 2011;Zlatev et al, 2012). Moreover, UV radiation causes the detrimental effects in the structure of RNA molecules and thus disrupts protein synthesis (Ulm and Nagy, 2005).…”

“…Antioxidant enzymes play a significant role in the dynamic equilibration between free oxygen radicals production and destruction. The responses of antioxidant enzymes to UV radiation vary among plants species ) Tossi et al, 2009;Salama et al, 2011;Czégény et al, 2016(. The increasing in the activities of antioxidant enzymes could be the indicator of build-up of a protective mechanism to reduce oxidative damages induced by stress (Harinasut et al, 2003;Chawla et al, 2013).…”

Effect of increased UV-B radiation on carotenoid accumulation and total antioxidant capacity in tobacco (Nicotiana tabacum L.) leaves

“…Carotenoids directly protect photosystems against UV radiation (Salama et al, 2011). In plants, carotenoids function as accessory pigments in light harvesting.…”

The effect of strong microwave electric field radiation on: (1) vegetable seed germination and seedling growth rate

“…Various experiments showed that HPM can affect plant growth and the prolonged exposure to microwave affects seed germination (Hamada, 2007;Aladjadjiyan, 2010;Salama et al, 2011). Oprica (2008) indicated that microwaves determined variations of catalase and peroxidase activities in Brassica napus depending on the microwave exposure time, age of the plants, and condition of seeds (germinated or non-germinated).…”