Influence of UV-B radiation and Cd2+ on chlorophyll fluorescence, growth and nutrient content in Brassica napus

Abstract

photochemical quenching (q NPQ ) was measured using a pulse amplitude modulated fluorometer. The q NPQ The possible interaction of two stresses, UV-B radiincreased with increasing Cd, while the combination ation and cadmium, applied simultaneously, was of cadmium and UV-B reduced the q NPQ compared to investigated in Brassica napus L. cv. Paroll with that in plants exposed only to cadmium or UV-B radirespect to chlorophyll fluorescence, growth and ation. The chlorophyll a5b ratio showed a reduction uptake of selected elements. Plants were grown in with UV-B at no or low Cd concentrations (0 mM, 0.5 mM nutrient solution containing CdCl 2 , (0, 0.5, 2 or 5 mM) CdCl 2 ), but not at the higher Cd concentrations used and irradiated with photosynthetically active radiation (2 mM, 5 mM CdCl 2 ). Thus in some instances there (PAR, 400-700 nm, 800 mmol m−2 s−1) with or withappeared to be a UV-B and Cd interaction, while in out supplemental ultraviolet-B radiation (UV-B, 280others plant response could be attributed to either 320 nm, 15 kJ m−2 d−1, weighted irradiance). After treatment alone. 14 d of treatment, the most pronounced effects were found at 2 and 5 mM CdCl 2 with and without supple-Key words: Brassica napus, cadmium, ultraviolet-B mental UV-B radiation. Exposure to cadmium significradiation. antly increased the amount of Cd in both roots and shoots. In addition, increases occurred in the concentration of Fe, Zn, Cu, and P in roots, while K was

Investigation of the effects of cadmium by micro analytical methods onLycopersicon esculentumMill. roots

“…durum [12], larsson et al on Brassica napus [14], gussarsson on Betula pendula [11], drazic et al on Glycine max [9], obata and umebayashi on phaseolus vulgaris and pisum sativum [22], Quariti et al [23] and moral et al on Lycopersicon esculentum [20]. We are also in agreement with the opinions of moral et al on Lycopersicon esculentum [20] and Zhang et al on triticum aestivum [36] concerning the decreases we established in phosphorus contents of epidermal cells.…”

“…capitata and Zea mays [34], and sidhu and Khurana on Brassica juncea and spinacia oleracea [26]. however, cadmiumcopper interactions in studies conducted on Brassica napus [14], Oryza sativa [17], also Oryza sativa, Zea mays, phaseolus vulgaris, pisum sativum [22] and Betula pendula [11] were presented as synergistic. among the researchers that conducted the first studies on nutrient element-heavy metal stress interactions, Cataldo et al [6] explained antagonistic correlations between cd 2+ with cu 2+ , fe 2+ , Zn 2+ and mn 2+ at uptake and transport stages with kinetic interactions suggesting dependency to a common transport spot or process in a study conducted on Glycine max seedlings.…”

“…In a study conducted on Brassica napus in order to shed light on the nutrient elementheavy metal stress interactions, while exposure to cadmium caused increases of iron, copper, zinc, and phosphorus concentrations in roots, it reduced potassium concentrations, and it was also observed that sulfur contents of shoots under cadmium stress were considerably high [14]. The addition of cadmium to soil significantly decreased calcium, iron, and manganese intakes in young Helianthus annuus seedlings [27].…”

Growth Responses of Nutrient-Stressed Cenchrus ciliaris Under Carbon Dioxide Enrichment

“…Pigment concentration was measured as an indicator of the Chlorophyll con-tent [10] using the following methodology: 5 ml of pure acetone was added to 25 mg of dry blades sample, where it was kept in 4 degrees C and darkness for 24h, grinded with a tissue grinder and kept overnight. The samples were exposed to sonication for 2 min before it was centrifuged in 4 degrees C, span at 3000 rpm for 15 min.…”

“…The samples were exposed to sonication for 2 min before it was centrifuged in 4 degrees C, span at 3000 rpm for 15 min. The extract absorbance was measured using spectrophotometer at 663.2 nm for Chlorophyll-a and 646.8 nm for Chlorophyll-b [10]. The chlorophyll content (mg.ml-1) was calculated using the formula: Chlorophyll content=A/Ed, where A is the observed absorbance, E is the extinction coefficient (=5 mg/ml), and d is the distance of the light path (=1 cm) SPSS [?]…”